ships abs ibc igc rules

Rules for Building and Classing

Steel Vessels1997

PART 5, SECTION 4Vessels Intended to CarryLiquefied Gases andChemical Cargoes in Bulk

Rules for Building and Classing

Steel Vessels

PART 5 SECTION 4Vessels Intended to CarryLiquefied Gases and ChemicalCargoes in Bulk

1997

American Bureau of ShippingIncorporated by Act of the Legislature ofand State of New York 1862

Copyright © 1997American Bureau of ShippingTwo World Trade Center106th FloorNew York, N.Y. 10048, U.S.A.

Compositor and PrinterPort City Press, Inc.Baltimore, Maryland

Contents

Vessels Intended to Carry Liquified Gases and Chemical Cargoesin Bulk

Foreword to the 1992 EditionForeword to the 1994 EditionIndex

ANNEXA Guidelines for the Uniform Application of the Survival

Requirements of the Bulk Chemical Code and the GasCarrier Code

B United States Coast Guard additional design and structuralrequirements for non-US flag vessels operating on thenavigable waters of the United States.

C Calculation of the Capacity of Foam Systems for ChemicalTankers

D Resolution A.473(XII)E Resolution A.567(14)

Foreword to the 1992 Edition

In June 1989, a project was initiated within ABS to expand the Rules for gas carriers andchemical carriers to include all information necessary for its clients in the construction ofthese vessels. This task is completed and a new Section 5/4 (old 24) now contains textof latest IGC and IBC Code together with additional requirements and interpretationsby IMO and ABS. Suitable identifications are made as to the source of the text ofSection 5/4 (old 24) as described in 5/4A.1S.2 on page 5/4/1.

For the convenience of the user, it was decided to publish the new Section 5/4(old 24) as a separate volume; therefore, applicable requirements in the rest of thecurrent Rules for Building and Classing Steel Vessels, including Section 1/1 Scope andConditions of Classification, are to be complied with.

Although this publication contains IGC/IBC Codes and their amendments in forceat time of publication, the reader is encouraged to check the subsequent amendmentsor proposed amendments to IGC/IBC Codes with International Maritime Organization,4 Albert Embankment, London SE1 7SR, United Kingdom, whose permission to repro-duce these codes is gratefully acknowledged.

Foreword to the 1994 Edition

This edition includes amendments to the IGC/IBC Codes up to and includingMSC.30(61) and MSC.28(61) as well as all interpretations developed since the 1992edition.

Effective 1 July 1994, this edition will replace the 1992 edition and subsequentchanges except that for gas carriers keel laid or in a similar stage of construction before1 October 1994, the requirements in Part A in force on 30 June 1994 will apply.

Once again, the kind permission by IMO to publish these Codes is gratefullyacknowledged.

INDEX

Liquefied Gas Carriers

Applications dry chemical powder fire-extinguishing systems, 5/4A.11.4fire safety requirements, 5/4A.11.15/4A.1S.1afire water main equipment, 5/4A.11.2firemen’s outfits, 5/4A.11.6Cargo Containmentwater spray system, 5/4A.11.35/4A.4

allowable stresses and corrosion allowances, 5/4A.4.5construction and testing, 5/4A.4.10 Generaldefinitions, 5/4A.4.2 5/4A.1design loads, 5/4A.4.3 application, 5/4.1S.1ageneral, 5/4A.4.1 definitions, 5/4A.1.3guidance formulae for acceleration components, 5/4A.4.12 equivalents, 5/4A.1.4insulation, 5/4A.4.8 hazards, 5/4A.1.2materials, 5/4A.4.9 surveys and certification, 5/4A.1.5secondary barrier, 5/4A.4.7stress categories, 5/4A.4.13 Hull Scantlingsstress relieving for type C independent tanks, 5/4A.4.11 5/4.1S.7structural analyses, 5/4A.4.4supports, 5/4A.4.6

Installation of Cargo TanksCargo Pressure/Temperature Control5/4A.1S.45/4A.7Instrumentation (Gauging, Gas Detection and Controls)general, 5/4A.7.15/4A.13refrigeration systems, 5/4A.7.2automatic or remote control of propulsion machinery, 5/Cargo Tank Vent Systems

4A.16S.175/4A.8cargo handling control systems, 5/4A.13S.1.3additional pressure relieving system for liquid level, 5/4A.8.3gas detection requirements, 5/4A.13.6general, 5/4A.8.1general, 5/4A.13.1pressure relief systems, 5/4A.8.2inert gas generators, 5/4A.9S.5.5size of valves, 5/4A.8.5level indicators for cargo tanks, 5/4A.13.2vacuum protection systems, 5/4A.8.4overflow control, 5/4A.13.3Classificationpressure gauges, 5/4A.13.45/4.1S.1atemperature indicating devices, 5/4A.13.5International Certificate of FitnessData Submission 5/4A.1S.75/4.1S.3

DefinitionsLoading Guidance5/4A.1.35/4.1A.5

Electrical InstallationsMaterials of Construction5/4A.105/4A.6general, 5/4A.10.1general, 5/4A.6.1types of equipment, 5/4A.10.2material requirements, 5/4A.6.2Environmental Controlwelding and non-destructive testing, 5/4A.6.35/4A.9Mechanical Ventilation in the Cargo Areacargo tank inerting, 5/4A.9.45/4A.12environmental control of spaces surrounding type Cspaces not normally entered, 5/4A.12.2independent tanks, 5/4A.9.3spaces required to be entered during, normal cargo handlingenvironmental control within cargo tanks and cargo piping

operations, 5/4A.12.1systems, 5/4A.9.1environmental control within the hold spaces (cargo

containment systems other then type C independent tanks, Operating Requirements5/4A.9.2 5/4A.18

inert gas production on board, 5/4A.9.5 additional operating requirements, 5/4A.18.9cargo information, 5/4A.18.1cargo transfer operations, 5/4A.18.8Filling Limits for Cargo Tanks

5/4A.15 carriage of cargo at low temperature, 5/4A.18.5compatibility, 5/4A.18.2general, 5/4A.15.1

information to be provided to the master, 5/4A.15.2 entry into spaces, 5/4A.18.4personnel training, 5/4A.18.3Fire Protection and Fire Extinction

5/4A.11 protective equipment, 5/4A.18.6systems and controls, 5/4A.18.7cargo compressor and pump rooms, 5/4A.11.5

INDEX | 1

Personnel Protection Special Construction Requirements5/4A.1S.15/4A.14

first-aid equipment, 5/4A.14.3 Special Requirements5/4A.17personnel protection requirements for individual products, 5/

4A.14.4 ammonia, 5/4A.17.13chlorine, 5/4A.17.14protective equipment, 5/4A.14.1

safety equipment, 5/4A.14.2 deck cargo piping, 5/4A.17.5diethyl ether and vinyl ethyl ether, 5/4A.17.15Process Pressure Vessels and Liquid, Vapour and Pressure

Piping Systems ethylene oxide, 5/4A.17.16exclusion of air from vapour spaces, 5/4A.17.65/4A.5

cargo and process piping, 5/4A.5.2 flame screens on vent outlets, 5/4A.17.10general, 5/4A.17.1cargo system valving requirements, 5/4A.5.6

cargo transfer methods, 5/4A.5.8 independent tanks, 5/4A.17.3inhibition, 5/4A.17.8general, 5/4A.5.1

piping fabrication and joining details, 5/4A.5.4 isopropylamine and monoethylamine, 5/4A.17.17materials of construction, 5/4A.17.2ship’s cargo hoses, 5/4A.5.7

testing of piping, 5/4A.5.5 maximum allowable quantity of cargo per tank, 5/4A.17.11methyl acetylene-propadiene mixtures, 5/4A.17.18type tests on piping components, 5/4A.5.3

vapour return connections, 5/4A.5.9 moisture control, 5/4A.17.7nitrogen, 5/4A.17.19permanently installed toxic gas detectors, 5/4A.17.9Ship Arrangementspropylene oxide and mixtures of ethylene oxide-propylene5/4A.3

oxide with ethylene oxide content of not more than 30% byaccess to spaces in the cargo area, 5/4A.3.5weight, 5/4A.17.20accommodation, service and machinery spaces and air-locks, 5/

refrigeration systems, 5/4A.17.44A.3.6submerged electric cargo pumps, 5/4A.17.12air-locks, 5/4A.3.6vinyl chloride, 5/4A.17.21arrangement of machinery spaces of category A, 5/4A.16.2Summary of Minimum Requirementsbilge, ballast and fuel oil arrangements, 5/4A.3.75/4A.19bow or stern loading and unloading arrangements, 5/4A.3.8Survey Requirementscargo control rooms, 5/4A.3.45/4A.1S.5cargo pump rooms and cargo compressor rooms, 5/4A.3.3

control stations, 5/4A.3.2Testingsegregation of the cargo area, 5/4A.3.15/4A.1.5Ship Survival Capabilityagenda, 5/4A.1S.35/4A.2initial, 5/4A.1S.6conditions of loading, 5/4A.2.4service, 5/4A.1S.2damage assumptions, 5/4A.2.5welding and non-destructive, 5/4A.6.3flooding assumptions, 5/4A.2.7

freeboard and intact stability, 5/4A.2.2location of cargo tanks, 5/4A.2.6 Use of Cargo as Fuel

5/4A.16overboard discharges below the freeboard deck, 5/4A.2.3standard of damage, 5/4A.2.8 gas fuel supply, 5/4A.16.3

general, 5/4A.16.1survival requirements, 5/4A.2.9

INDEX | 2

Chemical Carriers

Hull Scantlings5/4.1S.7Additional Measures for the Protection of the Marine

Environment5/4B.16A Incineration at Sea of Liquid Chemical Waste

5/4B.19condition of carriage, 5/4B.16A.2general, 5/4B.16A.1 cargo containment and incinerator standards, 5/4B.19.4

cargo tank environmental control, 5/4B.19.8procedures and arrangements manual, 5/4B.16A.3Application cargo transfer, 5/4B.19.5

electrical installation, 5/4B.19.95/4.1S.1bfire protection and fire extinguishing, 5/4B.19.10general, 5/4B.19.1Cargo Containmentinstrumentation and overflow control, 5/4B.19.125/4B.4materials of construction, 5/4B.19.6definitions, 5/4B.4.1mechanical ventilation in the cargo area and in the incineratortank type requirements for individual products, 5/4B.4.2

location, 5/4B.19.11Cargo Tank Venting and Gas-freeing Arrangementpersonnel protection, 5/4B.19.135/4B.8ship arrangements, 5/4B.19.3cargo tank gas-freeing, 5/4B.8.5ship survival capability and location of cargo tanks, 5/4B.19.2general, 5/4B.8.1tank vent systems, 5/4B.19.7types of tank vent systems, 5/4B.8.3Inert Gas Systems on Chemical Carriersventing requirements for individual products, 5/4B.5.45/4B.9S.1.1Cargo Temperature ControlInstrumentation5/4B.75/4B.13general, 5/4B.7.1cargo transfer control systems, 5/4B.5S.6.4additional requirements, 5/4B.7.2gauging, 5/4B.13.1Cargo Transfervapour detection, 5/4B.13.25/4B.5International Certificate of Fitnesscargo transfer control systems, 5/4B.5.65/4B.1S.3flange connections, 5/4B.5.3

piping arrangements, 5/4B.5.5piping fabrication and joining details, 5/4B.5.2 List of Chemicals to Which the Code does not Apply

5/4B.18piping scantlings, 5/4B.5.1ship’s cargo hoses, 5/4B.5.7 Loading Guidance

5/4.1S.5test requirements for piping, 5/4B.5.4Classification5/4.1S.1b Materials of Construction

5/4B.6general, 5/4B.6.1Data Submission

5/4.1S.3 special requirements for materials, 5/4B.6.2Mechanical Ventilation in the Cargo AreaDefinitions

5/4B.1.3 5/4B.12pump-rooms and other enclosed spaces normally entered, 5/

4B.12.2Electrical Installationsspaces normally entered during cargo handling operations, 5/5/4B.10

4B.12.1bonding, 5/4B.10.3spaces not normally entered, 5/4B.12.3electrical requirements for individual products, 5/4B.10.4

general, 5/4B.10.1hazardous locations and types of equipment and wiring, 5/ Operational Requirements

5/4B.164B.10.2Environmental Control additional operational requirements, 5/4B.16.7

cargo information, 5/4B.16.25/4B.9environmental control requirements for individual products, 5/ cargoes not to be exposed to excessive heat, 5/4B.16.6

maximum allowable quantity of cargo per tank, 5/4B.16.14B.9.2general, 5/4B.9.1 opening of and entry into cargo tanks, 5/4B.16.4

personnel training, 5/4B.16.3Equivalents5/4B.1.4 stowage of cargo samples, 5/4B.16.5

Personnel ProtectionFire Protection and Fire Extinction5/4B.11 5/4B.14

protective equipment, 5/4B.14.1application, 5/4B.11.1cargo area, 5/4B.11.3 safety equipment, 5/4B.14.2cargo pump-rooms, 5/4B.11.2special requirements, 5/4B.11.4 Ship ArrangementsFoam System 5/4B.3calculation of the capacity of foam system for chemical tankers, access to spaces in the cargo area, 5/4B.3.4

ANNEX D accommodation, service and machinery spaces and controlstations, 5/4B.3.2

bilge and ballast arrangements, 5/4B.3.5Hazards5/4B.1.2 bow or stern loading and unloading arrangements, 5/4B.3.7

INDEX | 3

cargo pump-rooms, 5/4B.3.3 diethyl ether, 5/4B.15.4cargo segregation, 5/4B.3.1 hydrogen peroxide solutions, 5/4B.15.5pump and pipeline identification, 5/4B.3.6 increased ventilation requirements, 5/4B.15.17Ship Survival Capability and Location of Cargo Tanks motor fuel anti-knock compounds (containing lead alkyls), 5/5/4B.2 4B.15.6conditions of loading, 5/4B.2.4 octyl nitrates, all isomers, 5/4B.15.20damage assumptions, 5/4B.2.5 overflow control, 5/4B.15.19flooding assumptions, 5/4B.2.7 phosphorus, yellow or white, 5/4B.15.7freeboard and intact stability, 5/4B.2.2 propylene oxide, 5/4B.15.8general, 5/4B.2.1 sodium chlorate solution, 50% or less, 5/4B.15.9location of cargo tanks, 5/4B.2.6 special cargo pump-room requirements, 5/4B.15.18shipside discharges below the freeboard deck, 5/4B.2.3 sulphur, liquid, 5/4B.15.10standard of damage, 5/4B.2.8 temperature sensors, 5/4B.15.21survival requirements, 5/4B.2.9

toxic products, 5/4B.15.12Special RequirementsSummary of Minimum Requirements5/4B.155/4B.17acetone cyanohydrin, 5/4B.15.1Surveysacids, 5/4B.15.115/4B.1.5ammonium nitrate solution, 93% or less, 5/4B.15.25/4B.1S.5carbon disulphide, 5/4B.15.3

cargo contamination, 5/4B.15.16cargoes protected by additives, 5/4B.15.13cargoes with low ignition temperature and cargoes with vapour

Transport of Liquid Chemical Wastespressure greater than 1.013 bar absolute at 37.8 °C, 5/4B.15.14 5/4B.20

INDEX | 4

PART 5 SECTION 4

Vessels Intended to Carry Liquefied Gases andChemical Cargoes in Bulk

5/4.1S General (ABS) safety and pollution hazards to such an extent as to warrantthe application of these Rules are found in 5/4B.18.

Liquids covered are those having a vapor pressure not5/4.1S.1 Classificationexceeding 2.8 bar (40.6 psi) absolute at a temperature ofa Liquefied Gas Carriers37.8C (100F).1 In accordance with 1/1.3.2, the classification of ✠A1

This section applies to the cargo containment systemLiquefied Gas Carrier is to be assigned to vesselsand related systems. The remainder of the vessel is todesigned and specifically fitted for the carriage ofcomply with the hull and machinery requirements of theliquefied gases and built to the requirements of PartRules except as modified in this Section.A of this section and other relevant sections of the

Rules.2 These requirements are intended to apply to steel 5/4.1S.2 Format

vessels with machinery aft regardless of their size, Part A of this section which are based on the technicalincluding those of less than 500 tons gross tonnage, requirements of the International Code for the Construc-engaged in carriage of liquefied gases having a vapor tion and Equipment of Ships Carrying Liquefied Gases inpressure exceeding 2.8 bar (40.6 psi) absolute at a Bulk (IGC Code) are all contained in their entirety andtemperature of 37.8C (100F) and other products as are required for classification.shown in 5/4A.19, when carried in bulk. Part B of this section which are based on technical re-

The requirements relating to the primary container quirements of the International Code for the Constructionapply only where noncorrosive cargoes are carried. If bal- and Equipment of Ships Carrying Dangerous Chemical inlast or corrosive cargoes are carried in the primary con- Bulk (IBC Code) are all contained in their entirety andtainer, the scantlings are to be suitably increased or an are required for classification.effective method of corrosion control is to be adopted. The term ‘‘should be’’ is to be understood to read as ‘‘is

This section applies to the cargo containment system to be’’ or ‘‘are to be’’ and unless otherwise specified, theand related systems. The remainder of the vessel is to term ‘‘Administration’’ is to be read as the ‘‘Bureau’’. Thecomply with the hull and machinery requirements of the numbering system of the technical requirements repro-Rules except as modified in this Section. duced herein are the same as the IGC and IBC Codes

b Chemical Carriers except a prefix of 5/4A has been added for the liquefied1 In accordance with 1/1.3.2, the classification of ✠A1 gas carriers and the prefix of 5/4B has been added for the

Chemical Carrier is to be assigned to vessels de- chemical carriers.signed and specifically fitted for the carriage of dan- The parts in this section which are classification require-gerous or noxious liquid chemical substances and built ments and not based on the Codes have a prefix of 5/to the requirements of Part B of this section and other 4A.1S.1, 5/4A.1S.2, 5/4B.2S.1, etc. Under these parts, alsorelevant sections of the Rules. interpretations of the Codes with their source such as IMO

2 These requirements are intended to apply to steel (International Maritime Organization), IACS (Interna-vessels with machinery aft regardless of their size, tional Association of Classification Societies), etc. and addi-including those of less than 500 tons gross tonnage, tional Bureau requirements.engaged in carriage of bulk cargo of dangerous or The parts of this section which are operational, training,noxious liquid chemical substances, other than petro- or national requirements are shown in italics, are not re-leum or similar flammable products as follows: quired for classification, and are shown for information

only.a products having significant fire hazards in excess of A vertical line is placed in the margin of all text which

those of petroleum products and similar flammable is not of the IGC or IBC Codes.products.

b products having significant hazards in addition to orother than flammability. 5/4.1S.3 Submission of Data

The following plans, calculations, and information as appro-These Rules are limited to the liquids shown in thesummary of minimum requirements in 5/4B.17. Products priate are to be submitted in addition to those required

by 1/1.9.that have been reviewed and determined not to present

PART 5 SECTION 4 | 1 Vessels Intended to Carry Liquefied Gas and Chemical Cargoes in Bulk

a Full particulars of the intended cargo or cargoes and its l Schematic diagram of the ventilation system indicatingproperties, including flashpoint, maximum vapor pressure, the vent pipe sizes and height of the openings above the

main deckminimum and, if necessary, maximum temperature, andloading and carriage procedures. m Schematic diagram of the refrigeration system to-

gether with the calculations concerning the refrigeratingb General arrangement plans of the vessel showing thecapacityposition of the following:

n Details of the electrical equipment installed in theCargo containment system, cargo tanks, fuel oil, watercargo area and of the electrical bonding of the cargo tanksballast and other tanks, and void spacesand pipingManholes in cargo tanks, opening for tank cleaning, anyo Where fitted, plans and specifications relative to the useother opening of the cargo tanksof the cargo as fuel for boilers and internal combustionDoors and other openings in cargo pump and compressorengines (general installations; schematic diagram of therooms and other gas dangerous roomsfuel-gas lines with the indication of all the valves and safetyVentilation ducts of cargo pump and compressor roomsdevices; compressors of the fuel gas and relevant engines;and other ‘‘gas dangerous’’ spacesfuel-gas heaters and pressure vessels; installation of theDoor, air-locks, manholes, ducts and other openings forburners of the fuel-gas and of the fuel oil; electrical bonding‘‘non-gas dangerous’’ spaces which are, however, adjacentsystems)to the cargo area including rooms inside and under thep Details of testing procedures of cargo tanks and liquidforecastle deckand vapor systemsCargo piping, both liquid and gaseous phases, located un-q Diagram of inert-gas system or hold-space environmen-der and above decktal-control systemVent piping and gas freeing piping and protective devicesr Diagram of gas-detection systemsuch as flame screens, etc. fitted at the outlet end of thes Jettison arrangements, if providedvents etc.t Schematic-wiring diagramsGas dangerous spacesu Details of all cargo and vapor handling equipmentc Plans of the hull structure in way of the cargo tanks,v Details of fire extinguishing systemsincluding the installation of attachments, accessories, inter-w Welding procedurenal reinforcements, saddles for support, and tie-down de-x Emergency shutdown arrangementsvices.y Construction details of cargo and booster pumps andd Plans of the structure of the cargo containment system,compressors including material specification.including the installation of attachments, supports, andz Hazardous area drawing showing access, openings, ventattachment of accessoriesoutlets.For independent pressure cargo tanks, the standard oraa Bilge and ballast arrangement for the cargo area.Code adopted for the construction and design is to be

identified. Detailed construction drawings together withdesign calculations for the pressure boundary, tank support 5/4.1S.4 Still-water Bending-moment Calculationsarrangement and analysis for the load distribution. Anti Still-water bending-moment calculations for the antici-collision, chocking arrangement and design calculations. pated loaded and ballasted conditions are to be submitted

for all liquefied gas carriers and chemical carriers.e Distribution of the grades and of the types of steel pro-posed for the structures of the hull and of the cargo contain-ment system, including attachments, accessories, etc., to- 5/4.1S.5 Loading Guidancegether with the calculation of the temperatures on all the Loading guidance is to be as required by 3/6.7. Liquefiedstructures which can be affected by the low temperatures gas carriers and chemical carriers of less than 65 metersof the cargo (213 ft) in length, with uneven distribution of cargo orf Results of direct calculations of the stresses in the hull ballast, are to be provided with loading guidance.and in the cargo containment systemg Specifications and plans of the insulation system and 5/4.1S.7 Hull Scantlingscalculation of the heat balance The scantlings of the hull structure are to be generally inh Procedures and calculations of the cooling down, load- accordance with Sections 5/2, 5/3, and other applicableing, and unloading operations sections of the Rules, which may be modified in accordancei Loading and unloading systems, venting systems, and with the following paragraphs.gas-freeing systems as well as a schematic diagram of the a Bulkheadsremote controlled valve system 1 Transverse Bulkheads Transverse bulkheads used forj Details and installation of the safety valves and relevant ballast or cargo are to comply with Section 5/2B. Bulkheadscalculations of their relieving capacity not subject to hydrostatic loads are to be in accordance

with Section 3/12. When the cargo containment system isk Details and installation of the various monitoring andcontrol systems, including the devices for measuring the either a membrane or semi-membrane system, the trans-

verse bulkheads are also to be designed to withstand thelevel of the cargoes in the tanks and the temperatures inthe containment system dynamic forces from the cargo.


2 Cofferdam Bulkheads Where a transverse cofferdam piping system or one of the power units, the defect can beis used as a tank, the local stiffener and plate scantlings of isolated so that this steering capability can be maintained or

regained in 45 seconds or less.transverse bulkheads subject to internal hydrostatic pres-sure are to be in accordance with Section 3/13.Where a cofferdam is of a cellular-type construction and 5/4.1S.8 No Text.is used as a tank and not subject to a hydrostatic load onexternal side, the depth of the internal diaphragm plates, 5/4.1S.9 Changes to Codeseither horizontal or vertical, are to be at least 63 mm/ Changes to IGC/IBC Codes, other than those of opera-m (0.75 in./ft) of the lesser of the horizontal or vertical tional nature, will become ABS Rule requirements as ofunsupported span of the cofferdam bulkhead and is to be the effective date of the particular change to the Code.of sufficient depth to provide ready access.

3 Longitudinal Bulkheads Scantlings of longitudinalbulkheads forming narrow wing tanks are to be in accord-ance with Section 5/2B, except that the vertical distance Part A Liquefied Gas Carriersh as used in the equations for supporting members maybe measured to a point 1.22 m (4 ft) above the deck at the

5/4A.1S.1 Special Construction Requirementsside. Where the wing-tank-space bulkhead to side-shella Material In addition to the material requirements in-plating, is of a cellular-type construction, the depth of

dicated in 5/4A.6, hull structural material is to be in accord-internal diaphragm plates is to be at least 83 mm/m (1 in./ance with Sections 3/2 and 2/1.ft) of length and is to be of sufficient depth to provide

b Low Temperature Cargo For all liquefied gas carri-ready access.ers, where low temperature cargo is carried, the grade ofb Reduction in Plate Thickness The thickness of thematerial for the strength deck stringer, sheer strake andtank bulkhead plating described in 5/4.1S.7a2 and 7a3 maybilge strake outside 0.4L amidships is to be the same asbe reduced by 10% but not more than 1.5 mm (0.06 in.)would be required within 0.4L amidships for the particularwhere the space on one side is intended to be dry at allthickness. The strakes of this material are to extend beyondtimes.the ends of spaces containing low temperature cargo.c Webs and Transverses The thicknesses of diaphragm

c Cold Deformation Materials subjected to cold defor-plates between the two boundary surfaces of wing tanksmation or strain are to be dealt with as may be requiredor cofferdams of a cellular-type construction are to be equalto maintain the specific impact properties. For formedto or greater than obtained from the following equation.material see 2/3A.3.7.

d Welding Welding details are to be in accordance witht = 0.036L + 4.7 mm Section 2/3. Details of all joints subject to impact testingt = 0.00043L + 0.18 in. are to be indicated on the plans; preliminary tests are made

to ascertain that the Charpy V-notch impact properties oft = thickness in mm or in. the various types of butt welds to be used are equal to the

L = length of vessel as defined in 3/1.1 in m or ft requirements noted in 5/4A.6.d Double Bottom Double bottoms, where fitted, are to

5/4A.1S.2 Service Testbe in accordance with Section 3/7. The minimum depthAll primary containers for low-temperature cargoes, theof the double bottom is to be in compliance with theinsulation, and the cargo-handling equipment are to besurvivability requirements of 5/4A.2 and 5/4B.2. Doubletested under service conditions prior to final action inbottoms are to be designed to withstand the dynamic forcesregard to classification. The primary containers are to befrom the cargo containment system.filled to the normal-capacity level with cargo at the mini-e Shell Plating The bottom and side shell plating is tomum service temperature.be in accordance with Section 3/15.Final acceptance of the insulating arrangements is subjectf Deck Plating Upper decks are to be in accordanceto confirmation of their effectiveness under operating con-with Section 3/16. Where the deck is of the two-plateditions. If the service tests or subsequent operation arecellular-type construction, special consideration may benot satisfactory, changes in the insulating arrangementsgiven to plate thicknesses.may be required.g Arrangement Tanks forward of the collision bulkhead

are not to be arranged for the carriage of oil or other liquidsubstances that are flammable. 5/4A.1S.3 Test Agenda

The agenda for the tests required by this section is to beh Hull Structure in Way of Tanks The hull structurein way of primary containers, the foundations, chocks, keys submitted for review. The tests are to be witnessed by a

Surveyor and a complete report of the results is to beand sway braces is to be of sufficient strength to supportthe containment system when subjected to design loadings. submitted for consideration prior to final approval of the

i Steering Gear The Steering gear is to be in accordance primary container, non-structural secondary barrier andthe adjacent hull structure. In addition, for hydrostaticwith Section 3/5 with the modification that the steering

gear is to be arranged so that after a single failure in its testing of pressure vessel type cargo tanks, see 4/2.39.2.


5/4A.1S.4 Installation of Cargo Tanks 5/4A.1.1.4.1 When cargo tanks contain products forwhich the Code requires a type 1G ship, neither flammablea Access around Tanks Pressure containers for lique-

fied gas are to be arranged in the holds so as to provide liquids having a flashpoint of 60°C (closed cup test) or lessnor flammable products listed in 5/4A.19 should be carriedadequate clearance around the tanks to provide access for

inspection. Where more than one tank is installed, the in tanks located within the protective zones described in5/4A.2.6.1.1.distance between such tanks and between the tanks and

the vessel’s structure is to be adequate to permit access 5/4A.1.1.4.2 Similarly, when cargo tanks contain prod-for inspection and maintenance of all tank surfaces and ucts for which the Code requires a type 2G/2PG ship, thehull structure. Also see 5/4A.3.5 above-mentioned flammable liquids should not be carried

b Horizontal Pressure Tanks Foundations for hori- in tanks located within the protective zones described inzontal tanks are to generally have supports fitted at only 5/4A.2.6.1.2.two locations so as to prevent absorbing hull deflections. 5/4A.1.1.4.3 In each case the restriction applies to theWhere due to the design three or more supports are fitted, protective zones within the longitudinal extent of the holdthe calculations required by 5/4A.4.4.6.3.2 are to include spaces for the cargo tanks loaded with products for whichthe effects of vertical deflections imposed upon the tank the Code requires a type 1G or 2G/2PG ship.through the tank/hull girder interaction for all contem- 5/4A.1.1.4.4 The above-mentioned flammable liquidsplated loading conditions. In addition to the foundation, and products may be carried within these protective zoneschocks are to be fitted to prevent shifting, but these chocks when the quantity retained in the cargo tanks of productsneed not be in contact with the tank shell. for which the Code requires a type 1G or 2G/PG ship is

solely used for cooling, circulation or fuelling purposes.5/4A.1S.5 Surveys 5/4A.1.1.5 Except as provided in 5/4A.1.1.7.1, when itSee 1/3.23 for survey requirements for vessels in service is intended to carry products covered by this Code andintended to carry liquefied gases. products covered by the International Code for the Con-

struction and Equipment of Ships Carrying Dangerous5/4A.1S.6 Initial Testing Chemicals in Bulk adopted by the Maritime Safety Com-

a Primary Barriers All integral and independent tanks mittee under the authority of the Assembly of the Organiza-(other than pressure vessels complying with Section 4/2) tion conferred by resolution A.490(XII), as may beare to be hydropneumatically or hydrostatically tested to amended by the Organization (IBC Code), the ship shouldapproximate the design stresses and so that the pressure comply with the requirements of both Codes appropriateat the top of the tank corresponds to the maximum allow- to the products carried.able relief valve setting (MARVS). Techniques for testing 5/4A.1.1.6 Where it is proposed to carry products whichof membrane tanks are to be submitted for approval. Also may be considered to come within the scope of the Codesee Section 1/2. but are not at present designated in 5/4A.19, the Adminis-

b Ballast or Fuel Oil Tanks Requirements for testing tration* and the port Administrations involved in suchare contained in Section 1/2. carriage should establish preliminary suitable conditions

of carriage based on the principles of the Code and notify5/4A.1S.7 International Certificate of Fitness the Organization of such conditions.When the vessel is issued an International Certificate of 5/4A.1.1.7.1 The requirements of this Code should takeFitness For The Carriage of Liquefied Gases In Bulk by precedence when a ship is designed and constructed forthe Country of Registration Administration or its agents the carriage of the following products:other than the Bureau, such certificate will be accepted as .1 those listed exclusively in 5/4A.19 of this Code; andevidence of compliance with the following requirements .2 one or more of the products which are listed both inof this section. this Code and in the International Bulk Chemical5/4A.2.2 Freeboard and intact stability Code. These products are marked with an asterisk5/4A.2.5 Damage assumptions (*) in column ‘‘a’’ in the table of 5/4A.19.5/4A.2.7 Flooding assumptions 5/4A.1.1.7.2 When a ship is intended exclusively to5/4A.2.8 Standard of damage carry one or more of the products noted in 5/4A.1.1.7.1.2,5/4A.2.9 Survival requirements the requirements of the International Bulk Chemical Code5/4A.11.1 Structural fire protection requirements as amended should apply. ‘‘Administration’’ means ‘‘Flag

State Administration.’’On all other vessels, the Bureau will review the dataand plans for compliance with these requirements.

When authorized by the Country of Registration Admin- 5/4A.1.2 Hazardsistration and upon the request of the Owners of a classed Hazards of gases considered in this Code include fire,vessel or one intended to be classed, the Bureau will review toxicity, corrosivity, reactivity, low temperature andthe plans, data, etc. and survey the vessel for compliance pressure.of these Rules and issue The International Certificate ofFitness For The Carriage of Liquefied Gases in Bulk inaddition to the classification indicated in 5/4.1S.1. *‘‘Administration’’ means ‘‘Flag State Administration’’


5/4A.1.3 Definitions 5/4A.1.3.12 ‘‘Cofferdam’’ is the isolating space betweentwo adjacent steel bulkheads or decks. This space may beExcept where expressly provided otherwise, the following

definitions apply to the Code. Additional definitions are a void space or a ballast space.given in 5/4A.4. 5/4A.1S.3.12 ‘‘Contiguous hull structure’’ means hull

5/4A.1.3.1 ‘‘Accommodation spaces’’ are those spaces structure that includes the inner deck, the inner bottomused for public spaces, corridors, lavatories, cabins, offices, plating, longitudinal bulkhead plating, transverse bulkheadhospitals, cinemas, games and hobbies rooms, barber plating, floors, webs, stringers, and all attached stiffen-shops, pantries containing no cooking appliances and simi- ers. (ABS)lar spaces. Public spaces are those portions of the accom- 5/4A.1.3.13 ‘‘Control stations’’ are those spaces in whichmodation which are used for halls, dining rooms, lounges ships’ radio or main navigating equipment or the emer-and similar permanently enclosed spaces. gency source of power is located or where the fire-re-

5/4A.1.3.2 ‘‘ ‘A’ class divisions’’ means divisions as de- cording or fire-control equipment is centralized. This doesfined in regulation II-2/3.3 of the 1983 SOLAS amend- not include special fire-control equipment which can bements. most practically located in the cargo area.

5/4A.1.3.3.1 ‘‘Administration’’ means the Government 5/4A.1S.3.13a ‘‘Design temperature.’’ see 5/4A.4.2.6of the State whose flag the ship is entitled to fly. 5/4A.1S.3.13b ‘‘Design vapor pressure.’’ see 5/4A.4.2.7

For the purpose of classification the term ‘‘Administra- 5/4A.1.3.14 ‘‘Flammable products’’ are those identifiedtion’’, unless otherwise specified, is to be read as the ‘‘Bu- by an ‘‘F’’ in column ‘‘f’’ in the table of 5/4A.19.reau’’. See 5/4.1S.2. 5/4A.1.3.15 ‘‘Flammability limits’’ are the conditions de-

5/4A.1.3.3.2 ‘‘Port Administration’’ means the appro- fining the state of fuel-oxidant mixture at which applicationpriate authority of the country in the port of which the of an adequately strong external ignition source is only justship is loading or unloading. capable of producing flammability in a given test apparatus.

5/4A.1.3.4 ‘‘Boiling point’’ is the temperature at which 5/4A.1S.3.15 ‘‘Flammable range’’ means the range be-a product exhibits a vapour pressure equal to the atmo- tween the minimum and maximum concentrations of vaporspheric pressure. in air which form a flammable mixture. (ABS)

5/4A.1.3.5 ‘‘Breadth (B)’’ means the maximum breadth 5/4A.1.3.16 ‘‘Gas carrier’’ is a cargo ship constructed orof the ship, measured amidships to the moulded line of adapted and used for the carriage in bulk of any liquefiedthe frame in a ship with a metal shell and to the outer gas or other products listed in the table of 5/4A.19.surface of the hull in a ship with a shell of any other 5/4A.1.3.17 ‘‘Gas-dangerous space or zone’’ is:material. The breadth (B) should be measured in metres. .1 a space in the cargo area which is not arranged or

5/4A.1.3.6 ‘‘Cargo area’’ is that part of the ship which equipped in an approved manner to ensure that itscontains the cargo containment system and cargo pump atmosphere is at all times maintained in a gas-safeand compressor rooms and includes deck areas over the condition;full length and breadth of the part of the ship over the .2 an enclosed space outside the cargo area throughabove-mentioned spaces. Where fitted, the cofferdams, which any piping containing liquid or gaseous prod-ballast or void spaces at the after end of the aftermost hold ucts passes, or within which such piping terminates,space or at the forward end of the forwardmost hold space unless approved arrangements are installed to pre-are excluded from the cargo area. vent any escape of product vapour into the atmo-

5/4A.1.3.7 ‘‘Cargo containment system’’ is the arrange- sphere of that space;ment for containment of cargo including, where fitted, a .3 a cargo containment system and cargo piping;primary and secondary barrier, associated insulation and .4.1 a hold space where cargo is carried in a cargo con-any intervening spaces, and adjacent structure if necessary tainment system requiring a secondary barrier;for the support of these elements. If the secondary barrier .4.2 a hold space where cargo is carried in a cargo con-is part of the hull structure it may be a boundary of the tainment system not requiring a secondary barrier;hold space. .5 a space separated from a hold space described in

5/4A.1.3.8 ‘‘Cargo control room’’ is a space used in the .4.1 by a single gastight steel boundary;control of cargo handling operations and complying with .6 a cargo pump room and cargo compressor room;the requirements of 5/4A.3.4. .7 a zone on the open deck, or semi-enclosed space

5/4A.1.3.9 ‘‘Cargoes’’ are products listed in 5/4A.19 car- on the open deck, within 3 m of any cargo tankried in bulk by ships subject to the Code. outlet, gas or vapour outlet, cargo pipe flange or

5/4A.1.3.10 ‘‘Cargo service spaces’’ are spaces within cargo valve or of entrances and ventilation openingsthe cargo area used for workshops, lockers and store-rooms to cargo pump rooms and cargo compressor rooms;of more than 2 m2 in area, used for cargo handling .8 the open deck over the cargo area and 3 m forwardequipment. and aft of the cargo area on the open deck up to a

height of 2.4 m above the weather deck;5/4A.1.3.11 ‘‘Cargo tank’’ is the liquid-tight shell de-signed to be the primary container of the cargo and includes .9 a zone within 2.4 m of the outer surface of a cargo

containment system where such surface is exposedall such containers whether or not associated with insula-tion or secondary barriers or both. to the weather;


.10 an enclosed or semi-enclosed space in which pipes has in the aggregate a total power output of not lessthan 375 kW; orcontaining products are located. A space which con-

tains gas detection equipment complying with 5/ .3 any oil-fired boiler or oil fuel unit.4A.13.6.5 and a space utilizing boil-off gas as fuel 5/4A.1.3.25 ‘‘Machinery spaces’’ are all machineryand complying with 5/4A.16 are not considered gas- spaces of category A and all other spaces containing propel-dangerous spaces in this context; ling machinery, boilers, oil fuel units, steam and internal

.11 a compartment for cargo hoses; or combustion engines, generators and major electrical ma-

.12 an enclosed or semi-enclosed space having a direct chinery, oil filling stations, refrigerating, stabilizing, venti-opening into any gas-dangerous space or zone. lation and air-conditioning machinery, and similar spaces;

5/4A.1.3.18 ‘‘Gas-safe space’’ is a space other than a gas- and trunks to such spaces.dangerous space. 5/4A.1.3.26 ‘‘MARVS’’ is the maximum allowable relief

5/4A.1.3.19 ‘‘Hold space’’ is the space enclosed by the valve setting of a cargo tank.ship’s structure in which a cargo containment system is 5/4A.1S.3.26 ‘‘Membrane tanks.’’ see 5/4A.4.2.2situated. 5/4A.1.3.27 ‘‘Oil fuel unit’’ is the equipment used for

5/4A.1S.3.19 ‘‘IMO’’ means the International Maritime the preparation of oil fuel for delivery to an oil-fired boiler,Organization or equipment used for the preparation for delivery of

5/4A.1.3.20 ‘‘Independent’’ means that a piping or vent- heated oil to an internal combustion engine, and includesing system, for example, is in no way connected to another any oil pressure pumps, filters and heaters dealing withsystem and there are no provisions available for the poten- oil at a pressure of more than 1.8 bar gauge.tial connection to other systems. 5/4A.1.3.28 ‘‘Organization’’ is the International Mari-

5/4A.1S.3.20a ‘‘Independent tank.’’ see 5/4A.4.2.4.1 time Organization (IMO).5/4A.1S.3.20b ‘‘Independent tank, type A.’’ see 5/ 5/4A.1.3.29 ‘‘Permeability’’ of a space means the ratio

4A.4.2.4.2 of the volume within that space which is assumed to be5/4A.1S.3.20c ‘‘Independent tank, type B.’’ see 5/ occupied by water to the total volume of that space.

4A.4.2.4.3 5/4A.1.3.30.1 ‘‘Primary barrier’’ is the inner element de-5/4A.1S.3.20d ‘‘Independent tank, type C.’’ see 5/ signed to contain the cargo when the cargo containment

4A.4.2.4.4 system includes two boundaries.5/4A.1S.3.20e ‘‘International Certificate of Fitness’’ 5/4A.1.3.30.2 ‘‘Secondary barrier’’ is the liquid-resisting

means an International Certificate of Fitness for Carriage outer element of a cargo containment system designed toof Liquefied Gases in Bulk issued under the ‘‘International afford temporary containment of any envisaged leakage ofCode for the Construction and Equipment of Ships Car- liquid cargo through the primary barrier and to preventrying Liquefied Gases in Bulk,’’ adopted by the Maritime the lowering of the temperature of the ship’s structure toSafety Committee of IMO. an unsafe level. Types of secondary barrier are more fully

defined in 5/4A.4.5/4A.1.3.21 ‘‘Insulation space’’ is the space, which mayor may not be an interbarrier space, occupied wholly or 5/4A.1S.3.30 ‘‘Process pressure vessel’’ means a pres-in part by insulation. sure vessel that is used in a reliquefaction, cargo heating,

5/4A.1S.3.21a ‘‘Integral tank.’’ see 5/4A.4.2.1 or other system that processes cargo on board. (ABS)5/4A.1S.3.21b ‘‘Internal insulation tanks’’ see 5/ 4A.4.2.5 5/4A.1.3.31 ‘‘Relative density’’ is the ratio of the mass

of a volume of a product to the mass of an equal volume5/4A.1.3.22 ‘‘Interbarrier space’’ is the space betweenof fresh water.a primary and a secondary barrier, whether or not com-

pletely or partially occupied by insulation or other material. 5/4A.1S.3.31 ‘‘Semi-membrane tank’’ see 5/4A.4.2.3.5/4A.1.3.23 ‘‘Length (L)’’ means 96% of the total length 5/4A.1.3.32 ‘‘Separate’’ means that a cargo piping sys-

on a waterline at 85% of the least moulded depth measured tem or cargo vent system, for example, is not connectedfrom the top of the keel, or the length from the foreside to another cargo piping or cargo vent system. This separa-of the stern to the axis of the rudder stock on that waterline, tion may be achieved by the use of design or operationalif that be greater. In ships designed with a rake of keel, methods. Operational methods should not be used withinthe waterline on which this length is measured should be a cargo tank and should consist of one of the followingparallel to the designed waterline. The length (L) should types:be measured in metres. .1 removing spool pieces or valves and blanking the

pipe ends;5/4A.1S.3.23 ‘‘Liquefied gas’’ means a cargo having a.2 arrangement of two spectacle flanges in series withvapor pressure of 2.8 bars absolute (40.6 psia) or more at

provisions for detecting leakage into the pipe between37.8 C (100 F).the two spectacle flanges.5/4A.1.3.24 ‘‘Machinery spaces of category A’’ are those

spaces and trunks to such spaces which contain: 5/4A.1.3.33 ‘‘Service spaces’’ are those spaces used forgalleys, pantries containing cooking appliances, lockers,.1 internal combustion machinery used for main propul-

sion; or mail and specie rooms, store-rooms, workshops other thanthose forming part of the machinery spaces and similar.2 internal combustion machinery used for purposes

other than main propulsion where such machinery spaces and trunks to such spaces.


5/4A.1S.3.33 Interpretation of 5/4A1.3.33 (ABS) the same to other Contracting Governments to the 1974SOLAS Convention for the information of their officers.The ‘‘service spaces’’ refer to normal stores for hotel ser-

vices and other similar spaces. Boatswain stores, lamp lock-ers, and carpenter shops would not be considered a ‘‘service 5/4A.1.5 Surveys and certificationspace’’. 5/4A.1.5.1 Survey procedure

5/4A.1S.3.33a ‘‘Shut-off valve’’ means a valve in a cargo 5/4A.1.5.1.1 The survey of ships, so far as regards theliquid or vapor line that fully closes a pipeline and provides enforcement of the provisions of the regulations and thenominal metal to metal contact between the valve operating granting of exemptions therefrom, should be carried outparts, including the disc and gate, and the valve body. by officers of the Administration. The Administration may,(ABS). however, entrust the surveys either to surveyors nominated

5/4A.1.3.34 ‘‘1974 SOLAS Convention’’ means the In- for the purpose or to organizations recognized by it.ternational Convention for the Safety of Life at Sea, 1974. 5/4A.1.5.1.2 The Administration nominating surveyors

5/4A.1.3.35 ‘‘1983 SOLAS amendments’’ means amend- or recognizing organizations to conduct surveys should, as aments to the 1974 SOLAS Convention adopted by the minimum, empower any nominated surveyor or recognizedMaritime Safety Committee of the Organization at its forty- organization to:eighth session on 17 June 1983 by resolution MSC.6(48). .1 require repairs to a ship; and

5/4A.1.3.36 ‘‘Tank cover’’ is the protective structure in- .2 carry out surveys if requested by the port State au-tended to protect the cargo containment system against thority* concerned.damage where it protrudes through the weather deck or The Administration should notify the Organization of theto ensure the continuity and integrity of the deck structure. specific responsibilities and conditions of the authority del-

egated to nominated surveyors or recognized organizations5/4A.1.3.37 ‘‘Tank dome’’ is the upward extension of aportion of a cargo tank. In the case of below-deck cargo for circulation to the Contracting Governments.containment systems the tank dome protrudes through the 5/4A.1.5.1.3 When a nominated surveyor or recognizedweather deck or through a tank cover. organization determines that the condition of the ship or

its equipment does not correspond substantially with the5/4A.1.3.38 ‘‘Toxic products’’ are those identified by a‘‘T’’ in column ‘‘f’’ in the table of 5/4A.19. particulars of the certificate or is such that the ship is not

fit to proceed to sea without danger to the ship, or persons5/4A.1.3.39 ‘‘Vapour pressure’’ is the equilibrium pres-on board, such surveyor or organization should immedi-sure of the saturated vapour above the liquid expressed inately ensure that corrective action is taken and should inbars absolute at a specified temperature.due course notify the Administration. If such corrective5/4A.1.3.40 ‘‘Void space’’ is an enclosed space in theaction is not taken the relevant certificate should be with-cargo area external to a cargo containment system, otherdrawn and the Administration should be notified immedi-than a hold space, ballast space, fuel oil tank, cargo pump orately; and, if the ship is in a port of another Contractingcompressor room, or any space in normal use by personnel.Government, the port State authority concerned shouldalso be notified immediately.5/4A.1.4 Equivalents

5/4A.1.5.2 Survey requirements5/4A.1.4.1 Where the Code requires that a particular5/4A.1.5.2.1 The structure, equipment, fittings, arrange-fitting, material, appliance, apparatus, item of equipment

ments and material (other than items in respect of whichor type thereof should be fitted or carried in a ship, or thata Cargo Ship Safety Construction Certificate, Cargo Shipany particular provision should be made, or any procedureSafety Equipment Certificate and Cargo Ship Safety Radio-or arrangement should be complied with, the Administra-telegraphy Certificate or Cargo Ship Safety Radioteleph-tion may allow any other fitting, material, appliance, appa-ony Certificate is issued) of a gas carrier should be sub-ratus, item of equipment or type thereof to be fitted orjected to the following surveys:carried, or any other provision, procedure or arrangement

.1 An initial survey before the ship is put in service orto be made in that ship, if it is satisfied by trial thereof orbefore the International Certificate of Fitness for theotherwise that such fitting, material, appliance, apparatus,Carriage of Liquefied Gases in Bulk is issued for theitem of equipment or type thereof or that any particularfirst time, which should include a complete examina-provision, procedure or arrangement is at least as effectivetion of its structure, equipment, fittings, arrange-as that required by the Code. However, the Administrationments and material in so far as the ship is coveredmay not allow operational methods or procedures to beby the Code. This survey should be such as to ensuremade an alternative to a particular fitting, material, appli-that the structure, equipment, fittings, arrangementsance, apparatus, item of equipment, or type thereof whichand material fully comply with the applicable provi-is prescribed by the Code.sions of the Code.5/4A.1.4.2 When the Administration so allows any fit-

.2 A periodical survey at intervals specified by the Ad-ting, material, appliance, apparatus, item of equipment, orministration, but not exceeding 5 years which shouldtype thereof, or provision, procedure or arrangement to

be substituted, it should communicate to the Organizationthe particulars thereof together with a report on the evi- *Port State authority has the meaning as presented in chapter I, regulation

19 of the 1978 Protocol to the 1974 SOLAS Convention.dence submitted, so that the Organization may circulate


be such as to ensure that the structure, equipment, immediately to the port State authority concerned andthe nominated surveyor or recognized organization shouldfittings, arrangements and material comply with the

applicable provisions of the Code. ascertain that such a report has been made..3 A minimum of one intermediate survey during the 5/4A.1.5.4 Issue of certificate

period of validity of the International Certificate of5/4A.1.5.4.1 A certificate called an International Certifi-Fitness for the Carriage of Liquefied Gases in Bulk.

cate of Fitness for the Carriage of Liquefied Gases in Bulk,In cases where only one such intermediate survey isthe model form of which is set out in the appendix, shouldcarried out in any one certificate validity period, itbe issued after an initial or periodical survey to a gas carriershould be held not before 6 months prior to, norwhich complies with the relevant requirements of thelater than 6 months after, the half-way date of theCode.certificate’s period of validity. Intermediate surveys

should be such as to ensure that the safety equipment, 5/4A.1.5.4.2 The certificate issued under the provisionsand other equipment, and associated pump and pip- of this section should be available on board for inspectioning systems comply with the applicable provisions of at all times.the Code and are in good working order. Such surveys

5/4A.1.5.4.3 When a ship is designed and constructedshould be endorsed on the International Certificateunder the provisions of 5/4A.1.1.5, International Certifi-of Fitness for the Carriage of Liquefied Gases in Bulk.cates of Fitness should be issued in accordance with the.4 A mandatory annual survey within 3 months beforerequirements of this section and with the requirements ofor after the anniversary date of the International Cer-section 5/4B.1.5 of the International Bulk Chemical Code.tificate of Fitness for the Carriage of Liquefied Gases

in Bulk which should include a general examination 5/4A.1.5.5 Issue or endorsement of certificate by an-to ensure that the structure, equipment, fittings, ar- other Governmentrangements and materials remain in all respects satis-

5/4A.1.5.5.1 A Contracting Government may, at the re-factory for the service for which the ship is intended.quest of another Government cause a ship entitled to flySuch a survey should be endorsed in the Internationalthe flag of the other State to be surveyed and, if satisfiedCertificate of Fitness for the Carriage of Liquefiedthat the requirements of the Code are complied with, issueGases in Bulk.or authorize the issue of the certificate to the ship, and,.5 An additional survey, either general or partial ac-where appropriate, endorse or authorize the endorsementcording to the circumstances, should be made whenof the certificate on board the ship in accordance with therequired after an investigation prescribed in 5/Code. Any certificate so issued should contain a statement4A.1.5.3.3, or whenever any important repairs or re-to the effect that it has been issued at the request of thenewals are made. Such a survey should ensure thatGovernment of the State whose flag the ship is entitledthe necessary repairs or renewals have been effec-to fly.tively made, that the material and workmanship of

such repairs or renewals are satisfactory; and that the 5/4A.1.5.6 Duration and validity of the certificateship is fit to proceed to sea without danger to the

5/4A.1.5.6.1 An International Certificate of Fitness forship or persons on board.the Carriage of Liquefied Gases in Bulk should be issued

5/4A.1.5.3 Maintenance of conditions after survey for a period specified by the Administration which should5/4A.1.5.3.1 The condition of the ship and its equipment not exceed 5 years from the date of the initial survey or

should be maintained to conform with the provisions of the periodical survey.the Code to ensure that the ship will remain fit to proceedto sea without danger to the ship or persons on board. 5/4A.1.5.6.2 No extension of the 5 year period of the

5/4A.1.5.3.2 After any survey of the ship under 5/ certificate should be permitted.4A.1.5.2 has been completed, no change should be made

5/4A.1.5.6.3 The certificate should cease to be valid:in the structure, equipment, fittings, arrangements andmaterial covered by the survey, without the sanction of

.1 if the surveys are not carried out within the periodthe Administration, except by direct replacement.specified by 5/4A.1.5.2;

5/4A.1.5.3.3 Whenever an accident occurs to a ship ora defect is discovered, either of which affects the safety of .2 upon transfer of the ship to the flag of another State.the ship or the efficiency or completeness of its life-saving A new certificate should only be issued when theappliances or other equipment, the master or owner of Government issuing the new certificate is fully satis-the ship should report at the earliest opportunity to the fied that the ship is in compliance with the require-Administration, the nominated surveyor or recognized orments of 5/4A.1.5.3.1 and 5/4A.1.5.3.2. Where a trans-ganization responsible for issuing the relevant certificate, fer occurs between Contracting Governments, thewho should cause investigations to be initiated to deter- Government of the State whose flag the ship wasmine whether a survey, as required by 5/4A.1.5.2.5 is nec- formerly entitled to fly should, if requested withinessary. If the ship is in a port of another Contracting Gov- 12 months after the transfer has taken place, as soon

as possible transmit to the Administration copies ofernment, the master or owner should also report


the certificates carried by the ship before the transfer correspond to that product having the most stringent shiptype requirement. The requirements for the location ofand, if available, copies of the relevant survey reports.individual cargo tanks, however, are those for ship typesrelated to the respective products intended to be carried.5/4A.2 Ship Survival CapabilityT and Location of

Cargo Tanks5/4A.2.2 Freeboard and intact stability

5/4A.2.1 General 5/4A.2.2.1 Ships subject to the Code may be assigned5/4A.2.1.1 Ships subject to the Code should survive the the minimum freeboard permitted by the International

normal effects of flooding following assumed hull damage Convention on Load Lines in force. However, the draughtcaused by some external force. In addition, to safeguard associated with the assignment should not be greater thanthe ship and the environment, the cargo tanks should be the maximum draught otherwise permitted by this Code.protected from penetration in the case of minor damage 5/4A.2.2.2 The stability of the ship in all seagoing condi-to the ship resulting, for example, from contact with a jetty tions and during loading and unloading cargo should beor tug, and given a measure of protection from damage in to a standard which is acceptable to the Administration.the case of collision or stranding, by locating them at speci- 5/4A.2.2.3 When calculating the effect of free surfacesfied minimum distances inboard from the ship’s shell plat- of consumable liquids for loading conditions it should being. Both the damage to be assumed and the proximity of assumed that, for each type of liquid, at least one transversethe tanks to the ship’s shell should be dependent upon the pair or a single centre tank has a free surface and the tankdegree of hazard presented by the product to be carried. or combination of tanks to be taken into account should

5/4A.2.1.2 Ships subject to the Code should be designed be those where the effect of free surfaces is the greatest.to one of the following standards: The free surface effect in undamaged compartments should

.1 A type 1G ship is a gas carrier intended to transport be calculated by a method acceptable to the Adminis-products indicated in 5/4A.19 which require maxi- tration.mum preventive measures to preclude the escape of 5/4A.2.2.4 Solid ballast should not normally be used insuch cargo. double bottom spaces in the cargo area. Where, however,

.2 A type 2G ship is a gas carrier intended to transport because of stability considerations, the fitting of solid bal-products indicated in 5/4A.19 which require signifi- last in such spaces becomes unavoidable, then its disposi-cant preventive measures to preclude the escape of tion should be governed by the need to ensure that thesuch cargo. impact loads resulting from bottom damage are not directly

.3 A type 2PG ship is a gas carrier of 150 m in length transmitted to the cargo tank structure.or less intended to transport products indicated in 5/ 5/4A.2.2.5 The master of the ship should be supplied4A.19 which require significant preventive measures with a Loading and Stability Information booklet. Thisto preclude escape of such cargo, and where the booklet should contain details of typical service conditions,products are carried in independent type C tanks loading, unloading and ballasting operations, provisions fordesigned (see 5/4A.4.2.4.4) for a MARVS of at least evaluating other conditions of loading and a summary of7 bar gauge and a cargo containment system design the ship’s survival capabilities. In addition, the booklettemperature of −55°C or above. Note that a ship of should contain sufficient information to enable the masterthis description but over 150 m in length is to be to load and operate the ship in a safe and seaworthyconsidered a type 2G ship. manner.

.4 A type 3G ship is a gas carrier intended to carry 5/4A.2S.2.5 Interpretation of 5/4A.2.2.5 (ABS)products indicated in 5/4A.19 which require moder- Loading Guidance meeting requirements of 5/4.1S.5 willate preventive measures to preclude the escape of comply with 5/4A.2.2.5 for loading information booklet.such cargo.

Thus a type 1G ship is a gas carrier intended for the5/4A.2.3 Shipside discharges below the freeboardtransportation of products considered to present the great-

deckest overall hazard and types 2G/2PG and type 3G for prod-5/4A.2.3.1 The provision and control of valves fitted toucts of progressively lesser hazards. Accordingly, a type

discharges led through the shell from spaces below the1G ship should survive the most severe standard of damagefreeboard deck or from within the superstructures andand its cargo tanks should be located at the maximumdeckhouses on the freeboard deck fitted with weathertightprescribed distance inboard from the shell plating.doors should comply with the requirements of the relevant5/4A.2.1.3 The ship type required for individual prod-regulation of the International Convention on Load Linesucts is indicated in column ‘‘c’’ in the table of 5/4A.19.in force, except that the choice of valves should be lim-

5/4A.2.1.4 If a ship is intended to carry more than one ited to:product listed in 5/4A.19. the standard of damage should .1 one automatic non-return valve with a positive means

of closing from above the freeboard deck; or.2 where the vertical distance from the summer loadT Reference is made to the Guidelines for Uniform Application of the

waterline to the inboard end of the discharge pipeSurvival Requirements of the Bulk Chemical Code and the Gas CarrierCode. See Annex A. exceeds 0.01L, two automatic non-return valves with-


.2.2 Transverse B/6 or 10 m, B/6 or 5 m,out positive means of closing, provided that the in-board valve is always accessible for examination un- extent: whichever is whichever is

less lessder service conditions.5/4A.2.3.2 For the purpose of this chapter ‘‘summer load

2.3 Vertical extent: B/15 or 2 m, B/15 or 2 m,waterline’’ and ‘‘freeboard deck’’, have the meanings de-whichever is whichever isfined in the International Convention on Load Lines inless measured less measuredforce.from the from the5/4A.2.3.3 The automatic non-return valves referred tomoulded line of moulded linein 5/4A.2.3.1.1 and 5/4A.2.3.1.2 should be of a type accept-the bottom of the bottomable to the Administration and should be fully effective inshell plating at shell plating atpreventing admission of water into the ship, taking intocentreline (see centreline (seeaccount the sinkage, trim and heel in survival requirements5/4A.2.6.3). 5/4A.2.6.3).in 5/4A.2.9.

5/4A.2.4 Conditions of loading Damage survival capa- 5/4A.2.5.2 Other damagebility should be investigated on the basis of loading infor- .1 If any damage of a lesser extent than the maximummation submitted to the Administration for all anticipated damage specified in 5/4A.2.5.1 would result in a moreconditions of loading and variations in draught and trim. severe condition, such damage should be assumed.The survival requirements need not be applied to the ship .2 Local side damage anywhere in the cargo area ex-when in the ballast conditionT, provided that any cargo tending inboard 760 mm measured normal to the hullretained on board is solely used for cooling, circulation or shell should be considered and transverse bulkheadsfuelling purposes. should be assumed damaged when also required by

the applicable subparagraphs of 5/4A.2.8.1.T The cargo content of small independent purge tanks on deck need notbe taken into account when assessing the ballast condition. 5/4A.2.6 Location of cargo tanks

5/4A.2.6.1 Cargo tanks should be located at the follow-ing distances inboard:

5/4A.2.5 Damage assumptions .1 Type 1G ships: from the side shell plating not less5/4A.2.5.1 The assumed maximum extent of damage than the transverse extent of damage specified in 5/

should be: 4A.2.5.1.1.2 and from the moulded line of the bottomshell plating at centreline not less than the vertical

.1 Side damage: extent of damage specified in 5/4A.2.5.1.2.3 and no-where less than 760 mm from the shell plating.

.1.1 Longitudinal 1/3L2/3 or 14.5 m, whichever is .2 Types 2G/2PG and 3G ships: from the moulded lineextent: less of the bottom shell plating at centreline not less than

the vertical extent of damage specified in 5/.1.2 Transverse B/5 or 11.5 m, whichever is less 4A.2.5.1.2.3 and nowhere less than 760 mm from the

extent: measured shell plating.inboard from the 5/4A.2.6.2 For the purpose of tank location, the verticalship’s side at extent of bottom damage should be measured to the innerright angles to bottom when membrane or semi-membrane tanks are used,the centreline at otherwise to the bottom of the cargo tanks. The transversethe level of the extent of side damage should be measured to the longitudi-summer load line nal bulkhead when membrane or semi-membrane tanks

are used, otherwise to the side of the cargo tanks (see.1.3 Vertical extent: upwards without limit figure 5/4A.2.1). For internal insulation tanks the extent of

from the moulded damage should be measured to the supporting tank plating.line of the bottom 5/4A.2S.6.2 Interpretation of 5/4A.2.6.2 (ABS)shell plating at Where the cargo tanks are located within the extent ofcentreline damage assumed in 5/4A.2.5 the stability is to be investi-

gated assuming the cargo tanks are damaged and also with.2 Bottom damage: For 0.3L from Any other part the cargo tanks undamaged (5/4A.2.5.2). Deck cargo tanks

the forward of the ship are to be located not less than 760 mm inboard from theperpendicular side shell.of the ship 5/4A.2.6.3 Except for type 1G ships, suction wells in-

stalled in cargo tanks may protrude into the vertical extent.2.1 Longitudinal 1/3L2/3 or 14.5 1/3L2/3 or 5 m, of bottom damage specified in 5/4A.2.5.1.2.3 provided that

such wells are as small as practicable and the protrusionextent: m, whichever is whichever isless less below the inner bottom plating does not exceed 25% of


FIGURE 5/4A.2.1Tank location requirements as set out in 5/4A.2.6

Intended for other liquids 0 to 0.95Tthe depth of the double bottom or 350 mm, whichever isless. Where there is no double bottom, the protrusion

T The permeability of partially filled compartments should be consistentbelow the upper limit of bottom damage should not exceedwith the amount of liquid carried in the compartment.350 mm. Suction wells installed in accordance with this

paragraph may be ignored in determining the compart-5/4A.2.7.3 Wherever damage penetrates a tank con-ments affected by damage.

taining liquids, it should be assumed that the contents arecompletely lost from that compartment and replaced by5/4A.2.7 Flooding assumptionssalt water up to the level of the final plane of equilibrium.

5/4A.2.7.1 The requirements of 5/4A.2.9 should be con-5/4A.2.7.4 Where the damage between transverse wa-firmed by calculations which take into consideration the

tertight bulkheads is envisaged as specified in 5/4A.2.8.1.4,design characteristics of the ship; the arrangements, config-.5, and .6, transverse bulkheads should be spaced at leasturation and contents of the damaged compartments; theat a distance equal to the longitudinal extent of damagedistribution, relative densities and the free surface effectsspecified in 5/4A.2.5.1.1.1 in order to be considered effec-of liquids; and the draught and trim for all conditions oftive. Where transverse bulkheads are spaced at a lesserloading.distance, one or more of these bulkheads within such extent5/4A.2.7.2 The permeabilities of spaces assumed to be of damage should be assumed as non-existent for the pur-damaged should be as follows: pose of determining flooded compartments. Further, any

Spaces Permeabilities portion of a transverse bulkhead bounding side compart-Appropriated to stores 0.60 ments or double bottom compartments should be assumed

damaged if the watertight bulkhead boundaries are withinOccupied by accommodation 0.95 the extent of vertical or horizontal penetration required byOccupied by machinery 0.85 5/4A.2.5. Also, any transverse bulkhead should be assumed

damaged if it contains a step or recess of more than 3 m inVoids 0.95 length located within the extent of penetration of assumeddamage. The step formed by the after peak bulkhead andIntended for consumable liquids 0 to 0.95T


after peak tank top should not be regarded as a step for .6 A type 3G ship less than 125 m in length should beassumed to sustain damage anywhere in its lengththe purpose of this paragraph.except involving transverse bulkheads spaced further5/4A.2.7.5 The ship should be so designed as to keepapart than the longitudinal extent of damage specifiedunsymmetrical flooding to the minimum consistent within 5/4A.2.5.1.1.1 and except damage involvingthe ma-efficient arrangements.chinery space when located aft. However, the ability5/4A.2.7.6 Equalization arrangements requiring me-to survive the flooding of the machinery space shouldchanical aids such as valves or cross-levelling pipes, ifbe considered by the Administration.fitted, should not be considered for the purpose of reducing

5/4A.2S.8.1 Interpretation of 5/4A.2.7.8 and 5/4A.2.8.1an angle of heel or attaining the minimum range of residual(IMO)stability to meet the requirements of 5/4A.2.9.1 and suffi-The longitudinal extent of damage to superstructure in thecient residual stability should be maintained during allinstance of side damage to a machinery space aft under 5/stages where equalization is used. Spaces which are linked4A.2.8.1 should be the same as the longitudinal extent ofby ducts of large cross-sectional area may be consideredthe side damage to the machinery space (see figure 5/to be common.4A.2.2).5/4A.2.7.7 If pipes, ducts, trunks or tunnels are situated

5/4A.2.8.2 In the case of small type 2G/2PG and 3Gwithin the assumed extent of damage penetration, as de-ships which do not comply in all respects with the appro-fined in 5/4A.2.5, arrangements should be such that pro-priate requirements of 5/4A.2.8.1.3, .4, and .6, special dis-gressive flooding cannot thereby extend to compartmentspensations may only be considered by the Administrationother than those assumed to be flooded for each case ofprovided that alternative measures can be taken whichdamage.maintain the same degree of safety. The nature of the5/4A.2.7.8 The buoyancy of any superstructure directlyalternative measures should be approved and clearly statedabove the side damage should be disregarded. The un-and be available to the port Administration. Any such dis-flooded parts of superstructures beyond the extent of dam-pensation should be duly noted on the International Certif-age, however, may be taken into consideration providedicate of Fitness for the Carriage of Liquefied Gases in Bulk.that:

.1 they are separated from the damaged space by water-tight divisions and the requirements of 5/4A.2.9.1.1 in 5/4A.2.9 Survival requirementsrespect of these intact spaces are complied with; and Ships subject to the Code should be capable of surviving

.2 openings in such divisions are capable of being closed the assumed damage specified in 5/4A.2.5 to the standardby remotely operated sliding watertight doors and provided in 5/4A.2.8 in a condition of stable equilibriumunprotected openings are not immersed within the and should satisfy the following criteria.minimum range of residual stability required in 5/

5/4A.2.9.1 In any stage of flooding4A.2.9.2.1; however the immersion of any other open-.1 the waterline, taking into account sinkage, heel andings capable of being closed weathertight may be

trim, should be below the lower edge of any openingpermitted.through which progressive flooding or downfloodingmay take place. Such openings should include air

5/4A.2.8 Standard of damage pipes and openings which are closed by means of5/4A.2.8.1 Ships should be capable of surviving the weathertight doors or hatch covers and may exclude

damage indicated in 5/4A.2.5 with the flooding assumptions those openings closed by means of watertight man-in 5/4A.2.7 to the extent determined by the ship’s typeaccording to the following standards:

.1 A type 1G ship should be assumed to sustain damage FIGURE 5/4A.2.2anywhere in its length; Longitudinal extent of damage to.2 A type 2G ship of more than 150 m in length should

superstructure (5/4A.2.7.8 and 5/be assumed to sustain damage anywhere in its length;.3 A type 2G ship of 150 m in length or less should be 4A.2.8.1)

assumed to sustain damage anywhere in its lengthexcept involving either of the bulkheads bounding amachinery space located aft;

.4 A type 2PG ship should be assumed to sustain damageanywhere in its length except involving transversebulkheads spaced further apart than the longitudinalextent of damage as specified in 5/4A.2.5.1.1.1;

.5 A type 3G ship of 125 m in length or more shouldbe assumed to sustain damage anywhere in its lengthexcept involving transverse bulkheads spaced furtherapart than the longitudinal extent of damage specifiedin 5/4A.2.5.1.1.1;


hole covers and watertight flush scuttles, small water- or fire hazard in the adjoining space, segregation may beby a single A-0 class division which is gastight.tight cargo tank hatch covers which maintain the high

integrity of the deck, remotely operated watertight 5/4A.3.1.4 When cargo is carried in a cargo containmentsliding doors, and sidescuttles of the non-opening system requiring a secondary barrier:type; .1 at temperatures below −10°C, hold spaces should be

.2 the maximum angle of heel due to unsymmetrical segregated from the sea by a double bottom; andflooding should not exceed 30°; and .2 at temperatures below −55°C, the ship should also

.3 the residual stability during intermediate stages of have a longitudinal bulkhead forming side tanks.flooding should be to the satisfaction of the Adminis- 5/4A.3.1.5 Any piping system which may contain cargotration. However, it should never be significantly less or cargo vapour should:than that required by 5/4A.2.9.2.1. .1 be segregated from other piping systems, except

5/4A.2.9.2 At final equilibrium after flooding where inter-connections are required for cargo-re-.1 the righting lever curve should have a minimum lated operations such as purging, gas-freeing or in-

range of 20° beyond the position of equilibrium in erting. In such cases, precautions should be taken toassociation with a maximum residual righting lever ensure that cargo or cargo vapour cannot enter suchof at least 0.1 m within the 20° range; the area under other piping systems through the inter-connections;the curve within this range should not be less than .2 except as provided in 5/4A.16, not pass through any0.0175 m.rad. Unprotected openings should not be accommodation space, service space or control stationimmersed within this range unless the space con- or through a machinery space other than a cargocerned is assumed to be flooded. Within this range, pump room or cargo compressor space;the immersion of any of the openings listed in 5/ .3 be connected into the cargo containment system di-4A.2.9.1.1 and other openings capable of being closed rectly from the open deck except that pipes installedweathertight may be permitted; and in a vertical trunkway or equivalent may be used to.2 the emergency source of power should be capable of traverse void spaces above a cargo containment sys-operating. tem and except that pipes for drainage, venting or

5/4A.2S.9.2.1 Interpretation of 5/4A.2.9.2.1 (IMO) purging may traverse cofferdams;The 20° range may be measured from any angle com- .4 except for bow or stern loading and unloading ar-

mencing between the position equilibrium and the angle rangements in accordance with 5/4A.3.8 and emer-of 25° (or 30° if no deck immersion occurs). gency cargo jettisoning piping systems in accordance

with 5/4A.3.1.6, and except in accordance with 5/5/4A.3 Ship Arrangements 4A.16, be located in the cargo area above the open

deck; and5/4A.3.1 Segregation of the cargo area .5 except for thwartship shore connection piping not

5/4A.3.1.1 Hold spaces should be segregated from ma- subject to internal pressure at sea or emergency cargochinery and boiler spaces, accommodation spaces, service jettisoning piping systems, be located inboard of thespaces and control stations, chain lockers, drinking and transverse tank location requirements of 5/4A.2.6.1.domestic water tanks and from stores. Hold spaces should 5/4A.3.1.6 Any emergency cargo jettisoning piping sys-be located forward of machinery spaces of category A, other tem should comply with 5/4A.3.1.5 as appropriate and maythan those deemed necessary by the Administration for be led aft externally to accommodation spaces, servicethe safety or navigation of the ship. spaces or control stations or machinery spaces, but should

5/4A.3S.1.1 Interpretation of 5/4A.3.1.1 (ABS) not pass through them. If an emergency cargo jettisoningBow thrusters, if fitted, may be located forward of the hold piping system is permanently installed a suitable means ofspaces. isolation from the cargo piping should be provided within

the cargo area.5/4A.3.1.2 Where cargo is carried in a cargo contain-ment system not requiring a secondary barrier, segregation 5/4A.3.1.7 Arrangements should be made for sealing theof hold spaces from spaces referred to in 5/4A.3.1.1 or weather decks in way of openings for cargo containmentspaces either below or outboard of the hold spaces may systems.be effected by cofferdams, fuel oil tanks or a single gastightbulkhead of all-welded construction forming an A-60 class 5/4A.3.2 Accommodation, service and machinerydivision. A gastight A-0 class division is satisfactory if there spaces and control stations. (1 Oct. 1994)is no source of ignition or fire hazard in the adjoining 5/4A.3.2.1 No accommodation space, service space orspaces. control station should be located within the cargo area.

The bulkhead of accommodation spaces, service spaces or5/4A.3.1.3 Where cargo is carried in a cargo contain-ment system requiring a secondary barrier, segregation of control stations which face the cargo area should be so

located as to avoid the entry of gas from the hold space tohold spaces from spaces referred to in 5/4A.3.1.1 or spaceseither below or outboard of the hold spaces which contain such spaces through a single failure of a deck or bulkhead

on a ship having a containment system requiring a second-a source of ignition or fire hazard should be effected bycofferdams or fuel oil tanks. If there is no source of ignition ary barrier.


5/4A.3.2.2 In order to guard against the danger of haz-ardous vapours, due consideration should be given to thelocation of air intakes and openings into accommodation,service and machinery spaces and control stations in rela-tion to cargo piping, cargo vent systems and machineryspace exhausts from gas burning arrangements.

5/4A.3S.2.1. Interpretation of 5/4A.3.2.1 (ABS)

5/4A.3S.2.2 Interpretation of 5/4A.3.2.2 (IMO) 5/4A.3S.2.4 Interpretation of 5/4A.3.2.4 (IMO)Air outlets are subject to the same requirements as airCompliance with other relevant paragraphs of the Codeinlets and air intakes. This interpretation also applies toand in particular with paragraphs 5/4A.3.2.4, 5/4A.3.8, 5/paragraphs 5/4A.3.2.2, 5/4A.3.8.4, and 5/4A.8.2.10.4A.8.2.10 and 5/4A.12.1.6 where applicable would also en-

sure compliance with this paragraph.5/4A.3.2.5 Sidescuttles in the shell below the uppermost

continuous deck and in the first tier of the superstructure5/4A.3.2.3 Access through doors, gastight or otherwise,or deckhouse should be of the fixed (non-opening) type.should not be permitted from a gas-safe space to a gas-

dangerous space, except for access to service spaces for-ward of the cargo area through air-locks as permitted by 5/4A.3.2.6 All air intakes and openings into the accom-5/4A.3.6.1 when accommodation spaces are aft. modation spaces, service spaces and control stations should

be fitted with closing devices. For toxic gases they shouldbe operated from inside the space.5/4A.3.2.4 Entrances, air inlets and openings to accom-

modation spaces, service spaces, machinery spaces and 5/4A.3S.2.6 Interpretation of 5/4A.3.2.6 (IACS)control stations should not face the cargo area. They should .1 The requirement for fitting air intakes and openingsbe located on the end bulkhead not facing the cargo area with closing devices operable from inside the spaceor on the outboard side of the superstructure or deckhouse in ships intended to carry toxic products should applyor on both at a distance of at least 4% of the length (L) to spaces which are used for the ships’ radio and mainof the ship but not less than 3 m from the end of the navigating equipment, cabins, mess rooms, toilets,superstructure or deckhouse facing the cargo area. This hospitals, galleys, etc., but should not apply to spacesdistance, however, need not exceed 5 m. Windows and not normally manned such as deck stores, forecastlesidescuttles facing the cargo area and on the sides of the stores, engine room casings, steering gear compart-superstructures or deckhouses within the distance men- ments, workshops. The requirement also does nottioned above should be of the fixed (non-opening) type. apply to cargo control rooms located within theWheelhouse windows may be non-fixed and wheelhouse cargo area.doors may be located within the above limits so long as .2 When internal closing is required, this should includethey are so designed that a rapid and efficient gas and both ventilation intakes and outlets.vapour tightening of the wheelhouse can be ensured. For .3 The closing devices should give a reasonable degreeships dedicated to the carriage of cargoes which have nei- of gas tightness. Ordinary steel fire-flaps without gas-ther flammable nor toxic hazards, the Administration may kets/seals should normally not be considered satis-

factory.approve relaxations from the above requirements.


5/4A.3.3 Cargo pump rooms and cargo compressor tion spaces, service spaces or control stations provided thefollowing conditions are complied with:rooms

.1 the cargo control room is a gas-safe space; and5/4A.3.3.1.1 Cargo pump rooms and cargo compressor.2.1 if the entrance complies with 5/4A.3.2.4, the controlrooms should be situated above the weather deck and

room may have access to the spaces describedlocated within the cargo area unless specially approved byabove;the Administration. Cargo compressor rooms should be

.2.2 if the entrance does not comply with 5/4A.3.2.4,treated as cargo pump rooms for the purpose of fire protec-the control room should have no access to the spacestion according to regulation 11-2/58 of the 1983 SOLASdescribed above and the boundaries to such spacesamendments.should be insulated to ‘‘A-60’’ class integrity.5/4A.3.3.1.2 When cargo pump rooms and cargo com-

5/4A.3.4.2 If the cargo control room is designed to bepressor rooms are permitted to be fitted above or belowa gas-safe space, instrumentation should, as far as possible,the weather deck at the after end of the aftermost holdbe by indirect reading systems and should in any case bespace or at the forward end of the forwardmost hold space,designed to prevent any escape of gas into the atmospherethe limits of the cargo area as defined in 5/4A.1.3.6 shouldof that space. Location of the gas detector within the cargobe extended to include the cargo pump rooms and cargocontrol room will not violate the gas-safe space if installedcompressor rooms for the full breadth and depth of thein accordance with 5/4A.13.6.5.ship and deck areas above those spaces.

5/4A.3.4.3 If the cargo control room for ships carrying5/4A.3.3.1.3 Where the limits of the cargo area are ex-flammable cargoes is a gas-dangerous space, sources oftended by 5/4A.3.3.1.2, the bulkhead which separates theignition should be excluded. Consideration should be paidcargo pump rooms and cargo compressor rooms from ac-to the safety characteristics of any electrical installations.commodation and service spaces, control stations and ma-

chinery spaces of category A should be so located as to 5/4A.3.5 Access to spaces in the cargo areaavoid the entry of gas to these spaces through a single 5/4A.3.5.1 Visual inspection should be possible of atfailure of a deck or bulkhead. least one side of the inner hull structure without the re-

5/4A.3S.3.1.3 Interpretation of 5/4A.3.3.1.2 and 5/ moval of any fixed structure or fitting. If such a visual4A.3.3.1.3 (IMO) inspection, whether combined with those inspections re-When cargo pump-room and compressor rooms are permit- quired in 5/4A.3.5.2, 5/4A.4.7.7 or 5/4A.4.10.16 or not, isted to be fitted at the after end of the aftermost hold space only possible at the outer face of the inner hull, the innerthe bulkhead which separates the cargo pump-rooms and hull should not be a fuel-oil tank boundary wall.compressor rooms from accommodation and service 5/4A.3.5.2 Inspection of one side of any insulation inspaces, control stations and machinery spaces of category hold spaces should be possible. If the integrity of the insula-A should be so located as to avoid the entry of gas to these tion system can be verified by inspection of the outside ofspaces through a single failure of a deck or bulkhead. The the hold space boundary when tanks are at service tempera-same condition should also be satisfied when cargo pump- ture, inspection of one side of the insulation in the holdrooms and compressor rooms, fitted within the cargo area, space need not be required.have a bulkhead in common with accommodation and ser- 5/4A.3.5.3 Arrangements for hold spaces, void spacesvice spaces, control stations and machinery spaces of cate- and other spaces that could be considered gas-dangerousgory A. and cargo tanks should be such as to allow entry and

5/4A.3.3.2 Where pumps and compressors are driven inspection of any such space by personnel wearing protec-by shafting passing through a bulkhead or deck, gastight tive clothing and breathing apparatus and in the event ofseals with efficient lubrication or other means of ensuring injury to allow unconscious personnel to be removed fromthe permanence of the gas seal should be fitted in way of the space and should comply with the following:the bulkhead or deck. .1 Access should be provided:

5/4A.3.3.3 Arrangements of cargo pump rooms and .1.1 to cargo tanks direct from the open deck;cargo compressor rooms should be such as to ensure safe .1.2 through horizontal openings, hatches or manholes,unrestricted access for personnel wearing protective cloth- the dimensions of which should be sufficient toing and breathing apparatus, and in the event of injury to allow a person wearing a breathing apparatus toallow unconscious personnel to be removed. All valves ascend or descend any ladder without obstructionnecessary for cargo handling should be readily accessible and also to provide a clear opening to facilitate theto personnel wearing protective clothing. Suitable arrange- hoisting of an injured person from the bottom ofments should be made to deal with drainage of pump and the space; the minimum clear opening should becompressor rooms. not less than 600 mm by 600 mm; and

.1.3 through vertical openings, or manholes providingpassage through the length and breadth of the

5/4A.3.4 Cargo control rooms space, the minimum clear opening of which shouldbe not less than 600 mm by 800 mm at a height of5/4A.3.4.1 Any cargo control room should be above the

weather deck and may be located in the cargo area. The not more than 600 mm from the bottom platingunless gratings or other footholds are provided.cargo control room may be located within the accommoda-


.2 The dimensions referred to in 5/4A.3.5.3.1.2 and.1.3 may be decreased if the ability to traverse such

FIGURE 5/4A.3.3

openings or to remove an injured person can beproved to the satisfaction of the Administration.

.3 The requirements of 5/4A.3.5.3.1.2 and .1.3 do notapply to spaces described in 5/4A.1.3.17.5. Suchspaces should be provided only with direct or indi-rect access from the open weather deck, not includ-ing an enclosed gas-safe space.

5/4A.3.5.4 Access from the open weather deck to gas-safe spaces should be located in a gas-safe zone at least2.4 m above the weather deck unless the access is by meansof an air-lock in accordance with 5/4A.3.6.

5/4A.3S.5 Interpretation of 5/4A.3.5 (IACS)

a Designated passage ways below and above cargo tanksshould have at least the cross sections as required by5/4A.3.5.3.1.3.

b For the purpose of 5/4A.3.5.1 or 5/4A.3.5.2 the follow- FIGURE 5/4A.3.4ing should apply:

.1 Where the surveyor requires to pass between thesurface to be inspected, flat or curved, and structuralelements such as deckbeams, stiffeners, frames, gird-ers etc., the distance between that surface and thefree edge of the structural elements should be at least380 mm. The distance between the surface to beinspected and the surface to which the above struc-tural elements are fitted, e.g. deck, bulkhead or shell,should be at least 450 mm in case of a curved tanksurface (e.g. in case of type C-tank) or 600 mm incase of a flat tank surface (e.g. in case of type A-tank).(See figure 5/4A.3.1)

.2 Where the surveyor does not require to pass betweenthe surface to be inspected and any part of the struc-ture, for visibility reasons the distance between the

.3 If for inspection of a curved surface the surveyorfree edge of that structural element and the surfacerequires to pass between that surface and anotherto be inspected should be at least 50 mm or half thesurface, flat or curved, to which no structural ele-breadth of the structure’s face plate, whichever is thements are fitted, the distance between both surfaceslarger. (See figure 5/4A.3.2)should be at least 380 mm. (See figure 5/4A.3.3)Where the surveyor does not require to pass betweenthat curved surface and another surface, a smallerFIGURE 5/4A.3.1 distance than 380 mm may be accepted taking intoaccount the shape of the curved surface.

.4 If for inspection of an approximately flat surface thesurveyor requires to pass between two approximatelyflat and approximately parallel surfaces, to which nostructural elements are fitted, the distance betweenthose surfaces should be at least 600 mm. (See figure5/4A.3.4)

.5 The minimum distances between a cargo tank sumpand adjacent double bottom structure in way of aFIGURE 5/4A.3.2suction wells should not be less than shown in figure5/4A.3.5. If there is no suction well, the distancebetween the cargo tank sump and the inner bottomshould not be less than 50 mm.

.6 The distance between a cargo tank dome and deckstructures should not be less than 150 mm. (See figure5/4A.3.6)


FIGURE 5/4A.3.5

FIGURE 5/4A.3.6

loss of overpressure in the space (see also 5/4A.10.2.5.4).Electrical equipment which is not of the certified safe typefor manoeuvering, anchoring and mooring equipment aswell as the emergency fire pumps should not be locatedin spaces to be protected by air-locks.

5/4A.3S.6.4 Interpretation of 5/4A.3.6.3 and 5/4A.3.6.4.7 If necessary for inspection fixed or portable staging (IMO)

should be installed. This staging should not impair The following means are considered acceptable alterna-the distances required under .1 to .4. tives to differential pressure sensing devices in spaces hav-

.8 If fixed or portable ventilation ducting has to be fitted ing a ventilation rate not less than 30 air changes per hour:in compliance wither 5/4A.12.2 such ducting should .1 monitoring of current or power in the electrical sup-not impair the distances required under .1 to .4. ply to the ventilation motors; or

c For the purpose of subparagraph 5/4A.3.5.3.1.2 and .2 air flow sensors in the ventilation ducts..1.3 the following should apply: In spaces where the ventilation rate is less than 30 air

.1 The term ‘‘minimum clear opening of not less than changes per hour and where one of the above alternatives600 × 600 mm’’ means that such openings may have is fitted, in addition to the alarms required by 5/4A.3.6.3,corner radii up to 100 mm maximum. the arrangements should be made to de-energize electrical

.2 The term ‘‘minimum clear opening of not less than equipment which is not of the certified safe type, if more600 × 800 mm’’ includes also an opening of the than one air lock door is moved from the closed position.following size: 5/4A.3.6.5 The air-lock space should be mechanically

.3 Circular access openings in type-C cargo tanks should ventilated from a gas-safe space and maintained at an over-have diameters of not less than 600 mm. pressure to the gas-dangerous zone on the open weather

deck.5/4A.3.6.6 The air-lock space should be monitored for5/4A.3.6 Air-locks

cargo vapour.5/4A.3.6.1 An air-lock should only be permitted be-5/4A.3.6.7 Subject to the requirements of the Interna-tween a gas-dangerous zone on the open weather deck

tional Convention on Load Lines in force, the door silland a gas-safe space and should consist of two steel doorsshould not be less than 300 mm in height.substantially gastight spaced at least 1.5 m but not more

than 2.5 m apart.5/4A.3.6.2 The doors should be self-closing and without 5/4A.3.7 Bilge, ballast and fuel oil arrangements

any holding back arrangements. 5/4A.3.7.1.1 Where cargo is carried in a cargo contain-5/4A.3.6.3 An audible and visual alarm system to give ment system not requiring a secondary barrier, hold spaces

a warning on both sides of the air-lock should be provided should be provided with suitable drainage arrangementsto indicate if more than one door is moved from the closed not connected with the machinery space. Means of de-position. tecting any leakage should be provided.

5/4A.3.7.1.2 Where there is a secondary barrier, suitable5/4A.3.6.4 In ships carrying flammable products, elec-trical equipment which is not of the certified safe type in drainage arrangements for dealing with any leakage into

the hold or insulation spaces through adjacent ship struc-spaces protected by air-locks should be de-energized upon


ture should be provided. The suction should not be led to .3 Arrangements should be made to allow such pipingto be purged and gas-freed after use. When not inpumps inside the machinery space. Means of detecting

such leakage should be provided. use, the spool pieces should be removed and the pipeends be blank-flanged. The vent pipes connected with5/4A.3.7.2 The interbarrier space should be providedthe purge should be located in the cargo area.with a drainage system suitable for handling liquid cargo

in the event of cargo tank leakage or rupture. Such arrange- 5/4A.3.8.4 Entrances, air inlets and openings to accom-ments should provide for the return of leakage to the modation spaces, service spaces, machinery spaces andcargo tanks. control stations should not face the cargo shore connection

location of bow or stern loading and unloading arrange-5/4A.3.7.3 In case of internal insulation tanks, meansof detecting leakage and drainage arrangements are not ments. They should be located on the outboard side of the

superstructure or deckhouse at a distance of at least 4%required for interbarrier spaces and spaces between thesecondary barrier and the inner hull or independent tank of the length of the ship but not less than 3 m from the

end of the superstructure or deckhouse facing the cargostructure which are completely filled by insulation materialcomplying with 5/4A.4.9.7.2. shore connection location of the bow or stern loading and

unloading arrangements. This distance, however, need not5/4A.3.7.4 Ballast spaces, fuel oil tanks and gas-safeexceed 5 m. Sidescuttles facing the shore connection loca-spaces may be connected to pumps in the machinerytion and on the sides of the superstructure or deckhousespaces. Duct keels may be connected to pumps in thewithin the distance mentioned above should be of the fixedmachinery spaces, provided the connections are led di-(non-opening) type. In addition, during the use of the bowrectly to the pumps and the discharge from the pumps ledor stern loading and unloading arrangements, all doors,directly overboard with no valves or manifolds in eitherports and other openings on the corresponding superstruc-line which could connect the line from the duct keel toture of deckhouse side should be kept closed. Where in thelines serving gas-safe spaces. Pump vents should not becase of small ships, compliance with 5/4A.3.2.4 and thisopen to machinery spaces.paragraph is not possible, the Administration may approverelaxations from the above requirements.

5/4A.3.8 Bow or stern loading and unloading 5/4A.3.8.5 Deck openings and air inlets to spaces withinarrangements distances of 10 m from the cargo shore connection location

5/4A.3.8.1 Subject to the approval of the Administration should be kept closed during the use of bow or stern loadingand to the requirements of this section, cargo piping may or unloading arrangements.be arranged to permit bow or stern loading and unloading. 5/4A.3.8.6 Electrical equipment within a zone of 3 m

5/4A.3.8.1.1 Bow or stern loading and unloading lines from the cargo shore connection location should be inwhich are led past accommodation spaces, service spaces accordance with 5/4A.10.or control stations should not be used for the transfer of

5/4A.3.8.7 Fire-fighting arrangements for the bow orproducts requiring a type 1G ship. Bow or stern loadingstern loading and unloading areas should be in accordanceand unloading lines should not be used for the transfer ofwith 5/4A.11.3.1.3 and 5/4A.11.4.7.toxic products as specified in 5/4A.1.3.38 unless specifically

5/4A.3.8.8 Means of communication between the cargoapproved by the Administration.control station and the shore connection location should

5/4A.3.8.2 Portable arrangements should not be per- be provided and if necessary certified safe.mitted.

5/4A.3.8.3 In addition to the requirements of 5/4A.5 5/4A.4 Cargo Containmentthe following provisions apply to cargo piping and relatedpiping equipment:

5/4A.4.1 General.1 Cargo piping and related piping equipment outside5/4A.4.1.1 Administrations should take appropriatethe cargo area should have only welded connections.

steps to ensure uniformity in the implementation and appli-The piping outside the cargo area should run on thecation of the provisions of this chapter.open deck and should be at least 760 mm inboard

except for thwartships shore connection piping. Such 5/4A.4.1.2 In addition to the definitions in 24.A.1.3, thepiping should be clearly identified and fitted with a definitions given in this chapter apply throughout theshutoff valve at its connection to the cargo piping Code.system within the cargo area. At this location, itshould also be capable of being separated by means

5/4A.4.2 Definitionsof a removable spool piece and blank flanges when5/4A.4.2.1 Integral tanksnot in use.5/4A.4.2.1.1 Integral tanks form a structural part of the.2 The piping is to be full penetration butt welded, and

ship’s hull and are influenced in the same manner and byfully radiographed regardless of pipe diameter andthe same loads which stress the adjacent hull structure.design temperature. Flange connections in the piping

are only permitted within the cargo area and at the 5/4A.4.2.1.2 The design vapour pressure Po as definedin 5/4A.4.2.6 should not normally exceed 0.25 bar. If, how-shore connection.


ever, the hull scantlings are increased accordingly, Po may 5/4A.4.2.4.4 Type C independent tanks (also referredto as pressure vessels) are tanks meeting pressure vesselbe increased to a higher value but less than 0.7 bar.criteria and having a design vapour pressure not less than:5/4A.4.2.1.3 Integral tanks may be used for products

provided the boiling point of the cargo is not below −10°C.A lower temperature may be accepted by the Administra-tion subject to special consideration. Po= 2 + AC (rr)

1.5 (bar)5/4A.4.2.2 Membrane tanks where:5/4A.4.2.2.1 Membrane tanks are non-self-supporting

tanks which consist of a thin layer (membrane) supportedA= 0.0185 1 sm

DsA2

2

through insulation by the adjacent hull structure. Themembrane is designed in such a way that thermal andother expansion or contraction is compensated for without

withundue stressing of the membrane.sm = design primary membrane stress5/4A.4.2.2.2 The design vapour pressure Po should not

DsA = allowable dynamic membrane stress (double amplitudenormally exceed 0.25 bar. If, however, the hull scantlingsat probability level Q = 10–8)are increased accordingly and consideration is given, where55 N/mm2 for ferritic/martensitic steelappropriate, to the strength of the supporting insulation,25 N/mm2 for aluminium alloy (5083-0)Po may be increased to a higher value but less than 0.7 bar.

C = a characteristic tank dimension to be taken as the greatest5/4A.4.2.2.3 The definition of membrane tanks does not of the following:

exclude designs such as those in which nonmetallic mem- h; 0.75b; or 0.45øbranes are used or in which membranes are included or withincorporated in insulation. Such designs require, however, h = height of tank (dimension in ship’s vertical direc-special consideration by the Administration. In any case tion) (m)the thickness of the membranes should normally not exceed b = width of tank (dimension in ship’s transverse direc-1 mm. tion) (m)

5/4A.4.2.3 Semi-membrane tanks ø = length of tank (dimension in ship’s longitudinal direc-tion) (m)5/4A.4.2.3.1 Semi-membrane tanks are non-self-sup-

rr = the relative density of the cargo (rr = 1 for fresh water)porting tanks in the loaded condition and consist of a layer,at the design temperature.parts of which are supported through insulation by the

adjacent hull structure, whereas the rounded parts of this However, the Administration may allocate a tank comply-layer connecting the above-mentioned supported parts are ing with the criterion of this subparagraph to type A ordesigned also to accommodate the thermal and other type B, dependent on the configuration of the tank andexpansion or contraction. the arrangement of its supports and attachments.

5/4A.4.2.3.2 The design vapour pressure Po should not 5/4A.4S.2.4.4 Interpretation of 4.2.4.4 (IACS)normally exceed 0.25 bar. If, however, the hull scantlings 1 If the carriage of products not covered by the Code*isare increased accordingly, and consideration is given, intended, it should be verified that the double ampli-where appropriate, to the strength of the supporting insula- tude of the primary membrane stress Dsm created bytion, Po may be increased to a higher value but less than the maximum dynamic pressure differential Ds does0.7 bar. not exceed the allowable double amplitude of the

dynamic membrane stress DsA as specified in para-5/4A.4.2.4 Independent tanksgraph 5/4A.4.2.4.4 i.e.:5/4A.4.2.4.1 Independent tanks are self-supporting;

they do not form part of the ship’s hull and are not essential Dsm ≤ DsAto the hull strength. There are three categories of indepen-

2 The dynamic pressure differential Dr should be calcu-dent tanks referred to in 5/4A.4.2.4.2 to 5/4A.4.2.4.4.lated as follows:

5/4A.4.2.4.2 Type A independent tanks are tanks whichare designed primarily using Recognized Standards of clas- Dr =

r

1.02 · 104 (ab1Zb1 − ab2Zb2) (bar)sical ship-structural analysis procedures. Where such tanksare primarily constructed of plane surfaces (gravity tanks), where r,ab, Zb are as defined in 5/4A.4.3.2.2, see alsothe design vapour pressure Po should be less than 0.7 bar. sketches below. ab1 and Zb1 are the ab-and Zb-values

giving the maximum liquid pressure hgdmax as defined5/4A.4.2.4.3 Type B independent tanks are tanks whichin 5/4A.4.3.2.are designed using model tests, refined analytical tools and

analysis methods to determine stress levels, fatigue life andcrack propagation characteristics. Where such tanks are

Note:primarily constructed of plane surfaces (gravity tanks) the *The outlined procedure is only applicable to products having a relative

density exceeding 1,0.design vapour pressure Po should be less than 0.7 bar.


In order to evaluate the maximum pressure differential 5/4A.4.2.6 Design vapour pressureDp, pressure differentials should be evaluated over the full 5/4A.4.2.6.1 The design vapour pressure Po is the maxi-range of the acceleration ellipse as shown in the sketches mum gauge pressure at the top of the tank which has beengiven below. used in the design of the tank.

5/4A.4.2.6.2 For cargo tanks where there is no tempera-ture control and where the pressure of the cargo is dictatedonly by the ambient temperature, Po should not be less thanthe gauge vapour pressure of the cargo at a temperature of45°C. However, lesser values of this temperature may beaccepted by the Administration for ships operating in re-stricted areas or on voyages of restricted duration andaccount may be taken in such cases of any insulation ofthe tanks. Conversely, higher values of this temperaturemay be required for ships permanently operating in areasof high ambient temperature.

5/4A.4.2.6.3 In all cases, including 5/4A.4.2.6.2, Po

should not be less than MARVS.5/4A.4.2.6.4 Subject to special consideration by the Ad-

ministration and to the limitations given in 5/4A.4.2.1 to5/4A.4.2.5 for the various tank types, a vapour pressure5/4A.4.2.5 Internal insulation tanks higher than Po may be accepted in harbour conditions,

5/4A.4.2.5.1 Internal insulation tanks are non-self-sup- where dynamic loads are reduced.porting and consist of thermal insulation materials which 5/4A.4.2.7 Design temperaturecontribute to the cargo containment and are supported by The design temperature for selection of materials is thethe structure of the adjacent inner hull or of an independent minimum temperature at which cargo may be loaded ortank. The inner surface of the insulation is exposed to the transported in the cargo tanks. Provision to the satisfactioncargo. of the Administration should be made to ensure that the

5/4A.4.2.5.2 The two categories of internal insulation tank or cargo temperature cannot be lowered below thetanks are: design temperature.

.1 Type 1 tanks which are tanks in which the insulationor a combination of the insulation and one or more

5/4A.4.3 Design loadsliners functions only as the primary barrier. The inner5/4A.4.3.1 Generalhull or an independent tank structure should function5/4A.4.3.1.1 Tanks together with their supports andas the secondary barrier when required.

other fixtures should be designed taking into account.2 Type 2 tanks which are tanks in which the insulationproper combinations of the following loads:or a combination of the insulation and one or more

liners functions as both the primary and the secondaryinternal pressurebarrier and where these barriers are clearly distin-external pressureguishable.dynamic loads due to the motions of the shipThe term ‘‘liner’’ means a thin, non-self-supporting, metal-thermal loadslic, nonmetallic or composite material which forms part ofsloshing loadsan internal insulation tank in order to enhance its fractureloads corresponding to ship deflectionresistance or other mechanical properties. A liner differstank and cargo weight with the corresponding reactionsfrom a membrane in that it is not intended to functionin way of supportsalone as a liquid barrier.insulation weight

5/4A.4.2.5.3 Internal insulation tanks should be of suit- loads in way of towers and other attachments.able materials enabling the cargo containment system to

The extent to which these loads should be consideredbe designed using model tests and refined analytical meth-depends on the type of tank, and is more fully detailed inods as required in 5/4A.4.4.7.the following paragraphs.5/4A.4.2.5.4 The design vapour pressure Po should not

5/4A.4.3.1.2 Account should be taken of the loads cor-normally exceed 0.25 bar. If, however, the cargo contain-responding to the pressure test referred to in 5/4A.4.10.ment system is designed for a higher vapour pressure, Po

5/4A.4.3.1.3 Account should be taken of an increase ofmay be increased to such higher value, but not exceedingvapour pressure in harbour conditions referred to in 5/0.7 bar, if the internal insulation tanks are supported by the4A.4.2.6.4.inner hull structure. However, a design vapour pressure of

more than 0.7 bar may be accepted by the Administration 5/4A.4.3.1.4 The tanks should be designed for the mostprovided the internal insulation tanks are supported by unfavourable static heel angle within the range 0° to 30°

without exceeding allowable stresses given in 5/4A.4.5.1.suitable independent tank structures.


5/4A.4.3.2 Internal pressure (1 Oct. 1994) heading when this consideration has also formed part ofthe hull strength assessment.5/4A.4.3.2.1 The internal pressure Peq in bars gauge re-

5/4A.4.3.4.2 For design against plastic deformation andsulting from the design vapour pressure Po and the liquidbuckling the dynamic loads should be taken as the mostpressure Pgd defined in 5/4A.4.3.2.2, but not including ef-probable largest loads the ship will encounter during itsfects of liquid sloshing, should be calculated as follows:operating life (normally taken to correspond to a probability

Peq = Po + (Pgd )max (bar) level of 10−8). Guidance formulae for acceleration compo-nents are given in 5/4A.4.12.Equivalent calculation procedures may be applied.

5/4A.4.3.4.3 When design against fatigue is to be consid-5/4A.4.3.2.2 The internal liquid pressures are those cre-ered, the dynamic spectrum should be determined by long-ated by the resulting acceleration of the centre of gravityterm distribution calculation based on the operating lifeof the cargo due to the motions of the ship referred toof the ship (normally taken to correspond to 108 wavein 5/4A.4.3.4.1. The value of internal liquid pressure Pgd encounters). If simplified dynamic loading spectra are usedresulting from combined effects of gravity and dynamicfor the estimation of the fatigue life, those should be spe-accelerations should be calculated as follows:cially considered by the Administration.

5/4A.4.3.4.4 For practical application of crack propaga-Pgd = ab Zb

r

1.02 × 10 4 (bar) tion estimates, simplified load distribution over a periodof 15 days may be used. Such distributions may be obtainedwhere: as indicated in figure 5/4A.4.3.

ab = dimensionless acceleration (i.e. relative to the accel-5/4A.4.3.4.5 Ships for restricted service may be giveneration of gravity), resulting from gravitational and

special consideration.dynamic loads, in an arbitrary direction b (see figure5/4A.4.3.4.6 The accelerations acting on tanks are esti-5/4A.4.1).

mated at their centre of gravity and include the followingZb = largest liquid height (m) above the point where thecomponents:pressure is to be determined, measured from thevertical acceleration: motion accelerations oftank shell in the b direction (see figure 5/4A.4.2).

heave, pitch and, possibly,Tank domes considered to be part of the acceptedroll (normal to the shiptotal tank volume should be taken into account whenbase);determining Zb unless the total volume of tank domes

transverse acceleration: motion accelerations of sway,Vd does not exceed the following value:yaw and roll; and gravitycomponent of roll;Vd = Vt 1100 − FL

FL 2 longitudinal acceleration: motion accelerations of surgeand pitch; and gravitywhere:component of pitch.

Vt = tank volume without any domesFL = filling limit according to 5/4A.15 5/4A.4.3.5 Sloshing loads

r = maximum cargo density (kg/m3) at the design tem- 5/4A.4.3.5.1 When partial filling is contemplated, theperature. risk of significant loads due to sloshing induced by any

of the ship motions referred to in 5/4A.4.3.4.6 should beThe direction which gives the maximum value (Pgd)max ofconsidered.Pgd should be considered. Where acceleration components

5/4A.4.3.5.2 When risk of significant sloshing-inducedin three directions need to be considered, an ellipsoidloads is found to be present, special tests and calculationsshould be used instead of the ellipse in figure 5/4A.4.1.should be required.The above formula applies only to full tanks. (Also see

5/4A.4S.3.5 Interpretation of 5/4A.4.3.5 (ABS)Figure 5/ 4A.4.2a)Where loading conditions are proposed including one or5/4A.4.3.3 External pressuremore partially filled tanks, calculations or model test areExternal design pressure loads should be based on therequired to show that the resulting loads and pressuresdifference between the minimum internal pressure (maxi-are within acceptable limits for the scantlings of the tanks.mum vacuum) and the maximum external pressure to

5/4A.4.3.6 Thermal loadswhich any portion of the tank may be subjected simultane-ously. 5/4A.4.3.6.1 Transient thermal loads during cooling

down periods should be considered for tanks intended for5/4A.4.3.4 Dynamic loads due to ship motionscargo temperatures below −55°C5/4A.4.3.4.1 The determination of dynamic loads should

5/4A.4.3.6.2 Stationary thermal loads should be consid-take account of the long-term distribution of ship motions,ered for tanks where design supporting arrangement andincluding the effects of surge, sway, heave, roll, pitch andoperating temperature may give rise to significant thermalyaw on irregular seas which the ship will experience duringstresses.its operating life (normally taken to correspond to 108 wave

encounters). Account may be taken of reduction in dynamic 5/4A.4.3.7 Loads on supportsThe loads on supports are covered by 5/4A.4.6.loads due to necessary speed reduction and variation of


FIGURE 5/4A.4.1Acceleration ellipse

5/4A.4.4 Structural analyses suitability of the membrane and of the associated insulationwith respect to plastic deformation and fatigue.5/4A.4.4.1 Integral tanks

The structural analysis of integral tanks should be in ac- 5/4A.4.4.2.2 Before approval is given, a model of bothcordance with Recognized Standards. The tank boundary the primary and secondary barriers, including corners andscantlings should meet at least the requirements for deep joints, should normally be tested to verify that they willtanks taking into account the internal pressure as indicated withstand the expected combined strains due to static,in 5/4A.4.3.2, but the resulting scantlings should not be dynamic and thermal loads. Test conditions should repre-less than normally required by such standards. sent the most extreme service conditions the cargo contain-

ment system will see in its life. Material tests should ensure5/4A.4S.4.1 Interpretation of 5/4A.4.4.1 (ABS)that ageing is not liable to prevent the materials fromIntegral tanks are to be designed and constructed in ac-carrying out their intended function.cordance with the requirements of these Rules. The scant-

lings of the tank boundary plating and stiffening are to be 5/4A.4.4.2.3 For the purpose of the test referred to innot less than required by Section 5/2 using the heads given 5/4A.4.4.2.2, a complete analysis of the particular motions,in that Section, or as derived from 5/4A.4.3.2., whichever accelerations and response of ships and cargo containmentis the greater. See also 5/4A.4.2.1.2. systems should be performed, unless these data are avail-

able from similar ships.5/4A.4.4.2 Membrane tanks5/4A.4.4.2.1 For membrane tanks, the effects of all static 5/4A.4.4.2.4 Special attention should be paid to the pos-

sible collapse of the membrane due to an overpressure inand dynamic loads should be considered to determine the


FIGURE 5/4A.4.2Determination of internal pressure heads

FIGURE 5/4A.4.2.a(ABS)

Note Small tank domes not considered to be part of the accepted total volume of the cargo tank need not be considered when determining Zb.


FIGURE 5/4A.4.3Simplified load distribution

Note Response scale is logarithmic, the value of 2.105 is given as an example of estimate

the interbarrier space, to a possible vacuum in the cargo 5/4A.4.4.4 Type A independent tankstank, to the sloshing effects and to hull vibration effects. 5/4A.4.4.4.1 A structural analysis should be performed

5/4A.4.4.2.5 A structural analysis of the hull should be to the satisfaction of the Administration taking into accountto the satisfaction of the Administration, taking into account the internal pressure as indicated in 5/4A.4.3.2. The cargothe internal pressure as indicated in 5/4A.4.3.2. Special tank plating thickness should meet at least the require-attention, however, should be paid to deflections of the hull ments of Recognized Standards for deep tanks taking intoand their compatibility with the membrane and associated account the internal pressure as indicated in 5/4A.4.3.2insulation. Inner hull plating thickness should meet at least and any corrosion allowance required by 5/4A.4.5.2.the requirements of Recognized Standards for deep tanks 5/4A.4.4.4.2 For parts such as structure in way of sup-taking into account the internal pressure as indicated in ports not otherwise covered by Recognized Standards,5/4A.4.3.2. The allowable stress for the membrane, mem- stresses should be determined by direct calculations, takingbrane-supporting material and insulation should be deter- into account the loads referred to in 5/4A.4.3 as far asmined in each particular case. applicable, and the ship deflection in way of supports.

5/4A.4S.4.2 Interpretation of 5/4A.4.4.2 (ABS) 5/4A.4.4.5 Type B independent tanksA structural analysis of the hull structure supporting the For tanks of this type the following applies:membrane tank are required using direct calculation proce- .1 The effects of all dynamic and static loads should bedures which are to be agreed with the Bureau at an early used to determine the suitability of the structure withstage in the design. respect to:The scantlings of the inner hull are not to be less thanrequired by Section 5/2 for the maximum head which could plastic deformationbe imposed. buckling

5/4A.4.4.3 Semi-membrane tanks fatigue failureA structural analysis should be performed in accordance crack propagation.with the requirements for membrane tanks or independenttanks as appropriate, taking into account the internal pres- Statistical wave load analysis in accordance with 5/sure as indicated in 5/4A.4.3.2. 4A.4.3.4, finite element analysis or similar methods

5/4A.4S.4.3 Interpretation of 5/4A.4.4.3 (ABS) and fracture mechanics analysis or an equivalent ap-The procedure indicated in 5/4A.4S.4.2 is generally to be proach, should be carried out.followed. .2 A three-dimensional analysis should be carried out

to evaluate the stress levels contributed by the ship’s


hull. The model for this analysis should include the the nil ductility transition temperature of the materialas fabricated, the type of joint and welding procedure,cargo tank with its supporting and keying system as

well as a reasonable part of the hull. but in this case an efficiency factor of not more than0.85 should be adopted. For special materials, the.3 A complete analysis of the particular ship accelera-

tions and motions in irregular waves and of the re- above-mentioned factors should be reduced de-pending on the specified mechanical properties ofsponse of the ship and its cargo tanks to these forces

and motions should be performed unless these data the welded joint.are available from similar ships. 5/4A.4.4.6.2 Buckling criteria should be as follows:

.4 A buckling analysis should consider the maximum .1 The thickness and form of pressure vessels subjectconstruction tolerances. to external pressure and other loads causing compres-

.5 Where deemed necessary by the Administration, sive stresses should be to a standard acceptable tomodel tests may be required to determine stress con- the Administration. These calculations in all casescentration factors and fatigue life of structural ele- should be based on generally accepted pressure ves-ments. sel buckling theory and should adequately account

.6 The cumulative effect of the fatigue load should com- for the difference in theoretical and actual bucklingply with: stress as a result of plate edge misalignment, ovality

and deviation from true circular form over a specifiedS

ni

Ni+

10 3

Nj≤ Cw arc or chord length.

.2 The design external pressure Pe used for verifyingthe buckling of the pressure vessels should not bewhere:less than that given by:

ni = number of stress cycles at each stress level duringthe life of the ship Pe = P1 + P2 + P3 + P4 (bar)

Ni = number of cycles to fracture for the respective stress where:level according to the Wohler (S-N) curveNj = number of cycles to fracture for the fatigue loads P1 = setting value of vacuum relief valves. For vessels not

due to loading and unloading fitted with vacuum relief valves P1 should be speciallyconsidered, but should not in general be taken as

Cw should be less than or equal to 0.5, except that the less than 0.25 bar.Administration may give special consideration to the use P2 = the set pressure of the pressure relief valves for com-of a value greater than 0.5 but not greater than 1.0, depen- pletely closed spaces containing pressure vessels ordent on the test procedure and data used to establish the parts of pressure vessels; elsewhere P2 = 0.Wohler (S-N) curve. P3 = compressive actions in the shell due to the weight and

contraction of insulation, weight of shell, including5/4A.4.4.6 Type C independent tankscorrosion allowance, and other miscellaneous exter-5/4A.4.4.6.1 Scantlings based on internal pressurenal pressure loads to which the pressure vessel mayshould be calculated as follows:be subjected. These include, but are not limited to,.1 The thickness and form of pressure-containing partsweight of domes, weight of towers and piping, effectof pressure vessels under internal pressure, includingof product in the partially filled condition, accelera-flanges should be determined according to a standardtions and hull deflection. In addition the local effectacceptable to the Administration. These calculationsof external or internal pressure or both should bein all cases should be based on generally acceptedtaken into account.pressure vessel design theory. Openings in pressure-

P4 = external pressure due to head of water for pressurecontaining parts of pressure vessels should be rein-vessels or part of pressure vessels on exposed decks;forced in accordance with a standard acceptable toelsewhere P4 = 0.the Administration.

.2 The design liquid pressure defined in 5/4A.4.3.25/4A.4.4.6.3 Stress analysis in respect of static and dy-should be taken into account in the above calcula-

namic loads should be performed as follows:tions..1 Pressure vessel scantlings should be determined in.3 The welded joint efficiency factor to be used in the

accordance with 5/4A.4.4.6.1 and .2.calculation according to 5/4A.4.4.6.1.1 should be 0.95.2 Calculations of the loads and stresses in way of thewhen the inspection and the non-destructive testing

supports and the shell attachment of the supportreferred to in 5/4A.4.10.9 are carried out. This figureshould be made. Loads referred to in 5/4A.4.3 shouldmay be increased up to 1.0 when account is taken ofbe used, as applicable. Stresses in way of the supportsother considerations, such as the material used, typeshould be to a standard acceptable to the Administra-of joints, welding procedure and type of loading. Fortion. In special cases a fatigue analysis may be re-process pressure vessels the Administration may ac-

cept partial non-destructive examinations, but not quired by the Administration..3 If required by the Administration, secondary stressesless than those of 5/4A.4.10.9.2.2 depending on such

factors as the material used, the design temperature, and thermal stresses should be specially considered.


5/4A.4S.4.6.3 Interpretation of 5/4A.4.4.6.3 (ABS) 5/4A.4.4.7.4.1 In order to confirm the design principles,prototype testing of composite models including structural‘‘Special cases’’ where fatigue analysis may be required by

the Bureau include, but are not limited to, novel designs elements should be carried out under combined effects ofstatic, dynamic and thermal loads.and designs where cyclic loading is determined to be a

factor by the design code used. 5/4A.4.4.7.4.2 Test conditions should represent themost extreme service conditions the cargo containment5/4A.4.4.6.4 For pressure vessels, the thickness calcu-system will be exposed to during the lifetime of the ship,lated according to 5/4A.4.4.6.1 or the thickness requiredincluding thermal cycles. For this purpose, 400 thermalby 5/4A.4.4.6.2 plus the corrosion allowance, if any, shouldcycles are considered to be a minimum, based upon 19be considered as a minimum without any negative tol-round voyages per year; where more than 19 round voyageserance.per year are expected, a higher number of thermal cycles5/4A.4.4.6.5 For pressure vessels, the minimum thick-will be required. These 400 thermal cycles may be dividedness of shell and heads including corrosion allowance, afterinto 20 full cycles (cargo temperature to 45°C) and 380forming, should not be less than 5 mm for carbon-manga-partial cycles (cargo temperature to that temperature ex-nese steels and nickel steels, 3 mm for austenitic steels orpected to be reached in the ballast voyage).7 mm for aluminium alloys.

5/4A.4.4.7.4.3 Models should be representative of the5/4A.4.4.7 Internal insulation tanksactual construction including corners, joints, pump5/4A.4.4.7.1 The effects of all static and dynamic loadsmounts, piping penetrations and other critical areas, andshould be considered to determine the suitability of theshould taken into account variations in any material proper-tank with respect to:ties, workmanship and quality control.

5/4A.4.4.7.4.4 Combined tension and fatigue testsfatigue failureshould be carried out to evaluate crack behaviour of thecrack propagation from both free and supported surfacesinsulation material in the case where a through crack devel-adhesive and cohesive strengthops in the inner hull or independent tank structure. Incompressive, tensile and shear strength.these tests, where applicable the crack area should besubjected to the maximum hydrostatic pressure of the bal-Statistical wave load analysis in accordance with 5/last water.4A.4.3.4, finite element analysis or similar methods and

fracture mechanics analysis or an equivalent approach 5/4A.4.4.7.5 The effects of fatigue loading should beshould be carried out. determined in accordance with 5/4A.4.4.5.6 or by an equiv-

alent method.5/4A.4.4.7.2.1 Special attention should be given to crack5/4A.4.4.7.6 For internal insulation tanks, repair proce-resistance and to deflections of the inner hull or indepen-

dures should be developed during the prototype testingdent tank structure and their compatibility with the insula-programme for both the insulation material and the innertion materials. A three-dimensional structure analysishull or the independent tank structure.should be carried out to the satisfaction of the Administra-

tion. This analysis is to evaluate the stress levels and defor-mations contributed either by the inner hull or by the 5/4A.4.5 Allowable stresses and corrosion allowancesindependent tank structure or both and should also take (Also See Annex B)into account the internal pressure as indicated in 5/ 5/4A.4.5.1 Allowable stresses4A.4.3.2. Where water ballast spaces are adjacent to the 5/4A.4.5.1.1 For integral tanks, allowable stressesinner hull forming the supporting structure of the internal should normally be those given for hull structure in Recog-insulation tank, the analysis should take account of the nized Standards.dynamic loads caused by water ballast under the influence 5/4A.4.5.1.2 For membrane tanks, reference is made toof ship motions. the requirements of 5/4A.4.4.2.5.

5/4A.4.4.7.2.2 The allowable stresses and associated de- 5/4A.4.5.1.3 For type A independent tanks primarilyflections for the internal insulation tank and the inner hull constructed of plane surfaces, the stresses for primary andstructure or independent tank structure should be deter- secondary members (stiffeners, web frames, stringers, gird-mined in each particular case. ers) when calculated by classical analysis procedures

5/4A.4.4.7.2.3 Thicknesses of plating of the inner hull should not exceed the lower of Rm/2.66 or Re/1.33 foror of an independent tank should at least comply with the carbon-manganese steels and aluminium alloys, where Rmrequirements of Recognized Standards, taking into account and Re are defined in 5/4A.4.5.1.7. However, if detailedthe internal pressure as indicated in 5/4A.4.3.2. Tanks con- calculations are carried out for the primary members, thestructed of plane surfaces should at least comply with Rec- equivalent stress s=\c as defined in 5/4A.4.5.1.8 may beognized Standards for deep tanks. increased over that indicated above to a stress acceptable

to the Administration; calculations should take into account5/4A.4.4.7.3 A complete analysis of the response of ship,cargo and any ballast to accelerations and motions in irregu- the effects of bending, shear, axial and torsional deforma-

tion as well as the hull/cargo tank interaction forces duelar waves of the particular ship should be performed tothe satisfaction of the Administration unless such analysis to the deflection of the double bottom and cargo tank

bottoms.is available for a similar ship.


5/4A.4S.4.5.1.3 Interpretation of 5/4A.5.1.3 (ABS) attached are not to have a section modulus less than thatThe scantlings of independent tanks, type A, are not to be required by the following equationless than that required by Section 3/13 (except 3/13.7) as

SMR = SM K1 K3/samodified belowa Head The value of ‘‘h’’ used in the various equations when SMR, SM, K1 and sa are defined in c above

may be modified for the maximum cargo density or asK3 = 124 N/mm2 (12.6 kgf/mm2, 17920 psi.)derived from 5/4A.4.3.2, whichever is the greater.

b Plating g Buckling For higher strength materials and alumi-1 Steel num alloys, calculations are to be submitted to show ade-

The plating thickness is to be determined from 3/13.3.1 quate provision to resist buckling.where Y is the specified minimum yield stress at room h Fatigue Strength Proportions and scantlings of struc-temperature. If the stress-strain curve does not show a tural members where deemed necessary may have to bedefined yield stress, the 0.2% proof stress (offset method) investigated to improve the fatigue strength especially inapplies. higher strength material and aluminum alloys.Where the cargo is non-corrosive, the thickness obtained 5/4A.4.5.1.4 For type B independent tanks, primarilymay be reduced by the corrosion allowance (CA) indicated constructed of bodies of revolution, the allowable stressesin e below. should not exceed:

2 Aluminum Alloysm ≤ fThe plating thickness is to be obtained from the followingsL ≤ 1.5fequationsb ≤ 1.5F

sL + sb ≤ 1.5Fta = 3ts − CA4 1Es

Ea2

13

sm + sb ≤ 1.5F

ta = required thickness of aluminum in mm or in. wherets = required thickness of steel from 3/13.1.1 with sm = equivalent primary general membrane stress

Q = 1.0 sL = equivalent primary local membrane stressCA = if cargo is non-corrosive, the value of the corrosion sb = equivalent primary bending stress

allowance is indicated in e below.the lesser of

Rm

Aor

Re

Bf =Es = Modulus of Elasticity of steel

Ea = Modulus of Elasticity of aluminumthe lesser of

Rm

Cor

Re

DF =c Stiffeners Each of the stiffeners in steel or aluminum

alloy in association with the plating to which it is attached with Rm and Re as defined in 5/4A.4.5.1.7. With regard tois not to have a section modulus less than that required the stresses sm , sL and sb see also the definition of stressby the following equation categories in 5/4A.4.13. The values of A, B, C and D should

be shown on the International Certificate of Fitness forSMR = SM K1 K2/sathe Carriage of Liquefied Gases in Bulk and should have

where at least the following minimum values:whereSMR = required section modulus of material proposed in

cm3 or in3

SM = required section modulus from 3/13.3.2 using c=1.0 and l is the distance in meters or feet betweensupports.

sa = allowable stress not exceeding the lower of RM/2.66 or Re/1.33 for steel or aluminum alloy, respec-tively and RM and Re as defined in 5/4A.4.5.1.7.

K1 = 0.9 for non-corrosive cargoes 1.0 for corrosivecargoes.

K2 = 108 N/mm2 (11.0 kgf/mm 2, 15680 psi)5/4A.4.5.1.5 For type B independent tanks, primarilyd Corrugated Bulkheads Corrugate bulkheads are not

constructed of plane surfaces, the Administration may re-to be used for primary barriers.quire compliance with additional or other stress criteria.e Corrosion Allowance Where the cargo is non-corro-

sive, the thickness of plating may be reduced by 3 mm 5/4A.4S.5.1.5 Interpretation of 5/4A.4.5.1.5 (ABS)(0.125 in) except that where the thickness of plating as For independent tanks, type B, primarily constructed of

plane surfaces, the equivalent stress, se, in members usingdetermined by 3/13.3.1 is less than 12.5 mm (0.50 in), thereduction is not to be greater than 20%. In no case is the a F.E.M. analysis are not to exceed the values of the lower

of Re/E or Rm/F for the materials indicated in the followingthickness of plating to be less than 6.5 mm (0.25 in).f Webs and Girders Webs and girders in steel and alu- table and Rm and Re as defined in 5/4A.4.5.1.7 and se is

defined in 5/4B.5.4.1.8.minum alloy in association with the plating to which it is


calculated separately and unless other methods of calcula-tion are justified, the total stresses should be calculatedMember Factor Nickel steels and Austenitic Alumin-according to:carbon-manganese steels ium

steels alloys

sx = sx.st 6 √S (sx.dyn) 2E 1.00 1.00 1.00

PLATINGF 2.00 2.00 2.00

sy = sy.st 6 √S (sy.dyn )2

STIFFENERS E 1.33 1.25 1.33F 2.00 2.50 2.50 txy = txy.st 6 √S (txy.dyn)2

WEB, GIRDERS, E 1.33 1.25 1.33 where:STRINGER F 2.00 2.50 2.50 sx.st , sy.st and txy.st = static stresses

sx.dyn , sy.dyn and txy.dyn = dynamic stresses5/4A.4.5.1.6 For type C independent tanks the maxi-

mum allowable membrane stress to be used in calculation all determined separately from acceleration componentsaccording to 5/4A.4.4.6.1.1 should be the lower of: and hull strain components due to deflection and torsion.

5/4A.4.5.1.10 For internal insulation tanks, reference isRm

Aor

Re

B made to the requirement of 5/4A.4.4.7.2.where: 5/4A.4.5.1.11 Allowable stresses for materials other than

those covered by 5/4A.6 should be subject to approval byRm and Re are as defined in 5/4A.4.5.1.7. the Administration in each case.

5/4A.4.5.1.12 Stresses may be further limited by fatigueThe values of A and B should be shown on the Internationalanalysis, crack propagation analysis and buckling criteria.Certificate of Fitness for the Carriage of Liquefied Gases

5/4A.4S.5.1 Interpretation of 5/4A.4.5.1in Bulk provided for in 5/4A.1.5, and should have at least(Permissible stress in way of supports of Type C cargothe minimum values indicated in the table of 5/4A.4.5.1.4.tanks) (IACS)

1. With reference to para. 5/4A.4.5.1, the following crite-5/4A.4.5.1.7 For the purpose of 5/4A.4.5.1.3, 5/rion for the allowable stresses in way of supports of type C-4A.4.5.1.4 and 5/4A.4.5.1.6 the following apply:cargo tanks, made of carbon manganese steel may be used:.1 Re = specified minimum yield stress at room tem-

perature (N/ mm2). If the stress-strain curvese = √(sn + sb)2 + 3t 2 ≤ sadoes not show a defined yield stress, the 0.2%

proof stress applies.where:

Rm = specified minimum tensile strength at roomse = equivalent stress (N/mm 2)temperature (N/mm2).sn = normal stress in the circumferential direction of theFor welded connections in aluminium alloys the respec- stiffening ring (N/mm 2)tive values of Re or Rm in annealed conditions shouldsb = bending stress in the circumferential direction ofbe used. the stiffening ring (N/mm 2)

.2 The above properties should correspond to the mini-t = shear stress in the stiffening ring (N/mm 2)

mum specified mechanical properties of the material, sa = allowable stress (N/mm 2), to be taken as the smallerincluding the weld metal in the as-fabricated condi- of the values:tion. Subject to special consideration by the Adminis-tration, account may be taken of enhanced yield stress 0.57 Rm or 0.85 Reand tensile strength at low temperature. The temper-ature on which the material properties are based Rm and Re as defined in 5/4A.4.5.1.7.1should be shown on the International Certificate of

Equivalent stress values se should be calculated over theFitness for the Carriage of Liquefied Gases in Bulk.full extent of the stiffening ring by a procedure acceptable5/4A.4.5.1.8 The equivalent stress sc (von Mises, to the Classification Society, for a sufficient number of load

Huber) should be determined by: cases as defined in 5/4A.4.6.2 and 5/4A.4.6.32. The following assumptions should be made for thesC = √sx

2 + sy2 − sx sy + 3t2

xystiffening rings:

where: 2.1 The stiffening ring should be considered as a circum-sx = total normal stress in x-direction ferential beam formed by web, face place, doubler plate,sy = total normal stress in y-direction if any, and associated shell plating.txy = total shear stress in x-y plane. The effective width of the associated plating should be

taken as:.1 For cylindrical shells:5/4A.4.5.1.9 When the static and dynamic stresses are


account rotational as well as translational effects. This ac-an effective width (mm) not greater than 0.78 √rt onceleration in a given direction may be determined as showneach side of the web. A doubler plate, if any, may bein figure 5/4A.4.1. The half axes of the ‘‘acceleration ellipse’’included within that distance.should be determined according to 5/4A.4.3.4.2.where:

5/4A.4.6.4 Suitable supports should be provided tor = means radius of the cylindrical shell (mm)withstand a collision force acting on the tank correspondingt = shell thickness (mm).to one half the weight of the tank and cargo in the forward.2 For longitudinal bulkheads (in the case of lobe tanks):direction and one quarter the weight of the tank and cargothe effective width should be determined according toin the aft direction without deformation likely to endangerestablished standards. A value of 20 tb on each side ofthe tank structure.the web may be taken as a guidance value.

5/4A.4.6.5 The loads mentioned in 5/4A.4.6.2 and 5/where:4A.4.6.4 need not be combined with each other or withtb = bulkhead thickness (mm).wave-induced loads.2.2 The stiffening ring should be loaded with circumferen-

5/4A.4.6.6 For independent tanks and, where appro-tial forces, on each side of the ring, due to the shear stress,priate, for membrane and semi-membrane tanks, provisiondetermined by the bi-dimensional shear flow theory fromshould be made to key the tanks against the rotationalthe shear force of the tank.effects referred to in 5/4A.4.6.3.3. The following factors should be taken into account:

5/4A.4.6.7 Antiflotation arrangements should be pro-3.1 Elasticity of support material (intermediate layer ofvided for independent tanks. The antiflotation arrange-wood or similar material)ments should be suitable to withstand an upward force3.2 Change in contact surface between tank and support,caused by an empty tank in a hold space flooded to theand of the relevant reactions, due to:summer load draught of the ship, without plastic deforma-—thermal shrinkage of tanktion likely to endanger the hull structure.—elastic deformations of tank and support material.

5/4A.4S.6 Interpretation of 5/4A.4.6 (ABS)The final distribution of the reaction forces at the supportsA design analysis substantiating the above criteria is to beshould not show any tensile forces.submitted.4. The bucking strength of the stiffening rings should

be examined.5/4A.4.7 Secondary barrier5/4A.4.5.2 Corrosion allowances

5/4A.4.7.1 Where the cargo temperature at atmospheric5/4A.4.5.2.1 No corrosion allowance should generallypressure is below −10°C, a secondary barrier should bebe required in addition to the thickness resulting from theprovided when required by 5/4A.4.7.3 to act as a temporarystructural analysis. However, where there is no environ-containment for any envisaged leakage of liquid cargomental control around the cargo tank, such as inerting, orthrough the primary barrier.where the cargo is of a corrosive nature, the Administration

5/4A.4.7.2 Where the cargo temperature at atmosphericmay require a suitable corrosion allowance.pressure is not below −55°C, the hull structure may act5/4A.4.5.2.2 For pressure vessels no corrosion allow-as a secondary barrier. In such a case:ance is generally required if the contents of the pressure

.1 the hull material should be suitable for the cargovessel are non-corrosive and the external surface is pro-temperature at atmospheric pressure as required bytected by inert atmosphere or by an appropriate insulation5/4A.4.9.2; andwith an approved vapour barrier. Paint or other thin coat-

.2 the design should be such that this temperature willings should not be credited as protection.not result in unacceptable hull stresses.Where special alloys are used with acceptable corrosion

5/4A.4.7.3 Secondary barriers in relation to tank typesresistance, no corrosion allowance should be required. Ifshould normally be provided in accordance with the follow-the above conditions are not satisfied, the scantlings calcu-ing table. For tanks which differ from the basic tank typeslated according to 5/4A.4.4.6 should be increased as appro-as defined in 5/4A.4.2 the secondary barrier requirementspriate.should be decided by the Administration in each case.

5/4A.4.6 Supports 5/4A.4.7.4 The secondary barrier should be so de-5/4A.4.6.1 Cargo tanks should be supported by the hull signed that:

in a manner which will prevent bodily movement of the .1 it is capable of containing any envisaged leakage oftank under static and dynamic loads while allowing con- liquid cargo for a period of 15 days, unless differenttraction and expansion of the tank under temperature varia- requirements apply for particular voyages, taking intotions and hull deflections without undue stressing of the account the load spectrum referred to in 5/4A.4.3.4.4;tank and of the hull. .2 it will prevent lowering of the temperature of the

5/4A.4.6.2 The tanks with supports should also be de- ship structure to an unsafe level in the case of leakagesigned for a static angle of heel of 30° without exceeding of the primary barrier as indicated in 5/4A.4.8.2; andallowable stresses given in 5/4A.4.5.1. .3 the mechanism of failure for the primary barrier does

not also cause the failure of the secondary barrier5/4A.4.6.3 The supports should be calculated for themost probable largest resulting acceleration, taking into and vice versa.


temperature given in 5/4A.6 for the grade of steel con-cerned, as detailed in 5/4A.4.9, when the cargo tanks areat their design temperature and the ambient temperaturesare 5°C for air and 0°C for seawater. These conditions maygenerally be used for world-wide service. However, highervalues of the ambient temperatures may be accepted bythe Administration for ships operated in restricted areas.Conversely, lesser values of the ambient temperatures maybe fixed by the Administration for ships trading occasion-ally or regularly to areas in latitudes where such lowertemperatures are expected during the winter months. Theambient temperatures used in the design should be shownon the International Certificate of Fitness for the Carriageof Liquefied Gases in Bulk provided for in 5/4A.1.5.

5/4A.4.8.2 Where a complete or partial secondary bar-rier is required, calculations should be made with the as-sumptions in 5/4A.4.8.1 to check that the temperature of1 A complete secondary barrier should normally be required if cargoesthe hull structure does not fall below the minimum allow-with a temperature at atmospheric pressure below −10°C are permittedable design temperature given in 5/4A.6 for the grade ofin accordance with 5/4A.4.2.1.3.

2 In the case of semi-membrane tanks which comply in all respects with steel concerned, as detailed in 5/4A.4.9. The complete orthe requirements applicable to type B independent tanks, except for the partial secondary barrier should be assumed to be at themanner of support, the Administration may, after special consideration, cargo temperature at atmospheric pressure.accept a partial secondary barrier.

5/4A.4.8.3 Calculations required by 5/4A.4.8.1 and 5/4A.4.8.2 should be made assuming still air and still water,and except as permitted by 5/4A.4.8.4, no credit should be5/4A.4.7.5 The secondary barrier should fulfil its func-given for means of heating. In the case referred to in 5/tions at a static angle of heel of 30°.4A.4.8.2, the cooling effect of the rising boil-off vapour5/4A.4.7.6.1 Where a partial secondary barrier is re-from the leaked cargo should be considered in the heatquired, its extent should be determined on the basis oftransmission studies. For members connecting inner andcargo leakage corresponding to the extent of failure re-outer hulls, the mean temperature may be taken for de-sulting from the load spectrum referred to in 5/4A.4.3.4.4termining the steel grade.after the initial detection of a primary leak. Due account

5/4A.4.8.4 In all cases referred to in 5/4A.4.8.1 and 5/may be taken of liquid evaporation, rate of leakage, pump-4A.4.8.2 and for ambient temperature conditions of 5°Cing capacity and other relevant factors. In all cases, how-for air and 0°C for seawater, approved means of heatingever, the inner bottom adjacent to cargo tanks should betransverse hull structural material may be used to ensureprotected against liquid cargo.that the temperatures of this material do not fall below the5/4A.4.7.6.2 Clear of the partial secondary barrier, pro-minimum allowable values. If lower ambient temperaturesvision such as a spray shield should be made to deflectare specified, approved means of heating may also be usedany liquid cargo down into the space between the primaryfor longitudinal hull structural material, provided this ma-and secondary barriers and to keep the temperature of theterial remains suitable for the temperature conditions ofhull structure to a safe level.5°C for air and 0°C for seawater without heating. Such5/4A.4.7.7 The secondary barrier should be capable ofmeans of heating should comply with the following require-being periodically checked for its effectiveness, by meansments:of a pressure/vacuum test, a visual inspection or another

.1 sufficient heat should be available to maintain thesuitable method acceptable to the Administration. Thehull structure above the minimum allowable tempera-method should be submitted to the Administration for ap-ture in the conditions referred to in 5/4A.4.8.1 andproval.5/4A.4.8.2;5/4A.4S.7 Interpretation of 5/4A.4.7 (ABS)

Extent of complete secondary barrier .2 the heating system should be so arranged that, in theevent of a failure in any part of the system, stand-byThe extent of the complete secondary barrier is to be not

less than that obtained assuming the cargo tank is breached heating could be maintained equal to not less than100% of the theoretical heat load;at a static angle of heel of 30° and there is an equalization

of liquid in the hold space. See Figure 5/4A.4.4. .3 the heating system should be considered as an essen-tial auxiliary; and

.4 the design and construction of the heating system5/4A.4.8 Insulation (Also see Annex B)should be to the satisfaction of the Administration.5/4A.4.8.1 (1 Oct. 1994) Where a product is carried at

a temperature below −10°C suitable insulation should be 5/4A.4S.4.8 Interpretation of 5/4A.4.8.4 (ABS)provided to ensure that the temperature of the hull struc- Where the cargo is carried in a containment system requir-

ing a secondary barrier, the hull heating system is to beture does not fall below the minimum allowable design


FIGURE 5/4A.4.4

contained solely within the cargo area or the drain returns 5/4A.4.9.3 Materials used in the construction of cargotanks should be in accordance with table 5/4A.6.1, 5/4A.6.2,from the hull heating coils in the wing tanks, cofferdams,

and double bottom are to be lead to a degassing tank. The or 5/4A.6.3.degassing tank is to be located in the cargo area, where 5/4A.4.9.4 Materials other than those referred to in 5/possible, and the vent outlets are to be located in a safe 4A.4.9.1, 5/4A.4.9.2 and 5/4A.4.9.3 used in the constructionposition and fitted with a flame screen. of the ship which are subject to reduced temperature due

to the cargo and which do not form part of the secondary5/4A.4.8.5 In determining the insulation thickness, dueregard should be paid to the amount of acceptable boil- barrier should be in accordance with table 5/4A.6.5 for

temperatures as determined by 5/4A.4.8. This includesoff in association with the reliquefaction plant on board,main propulsion machinery or other temperature control inner bottom plating, longitudinal bulkhead plating, trans-

verse bulkhead plating, floors, webs, stringers and allsystem.attached stiffening members.

5/4A.4.9.5 The insulation materials should be suitable5/4A.4.9 Materials (Also see Annex B)for loads which may be imposed on them by the adjacent5/4A.4.9.1 The shell and deck plating of the ship andstructure.all stiffeners attached thereto should be in accordance with

Recognized Standards, unless the calculated temperature 5/4A.4.9.6 Where applicable, due to location or environ-mental conditions, insulation materials should have suit-of the material in the design condition is below −5°C due

to the effect of the low temperature cargo, in which case able properties of resistance to fire and flame spread andshould be adequately protected against penetration of wa-the material should be in accordance with table 5/4A.6.5

assuming the ambient sea and air temperature of 0°C and ter vapour and mechanical damage.5°C respectively. In the design condition, the complete or 5/4A.4.9.7.1 Materials used for thermal insulationpartial secondary barrier should be assumed to be at the should be tested for the following properties as applicable,cargo temperature at atmospheric pressure and for tanks to ensure that they are adequate for the intended service:without secondary barriers, the primary barrier should be .1 compatibility with the cargoassumed to be at the cargo temperature. .2 solubility in the cargo

.3 absorption of the cargo5/4A.4.9.2 Hull material forming the secondary barriershould be in accordance with table 5/4A.6.2. Metallic mate- .4 shrinkage

.5 ageingrials used in secondary barriers not forming part of thehull structure should be in accordance with table 5/4A.6.2 .6 closed cell content

.7 densityor 5/4A.6.3 as applicable. Insulation materials forming asecondary barrier should comply with the requirements of .8 mechanical properties

.9 thermal expansion5/4A.4.9.7. Where the secondary barrier is formed by thedeck or side shell plating, the material grade required by .10 abrasion

.11 cohesiontable 5/4A.6.2 should be carried into the adjacent deck orside shell plating, where applicable, to a suitable extent. .12 thermal conductivity


.13 resistance to vibrations Heating, meeting the requirements of 5/4A.4.8.4, may beused in the above mentioned temperature calculations. If.14 resistance to fire and flame spread.lower ambient temperatures are used in the temperatures5/4A.4.9.7.2 In addition to meeting the above require-calculations, the longitudinal contiguous hull structures arements, insulation materials which form part of the cargoalso to meet the material of table 5/4A.6.5 without heatingcontainment as defined in 5/4A.4.2.5 should be tested forand with ambient still sea water and still air temperaturethe following properties after simulation of ageing andof 0C (32F) and 5C (41F), respectively. Also see Annex B.thermal cycling to ensure that they are adequate for the

intended service:5/4A.4.10 Construction and testing.1 bonding (adhesive and cohesive strength)

5/4A.4.10.1.1 All welded joints of the shells of indepen-.2 resistance to cargo pressuredent tanks should be of the butt weld, full penetration.3 fatigue and crack propagation propertiestype. For dome-to-shell connections, the Administration.4 compatibility with cargo constituents and any othermay approve tee welds of the full penetration type. Exceptagent expected to be in contact with the insulationfor small penetrations on domes, nozzle welds are alsoin normal servicegenerally to be designed with full penetration..5 where applicable the influence of presence of water

5/4A.4.10.1.2 Welding joint details for type C indepen-and water pressure on the insulation propertiesdent tanks should be as follows:should be taken into account

.1 All longitudinal and circumferential joints of pressure.6 gas de-absorbing.vessels should be of butt welded, full penetration,5/4A.4.9.7.3 The above properties, where applicable,double vee or single vee type. Full penetration buttshould be tested for the range between the expected maxi-welds should be obtained by double welding or bymum temperature in service and 5°C below the minimumthe use of backing rings. If used, backing rings shoulddesign temperature, but not lower than −196°C.be removed, unless specifically approved by the Ad-

5/4A.4.9.8 The procedure for fabrication, storage, han- ministration for very small process pressure vessels.dling, erection, quality control and control against harmful Other edge preparations may be allowed by the Ad-exposure to sunlight of insulation materials should be to ministration depending on the results of the teststhe satisfaction of the Administration. carried out at the approval of the welding procedure.

5/4A.4.9.9 Where powder or granulated insulation is .2 The bevel preparation of the joints between the pres-used, the arrangements should be such as to prevent com- sure vessel body and domes and between domes andpacting of the material due to vibrations. The design should relevant fittings should be designed according to aincorporate means to ensure that the material remains standard for pressure vessels acceptable to the Ad-sufficiently buoyant to maintain the required thermal con- ministration. All welds connecting nozzles, domes orductivity and also prevent any undue increase of pressure other penetrations of the vessel and all welds connect-on the cargo containment system. ing flanges to the vessel or nozzles should be full

penetration welds extending through the entire thick-5/4A.4S.9.4 Interpretation of 5/4A.4.8 and 5/4A.4.9ness of the vessel wall or nozzle wall, unless specially(ABS)approved by the Administration for small nozzle di-a Shell and Deck Plating The material quality of theameters.shell and deck plating is to be in accordance with 5/

5/4A.4.10.2 Workmanship should be to the satisfaction4A.1S.1, unless the calculated temperature is belowof the Administration. Inspection and non-destructive test-−5C(14F) due to the effect of the low temperature of theing of welds for tanks other than type C independent tankscargo assuming an ambient still sea water and still airshould be in accordance with the requirements of 5/temperature of 0C (32F) and 5C (41F) respectively. Where4A.6.3.7.calculated temperature of the shell and deck plating is less

than −5C (14F), the material quality is not to be less than 5/4A.4.10.3 For membrane tanks, quality assurancethat required by table 5/4A.6.5. measures, weld procedure qualification, design details, ma-

terials, construction, inspection and production testing ofThe secondary barriers are to assumed to be at the tempera-components, should be to standards developed during theture of the cargo for these temperature studies. Whereprototype testing programme.secondary barriers are not required, the cargo tanks are to

be assumed to be at the temperature of the cargo for these 5/4A.4.10.4 For semi-membrane tanks the relevant re-temperature studies. quirements in this section for independent tanks or forSome countries of registration may require lower ambient membrane tanks should be applied as appropriate.temperatures than those mentioned above. Also see Annex 5/4A.4.10.5.1 For internal insulation tanks, in order to5/4B. ensure uniform quality of the material, quality control pro-

b Contiguous hull structure Contiguous hull materials cedures including environmental control, application pro-(not forming part of the secondary barriers) subject to cedure qualification, corners, penetrations and other de-reduced temperature due to the cargo are to be in accord- sign details, materials specification, installation andance with table 5/4A.6.5 using the calculated temperature production testing of components should be to standards

developed during the prototype test programme.indicated in a above.


5/4A.4.10.5.2 A quality control specification including Surface crack detection:all welds 10%;maximum permissible size of constructional defects, tests

and inspections during the fabrication, installation and also reinforcement rings around holes, nozzles, etc.100%.sampling tests at each of these stages should be to the

satisfaction of the Administration. As an alternative, ultrasonic testing may be accepted as apartial substitute for the radiographic testing, if specially5/4A.4.10.6 Integral tanks should be hydrostatically orallowed by the Administration. In addition, the Administra-hydropneumatically tested to the satisfaction of the Admin-tion may require total ultrasonic testing on welding ofistration. The test in general should be so performed thatreinforcement rings around holes, nozzles, etc.the stresses approximate, as far as practicable, to the design

.2.2 Partial non-destructive testing referred to in 5/stresses and that the pressure at the top of the tank corres-4A.4.4.6.1.3:ponds at least to the MARVS.Radiography:5/4A.4.10.7 In ships fitted with membrane or semi-

butt welds: all welded crossing joints and at leastmembrane tanks, cofferdams and all spaces which may10% of the full length at selected positions uni-normally contain liquid and are adjacent to the hull struc-formly distributed andture supporting the membrane should be hydrostatically or

Surface crack detection:hydropneumatically tested in accordance with Recognizedreinforcement rings around holes, nozzles, etc.Standards. In addition, any other hold structure supporting100%:the membrane should be tested for tightness. Pipe tunnels

Ultrasonic testing:and other compartments which do not normally containas may be required by the Administration in eachliquid need not be hydrostatically tested.

instance.5/4A.4.10.8.1 In ships fitted with internal insulation

5/4A.4.10.10 Each independent tank should be sub-tanks where the inner hull is the supporting structure, alljected to a hydrostatic or hydropneumatic test as follows:inner hull structure should be hydrostatically or hydro-

.1 For type A independent tanks, this test should bepneumatically tested in accordance with Recognized Stan-so performed that the stresses approximate, as fardards, taking into account the MARVS.practicable, to the design stresses and that the pres-5/4A.4.10.8.2 In ships fitted with internal insulation sure at the top of the tank corresponds at leasttanks where independent tanks are the supporting struc- to the MARVS. When a hydropneumatic test isture, the independent tanks should be tested in accordance performed, the conditions should simulate, as farwith 5/4A.4.10.10.1. as practicable, the actual loading of the tank and of

5/4A.4.10.8.3 For internal insulation tanks where the its supports.inner hull structure or an independent tank structure acts .2 For type B independent tanks, the test should beas a secondary barrier, a tightness test of those structures performed as required in 5/4A.4.10.10.1 for typeshould be carried out using techniques to the satisfaction A independent tanks. In addition, the maximumof the Administration. primary membrane stress or maximum bending

5/4A.4.10.8.4 These tests should be performed before stress in primary members under test conditionsthe application of the materials which will form the internal should not exceed 90% of the yield strength of theinsulation tank. material (as fabricated) at the test temperature. To

ensure that this condition is satisfied, when calcula-5/4A.4.10.9 For type C independent tanks, inspectionand non-destructive testing should be as follows: tions indicate that this stress exceeds 75% of the

yield strength, the prototype test should be moni-.1 Manufacture and workmanship (1 Oct. 1994)—Thetolerances relating to manufacture and workman- tored by the use of strain gauges or other suitable

equipment.ship such as out-of-roundness, local deviations fromthe true form, welded joints alignment and tapering .3 Type C independent tanks should be tested as

follows:of plates having different thicknesses, should com-ply with standards acceptable to the Administration. .3.1 Each pressure vessel, when completely manufac-

tured, should be subjected to a hydrostatic test atThe tolerances should also be related to the buck-ling analysis referred to in 5/4A.4.4.6.2. a pressure measured at the top of the tanks, of not

less than 1.5 Po, but in no case during the pressure.2 Non-destructive testing—As far as completion andextension of non-destructive testing of welded joints test should the calculated primary membrane stress

at any point exceed 90% of the yield stress of theare concerned, the extent of non-destructive testingshould be total or partial according to standards material. The definition of Po is given in 5/4A.4.2.6.

To ensure that this condition is satisfied where cal-acceptable to the Administration, but the controls tobe carried out should not be less than the following: culations indicate that this stress will exceed 0.75

times the yield strength, the prototype test should.2.1 Total non-destructive testing referred to in 5/4A.4.4.6.1.3: be monitored by the use of strain gauges or other

suitable equipment in pressure vessels other thanRadiography:butt welds 100% and simple cylindrical and spherical pressure vessels.


.3.2 The temperature of the water used for the test 5/4A.4.10.18 For type C independent tanks, the re-quired marking of the pressure vessel should be achievedshould be at least 30°C above the nil ductility transi-

tion temperature of the material as fabricated. by a method which does not cause unacceptable local stressraisers..3.3 The pressure should be held for 2 h per 25 mm of

thickness but in no case less than 2 h..3.4 Where necessary for cargo pressure vessels, and 5/4A.4.11 Stress relieving for type C independent

with the specific approval of the Administration, a tankshydropneumatic test may be carried out under the 5/4A.4.11.1 For type C independent tanks of carbon andconditions prescribed in 5/4A.4.10.10.3.1, .2 and .3. carbon-manganese steel, post-weld heat treatment should

.3.5 Special consideration may be given by the Adminis- be performed after welding if the design temperature istration to the testing of tanks in which higher allow- below −10°C. Post-weld heat treatment in all other casesable stresses are used, depending on service tem- and for materials other than those mentioned above shouldperature. However, the requirements of 5/ be to the satisfaction of the Administration. The soaking4A.4.10.10.3.1 should be fully complied with. temperature and holding time should be to the satisfaction

.3.6 After completion and assembly, each pressure ves- of the Administration.sel and its related fittings should be subjected to 5/4A.4.11.2 (1 Oct. 1994) In the case of large cargo pres-an adequate tightness test. sure vessels of carbon or carbon-manganese steel for which

.3.7 Pneumatic testing of pressure vessels other than it is difficult to perform the heat treatment, mechanicalcargo tanks should be considered on an individual stress relieving by pressurizing may be carried out as ancase basis by the Administration. Such testing alternative to the heat treatment with the approval of theshould be permitted only for those vessels which Administration and subject to the following conditions:are so designed or supported that they cannot be .1 Complicated welded pressure vessel parts such assafely filled with water, or for those vessels which sumps or domes with nozzles, with adjacent shellcannot be dried and are to be used in a service plates should be heat treated before they are weldedwhere traces of the testing medium cannot be tol- to larger parts of the pressure vessel.erated.

5/4A.4.10.11 All tanks should be subjected to a tightnesstest which may be performed in combination with the

.2 The mechanical stress relieving process should prefer-ably be carried out during the hydrostatic pressure testrequired by paragraph 5/4A.4.10.10.3 by applying a

pressure test referred to in 5/4A.4.10.10 or separately. higher pressure than the test pressure required by 5/5/4A.4.10.12 Requirements with respect to inspection 4A.4.10.10.3.1. The pressurizing medium should be

of secondary barriers should be decided by the Administra- water.tion in each case. .3 For the water temperature paragraph 5/

5/4A.4.10.13 In ships fitted with type B independent 4A.4.10.10.3.2 applies.tanks, at least one tank and its support should be instru- .4 Stress relieving should be performed while the tankmented to confirm stress levels unless the design and ar- is supported by its regular saddles or supporting

structure or, when stress relieving cannot be carriedrangement for the size of ship involved are supported byout on board, in a manner which will give the samefull-scale experience. Similar instrumentation may be re-stresses and stress distribution as when supported byquired by the Administration for type C independent tanksits regular saddles or supporting structure.dependent on their configuration and on the arrangement

.5 The maximum stress relieving pressure should beof their supports and attachments.held for two hours per 25 mm of thickness but in no5/4A.4.10.14 The overall performance of the cargo con-case less than two hours.tainment system should be verified for compliance with

.6 The upper limits placed on the calculated stress levelsthe design parameters during the initial cool-down, loadingduring stress relieving should be the following:and discharging of the cargo. Records of the performance— equivalent general primary membraneof the components and equipment essential to verify the

stress: 0.9·Redesign parameters should be maintained and be available— equivalent stress composed of primary bendingto the Administration. (Also see 5/4A.1S.10)

stress plus membrane stress: 1.35·Re5/4A.4.10.15 Heating arrangements, if fitted in accord- where Re is the specified lower minimum yield stressance with 5/4A.4.8.4, should be tested for required heat or 0.2% proof stress at test temperature of the steeloutput and heat distribution. used for the tank.

5/4A.4.10.16 The hull should be inspected for cold spots .7 Strain measurements will normally be required tofollowing the first loaded voyage. prove these limits for at least the first tank of a series

5/4A.4.10.17 The insulation materials of internal insula- of identical tanks built consecutively.tion tanks should be subjected to additional inspection in The location of strain gauges should be included inorder to verify their surface conditions after the third the mechanical stress relieving procedure to be sub-loaded voyage of the ship, but not later than the first 6 mitted in accordance with 5/4A.4.11.2.14.months of the ship’s service after building or a major repair .8 The test procedure should demonstrate that a linear

relationship between pressure and strain is achievedwork is undertaken on the internal insulation tanks.


at the end of the stress relieving process when the where:pressure is again raised up to the design pressure.

length of the ship for determination ofLo =.9 High stress areas in way of geometrical discontinu-scantlings as defined in Recognized Stan-ities such as nozzles and other openings should bedards (m)checked for cracks by dye penetrant or magnetic par-

CB = block coefficientticle inspection after mechanical stress relieving. Par-B = greatest moulded breadth of the ship (m)ticular attention in this respect should be given tox = longitudinal distance (m) from amidshipsplates exceeding 30 mm in thickness.

to the centre of gravity of the tank with.10 Steels which have a ratio of yield stress to ultimatecontents; x is positive forward of amid-tensile strength greater than 0,8 should generallyships, negative aft of amidshipsnot be mechanically stress relieved.

z = vertical distance (m) from the ship’s actualIf, however, the yield stress is raised by a methodwaterline to the centre of gravity of tankgiving high ductility of the steel, slightly higher ra-with contents; z is positive above and nega-tios may be accepted upon consideration in eachtive below the waterline.case.

.11 Mechanical stress relieving cannot be substitutedfor heat treatment of cold formed parts of tanks if 0.2

V

√Lo

+34 −

600Lo

Loao =the degree of cold forming exceeds the limit above

which heat treatment is required.where: V = service speed (knots).12 The thickness of the shell and heads of the tank

K = 1. in general. For particular loading condi-should not exceed 40 mm. Higher thicknesses maytions and hull forms, determination of Kbe accepted for parts which are thermally stressaccording to the formula below may berelieved.necessary..13 Local buckling should be guarded against particu-

K = 13GM/B, where K ≥ 1.0 and GM = meta-larly when tori-spherical heads are used for tankscentric height (m).and domes.

ax, ay and az = maximum dimensionless accelerations (i.e..14 The procedure for mechanical stress relievingrelative to the acceleration of gravity) inshould be submitted beforehand to the Administra-the respective directions and they are con-tion for approval.sidered as acting separately for calculation5/4A.4S.11.2 (No Text—1 Oct. 1994)purposes, az does not include the compo-5/4A.4S.11.3 (ABS)nent due to the static weight, ay includesSee section 2/3B.17 for post-weld heat treatment require-the component due to the static weight inments in all other cases and for materials other than thosethe transverse direction due to rolling andmentioned above.ax includes the component due to the static5/4A.4.12 Guidance formulae for accelerationweight in the longitudinal direction due tocomponentspitching.The following formulae are given as guidance for the

components of acceleration due to ship’s motionscorresponding to a probability level of 10−8 in the North 5/4A.4.13 Stress categoriesAtlantic and apply to ships with a length exceeding 50 For the purpose of stress evaluation referred to in 5/m. 4A.4.5.1.4, stress categories are defined in this section.

5/4A.4.13.1 Normal stress is the component of stressVertical acceleration as defined in 5/4A.4.3.4.6normal to the plane of reference.

5/4A.4.13.2 Membrane stress is the component of nor-az= 6ao!1 + 15.3 −

45Lo

22

1 x

Lo+ 0.052

2

10.6CB

21-5

mal stress which is uniformly distributed and equal to theaverage value of the stress across the thickness of thesection under consideration.

Transverse acceleration as defined in 5/4A.4.3.4.6 5/4A.4.13.3 Bending stress is the variable stress acrossthe thickness of the section under consideration, after thesubtraction of the membrane stress.

ay= 6ao!0.6 + 2.5 1 x

Lo+ 0.052

2

+ K11 + 0.6 Kz

B 22

5/4A.4.13.4 Shear stress is the component of the stressacting in the plane of reference.

Longitudinal acceleration as defined in 5/4A.4.3.4.65/4A.4.13.5 Primary stress is a stress produced by the

imposed loading and which is necessary to balance theax= 6ao√0.06 + A2 − 0.25 Aexternal forces and moments. The basic characteristic of aprimary stress is that it is not self-limiting. Primary stresseswith:which considerably exceed the yield strength will result

10.7 −Lo

1200+ 5

z

Lo2 10.6

CB2A = in failure or at least in gross deformations.


5/4A.4.13.6 Primary general membrane stress is a pri- tanks from excessive stresses due to thermal movementand from movements of the tank and hull structure. Wheremary membrane stress which is so distributed in the struc-

ture that no redistribution of load occurs as a result of mechanical expansion joints are used in piping they shouldbe held to a minimum and, where located outside cargoyielding.tanks, should be of the bellows type.5/4A.4.13.7 Primary local membrane stress arises where

a membrane stress produced by pressure or other mechani- 5/4A.5.2.1.3 Low-temperature piping should be ther-mally isolated from the adjacent hull structure, where nec-cal loading and associated with a primary or a discontinuity

effect produces excessive distortion in the transfer of loads essary, to prevent the temperature of the hull from fallingbelow the design temperature of the hull material. Wherefor other portions of the structure. Such a stress is classified

as a primary local membrane stress although it has some liquid piping is dismantled regularly, or where liquid leak-age may be anticipated, such as at shore connections andcharacteristics of a secondary stress. A stress region may

be considered as local if: at pump seals, protection for the hull beneath should beprovided.

S1 ≤ 0.5 √Rt 5/4A.5.2.1.4 Where tanks or piping are separated fromand the ship’s structure by thermal isolation, provision should

be made for electrically bonding both the piping and theS2 ≥ 2.5 √Rttanks. All gasketed pipe joints and hose connections should

where: be electrically bonded.S1 = distance in the meridional direction over which the 5/4A.5.2.1.5 Suitable means should be provided to re-

equivalent stress exceeds 1.1f lieve the pressure and remove liquid contents from cargoS2 = distance in the meridional direction to another region loading and discharging crossover headers and cargo hoses

where the limits for primary general membrane stress to the cargo tanks or other suitable location, prior to discon-are exceeded necting the cargo hoses.

R = mean radius of the vessel 5/4A.5.2.1.6 All pipelines or components which may bet = wall thickness of the vessel at the location where the isolated in a liquid full condition should be provided withprimary general membrane stress limit is exceeded relief valves.f = allowable primary general membrane stress.

5/4A.5.2.1.7 Relief valves discharging liquid cargo from5/4A.4.13.8 Secondary stress is a normal stress or shear the cargo piping system should discharge into the cargo

stress developed by constraints of adjacent parts or by tanks; alternatively they may discharge to the cargo ventself-constraint of a structure. The basic characteristic of a mast if means are provided to detect and dispose of anysecondary stress is that it is self-limiting. Local yielding and liquid cargo which may flow into the vent system. Reliefminor distortions can satisfy the conditions which cause the valves on cargo pumps should discharge to the pumpstress to occur. suction.

5/4A.5.2.2 Scantlings based on internal pressure5/4A.5 Process Pressure Vessels and Liquid, Vapour, 5/4A.5.2.2.1 Subject to the conditions stated in 5/

and Pressure Piping Systems 4A.5.2.4, the wall thickness of pipes should not be less than:

5/4A.5.1 General t =to + b + c

1 −a

100

(mm)5/4A.5.1.1 Administrations should take appropriate

steps to ensure uniformity in the implementation and appli-cation of the provisions of this chapter.

where5/4A.5.1.2 The requirements for type C independent

to = theoretical thicknesstanks in 5/4A.4 may also apply to process pressure vessels

to = PD/(20 Ke+P ) (mm)if required by the Administration. If so required the term

with:‘‘pressure vessels’’ as used in 5/4A.4 covers both type Cindependent tanks and process pressure vessels.

P = design pressure (bar) referred to in 5/4A.5.2.3D = outside diameter (mm)

5/4A.5.2 Cargo and process piping K = allowable stress (N/mm2) referred to in 5/4A.5.2.45/4A.5.2.1 General e = efficiency factor equal to 1.0 for seamless pipes and5/4A.5.2.1.1 The requirements of 5/4A.5.2 to 5/4A.5.5 for longitudinally or spirally welded pipes, delivered

apply to product and process piping including vapour pip- by approved manufacturers of welded pipes, whiching and vent lines of safety valves or similar piping. Instru- are considered equivalent to seamless pipes whenment piping not containing cargo is exempt from these non-destructive testing on welds is carried out inrequirements. accordance with Recognized Standards. In other

cases an efficiency factor value depending on the5/4A.5.2.1.2 Provision should be made by the use ofoffsets, loops, bends, mechanical expansion joints such as manufacturing process may be determined by the

Administrationbellows, slip joints and ball joints or similar suitable meansto protect the piping, piping system components and cargo b = allowance for bending (mm). The value of b should


be chosen so that the calculated stress in the bend, The values of A and B should be shown on the InternationalCertificate of Fitness for the Carriage of Liquefied Gasesdue to internal pressure only, does not exceed the

allowable stress. Where such justification is not given, in Bulk as provided for in 5/4A.1.5 and have values of atleast A = 2.7 and B = 1.8.b should be:

5/4A.5.2.4.2 The minimum wall thickness should be inb =

Dto

2.5r(mm) accordance with Recognized Standards.

5/4A.5.2.4.3 Where necessary for mechanical strengthwith: to prevent damage, collapse, excessive sag or buckling

of pipes due to superimposed loads from supports, shipr = mean radius of the bend (mm)deflection or other causes, the wall thickness should bec = corrosion allowance (mm). If corrosion or erosion isincreased over that required by 5/4A.5.2.2, or, if this isexpected, the wall thickness of the piping should beimpracticable or would cause excessive local stresses, theseincreased over that required by other design require-loads should be reduced, protected against or eliminatedments. This allowance should be consistent with theby other design methods.expected life of the piping.

5/4A.5.2.4.4 Flanges, valves and other fittings should bea = negative manufacturing tolerance for thickness (%).to a standard acceptable to the Administration, taking into

5/4A.5.2.3 Design pressure account the design pressure defined in 5/4A.5.2.2. For5/4A.5.2.3.1 The design pressure P in the formula for bellows expansion joints used in vapour service, a lower

to in 5/4A.5.2.2.1 is the maximum gauge pressure to which minimum design pressure may be accepted by the Admin-the system may be subjected in service: istration.

5/4A.5.2.3.2 The greater of the following design condi- 5/4A.5.2.4.5 For flanges not complying with a standard,tions should be used for piping, piping systems and compo- the dimensions of flanges and related bolts should be tonents as appropriate: the satisfaction of the Administration.

.1 for vapour piping systems or components which may 5/4A.5S.2.4.5 (ABS)be separated from their relief valves and which may Design calculations, materials, dimensions and gasket datacontain some liquid: the saturated vapour pressure are to be submitted for non-standard flanges.at 45°C, or higher or lower if agreed upon by the5/4A.5.2.5 Stress analysisAdministration (see 5/4A.4.2.6.2);

When the design temperature is −110°C or lower, a com-.2 for systems or components which may be separatedplete stress analysis, taking into account all the stressesfrom their relief valves and which contain only vapourdue to weight of pipes, including acceleration loads if sig-at all times: the superheated vapour pressure at 45°Cnificant, internal pressure, thermal contraction and loadsor higher or lower if agreed upon by the Administra-induced by hog and sag of the ship for each branch of thetion (see 5/4A.4.2.6.2), assuming an initial conditionpiping system should be submitted to the Administration.of saturated vapour in the system at the system op-For temperatures of above −110°C, a stress analysis mayerating pressure and temperature; orbe required by the Administration in relation to such mat-.3 the MARVS of the cargo tanks and cargo processingters as the design or stiffness of the piping system and thesystems; orchoice of materials. In any case, consideration should be.4 the pressure setting of the associated pump or com-given to thermal stresses, even though calculations are notpressor discharge relief valve; orsubmitted. The analysis may be carried out according to.5 the maximum total discharge or loading head of thea code of practice acceptable to the Administration.cargo piping system; or

5/4A.5.2.6 Materials.6 the relief valve setting on a pipeline system.5/4A.5.2.3.3 The design pressure should not be less than 5/4A.5.2.6.1 The choice and testing of materials used in

10 bar gauge except for open-ended lines where it should piping systems should comply with the requirements of 5/be not less than 5 bar gauge. 4A.6 taking into account the minimum design temperature.

5/4A.5.2.4 Permissible stresses However, some relaxation may be permitted in the qualityof material of open-ended vent piping, provided the tem-5/4A.5.2.4.1 For pipes, the permissible stress to be con-perature of the cargo at the pressure relief valve setting issidered in the formula for t in 5/4A.5.2.2.1 is the lower of−55°C or greater and provided no liquid discharge to thethe following values:vent piping can occur. Similar relaxations may be permittedunder the same temperature conditions to open-ended pip-Rm

Aor

R e

B ing inside cargo tanks, excluding discharge piping and allpiping inside membrane and semi-membrane tanks.where:

5/4A.5.2.6.2 Materials having a melting point belowRm = specified minimum tensile strength at room temper-925°C should not be used for piping outside the cargoature (N/mm2)tanks except for short lengths of pipes attached to the cargoRe = specified minimum yield stress at room temperaturetanks, in which case fire-resisting insulation should be pro-(=\N/mm2). If the stress-strain curve does not show

a defined yield stress, the 0.2% proof stress applies. vided.


5/4A.5.3 Type tests on piping components 5/4A.5.4.2 The following direct connection of pipelengths, without flanges, may be considered:5/4A.5.3.1 Each type of piping component should be

.1 Butt welded joints with complete penetration at thesubject to type tests.root may be used in all applications. For design tem-5/4A.5.3.2.1 Each size and type of valve intended to beperatures below −10°C, butt welds should be eitherused at a working temperature below −55°C should bedouble welded or equivalent to a double welded buttsubjected to a tightness test to the minimum design tem-joint. This may be accomplished by use of a backingperature or lower, and to a pressure not lower than thering, consumable insert or inert gas back-up on thedesign pressure of the valve. During the test the satisfactoryfirst pass. For design pressures in excess of 10 baroperation of the valve should be ascertained.and design temperatures of −10°C or lower, backing5/4A.5.3.2.2 The following type tests should be per-rings should be removed.formed on each type of expansion bellows intended for

.2 Slip-on welded joints with sleeves and related weld-use on cargo piping outside the cargo tank and, whereing, having dimensions satisfactory to the Administra-required, on those expansion bellows installed within thetion, should only be used for open-ended lines withcargo tanks:external diameter of 50 mm or less and design temper-.1 A type element of the bellows, not precompressed,atures not lower than −55°C.should be pressure tested at not less than 5 times the

.3 Screwed couplings acceptable to the Administrationdesign pressure without bursting. The duration of theshould only be used for accessory lines and instru-test should not be less than 5 min.mentation lines with external diameters of 25 mm.2 A pressure test should be performed on a type expan-or less.sion joint complete with all the accessories such as

5/4A.5.4.3.1 Flanges in flange connections should be offlanges, stays and articulations, at twice the designthe welded neck, slip-on or socket welded type.pressure at the extreme displacement conditions rec-

ommended by the manufacturer without permanent 5/4A.5.4.3.2 Flanges should comply with standards ac-deformation. Depending on the materials used, the ceptable to the Administration as to their type, manufactureAdministration may require the test to be at the mini- and test. In particular, for all piping except open ended,mum design temperature. the following restrictions apply:

.3 A cyclic test (thermal movements) should be per- .1 For design temperatures lower than −55°C, onlyformed on a complete expansion joint, which is to welded neck flanges should be used.successfully withstand at least as many cycles, under .2 For design temperatures lower than −10°C, slip-onthe conditions of pressure, temperature, axial move- flanges should not be used in nominal sizes abovement, rotational movement and transverse move- 100 mm and socket welded flanges should not bement, as it will encounter in actual service. Testing used in nominal sizes above 50 mm.at ambient temperature is permitted, when this test- 5/4A.5.4.4 Piping connections, other than those men-ing is at least as severe as testing at the service tem- tioned in 5/4A.5.4.2 and .3, may be accepted by the Admin-perature. istration in each case.

.4 A cyclic fatigue test (ship deformation) should be 5/4A.5.4.5 Bellows and expansion joints should be pro-performed on a complete expansion joint, without vided to allow for expansion of piping.internal pressure, by simulating the bellows move- .1 If necessary, bellows should be protected againstment corresponding to a compensated pipe length, icing.for at least 2,000,000 cycles at a frequency not higher .2 Slip joints should not be used except within thethan 5 cycles/s. This test is only required when, due cargo tanks.to the piping arrangement, ship deformation loads

5/4A.5.4.6 Welding, post-weld heat treatment and non-are actually experienced.destructive testing (1 Oct. 1994).5 The Administration may waive performance of the

.1 Welding should be carried out in accordance with 5/tests referred to in this paragraph provided that com-4A.6.3.plete documentation is supplied to establish the suit-

.2 Post-weld heat treatment should be required for allability of the expansion joints to withstand the ex-butt welds of pipes made with carbon, carbon-manga-pected working conditions. When the maximumnese and low alloy steels. The Administration mayinternal pressure exceeds 1.0 bar gauge this docu-waive the requirement for thermal stress relieving ofmentation is to include sufficient test data to justifypipes having wall thickness less than 10 mm in rela-the design method used, with particular reference totion to the design temperature and pressure of thecorrelation between calculation and test results.piping system concerned.

.3 In addition to normal controls before and during the5/4A.5.4 Piping fabrication and joining details welding and to the visual inspection of the finished

welds, as necessary for proving that the welding has5/4A.5.4.1 The requirements of this section apply tobeen carried out correctly and according to the re-piping inside and outside the cargo tanks. However, thequirements of this paragraph, the following testsAdministration may accept relaxations from these require-

ments for piping inside cargo tanks and open-ended piping. should be required:


.3.1 100% radiographic inspection of butt welded joints controlled but should be capable of local manual oper-for piping systems with design temperatures lower ation and provide full closure. One or more remotelythan −10°C and with inside diameters of more than controlled emergency shutdown valves should be75 mm or wall thicknesses greater than 10 mm. provided on the ship for shutting down liquid andWhen such butt welded joints of piping sections vapour cargo transfer between ship and shore. Suchare made by automatic welding procedures in the valves may be arranged to suit the ship’s design andpipe fabrication shop, upon special approval by the may be the same valve as required in 5/4A.5.6.3 andAdministration, the extent of radiographic inspec- should comply with the requirements of 5/4A.5.6.4.tion may be progressively reduced but in no case .2 For cargo tanks with a MARVS exceeding 0.7 barto less than 10% of each joint. If defects are revealed gauge, all liquid and vapour connections, exceptthe extent of examination should be increased to safety relief valves and liquid level gauging devices,100% and should include inspection of previously should be equipped with a manually operated stopaccepted welds. This special approval can only be valve and a remotely controlled emergency shutdowngranted if well-documented quality assurance pro- valve. These valves should be located as close to thecedures and records are available to enable the tank as practicable. Where the pipe size does notAdministration to assess the ability of the manufac- exceed 50 mm in diameter, excess flow valves mayturer to produce satisfactory welds consistently. be used in lieu of the emergency shutdown valve. A

.3.2 For other butt welded joints of pipes not covered single valve may be substituted for the two separateby 5/4A.5.4.6.3.1, spot radiographic tests or other valves provided the valve complies with the require-non-destructive tests should be carried out at the ments of 5/4A.5.6.4, is capable of local manual opera-discretion of the Administration depending upon tion and provides full closure of the line.service, position and materials. In general, at least .3 Cargo pumps and compressors should be arranged to10% of butt welded joints of pipes should be radio- shutdown automatically if the emergency shutdowngraphed. valves required by 5/4A.5.6.1.1 and .2 are closed by

the emergency shutdown system required by 5/5/4A.5.5 Testing of piping 4A.5.6.4.

5/4A.5.5.1 The requirements of this section apply to 5/4A.5.6.2 Cargo tank connections for gauging or mea-piping inside and outside the cargo tanks. However, the suring devices need not be equipped with excess flow orAdministration may accept relaxations from these require- emergency shutdown valves provided that the devices arements for piping inside cargo tanks and open-ended piping. so constructed that the outward flow of tank contents can-

5/4A.5.5.2 After assembly, all cargo and process piping not exceed that passed by a 1.5 mm diameter circular hole.should be subjected to a hydrostatic test to at least 1.5 5/4A.5S.6.2 Interpretation of 5/4A.5.6.2 (IMO)times the design pressure. When piping systems or parts

The requirements of 5/4A.5.6.2, providing relaxations forof systems are completely manufactured and equipped withcargo tanks referred to in 5/4A.5.6.1.2, should not applyall fittings, the hydrostatic test may be conducted prior toto cargo tank connections for gauging or measuring devicesinstallation aboard ship. Joints welded on board shouldof cargo tanks referred to in 5/4A.5.6.1.1.be hydrostatically tested to at least 1.5 times the design

5/4A.5.6.3 One remotely operated emergency shutdownpressure. Where water cannot be tolerated and the pipingvalve should be provided at each cargo hose connectioncannot be dried prior to putting the system into service,in use. Connections not used in transfer operations mayproposals for alternative testing fluids or testing meansbe blinded with blank flanges in lieu of valves.should be submitted to the Administration for approval.

5/4A.5.5.3 After assembly on board, each cargo and pro- 5/4A.5.6.4 The control system for all required emer-cess piping system should be subjected to a leak test using gency shutdown valves should be so arranged that all suchair, halides, or other suitable medium to a pressure de- valves may be operated by single controls situated in atpending on the leak detection method applied. least two remote locations on the ship. One of these loca-

5/4A.5.5.4 All piping systems including valves, fittings tions should be the control position required by 5/4A.13.1.3and associated equipment for handling cargo or vapours or cargo control room. The control system should alsoshould be tested under normal operating conditions not be provided with fusible elements designed to melt atlater than at the first loading operation. temperatures between 98°C and 104°C which will cause

the emergency shutdown valves to close in the event offire. Locations for such fusible elements should include5/4A.5.6 Cargo system valving requirementsthe tank domes and loading stations. Emergency shutdown5/4A.5.6.1 Every cargo piping system and cargo tankvalves should be of the fail-closed (closed on loss of power)should be provided with the following valves, as applicable:type and be capable of local manual closing operation..1 For cargo tanks with a MARVS not exceeding 0.7Emergency shutdown valves in liquid piping should fullybar gauge, all liquid and vapour connections, exceptclose under all service conditions within 30 s of actuation.safety relief valves and liquid level gauging devices,Information about the closing time of the valves and theirshould have shutoff valves located as close to the

tank as practicable. These valves may be remotely operating characteristics should be available on board and


the closing time should be verifiable and reproducible. 5/4A.6 Materials of ConstructionSuch valves should close smoothly.

5/4A.6.1 General5/4A.5.6.5 Excess flow valves should close automaticallyat the rated closing flow of vapour or liquid as specified 5/4A.6.1.1 Administrations should take appropriateby the manufacturer. The piping including fittings, valves, steps to ensure uniformity in the implementation and appli-and appurtenances protected by an excess flow valve, cation of the provisions of this chapter.should have a greater capacity than the rated closing flow 5/4A.6.1.2 This chapter gives the requirements forof the excess flow valve. Excess flow valves may be de- plates, sections, pipes, forgings, castings and weldmentssigned with a bypass not exceeding an area of 1.0 mm used in the construction of cargo tanks, cargo process pres-diameter circular opening to allow equalization of pressure, sure vessels, cargo and process piping, secondary barriersafter an operating shutdown. and contiguous hull structures associated with the trans-

portation of the products. The requirements for rolled ma-terials, forgings and castings are given in 5/4A.6.2 and

5/4A.5.7 Ship’s cargo hoses tables 5/4A.6.1 to 5/4A.6.5. The requirements for weld-5/4A.5.7.1 Liquid and vapour hoses used for cargo trans- ments are given in 5/4A.6.3.

fer should be compatible with the cargo and suitable for 5/4A.6.1.3 The manufacture, testing, inspection andthe cargo temperature. documentation should be in accordance with Recognized

5/4A.5.7.2 Hoses subject to tank pressure, or the dis- Standards and the specific requirements given in this Code.charge pressure of pumps or vapour compressors, should 5/4A.6S.1.3 Interpretation of 5/4A.6.1.3 (ABS)be designed for a bursting pressure not less than 5 times Testing of plating, rolled sections, pipes process pressurethe maximum pressure the hose will be subjected to during vessels, valves, forgings, castings.cargo transfer.

Test and Test Data5/4A.5.7.3 Each new type of cargo hose, complete withend fittings, should be prototype tested to a pressure not Witness Test The designation (W) indicates that the Sur-less than 5 times its specified maximum working pressure. veyor is to witness the testing unless the plant and productThe hose temperature during this prototype test should is approved under the Bureau’s Quality Assurancebe the intended extreme service temperature. Hoses used Program.for prototype testing should not be used for cargo service.

Manufacturer’s Data The designation (M) indicates thatThereafter, before being placed in service, each new lengthtest data is to be provided by the manufacturer withoutof cargo hose produced should be hydrostatically tested atverification by a Surveyor of the procedures used or theambient temperature to a pressure not less than 1.5 timesresults obtained.its specified maximum working pressure nor more than two

fifths its bursting pressure. The hose should be stencilled or Cargo Tanks (Types A, B and C) & Process Pressureotherwise marked with its specified maximum working Vesselspressure and, if used in other than ambient temperatureservices, its maximum or minimum service temperature or A. Plating Wboth. The specified maximum working pressure should not B. Rolled Sections Wbe less than 10 bar gauge. C. Castings & forgings W

D. Membrane W (Tensiontest

5/4A.5.8 Cargo transfer methods only)5/4A.5.8.1 Where cargo transfer is by means of cargo

Secondary Barriers (Metallic)pumps not accessible for repair with the tanks in service,at least two separate means should be provided to transfer a. Membrane W (Tensioncargo from each cargo tank and the design should be such testthat failure of one cargo pump, or means of transfer, will only)not prevent the cargo transfer by another pump or pumps, b. Plates and Rolled sections Wor other cargo transfer means.

Cargo and vapor piping5/4A.5.8.2 The procedure for transfer of cargo by gaspressurization should preclude lifting of the relief valves A. Design Temperature at or below Wduring such transfer. Gas pressurization may be accepted −18C (OF)as a means of transfer of cargo for those tanks so designed B. Design Temperatures above Mthat the design factor of safety is not reduced under the −18C (OF) and pressure 10.3 barconditions prevailing during the cargo transfer operation. (10.5 kgf/cm2, 150psi) or below

C. Pressure above 10.3 bar (10.5 kgf/ Wcm2, 150psi)5/4A.5.9 Vapour return connections

Connections for vapour return lines to the shore Valves, castings and forgings in cargo Mand vapor piping systemsinstallations should be provided.


5/4A.6.1.4.1 Acceptance tests should include Charpy V- 5/4A.6.1.8 Where post-weld heat treatment is specifiedor required, the properties of the base material should benotch toughness tests unless otherwise specified by the

Administration. The specified Charpy V-notch require- determined in the heat treated condition in accordancewith the applicable table of this chapter and the weldments are minimum average energy values for three full

size (10 mm × 10 mm) specimens and minimum single properties should be determined in the heat treatmentcondition in accordance with 5/4A.6.3. In cases where aenergy values for individual specimens. Dimensions and

tolerances of Charpy V-notch specimens should be in ac- post-weld heat treatment is applied, the test requirementsmay be modified at the discretion of the Administration.cordance with Recognized Standards. The testing and re-

quirements for specimens smaller than 5.0 mm size should 5/4A.6.1.9 Where reference is made in this chapter tobe in accordance with Recognized Standards. Minimum A, B, D, E, AH, DH and EH hull structural steels, theseaverage values for subsized specimens should be: steel grades are hull structural steels according to Recog-

nized Standards.

5/4A.6.2 Material requirementsThe requirements for materials of construction areshown in the tables as follows:

Table 5/4A.6.1: Plates, pipes (seamless and welded),sections and forgings for cargo tanksand process pressure vessels fordesign temperatures not lower than0°C.

Table 5/4A.6.2: Plates, sections and forgings for cargowhere: E = the energy values (J) specified in tables 5/4A.6.1 to 5/4A.6.4.tanks, secondary barriers and processpressure vessels for designtemperatures below 0°C and down toOnly one individual value may be below the specified−55°C.average value provided it is not less than 70% of that value.

Table 5/4A.6.3: Plates, sections and forgings for cargo5/4A.6.1.4.2 In all cases, the largest size Charpy speci-tanks, secondary barriers and processmens possible for the material thickness should be ma-pressure vessels for designchined with the specimens located as near as practicabletemperatures below −55°C and downto a point midway between the surface and the centre ofto −165°C.the thickness and the length of the notch perpendicular

Table 5/4A.6.4: Pipes (seamless and welded), forgingsto the surface (see figure 5/4A.6.1). If the average value ofand castings for cargo and processthe three initial Charpy V-notch specimens fails to meetpiping for design temperatures belowthe stated requirements, or the value for more than one0°C and down to −165°C.specimen is below the required average value, or when

Table 5/4A.6.5: Plates and sections for hull structuresthe value for one specimen is below the minimum valuerequired by 5/4A.4.9.1 and 5/4A.4.9.4.permitted for a single specimen, three additional speci-

5/4A.6S.2 Interpretation of 5/4A.6.1 and 5/4A.6.2 (ABS)mens from the same material may be tested and the results5/4A.6S.2.1 Definitionscombined with those previously obtained to form a new

average. If this new average complies with the require-(a) Piece: the term ‘‘piece’’ is understood to mean thements and if no more than two individual results are lower

rolled product from a single slab, billet or inthan the required average and no more than one result isgot if this is rolled directly into plates, sec-lower than the required value for a single specimen, thetions or bars.piece or batch may be accepted. At the discretion of the

(b) Batch: a number of similar pieces presented as aAdministration other types of toughness tests, such as agroup for acceptance tests.drop weight test, may be used. This may be in addition to

or in lieu of the Charpy V-notch test. 5/4A.6S.2.2 Test Samples5/4A.6.1.5 Tensile strength, yield stress and elongation a) All material in a batch presented for acceptance tests

should be to the satisfaction of the Administration. For is to be of the same product form e.g. plates, flats,carbon-manganese steel and other materials with definitive sections, etc. from the same cast and in the sameyield points, consideration should be given to the limitation condition of supply.of the yield to tensile ratio. b) The test samples are to be fully representative of the

5/4A.6.1.6 The bend test may be omitted as a material material and, where appropriate, are not to be cutacceptance test, but is required for weld tests. from the material until heat treatment has been com-

pleted.5/4A.6.1.7 Materials with alternative chemical composi-tion or mechanical properties may be accepted by the c) The test specimens are not to be separately heat

treated in any way.Administration.


TABLE 5/4A.6.1

d) Unless otherwise agreed the test samples are to be longitudinal axes transverse to the final direction oftaken from the following positions: rolling.

(ii) Flats with a width < 600 mm, bulb flats and other sec-(i) Plates and flats with a width ≥ 600 mm. The testsamples are to be taken from one end at a position tions. The test samples are to be taken from one end at

a position approximately one third from the outer edgeapproximately midway between the axis in the direc-tion of rolling and the edge of the rolled product (see Figures 5/4A.6S.2, .3 and .4) or in the case of small

sections, as near as possible to this position. In the case(see Figure 5/4A.6S.1). Unless otherwise agreed thetension test specimens are to be prepared with their of channels, beams or bulb angles, the test samples may


TABLE 5/4A.6.2

alternatively be taken from a position approximately stainless steels, and may form the basis for acceptancetesting of other material. At the discretion of the Adminis-one quarter of the width from the web centre line or

axis (see Figure 5/4A.6S.3). The tension test specimens tration, impact testing of stainless steel and aluminiumalloy weldments may be omitted and other tests may bemay beprepared with their longitudinal axeseither par-

allel or transverse to the final direction of rolling. specially required for any material.5/4A.6.3.2 Welding consumables(iii) Bars and other similar products. The test samples are

Welding consumables intended for welding of cargo tanksto be taken so that the longitudinal axes of the testshould be in accordance with Recognized Standards unlessspecimens are parallel to the direction of rolling.otherwise agreed with the Administration. Deposited weld

5/4A.6.3 Welding and non-destructive testing metal tests and butt weld tests should be required for allwelding consumables, unless otherwise specially agreed5/4A.6.3.1 General

The requirements of this section are those generally em- with the Administration. The results obtained from tensionand Charpy V-notch impact tests should be in accordanceployed for carbon, carbon-manganese, nickel alloy and


Notes for TABLE 5/4A.6.2

with Recognized Standards. The chemical composition of .1 Cross-weld tension tests..2 Transverse bend tests which may be face, root orthe deposited weld metal should be recorded for informa-

tion and approval. side bends at the discretion of the Administration.However, longitudinal bend tests may be required5/4A.6.3.3 Welding procedure tests for cargo tanks andin lieu of transverse bend tests in cases where theprocess pressure vesselsbase material and weld metal have different strength5/4A.6.3.3.1 Welding procedure tests for cargo tankslevels.and process pressure vessels are required for all butt welds

.3 One set of three Charpy V-notch impacts, generallyand the test assemblies should be representative of:at each of the following locations, as shown in figureeach base material5/4A.6.1:each type of consumable and welding process

each welding position. Centreline of the weldsFor butt welds in plates, the test assemblies should be so Fusion line (F.L.)prepared that the rolling direction is parallel to the direc- 1 mm from the F.L.tion of welding. The range of thickness qualified by each 3 mm from the F.L.welding procedure test should be in accordance with Rec- 5 mm from the F.L.ognized Standards. Radiographic or ultrasonic testing may

.4 Macrosection, microsection and hardness survey maybe performed at the option of the fabricator or the Adminis-also be required by the Administration.tration. Procedure tests for consumables intended for fillet5/4A.6.3.4 Test requirementswelding should be in accordance with Recognized Stan-

dards. In such cases consumables should be selected which 5/4A.6.3.4.1 Tension tests: Generally, tensile strengthexhibit satisfactory impact properties. should not be less than the specified minimum tensile

strength for the appropriate parent materials. The Adminis-5/4A.6.3.3.2 The following welding procedure tests forcargo tanks and process pressure vessels should be made tration may also require that the transverse weld tensile

strength should not be less than the specified minimumfrom each test assembly:


Table 5/4A.6S.2Requirements for Design Temperatures Below 0C (32F)and Down to −55C (−67F) (1995)

Note: Supplementary to Table 5/4A.6.2.

Tension Test

Tensile Strength 400–490 N/mm2 490–620 N/mm2

(41–50 kgf/mm2, 58,000–71,000 psi) (50–63 kgf/mm, 71,000–90,000 psi)

Yield Strength2 Min. 235 N/mm2 (24 kgf/mm2, 34,000 psi)

355 N/mm2

(36 kgf/mm2, 51,000 psi)

Elongation (%) in200 mm (8 in.) or 21 1950 mm (2 in.) or 24 22

22 205.65√A

A = Cross Sectional area of specimen in mm2 or in2

Marking (see 2/1.6.5 and Note 2) AB/V-OXX AB/VH-OXX

Impact Test (Charpy V-notch)Frequency: Plates—See Table 5/4A.6.2 Sections—each 15 tons of each heat

Heat Treatment: See Table 5/4A.6.2 and Note 1 for Table 5/4A.6.S.2.

Notes

1 Control Rolled (for sections only) or Thermo-Mechanical Controlled Process may also be considered as an alternative to normalizingor quenching and tempering.

2 For materials which exhibit a definite yield point exceeding 80% of the tensile strength, a letter ‘‘Y’’ is to be added at the end ofthe marking thus AB/V-OXXY or AB/VH-OXXY.

tensile strength for the weld metal, where the weld metal 5/4A.6.3.5 Welding procedure tests for pipingWelding procedure tests for piping should be carried outhas a lower tensile strength than that of the parent metal.

In every case, the position of fracture is to be reported for and should be similar to those detailed for cargo tanksin 5/4A.6.3.3. Unless otherwise specially agreed with theinformation.Administration, the test requirements should be in accord-

5/4A.6.3.4.2 Bend tests: No fracture is acceptable after ance with 5/4A.6.3.4.a 180° bend over a former of a diameter 4 times the thick- 5/4A.6.3.6 Production weld testsness of the test pieces, unless otherwise specially required

5/4A.6.3.6.1 For all cargo tanks and process pressureby or agreed with the Administration.vessels except integral and membrane tanks, productionweld tests should generally be performed for approximately5/4A.6.3.4.3 Charpy V-notch impact tests: Charpy testseach 50 m of butt weld joints and should be representativeshould be conducted at the temperature prescribed for theof each welding position. For secondary barriers, the samebase material being joined. The results of weld metal im-type production tests as required for primary tanks shouldpact tests, minimum average energy (E), should be nobe performed except that the number of tests may beless than 27 J. The weld metal requirements for subsizereduced subject to agreement with the Administration.specimens and single energy values should be in accord-Tests, other than those specified in 5/4A.6.3.6.2, .3 and .4,ance with 5/4A.6.1.4. The results of fusion line and heatmay be required for cargo tanks or secondary barriers ataffected zone impact tests should show a minimum averagethe discretion of the Administration.energy (E) in accordance with the transverse or longitudi-

nal requirements of the base material, whichever is applica- 5/4A.6.3.6.2 The production tests for types A and Bindependent tanks and semi-membrane tanks should in-ble, and for subsize specimens, the minimum average en-

ergy (E) should be in accordance with 5/4A.6.1.4. If the clude the following tests:.1 Bend tests, and where required for procedure testsmaterial thickness does not permit machining either full-

size or standard subsize specimens, the testing procedure one set of three Charpy V-notch tests should be madefor each 50 m of weld. The Charpy V-notch testsand acceptance standards should be in accordance with

Recognized Standards. should be made with specimens having the notch


TABLE 5/4A.6.3

alternately located in the centre of the weld and in at the temperature at which the Charpy tests wereconducted.the heat affected zone (most critical location based

on procedure qualification results). For austenitic 5/4A.6.3.6.3 In addition to those tests listed in 5/stainless steel, all notches should be in the centre of 4A.6.3.6.2.1 for Type C independent tanks and processthe weld. pressure vessels, transverse weld tension tests are required.

.2 The test requirements are the same as the applicable The test requirements are listed in 5/4A.6.3.4 except thattest requirements listed in 5/4A.6.3.4 except that im- impact tests that do not meet the prescribed energy re-pact tests that do not meet the prescribed energy quirements may still be accepted upon special consider-requirements may still be accepted, upon special con- ation by the Administration, by passing a drop weight test.sideration by the Administration, by passing a drop In such cases, two drop weight specimens should be testedweight test. In such cases, two drop weight specimens for each set of Charpy specimens that failed, and both mustshould be tested for each set of Charpy specimens that show ‘‘no break’’ performance at the temperature at which

the Charpy tests were conducted.failed and both must show ‘‘no break’’ performance


Notes for TABLE 5/4A.6.3

5/4A.6.3.6.4 Production tests for integral and membrane at selected locations. Further, the Administration may re-quire ultrasonic testing in addition to normal radiographictanks should be in accordance with Recognized Standards.inspection.5/4A.6.3.7 Non-destructive testing

5/4A.6.3.7.1 For type A independent tanks and semi- 5/4A.6.3.7.2 Inspection of type C independent tanks andmembrane tanks where the design temperature is −20°C process pressure vessels should be carried out in accord-or less, and for type B independent tanks regardless of ance with 5/4A.4.10.9.temperature, all full penetration butt welds of the shell 5/4A.6.3.7.3 For integral and membrane tanks, specialplating of cargo tanks should be subjected to 100% radio- weld inspection procedures and acceptance criteria shouldgraphic inspection. be in accordance with Recognized Standards.

5/4A.6.3.7.1.1 Where the design temperature is higher5/4A.6.3.7.4 The inspection and non-destructive testingthan −20°C, all full penetration butt welds in way of inter-

of the inner hull or the independent tank structures sup-sections and at least 10% of the remaining full penetrationporting internal insulation tanks should take into accountwelds of tank structures should be subjected to radio-the design criteria given in 5/4A.4.4.7. The schedule forgraphic inspection.inspection and non-destructive testing should be to the

5/4A.6.3.7.1.2 In each case the remaining tank structure satisfaction of the Administration.including the welding of stiffeners and other fittings and 5/4A.6.3.7.5 Inspection of piping should be carried outattachments should be examined by magnetic particle or in accordance with the requirements of 5/4A.5.dye penetrant methods as considered necessary by the 5/4A.6.3.7.6 The secondary barrier should be radio-Administration. graphed as considered necessary by the Administration.

5/4A.6.3.7.1.3 All test procedures and acceptance stan- Where the outer shell of the hull is part of the secondarydards should be in accordance with Recognized Standards. barrier, all sheer strake butts and the intersections of allThe Administration may accept an approved ultrasonic test butts and seams in the side shell should be tested byprocedure in lieu of radiographic inspection, but may in radiography.addition require supplementary inspection by radiography


TABLE 5/4A.6.4


TABLE 5/4A.6.5

5/4A.7 Cargo Pressure/Temperature Control cargo vapours to the atmosphere at sea. This may bealso permitted in port with the permission of the portAdministration.5/4A.7.1 General (Also see Annex B)

5/4A.7.1.1 Unless the entire cargo system is designed 5/4A.7.1.2 The systems required by 5/4A.7.1.1 shouldto withstand the full gauge vapour pressure of the cargo be constructed, fitted and tested to the satisfaction of theunder conditions of the upper ambient design tempera- Administration. Materials used in their construction shouldtures, maintenance of the cargo tank pressure below the be suitable for use with the cargoes to be carried. ForMARVS should be provided by one or more of the following normal service, the upper ambient design temperaturemeans, except as otherwise provided in this section: should be:

.1 a system which regulates the pressure in the cargo sea 32°Ctanks by the use of mechanical refrigeration; air 45°C.

.2 a system whereby the boil-off vapours are utilized as For service in especially hot or cold zones these designfuel for shipboard use or waste heat system subject temperatures should be increased or reduced, as appro-to the provisions of 5/4A.16. This system may be priate, by the Administration.used at all times, including while in port and while 5/4A.7.1.3 For certain highly dangerous cargoes speci-manoeuvring, provided that a means of disposing of fied in 5/4A.17, the cargo containment system should beexcess energy is provided, such as a steam dump capable of withstanding the full vapour pressure of thesystem, that is satisfactory to the Administration; cargo under conditions of the upper ambient design tem-

.3 a system allowing the product to warm up and in- peratures irrespective of any system provided for dealingcrease in pressure. The insulation or cargo tank design with boil-off gas.pressure or both should be adequate to provide fora suitable margin for the operating time and tempera-

5/4A.7.2 Refrigeration systemstures involved. The system should be acceptable tothe Administration in each case; 5/4A.7.2.1 A refrigeration system should consist of one

or more units capable of maintaining the required cargo.4 other systems acceptable to the Administration;.5 in addition to the above means, the Administration pressure/temperature under conditions of the upper ambi-

ent design temperatures. Unless an alternative means ofmay permit certain cargoes to be controlled by venting


FIGURE 5/4A.6.1Orientation of weld test specimen


special consideration should be given to the refrigerationFIGURE 5/4A.6S.1 FIGURE 5/4A.6S.2systems to avoid the possibility of mixing cargoes.

5/4A.7.2.3 Where cooling water is required in refrigera-tion systems, an adequate supply should be provided bya pump or pumps used exclusively for this purpose. Thispump or these pumps should have at least two sea suctionlines, where practicable leading from sea-chests, one portand one starboard. A spare pump of adequate capacityshould be provided, which may be a pump used for otherservices so long as its use for cooling would not interferewith any other essential service.

5/4A.7.2.4 The refrigeration system may be arranged inone of the following ways:

.1 a direct system where evaporated cargo is com-FIGURE 5/4A.6S.3 FIGURE 5/4A.6S.4pressed, condensed and returned to cargo tanks. Forcertain cargoes specified in 5/4A.17 this systemshould not be used;

.2 an indirect system where cargo or evaporated cargois cooled or condensed by refrigerant without beingcompressed;

.3 a combined system where evaporated cargo is com-pressed and condensed in a cargo/refrigerant heatexchanger and returned to the cargo tanks. For cer-tain cargoes specified in 5/4A.17 this system shouldnot be used.

5/4A.7.2.5 All primary and secondary refrigerants mustbe compatible with each other and with the cargo withwhich they come into contact. The heat exchange may takeplace either remotely from the cargo tank or by coolingcoils fitted inside or outside the cargo tank.

5/4A.7S.2 Cargo-refrigeration System (ABS)Where the vessel is equipped with a refrigerating systemfor cooling cargo or with a reliquefaction plant for treatingboil-off gas, the arrangements will be specially considered.controlling the cargo pressure/temperature is provided toIn general such equipment is to comply with the require-the satisfaction of the Administration, a stand-by unit (orments of Section 4/12 and this Section.units) affording spare capacity at least equal to the largest

5/4A.7S.2 Interpretation of 5/4A.7.2 (IACS)required single unit should be provided. A stand-by unitshould consist of a compressor with its driving motor, con- Reliquefaction plant of motor-driven LNG-carrierstrol system and any necessary fittings to permit operationindependently of the normal service units. A stand-by heat 1 Mechanical refrigeration fitted as the primary systemexchanger should be provided unless the normal heat ex- for cargo pressure controlchanger for the unit has an excess capacity of at least 25% 1.1 5/4A.7.2 is based on the assumption that 5/4A.7.1.1 isof the largest required capacity. Separate piping systems being complied with by using means defined in 5/are not required. 4A.7.1.1.1. That is to say, a mechanical refrigeration system

5/4A.7.2.2.1 Where two or more refrigerated cargoes is fitted as the primary means of maintaining the cargowhich may react chemically in a dangerous manner are tank pressure below MARVS.carried simultaneously, special consideration should be 1.2 5/4A.7.2 should apply to refrigeration systems whengiven to the refrigeration systems to avoid the possibility of fitted on LNG carriers, i. e. stand-by capacity will bemixing cargoes. For the carriage of such cargoes, separate required as detailed in 5/4A.7.2.1. A stand-by LNG/refrigeration systems, each complete with a stand-by unit refrigerant heat exchanger need not be provided and theas specified in 5/4A.7.2.1, should be provided for each fitted LNG/refrigerant heat exchanger will not be requiredcargo. However, where cooling is provided by an indirect to have 25% excess capacity over that for normalor combined system and leakage in the heat exchangers requirements1. Other heat exchangers utilizing watercannot cause mixing of the cargoes under any envisaged cooling should have a stand-by or have at least 25 per centcondition, separate refrigeration units need not be fitted. excess capacity.

5/4A.7.2.2.2 Where two or more refrigerated cargoesare not mutually soluble under the conditions of carriage, 1 The reason for this relaxation is that corrosion and fouling problems

are not expected in LNG/refrigerant heat exchangers.so that their vapour pressures would be additive on mixing,


1.3 5/4A.7.2.1 states that unless an alternative means of controlling the arrangement of pressure relief valves on cargo tanks subjectcargo pressure/temperature is provided to the satisfaction of the Adminis- to low ambient temperatures.tration, a stand-by unit (or units) affording spare capacity at least equal 5/4A.8.2.5 Pressure relief valves should be prototypeto the largest required single unit should be fitted. tested to ensure that the valves have the capacity required.For the purpose of complying with the above, a suitable alternative means

Each valve should be tested to ensure that it opens at theof pressure/temperature control would be:prescribed pressure setting with an allowance not ex-1.3.1. Auxiliary boiler(s) capable of burning the boil-off vapours andceeding 6 10% for 0 to 1.5 bar, 6 6% for 1.5 to 3.0 bar,disposing of the generated steam or an alternative waste heat system6 3% for 3.0 bar and above. Pressure relief valves shouldacceptable to the Society. Consideration will be given to systems burn-

ing only part of the boil-off vapour if it can be shown that MARVS be set and sealed by a competent authority acceptable towill not be reached within a period of 21 days. the Administration and a record of this action, including1.3.2 Controlled venting of cargo vapours as specified in 5/4A.7.1.1.5 the values of set pressure should be retained aboard the ship.if permitted by the Administrations concerned. 5/4A.8.2.6 In the case of cargo tanks permitted to have

more than one relief valve setting this may be accom-2 Mechanical refrigeration fitted as the secondary plished by:

system for cargo pressure control .1 installing two or more properly set and sealed valvesWhere a refrigeration plant is fitted as a means of disposing and providing means as necessary for isolating theof excess energy as detailed in the 2nd sentence of 5/ valves not in use from the cargo tank; or4A.7.1.1.2, no stand-by unit will be required for the .2 installing relief valves whose settings may be changedrefrigeration plant. by the insertion of previously approved spacer pieces

or alternative springs or by other similar means notrequiring pressure testing to verify the new set pres-sure. All other valve adjustments should be sealed.5/4A.8 Cargo Tank Vent Systems

5/4A.8.2.7 The changing of the set pressure under theprovisions of 5/4A.8.2.6 should be carried out under the5/4A.8.1 Generalsupervision of the master in accordance with proceduresAll cargo tanks should be provided with a pressure reliefapproved by the Administration and specified in the ship’ssystem appropriate to the design of the cargo containmentoperating manual. Changes in set pressures should be re-system and the cargo being carried. Hold spaces, interbar-corded in the ship’s log and a sign posted in the cargorier spaces and cargo piping which may be subject tocontrol room, if provided, and at each relief valve, statingpressures beyond their design capabilities should also bethe set pressure.provided with a suitable pressure relief system. The pres-

5/4A.8.2.8 Stop valves or other means of blanking offsure relief system should be connected to a vent pipingpipes between tanks and pressure relief valves to facilitatesystem so designed as to minimize the possibility of cargomaintenance should not be fitted unless all the followingvapour accumulating on the decks, or entering accommo-arrangements are provided:dation spaces, service spaces, control stations and machin-

.1 suitable arrangements to prevent more than one pres-ery spaces, or other spaces where it may create a dangeroussure relief valve being out of service at the same time;condition. Pressure control systems specified by 5/4A.7

.2 a device which automatically and in a clearly visibleshould be independent of the pressure relief valves.way indicates which one of the pressure relief valvesis out of service; and

5/4A.8.2 Pressure relief systems .3 pressure relief valve capacities such that if one valve is5/4A.8.2.1 Each cargo tank with a volume exceeding 20 out of service the remaining valves have the combined

m3 should be fitted with at least two pressure relief valves relieving capacity required by 5/4A.8.5. However,of approximately equal capacity, suitably designed and con- this capacity may be provided by the combined capac-structed for the prescribed service. For cargo tanks with ity of all valves, if a suitably maintained spare valvea volume not exceeding 20 m3, a single relief valve may is carried on board.be fitted. 5/4A.8.2.9 Each pressure relief valve installed on a cargo

5/4A.8.2.2 Interbarrier spaces should be provided with tank should be connected to a venting system, which shouldpressure relief devices to the satisfaction of the Adminis- be so constructed that the discharge of gas will be directedtration. upwards and so arranged as to minimize the possibility of

water or snow entering the vent system. The height of vent5/4A.8.2.3 The setting of the pressure relief valvesexits should be not less than B/3 or 6 m whichever isshould not be higher than the vapour pressure which hasgreater, above the weather deck and 6 m above the workingbeen used in the design of the tank.area and the fore and aft gangway.5/4A.8.2.4 Pressure relief valves should be connected

to the highest part of the cargo tank above deck level. 5/4A.8.2.10 Cargo tank pressure relief valve vent exitsshould be arranged at a distance at least equal to B or 25Pressure relief valves on cargo tanks with a design tempera-

ture below 0°C should be arranged to prevent their becom- m, whichever is less, from the nearest air intake or openingto accommodation spaces, service spaces and control sta-ing inoperative due to ice formation when they are closed.

Due consideration should be given to the construction and tions, or other gas-safe spaces. For ships less than 90 m


in length, smaller distances may be permitted by the Ad- TABLE 5/4A.8.1ministration. All other vent exits connected to the cargo Factor mcontainment system should be arranged at a distance ofat least 10 m from the nearest air intake or opening toaccommodation spaces, service spaces and control stations,or other gas-safe spaces.

5/4A.8.2.11 All other cargo vent exits not dealt with inother chapters should be arranged in accordance with 5/4A.8.2.9 and 5/4A.8.2.10.

5/4A.8.2.12 If cargoes which react in a hazardous man-ner with each other are carried simultaneously, a separatepressure relief system should be fitted for each cargocarried.

5/4A.8.2.13 In the vent piping system, means for drain-ing liquid from places where it may accumulate should beprovided. The pressure relief valves and piping shouldbe so arranged that liquid can under no circumstancesaccumulate in or near the pressure relief valves.

5/4A.8.2.14 Suitable protection screens should be fittedon vent outlets to prevent the ingress of foreign objects.

5/4A.8S.2.14 Interpretation of 5/4A.8.2.14 (ABS)Protection screens need not be flame screens.

5/4A.8.2.15 All vent piping should be so designed andarranged that it will not be damaged by temperature varia-tions to which it may be exposed, or by the ship’s motions.

5/4A.8.2.16 The back pressure in the vent lines from Q ′ = FG ′A0.82 (m3/s)the pressure relief valves should be taken into account in

where:determining the flow capacity required by 5/4A.8.5.Q ′ = minimum required rate of discharge of air at stan-5/4A.8.2.17 Pressure relief valves should be positioned

dard conditions of 273 K and 1.013 bar.on the cargo tank so that they will remain in the vapourphase under conditions of 15° list and 0.015 L trim, where

G ′ =12.4

(L + rrm) D !Z .T ′ML is as defined in 5/4A.1.3.23.

with:5/4A.8.3 Additional pressure relieving system for rr = relative density of liquid phase of product at relieving

liquid level control conditions (rr = 1.0 for fresh water);5/4A.8.3.1 Where required by 5/4A.15.1.4.2, an addi- = −di/drr

= gradient of decrease of liquid phase en-tional pressure relieving system to prevent the tank from m thalpy against increase of liquid phase density (kJ/becoming liquid full at any time during relief under the kg) at relieving conditions. For set pressures notfire exposure conditions referred to in 5/4A.8.5 should be higher than 2.0 bar the values in table 5/4A.8.1 mayfitted to each tank. This pressure relieving system should be used. For products not listed in the table andconsist of: for higher set pressures, the value of m should be

.1 one or more relief valves set at a pressure correspond- calculated on the basis of the thermodynamic data ofing to the gauge vapour pressure of the cargo at the the product itself;reference temperature defined in 5/4A.15.1.4.2; and i = enthalpy of liquid (kJ/kg);

.2 an override arrangement, whenever necessary, to T = temperature in kelvins (K) at relieving conditions,prevent its normal operation. This arrangement i.e. at the pressure at which the additional pressureshould include fusible elements designed to melt at relieving system is set;temperatures between 98°C and 104°C and to cause F,A,L,D,Z and M are defined in 5/4A.8.5.2.relief valves specified in 5/4A.8.3.1.1 to become oper-

5/4A.8.3.3 Compliance with 5/4A.8.3.1.1 requiresable. The fusible elements should be located, in par-changing of the setting of the relief valves provided for inticular, in the vicinity of relief valves. The systemthis section. This should be accomplished in accordanceshould become operable upon loss of system powerwith the provisions of 5/4A.8.2.6 and 5/4A.8.2.7.if provided. The override arrangement should not be

dependent on any source of ship’s power. 5/4A.8.3.4 Relief valves mentioned under 5/4A.8.3.1.1Also see 5/4A.15S.1.4.2 above may be the same as the pressure relief valves men-

tioned in 5/4A.8.2, provided the setting pressure and the5/4A.8.3.2 The total relieving capacity of the additionalpressure relieving system at the pressure mentioned in 5/ relieving capacity are in compliance with the requirements

of this section.4A.8.3.1.1 should not be less than:


5/4A.8.3.5 The exhaust of such pressure relief valves Q = FGA0.82 (m3/s)may be led to the venting system referred to in 5/4A.8.2.9. where:If separate venting arrangements are fitted these should Q = minimum required rate of discharge of air at standardbe in accordance with the requirements of 5/4A.8.2.9 to conditions of 273 K and 1.013 bar.5/4A.8.2.15. F = fire exposure factor for different cargo tank types:

F = 1.0 for tanks without insulation located on deck;F = 0.5 for tanks above the deck when insulation is

5/4A.8.4 Vacuum protection systems approved by the Administration. (Approval willbe based on the use of an approved fireproofing5/4A.8.4.1 Cargo tanks designed to withstand a maxi-

mum external pressure differential exceeding 0.25 bar and material, the thermal conductance of insulation,and its stability under fire exposure);capable of withstanding the maximum external pressure

differential which can be attained at maximum discharge F = 0.5 for uninsulated independent tanks installedin holds;rates with no vapour return into the cargo tanks, or by

operation of a cargo refrigeration system, need no vacuum F = 0.2 for insulated independent tanks in holds (oruninsulated independent tanks in insulatedrelief protection.holds);5/4A.8.4.2 Cargo tanks designed to withstand a maxi-

F = 0.1 for insulated independent tanks in inertedmum external pressure differential not exceeding 0.25 barholds (or uninsulated independent tanks in in-or tanks which cannot withstand the maximum externalerted, insulated holds);pressure differential that can be attained at maximum dis-

F = 0.1 for membrane and semi-membrane tanks.charge rates with no vapour return into the cargo tanks,For independent tanks partly protruding through theor by operation of a cargo refrigeration system, or by send-open deck, the fire exposure factor should be deter-ing boil-off vapour to the machinery spaces, should bemined on the basis of the surface areas above andfitted with:below deck..1 two independent pressure switches to sequentially

G = gas factoralarm and subsequently stop all suction of cargo liquidor vapour from the cargo tank, and refrigeration

G =12.4LD !Z .T

Mequipment if fitted, by suitable means at a pressuresufficiently below the maximum external designed

with:pressure differential of the cargo tank; orT = temperature in kelvins (K) at relieving conditions,.2 vacuum relief valves with a gas flow capacity at least

i.e. 120% of the pressure at which the pressure reliefequal to the maximum cargo discharge rate per cargovalve is set;tank, set to open at a pressure sufficiently below

L = latent heat of the material being vaporized at reliev-the external design differential pressure of the cargoing conditions, in kJ/kg;tank; or

D = constant based on relation of specific heats k, shown.3 other vacuum relief systems acceptable to the Admin-in table 5/4A.8.2; if k is not known, D = 0.606 shouldistration.be used. The constant D may also be calculated by5/4A.8.4.3 Subject to the requirements of 5/4A.17, thethe following formula:vacuum relief valves should admit an inert gas, cargo va-

pour or air to the cargo tank and should be arranged tominimize the possibility of the entrance of water or snow.

D = !k1 2k + 12

k + 1k − 1If cargo vapour is admitted, it should be from a source

other than the cargo vapour lines.5/4A.8.4.4 The vacuum protection system should be ca- Z = compressibility factor of the gas at relieving condi-

pable of being tested to ensure that it operates at the tions; if not known, Z= 1.0 should be used.prescribed pressure. M = molecular mass of the product

A = external surface area of the tank (m2) for differenttank types:for body-of-revolution type tanks:5/4A.8.5 Size of valves

Pressure relief valves should have a combined relieving A = external surface area;for other than body-of-revolution type tasks:capacity for each cargo tank to discharge the greater of

the following with not more than a 20% rise in cargo A = external surface area less the projected bottomsurface area;tank pressure above the MARVS:

.1 the maximum capacity of the cargo tank inerting sys- for tanks consisting of an array of pressure vesseltanks:tem if the maximum attainable working pressure of

the cargo tank inerting system exceeds the MARVS − insulation on the ship’s structure:A = external surface of the hold less its projectedof the cargo tanks; or

.2 vapours generated under fire exposure computed us- area;− insulation on the tank structure:ing the following formula:


5/4A.9.1.3 For flammable gases, the system should beTABLE 5/4A.8.2arranged to minimize the possibility of a flammable mixtureConstant Dexisting in the cargo tank during any part of the gas-freeingoperation by utilizing an inerting medium as an intermedi-ate step. In addition, the system should enable the cargotank to be purged with an inerting medium prior to fillingwith cargo vapour or liquid, without permitting a flamma-ble mixture to exist at any time within the cargo tank.

5/4A.9.1.4 Piping systems which may contain cargoshould be capable of being gas-freed and purged as pro-vided in 5/4A.9.1.1 and 5/4A.9.1.3.

5/4A.9.1.5 Inert gas utilized in these procedures maybe provided from the shore or from the ship.

5/4A.9S.1 SOLAS AmendmentsSee 5/4B.9S.1

5/4A.9.2 Environmental control within the hold spaces(cargo containment systems other than type C independenttanks)

5/4A.9.2.1 Interbarrier and hold spaces associated withcargo containment systems for flammable gases requiringfull secondary barriers should be inerted with a suitabledry inert gas and kept inerted with make-up gas providedby a shipboard inert gas generation system, or by shipboardstorage which should be sufficient for normal consumptionfor at least 30 days.A = external surface area of the array of pressure

5/4A.9.2.2.1 Interbarrier and hold spaces associatedvessels excluding insulation, less the projectedwith cargo containment systems for flammable gases re-bottom area as shown in figure 5/4A.8.1.quiring partial secondary barriers should be inerted withsuitable dry inert gas and kept inerted with make-up gas

5/4A.9 Environmental Control provided by a shipboard inert gas generation system or byshipboard storage which should be sufficient for normalconsumption for at least 30 days.

9.1 Environmental control within cargo tanks and 5/4A.9.2.2.2 Alternatively, subject to the restrictionscargo piping systems specified in 5/4A.17, the Administration may allow the

5/4A.9.1.1 A piping system should be provided to enable spaces referred to in 5/4A.9.2.2.1 to be filled with dry aireach cargo tank to be safely gas-freed, and to be safely provided that the ship maintains a stored charge of inertpurged with cargo gas from a gas-free condition. The sys- gas or is fitted with an inert gas generation system sufficienttem should be arranged to minimize the possibility of pock- to inert the largest of these spaces; and provided that theets of gas or air remaining after gas-freeing or purging. configuration of the spaces and the relevant vapour detec-

5/4A.9.1.2 A sufficient number of gas sampling points tion systems, together with the capability of the inertingshould be provided for each cargo tank in order to ade- arrangements, ensure that any leakage from the cargo tanksquately monitor the progress of purging and gas-freeing. will be rapidly detected and inerting effected before aGas sampling connections should be valved and capped dangerous condition can develop. Equipment for the provi-above the main deck. sion of sufficient dry air of suitable quality to satisfy the

expected demand should be provided.5/4A.9.2.3 For non-flammable gases, the spaces referredFIGURE 5/4A.8.1 to in 5/4A.9.2.1 and 5/4A.9.2.2.1 may be maintained with

a suitable dry air or inert atmosphere.5/4A.9.2.4 In case of internal insulation tanks, environ-

mental control arrangements are not required for interbar-rier spaces and spaces between the secondary barrier andthe inner hull or independent tank structures completelyfilled with insulation materials complying with 5/4A.4.9.7.2.

5/4A.9.3 Environmental control of spacessurrounding type C independent tanks

Spaces surrounding refrigerated cargo tanks not havingsecondary barriers should be filled with suitable dry


inert gas or dry air and be maintained in this condition inert gas main in the cargo area as required in 5/4A.9.5.2.Inert gas piping should not pass through accommodationwith make-up inert gas provided by a shipboard inert

gas generation system, shipboard storage of inert gas, or spaces, service spaces or control stations.dry air provided by suitable air drying equipment. 5/4A.9.5.4 Flame burning equipment for generating in-

ert gas should not be located within the cargo area. Specialconsideration may be given to the location of inert gas5/4A.9.4 Inertinggenerating equipment using the catalytic combustion5/4A.9.4.1 Inerting refers to the process of providing aprocess.non-combustible environment by the addition of compati-

5/4A.9S.5.5 (1994) Inert gas generators intended forble gases, which may be carried in storage vessels or pro-automatic operations or operations from a remote controlduced on board the ship or supplied from the shore. Thestation are to comply with 4/11.17. (ABS)inert gases should be compatible chemically and operation-

ally, at all temperatures likely to occur within the spacesto be inerted, with the materials of construction of the 5/4A.10 Electrical Installationsspaces and the cargo. The dew points of the gases shouldbe taken into consideration. 5/4A.10.1 General

5/4A.9.4.2 Where inert gas is also stored for fire-fighting 5/4A.10.1.1 The provisions of this chapter are applicablepurposes, it should be carried in separate containers and to ships carrying flammable products and should be appliedshould not be used for cargo services. in conjunction with part D of chapter II-1 of the 1983

5/4A.9.4.3 Where inert gas is stored at temperatures SOLAS amendments.below 0°C, either as a liquid or as a vapour, the storage 5/4A.10.1.2 Electrical installations should be such as toand supply system should be so designed that the tempera- minimize the risk of fire and explosion from flammableture of the ship’s structure is not reduced below the limiting products. Electrical installations complying with this chap-values imposed on it. ter need not be considered as a source of ignition for the

5/4A.9.4.4 Arrangements suitable for the cargo carried purposes of 5/4A.3.should be provided to prevent the backflow of cargo vapour 5/4A.10.1.3 Administrations should take appropriateinto the inert gas system. steps to ensure uniformity in the implementation and appli-

5/4A.9.4.5 The arrangements should be such that each cation of the provisions of this chapter in respect of electri-space being inerted can be isolated and the necessary cal installations.Tcontrols and relief valves etc. should be provided for con- 5/4A.10.1.4 Electrical equipment or wiring should nottrolling pressure in these spaces. be installed in gas-dangerous spaces or zones unless essen-

tial for operational purposes, when the exceptions listedin 5/4A.10.2 are permitted.5/4A.9.5 Inert gas production on board

5/4A.10.1.5 Where electrical equipment is installed in5/4A.9.5.1 The equipment should be capable of produc-gas-dangerous spaces or zones as provided in 5/4A.10.1.4,ing inert gas with an oxygen content at no time greaterit should be to the satisfaction of the Administration andthan 5% by volume subject to the special requirements ofapproved by the relevant authorities recognized by the5/4A.17. A continuous-reading oxygen content meterAdministration for operation in the flammable atmosphereshould be fitted to the inert gas supply from the equipmentconcerned.and should be fitted with an alarm set at a maximum of

5/4A.10S.1.6 Cable Installation (ABS)5% oxygen content by volume subject to the requirementsA grounded distribution or a hull-return system is not toof 5/4A.17. Additionally, where inert gas is made by an on-be used. Electric conductors are to be run with a view toboard process of fractional distillation of air which involvesavoiding, as far as practicable, gas dangerous spaces andthe storage of the cryogenic liquefied nitrogen for subse-they are not to pass through gas dangerous spaces, exceptquent release, the liquefied gas entering the storage vesselthat certain electrical devices such as echo depth-soundingshould be monitored for traces of oxygen to avoid possibleapparatus, cathodic protection anodes, or safe instrumentsinitial high oxygen enrichment of the gas when releasedwill be specially considered for installation in these spaces;for inerting purposes.complete-details and arrangements are to be submitted.5/4A.9.5.2 An inert gas system should have pressure

5/4A.10S.1.7 Cable Type (ABS)controls and monitoring arrangements appropriate to theAll cables installed within gas dangerous spaces and zonescargo containment system. A means acceptable to the Ad-are to be moisture-resistant jacketed (impervious-ministration, located in the cargo area, of preventing thesheathed) and armored or mineral-insulated metal-backflow of cargo gas should be provided.sheathed and all metallic protective coverings are to be5/4A.9.5.3 Spaces containing inert gas generating plantsgrounded in accordance with 4/5B4.9.should have no direct access to accommodation spaces,

service spaces or control stations, but may be located inmachinery spaces. If such plants are located in machinery T Reference is made to the Recommendations published by the Interna-spaces or other spaces outside the cargo area, two non- tional Electrotechnical Commission and in particular to Publication

92-502.return valves, or equivalent devices should be fitted in the


5/4A.10.2 Types of equipment vided between at least two branch circuits. Allswitches and protective devices should interrupt allCertified safe type equipment may be fitted in gas-

dangerous spaces and zones in accordance with the poles or phases and be located in a gas-safe space; andfollowing provisions: .3 electrical depth sounding or log devices and impres-

5/4A.10.2.1 Gas-dangerous spaces and zones, general sed current cathodic protection system anodes orIntrinsically safe electrical equipment and wiring may be electrodes. These devices should be housed in gas-fitted in all gas-dangerous spaces and zones as defined in tight enclosures;5/4A.1.3.17. and only in spaces described in 5/4A.1.3.17.5:

.4 flameproof motors for valve operation for cargo or5/4A.10.2.2 Cargo containment systemsballast systems; andSubmerged cargo pump motors and their supply cables

.5 flameproof general alarm audible indicators.may be fitted in cargo containment systems, Arrangementsshould be made to automatically shut down the motors in 5/4A.10.2.4 Cargo pump and cargo compressor roomsthe event of low liquid level. This may be accomplished 5/4A.10.2.4.1 Lighting fittings should have pressurizedby sensing low pump discharge pressure, low motor cur- enclosures or should be of the flameproof type. The lightingrent, or low liquid level. This shutdown should be alarmed system should be divided between at least two branchat the cargo control station. Cargo pump motors should be circuits. All switches and protective devices should inter-capable of being isolated from their electrical supply during rupt all poles or phases and be located in a gas-safe space.gas-freeing operations. 5/4A.10.2.4.2 Electric motors for driving cargo pumps

5/4A.10S.2.2.1 Submerged Motor Cargo Pump (ABS) or cargo compressors should be separated from thesea Design Arrangement and details are to be submitted spaces by a gastight bulkhead or deck. Flexible couplings

for approval. or other means of maintaining alignment should be fittedb Motor Operation Motors are to be capable of being to the shafts between the driven equipment and its motors

energized for discharging purposes only when the condi- and, in addition, suitable glands should be provided wheretions c is satisfied by such means as the use of a pressure the shafts pass through the gastight bulkhead or deck. Suchcut-out switch with a manual reset. electric motors and associated equipment should be located

in a compartment complying with 5/4A.12.c Provision for Safe Environment Provisions are to bemade to exclude air from the tanks at all times by main- 5/4A.10.2.4.3 Where operational or structural require-taining a positive head with either cargo vapors or inert ments are such as to make it impossible to comply with thegas when the tanks contain flammable gases in either liquid method described in 5/4A.10.2.4.2, motors of the followingor vapor phase certified safe types may be installed:

.1 increased safety type with flameproof enclosure; and5/4A.10S.2.2.2 Portable Cargo Pumps (ABS) Where

.2 pressurized type.portable cargo pumps are carried on board the vessel, inaddition to the pumps required by 5/4A.5.8.1, for use in 5/4A.10.2.4.4 General alarm audible indicators shouldcargo discharge in an emergency, they are to comply with have flameproof enclosures.the requirements in 5/4A.10S.2.2.1. Also, the pump motors 5/4A.10.2.5 Zones on open decks, spaces other thanshould be capable of being isolated from their electrical hold spacessupply during gas-freeing operations and the arrangements 5/4A.10.2.5.1 In zones on open decks or non-enclosedare to be such as to permit the shutdown of the pump spaces on the open deck, within 3 m of any cargo tankmotors in the event of low liquid level. The electrical outlet, gas or vapour outlet, cargo pipe flange, cargo valvesoutlets are to be in compliance with 5/4A.10S.2.5.1. Cables or entrances and ventilation openings to cargo pump roomsare to comply with 5/4A.10S.1.7. Flexible unarmored ca- and cargo compressor rooms; in zones on the open deckbles of the heavy duty type shown to be suitable for use over the cargo area and 3 m forward and aft of the cargoin a low temperature environment may be specially consid- area on the open deck and up to a height of 2.4 m aboveered upon submission of complete cable construction stan- the deck; in zones within 2.4 m of the outer surface of adards. cargo containment system where such surface is exposed

5/4A.10.2.3 Hold spaces and certain other spaces to the weather the following may be installed:5/4A.10.2.3.1 In hold spaces where cargo is carried in .1 certified safe type equipment; and

a cargo containment system requiring a secondary barrier, .2 through runs of cables.supply cables for submerged cargo pump motors may be 5/4A.10S.2.5.1 Socket-Outlets (IEC 92-502) Certifiedinstalled. safe-type socket-outlets may be considered for supplying

5/4A.10.2.3.2 In hold spaces where cargo is carried in portable cargo pumps which are used in emergency cir-a cargo containment system not requiring a secondary bar- cumstances. In such cases, special additional precautionsrier and in spaces described in 5/4A.1.3.17.5, the following are to be taken such as link connections, or key interlockedmay be installed: change-over switches, to disconnect and earth the cables

.1 through runs of cables; to socket-outlets when they are not in use; also a pilotindicator showing when these cables are energized. Such.2 lighting fittings with pressurized enclosures or of the

flameproof type. The lighting system should be di- socket-outlets are to be supplied through an isolating trans-


former separating the circuit from the main supply. See 1983 SOLAS amendments, except that the required firepump capacity and fire main and water service pipe diame-also 5/4A.10.1.5.ter should not be limited by the provisions of regulations5/4A.10.2.5.2 In enclosed or semi-enclosed spaces in4.2.1 and 4.4.1 when the fire pump and fire main arewhich pipes containing cargoes are located and in compart-used as part of the water spray system as permitted by 5/ments for cargo hoses the following may be installed:4A.11.3.3. In addition, the requirements of regulation 4.4.2.1 lighting fittings with pressurized enclosures, or ofshould be met at a pressure of at least 5.0 bar gauge.the flameproof type. The lighting system should be

divided between at least two branch circuits. All 5/4A.11.2.2 The arrangements should be such that atswitches and protective devices should interrupt all least two jets of water can reach any part of the deck inpoles or phases and be located in a gas-safe space; and the cargo area and those portions of the cargo containment

.2 through runs of cables. system and tank covers above the deck. The necessarynumber of fire hydrants should be located to satisfy the5/4A.10.2.5.3 In enclosed or semi-enclosed spaces hav-above arrangements and to comply with the requirementsing a direct opening into any gas-dangerous space or zoneof regulations II-2/4.5.1 and II-2/4.8 of the 1983 SOLASthere should be installed electrical installations complyingamendments, with hose lengths not exceeding 33 m.with the requirements for the space or zone to which the

opening leads. 5/4A.11.2.3 Stop valves should be fitted in any crossoverprovided and in the fire main or mains at the poop front5/4A.10.2.5.4 Electrical equipment within spaces pro-and at intervals of not more than 40 m between hydrantstected by air-locks should be of the certified safe typeon the deck in the cargo area for the purpose of isolatingunless arranged to be de-energized by measures requireddamaged sections of the main.by 5/4A.3.6.4.

5/4A.11.2.4 All water nozzles provided for fire-fighting5/4A.11 Fire Protection and Fire Extinction use should be of an approved dual-purpose type capable

of producing either a spray or a jet. All pipes, valves nozzles5/4A.11.1 Fire safety requirements and other fittings in the fire-fighting systems should be

resistant to corrosion by seawater, for which purpose galva-5/4A.11.1.1 The requirements for tankers in chapter II-nized pipe, for example, may be used, and to the effect2 of the 1983 SOLAS amendments should apply to shipsof fire.covered by the Code, irrespective of tonnage including

ships of less than 500 tons gross tonnage, except that: 5/4A.11.2.5 Where the ship’s engine-room is unat-.1 regulation 56.6 does not apply; tended, arrangements should be made to start and connect.2 regulation 4 as applicable to cargo ships and regula- to the fire main at least one fire pump by remote control

tion 7 should apply as they would apply to tankers from the navigating bridge or other control station outsideof 2,000 tons gross tonnage and over; the cargo area.

.3 the following regulations of chapter II-2 of the 1983SOLAS amendments related to tankers do not apply 5/4A.11.3 Water spray systemand are replaced by chapters and sections of the Code 5/4A.11.3.1 On ships carrying flammable or toxic prod-as detailed below: ucts or both, a water spray system for cooling, fire preven-

tion and crew protection should be installed to cover:Regulation Replaced by .1 exposed cargo tank domes and any exposed parts of

cargo tanks;17 5/4A.11.6.2 exposed on-deck storage vessels for flammable or56.1 and 56.2 5/4A.3

toxic products;60, 61, 62 5/4A.11.3 and 5/4A.11.4.3 cargo liquid and vapour discharge and loading mani-63 5/4A.11.5

folds and the area of their control valves and any5/4A.11.1.2 All sources of ignition should be excluded other areas where essential control valves are situated

from spaces where flammable vapour may be present ex- and which should be at least equal to the area of thecept as otherwise provided in 5/4A.10 and 5/4A.16. drip trays provided; and

5/4A.11.1.3 The provisions of this section apply in con- .4 boundaries of superstructures and deckhouses nor-junction with 5/4A.3. mally manned, cargo compressor rooms, cargo pump

5/4A.11.1.4 For the purposes of fire fighting, any open rooms, store-rooms containing high fire risk itemsdeck areas above cofferdams, ballast or void spaces at the and cargo control rooms, all facing the cargo area.after end of the aftermost hold space or at the forward end Boundaries of unmanned forecastle structures notof the forwardmost hold space should be included in the containing high fire risk items or equipment do notcargo area. require water spray protection.

5/4A.11.3.2 The system should be capable of covering5/4A.11.2 Fire water main equipment all areas mentioned in 5/4A.11.3.1 with a uniformly distrib-

uted water spray of at least 10 ø/m2 per minute for hori-5/4A.11.2.1 All ships, irrespective of size, carrying prod-ucts which are subject to this Code should comply with zontal projected surfaces and 4 ø/ m2 per minute for vertical

surfaces. For structures having no clearly defined hori-the requirements of regulations II-2/4 and II-2/7 of the


zontal or vertical surfaces, the capacity of the water spray nitrogen, used exclusively for this purpose and stored inpressure vessels adjacent to the powder containers.system should be the greater of the following:

.1 projected horizontal surface multiplied by 10 ø/m2 5/4A.11.4.3 The system for use in the cargo area shouldper minute; or consist of at least two independent self-contained dry

.2 actual surface multiplied by 4 ø/m2 per minute. chemical powder units with associated controls, pressuriz-On vertical surfaces, spacing of nozzles protecting lower ing medium fixed piping, monitors or hand hose lines. Forareas may take account of anticipated rundown from higher ships with a cargo capacity of less than 1,000 m3 onlyareas. Stop valves should be fitted at intervals in the spray one such unit need be fitted, subject to approval by themain for the purpose of isolating damaged sections. Alter- Administration. A monitor should be provided and so ar-natively, the system may be divided into two or more ranged as to protect the cargo loading and discharge mani-sections which may be operated independently provided fold areas and be capable of actuation and discharge locallythe necessary controls are located together, aft of the cargo and remotely. The monitor is not required to be remotelyarea. A section protecting any area included in 5/ aimed if it can deliver the necessary powder to all required4A.11.3.1.1 and .2 should cover the whole of the areas of coverage from a single position. All hand hoseathwartship tank grouping which includes that area. lines and monitors should be capable of actuation at the

hose storage reel or monitor. At least one hand hose line or5/4A.11S.3.2 Interpretation of 5/4A.11.3.2 (ABS)monitor should be situated at the after end of the cargo area.The vertical distances between water spray nozzles for

protection of vertical surfaces is not to exceed 3.7 m (12 ft). 5/4A.11.4.4 A fire-extinguishing unit having two or moremonitors, hand hose lines, or combinations thereof, should5/4A.11.3.3 The capacity of the water spray pumpshave independent pipes with a manifold at the powdershould be sufficient to deliver the required amount of watercontainer, unless a suitable alternative means is providedto all areas simultaneously or where the system is dividedto ensure proper performance as approved by the Adminis-into sections, the arrangements and capacity should betration. Where two or more pipes are attached to a unitsuch as to supply water simultaneously to any one sectionthe arrangement should be such that any or all of theand to the surfaces specified in 5/4A.11.3.1.3 and .4. Alter-monitors and hand hose lines should be capable of simulta-natively, the main fire pumps may be used for this serviceneous or sequential operation at their rated capacities.provided that their total capacity is increased by the

amount needed for the spray system. In either case, a 5/4A.11.4.5 The capacity of a monitor should be not lessconnection, through a stop valve, should be made between than 10 kg/s. Hand hose lines should be non-kinkable andthe fire main and water spray main outside the cargo area. be fitted with a nozzle capable of on/off operation and

discharge at a rate not less than 3.5 kg/s. The maximum5/4A.11.3.4 Subject to the approval of the Administra-discharge rate should be such as to allow operation by onetion, water pumps normally used for other services mayman. The length of a hand hose line should not exceed 33be arranged to supply the water spray main.m. Where fixed piping is provided between the powder5/4A.11.3.5 All pipes, valves, nozzles and other fittingscontainer and a hand hose line or monitor, the length ofin the water spray systems should be resistant to corrosionpiping should not exceed that length which is capable ofby seawater, for which purpose galvanized pipe, for exam-maintaining the powder in a fluidized state during sus-ple, may be used, and to the effect of fire.tained or intermittent use, and which can be purged of5.4A.11.3.6 (1 Oct. 1994) Remote starting of pumps sup-powder when the system is shut down. Hand hose linesplying the water spray system and remote operation of anyand nozzles should be of weather-resistant construction ornormally closed valves in the system should be arrangedstored in weather-resistant housing or covers and be readilyin suitable locations outside the cargo area, adjacent to theaccessible.accommodation spaces and readily accessible and operable

5/4A.11.4.6 A sufficient quantity of dry chemical powderin the event of fire in the areas protected.should be stored in each container to provide a minimum45 seconds discharge time for all monitors and hand hoselines attached to each powder unit. Coverage from fixed5/4A.11.4 Dry chemical powder fire-extinguishingmonitors should be in accordance with the following re-systemsquirements:5/4A.11.4.1 Ships in which the carriage of flammable

products is intended should be fitted with fixed dry chemi- Capacity of fixed monitors (kg/s) each 10 25 45cal powder type extinguishing systems for the purpose of Maximum distance of coverage (m) 10 30 40fighting fire on the deck in the cargo area and bow or sterncargo handling areas if applicable. The system and the dry Hand hose lines should be considered to have a maximumchemical powder should be adequate for this purpose and effective distance of coverage equal to the length of hose.satisfactory to the Administration. Special consideration should be given where areas to be

protected are substantially higher than the monitor or hand5/4A.11.4.2 The system should be capable of deliveringhose reel locations.powder from at least two hand hose lines or combination

monitor/hand hose lines to any part of the above-deck 5/4A.11.4.7 Ships fitted with bow or stern loading anddischarge arrangements should be provided with an addi-exposed cargo area including above-deck product piping.

The system should be activated by an inert gas such as tional dry chemical powder unit complete with at least


one monitor and one hand hose line complying with the 5/4A.11.6.2 Additional requirements for safety equip-ment are given in 5/4A.14.requirements of 5/4A.11.4.1 to 5/4A.11.4.6. This additional

unit should be located to protect the bow or stern loading 5/4A.11.6.3 Any breathing apparatus required as part ofand discharge arrangements. The area of the cargo line a fireman’s outfit should be a self-contained air-breathingforward or aft of the cargo area should be protected by apparatus having a capacity of at least 1,200 ø of free air.hand hose lines.

5/4A.12 Mechanical Ventilation in the Cargo Area5/4A.11.5 Cargo compressor and pump rooms (1 Oct.1994)

The requirements of this subsection 5/4A.12 should be5/4A.11.5.1 The cargo compressor and pump rooms ofsubstituted for regulation II-2/ 59.3 of the 1983any ship should be provided with a carbon dioxide systemSOLAS amendments.as specified in regulation II-2/5.1 and .2 of the 1974 SOLAS5/4A.12.1 Spaces required to be entered duringConvention, as amended. A notice should be exhibited at

normal cargo handling operationsthe controls stating that the system is only to be used forfire-extinguishing and not for inerting purposes, due to 5/4A.12.1.1 Electric motor rooms, cargo compressorthe electrostatic ignition hazard. The alarms referred to and pump rooms, other enclosed spaces which containin regulation II-2/5.1.6 of the 1983 SOLAS amendments cargo handling equipment and similar spaces in whichshould be safe for use in a flammable cargo vapour-air cargo handling operations are performed should be fittedmixture. For the purpose of this requirement, an extin- with mechanical ventilation systems capable of being con-guishing system should be provided which would be suit- trolled from outside such spaces. Provision should be madeable for machinery spaces. However, the amount of carbon to ventilate such spaces prior to entering the compartmentdioxide gas carried should be sufficient to provide a quan- and operating the equipment and a warning notice requiringtity of free gas equal to 45% of the gross volume of the the use of such ventilation should be placed outside thecargo compressor and pump-rooms in all cases. compartment.

5/4A.11S.5.1 Interpretation of 5/4A.11.5.1 (IACS) 5/4A.12.1.2 Mechanical ventilation inlets and outletsSince the presence of flames in a room make ineffective should be arranged to ensure sufficient air movementelectrostatic charges, possibly caused by the discharge of through the space to avoid the accumulation of flammablecarbon dioxide, the above sentence may be interpreted in or toxic vapours and to ensure a safe working environment,the sense that fixed carbon dioxide systems are allowed to but in no case should the ventilation system have a capacitybe used for smothering fires in gas dangerous enclosed of less than 30 changes of air per hour based upon thespaces provided that: total volume of the space. As an exception, gas-safe cargo

control rooms may have eight changes of air per hour.a alarms for the release of carbon dioxide into such5/4A.12.1.3 Ventilation systems should be fixed and, ifspaces are to be of the pneumatic type or electric type.

of the negative pressure type, permit extraction from either1 Pneumatically operated alarms the upper or the lower parts of the spaces, or from both

In cases where the periodic testing of such alarms is re- the upper and the lower parts, depending on the densityquired, CO2 operated alarms should not be used owing to of the vapours of the products carried.the possibility of the generation of static electricity in the 5/4A.12.1.4 In rooms housing electric motors drivingCO2 cloud. Air operated alarms may be used provided the cargo compressors or pumps, spaces except machineryair supply is clean and dry. spaces containing inert gas generators, cargo control rooms

2 Electrically operated alarms if considered as gas-safe spaces and other gas-safe spacesWhen electrically operated alarms are used, the arrange- within the cargo area, the ventilation should be of thements are to be such that the electric actuating mechanism positive pressure type.is located outside the space except where the alarms are

5/4A.12.1.5 In cargo compressor and pump rooms andcertified intrinsically safe.in cargo control rooms if considered gas-dangerous, the5/4A.11.5.2 Cargo compressor and pump rooms of ships ventilation should be of the negative pressure type.which are dedicated to the carriage of a restricted number

5/4A.12.1.6 Ventilation exhaust ducts from gas-danger-of cargoes should be protected by an appropriate fire-ous spaces should discharge upwards in locations at leastextinguishing system approved by the Administration.10 m in the horizontal direction from ventilation intakesand openings to accommodation spaces, service spaces and5/4A.11.6 Firemen’s outfitscontrol stations and other gas-safe spaces.5/4A.11.6.1 (1 Oct. 1994) Every ship carrying flamma-

5/4A.12.1.7 Ventilation intakes should be so arranged asble products should carry firemen’s outfits complying withto minimize the possibility of re-cycling hazardous vapoursthe requirements of regulation II-2/ 17 of the 1983 SOLASfrom any ventilation discharge opening.amendments as follows:

5/4A.12.1.8 Ventilation ducts from gas-dangerousTotal cargo capacity Number of outfits spaces should not be led through accommodation, service

and machinery spaces or control stations, except as allowed5,000 m3 and below 4above 5,000 m3 5 in 5/4A.16.


5/4A.12.1.9 Electric motors driving fans should be iv any combination of ferrous (including austeniticplaced outside the ventilation ducts if the carriage of flam- stainless steel) impellers and housings with not

less than 13mm tip design clearance.mable products is intended. Ventilation fans should notproduce a source of vapour ignition in either the ventilated d The following impellers and housings are consid-

ered as sparking and are not permitted:space or the ventilation system associated with the space.Ventilation fans and fan ducts, in way of fans only, for gas- i impellers of an aluminum alloy or a magnesiumdangerous spaces should be of nonsparking construction alloy and a ferrous housing, regardless of tip

clearance;defined as:.1 impellers or housing of nonmetallic construction, due ii housing made of aluminum alloy or a magnesium

alloy and a ferrous impeller, regardless of tipregard being paid to the elimination of static elec-tricity; clearance;

iii any combination of ferrous impeller and housing.2 impellers and housing of nonferrous materials;.3 impellers and housing of austenitic stainless steel; and with less than 13mm design tip clearance..4 ferrous impellers and housing with not less than 13

4 Type Testmm design tip clearance.Type tests on the finished product are to be carried outAny combination of an aluminium or magnesium alloy fixedusing an acceptable national or international standard.or rotating component and a ferrous fixed or rotating com-The tests need not to be witnessed by the Surveyor forponent, regardless of tip clearance, is considered a sparkingindividual fans produced on a production line basis,hazard and should not be used in these places.provided the Surveyor is satisfied from periodic in-spections and the manufacturer’s quality assuranceprocedures that the fans are being satisfactorily tested

5/4A.12S.1.9 Interpretation of 5/4A.12.1.9 (IACS/ABS) to appropriate standards. See also 4/1.2.(1993) 5/4A.12.1.10 Spare parts should be carried for each type

1 General of fan on board referred to in the paragraph.A fan is considered as nonsparking if in both normal 5/4A.12.1.11 Protection screens of not more than 13and abnormal conditions it is unlikely to produce mm square mesh should be fitted in outside openings ofsparks. ventilation ducts.

2 Design Criteria (1993)a The air gap between the impeller and the casing

5/4A.12S.1.11 Interpretation of 5/4A.12.1.11 (ABS)shall be not less than 10% of the impeller shaft(1993)diameter in way of the bearing but not less than

5/4A.12.1.11 applies to ventilation systems for which non-2mm. It need not be more than 13mm.sparking fans/ducts are not required by 5/4A.12.1.9. Forb Protection screens of not more than 13mm squareother systems, see 5/4A.12S.1.9 sub item 2b.mesh are to be fitted in the inlet and outlet of

ventilation ducts to prevent the entrance of objects5/4A.12.2 Spaces not normally enteredinto the fan housing.Hold spaces, interbarrier spaces, void spaces, cofferdams,

3 Materials spaces containing cargo piping and other spaces wherea Except as indicated in c below, the impeller and cargo vapours may accumulate, should be capable of being

the housing in way of the impeller are to be made ventilated to ensure a safe environment when entry intoof alloys which are recognized as being spark proof the spaces is necessary. Where a permanent ventilationby appropriate test. system is not provided for such spaces, approved means

b Electrostatic charges both in the rotating body and of portable mechanical ventilation should be provided.the casing are to be prevented by the use of anti- Where necessary owing to the arrangement of spaces, suchstatic materials. Furthermore, the installation on as hold spaces and interbarrier spaces, essential ductingboard of the ventilation units is to be such as to for such ventilation should be permanently installed. Fansensure the safe bonding to the hull of the units or blowers should be clear of personnel access openings,themselves. and should comply with 5/4A.12.1.9.

c Tests referred to in 3a above are not required forfans having the following combinations: 5/4A.12S.2 Interpretation of 5/4A.12.2 (IACS)

i impellers and/or housings of nonmetallic mate-Sizing pressure relief systems for interbarrier spacesrial, due regard being paid to the elimination of

static electricity;ii impellers and housings of non-ferrous materials;

iii impellers of aluminum alloys or magnesium 1. General1.1 The formula for determining the relieving capacityalloys and a ferrous (including austenitic stain-

less steel) housing on which a ring of suitable given in 2 is developed for interbarrier spaces sur-rounding independent type A cargo tanks, where thethickness of non-ferrous materials is fitted in way

of the impeller; thermal insulation is fitted to the cargo tanks.


1.2 The relieving capacity of pressure relief devices of 5/4A.13 Instrumentation (Gauging, Gas Detection andCargo Handling Controls)interbarrier spaces surrounding independent type B

cargo tanks may be determined on the basis of themethod given in 2, however, the leakage rate is to bedetermined in accordance with 5/4A.4.7.6.1. 5/4A.13.1 General

1.3 The relieving capacity of pressure relief devices for 5/4A.13.1.1 Each cargo tank should be provided withinterbarrier spaces of membrane and semi-membrane means for indicating level, pressure and temperature of thetanks is to be evaluated on the basis of the specific cargo. Pressure gauges and temperature indicating devicesmembrane/semi-membrane tank design. should be installed in the liquid and vapour piping systems,

1.4 The relieving capacity of pressure relief devices for in cargo refrigerating installations and in the inert gasinterbarrier spaces adjacent to integral type cargo tanks systems as detailed in this chapter.may, if applicable, be determined as for type A inde- 5/4A.13.1.2 Where a secondary barrier is required, per-pendent cargo tanks. manently installed instrumentation should be provided to

1.5 Interbarrier space pressure relief devices in the scope detect when the primary barrier fails to be liquid-tight atof this interpretation are emergency devices for pro- any location or when liquid cargo is in contact with thetecting the hull structure from being unduly overs- secondary barrier at any location. This instrumentationtressed in case of a pressure rise in the interbarrier should consist of appropriate gas detecting devices ac-space due to primary barrier failure. Therefore such cording to 5/4A.13.6. However, the instrumentation needdevices need not to comply with the requirements of not be capable of locating the area where liquid cargo leaks5/4A.8.2.9 and 5/4A.8.2.10. through the primary barrier of where liquid cargo is in

contact with the secondary barrier.5/4A.13.1.3 If the loading and unloading of the ship is

performed by means of remotely controlled valves and2. Size of pressure relief devicespumps, all controls and indicators associated with a givenThe combined relieving capacity of the pressure reliefcargo tank should be concentrated in one control position.devices for interbarrier spaces surrounding type A

independent cargo tanks where the insulation is fitted tothe cargo tanks may be determined by the following 5/4A.13S.1.3 Remote Cargo Handling Controlformula: Systems (ABS) (1994)

Remote cargo handling control systems are to comply with4/11.27.Qsa = 3,4 · Ac

rrv

√h (m3/s )5/4A.13.1.4 Instruments should be tested to ensure reli-

ability in the working conditions and recalibrated at regularwhere:intervals. Test procedures for instruments and the intervalsQsa = minimum required discharge rate of air at stan-between recalibration should be approved by the Adminis-dard conditions of 273 K and 1.013 bartration.Ac = design crack opening area (m2)

Ac = p

4d · 1 (m2) 5/4A.13.2 Level indicators for cargo tanks

5/4A.13.2.1 Each cargo tank should be fitted with atd = max, crack opening width (m)least one liquid level gauging device, designed to operated = 0,2 · t (m)at pressures not less than the MARVS of the cargo tank andt = thickness of tank bottom plating (m)at temperatures within the cargo operating temperaturel = design crack length (m) equal to the diagonalrange. Where only one liquid level gauge is fitted it shouldof the largest plate panel of the tank bottom,be so arranged that any necessary maintenance can besee sketch.carried out while the cargo tank is in service.h = max. liquid height above tank bottom plus 10

· MARVS (m) 5/4A.13S.2.1 Interpretation of 5/4A.13.2.1 (IACS)r = density of product liquid phase (kg/m3) at the In order to assess whether or not only one level gauge

is acceptable in relation to the aforesaid sentence, ‘anyset pressure of the interbarrier space reliefdevice maintenance’ means that ‘any part’ of the level gauge can

be overhauled while the cargo tank is in service.rv = density of product vapour phase (kg/m3) at theset pressure of the interbarrier space relief de- 5/4A.13.2.2 Cargo tank liquid level gauges may be ofvice and a temperature of 273 K. the following types subject to any special requirement for

MARVS = max. allowable relief valve setting of the cargo particular cargoes shown in column ‘‘g’’ in the table of 5/tank (bar) 4A.19:

.1 indirect devices, which determine the amount ofcargo by means such as weighing or pipe flow meters;5/4A.12S.3 Interpretation of 5/4A.12.2 (ABS)

The ventilation system for spaces not normally entered .2 closed devices, which do not penetrate the cargoshall have a capacity of not less than 8 changes per hour tank, such as devices using radioisotopes or ultrasonic

devices;based on the total volume of the space.


.3 closed devices, which penetrate the cargo tank, but level alarm should automatically actuate a shutoff valve ina manner which will both avoid excessive liquid pressurewhich form part of a closed system and keep the

cargo from being released, such as float type systems, in the loading line and prevent the tank from becomingliquid full. The emergency shutdown valve referred to inelectronic probes, magnetic probes and bubble tube

indicators. If a closed gauging device is not mounted 5/4A.5.6.4 may be used for this purpose. If another valveis used for this purpose, the same information as referred todirectly on the tank it should be provided with a

shutoff valve located as close as possible to the in 5/4A.5.6.4 should be available on board. During loading,whenever the use of these valves may possibly create atank; andpotential excess pressure surge in the loading system, the.4 restricted devices, which penetrate the tank andAdministration and the port Administration may agree towhen in use permit a small quantity of cargo vapouralternative arrangements such as limiting the loadingor liquid to escape to the atmosphere, such as fixedrate, etc.tube and slip tube gauges. When not in use, the

devices should be kept completely closed. The design 5/4A.13S.3.1 Interpretation of 5/4A.13.3.1 (IMO)and installation should ensure that no dangerous es- The sensor for automatic closing of the loading valve for

overflow control as required in 5/4A.13.3.1 may be com-cape of cargo can take place when opening the device.Such gauging devices should be so designed that the bined with the liquid level indicators required by 5/

4A.13.2.1.maximum opening does not exceed 1.5 mm diameteror equivalent area unless the device is provided with 5/4A.13.3.2 A high liquid level alarm and automatican excess flow valve. shutoff of cargo tank filling need not be required when

the cargo tank:5/4A.13.2.3 Sighting ports with a suitable protectivecover and situated above the liquid level with an internal .1 is a pressure tank with a volume not more than 200

m3; orscale may be allowed by the Administration as a secondarymeans of gauging for cargo tanks having a design vapour .2 is designed to withstand the maximum possible pres-

sure during the loading operation and such pressurepressure not higher than 0.7 bar.is below that of the start-to-discharge pressure of the5/4A.13.2.4 Tubular gauge glasses should not be fitted.cargo tank relief valve.Gauge glasses of the robust type as fitted on high-pressure

boilers and fitted with excess flow valves may be allowed 5/4A.13.3.3 Electrical circuits, if any, of level alarmsshould be capable of being tested prior to loading.by the Administration for deck tanks, subject to any provi-

sions of 5/4A.17.5/4A.13.4 Pressure gauges

5/4A.13.3 Overflow control 5/4A.13.4.1 The vapour space of each cargo tank shouldbe provided with a pressure gauge which should incorpo-5/4A.13.3.1 Except as provided in 5/4A.13.3.2, each

cargo tank should be fitted with a high liquid level alarm rate an indicator in the control position required by 5/4A.13.1.3. In addition, a high-pressure alarm and, if vac-operating independently of other liquid level indicators

and giving an audible and visual warning when activated. uum protection is required, a low-pressure alarm, shouldbe provided on the navigating bridge. Maximum and mini-Another sensor operating independently of the high liquid


mum allowable pressures should be marked on the indica- be carried and the dilution resulting from compartmentpurging or ventilation.tors. The alarms should be activated before the set pres-

sures are reached. For cargo tanks fitted with pressure 5/4A.13.6.3 Pipe runs from sampling heads should notrelief valves, which can be set at more than one set pressure be led through gas-safe spaces except as permitted by 5/in accordance with 5/4A.8.2.6, high-pressure alarms should 4A.13.6.5.be provided for each set pressure. 5/4A.13.6.4 Audible and visual alarms from the gas de-

5/4A.13.4.2 Each cargo pump discharge line and each tection equipment, if required by this section, should beliquid and vapour cargo manifold should be provided with located on the navigating bridge, in the control positionat least one pressure gauge. required by 5/4A.13.1.3, and at the gas detector readout

5/4A.13.4.3 Local-reading manifold pressure gauges location.should be provided to indicate the pressure between stop 5/4A.13.6.5 Gas detection equipment may be locatedvalves and hose connections to the shore. in the control position required by 5/4A.13.1.3, on the

5/4A.13.4.4 Hold spaces and interbarrier spaces without navigating bridge or at other suitable locations. When suchopen connection to the atmosphere should be provided equipment is located in a gas-safe space the followingwith pressure gauges. conditions should be met:

.1 gas-sampling lines should have shutoff valves or anequivalent arrangement to prevent cross-communica-5/4A.13.5 Temperature indicating devicestion with gas-dangerous spaces; and5/4A.13.5.1 Each cargo tank should be provided with

.2 exhaust gas from the detector should be dischargedat least two devices for indicating cargo temperatures, oneto the atmosphere in a safe location.placed at the bottom of the cargo tank and the second near

the top of the tank, below the highest allowable liquid level. 5/4A.13.6.6 Gas detection equipment should be so de-The temperature indicating devices should be marked to signed that it may readily be tested. Testing and calibrationshow the lowest temperature for which the cargo tank has should be carried out at regular intervals. Suitable equip-been approved by the Administration. ment and span gas for this purpose should be carried on

board. Where practicable, permanent connections for such5/4A.13.5.2 When a cargo is carried in a cargo contain-equipment should be fitted.ment system with a secondary barrier at a temperature

lower than −55°C, temperature indicating devices should 5/4A.13.6.7 A permanently installed system of gas de-be provided within the insulation or on the hull structure tection and audible and visual alarms should be pro-adjacent to cargo containment systems. The devices should vided for:give readings at regular intervals and, where applicable, .1 cargo pump rooms;audible warning of temperatures approaching the lowest .2 cargo compressor rooms;for which the hull steel is suitable. .3 motor rooms for cargo handling machinery;

.4 cargo control rooms unless designated as gas-safe;5/4A.13.5.3 If cargo is to be carried at temperatures

.5 other enclosed spaces in the cargo area where vapourlower than −55°C, the cargo tank boundaries, if appro-may accumulate including hold spaces and interbar-priate for the design of the cargo containment system,rier spaces for independent tanks other than type C;should be fitted with temperature indicating devices as

.6 ventilation hoods and gas ducts where required byfollows:5/4A.16; and.1 A sufficient number of devices to establish that an

.7 air-locks.unsatisfactory temperature gradient does not occur..2 On one tank a number of devices in excess of those 5/4A.13.6.8 The gas detection equipment should be ca-

required in 5/4A.13.5.3.1 in order to verify that the pable of sampling and analysing from each sampling headinitial cool down procedure is satisfactory. These de- location sequentially at intervals not exceeding 30 min,vices may be either temporary or permanent. When except that in the case of gas detection for the ventilationa series of similar ships is built, the second and succes- hoods and gas ducts referred to in 5/4A.13.6.7.6 samplingsive ships need not comply with the requirements of should be continuous. Common sampling lines to the de-this subparagraph. tection equipment should not be fitted.

5/4A.13.5.4 The number and position of temperature 5/4A.13.6.9 In the case of products which are toxic orindicating devices should be to the satisfaction of the Ad- both toxic and flammable, the Administration, except whenministration. column ‘‘h’’ in the table of 5/4A.19 refers to 5/4A.17.9, may

authorize the use of portable equipment for detection of5/4A.13.6 Gas detection requirements toxic products as an alternative to a permanently installed

system, if such equipment is used before personnel enter5/4A.13.6.1 Gas detection equipment acceptable to thethe spaces listed in 5/4A.13.6.7 and at 30 min intervalsAdministration and suitable for the gases to be carriedwhile they remain therein.should be provided in accordance with column ‘‘f’’ in the

table of 5/4A.19. 5/4A.13.6.10 For the spaces listed in 5/4A.13.6.7, alarmsshould be activated for flammable products when the va-5/4A.13.6.2 In every installation, the positions of fixed

sampling heads should be determined with due regard to pour concentration reaches 30% of the lower flammabil-ity limit.the density of the vapours of the products intended to


5/4A.13.6.11 (1 Oct. 1994) In the case of flammable a charging manifold capable of dealing with sufficientspare breathing apparatus air bottles for the breathingproducts, where cargo containment systems other than

independent tanks are used, hold spaces and interbarrier apparatus required by 5/4A.14.2.1; or.2 fully charged spare air bottles with a total free airspaces should be provided with a permanently installed

gas detection system capable of measuring gas concentra- capacity of at least 6,000l for each breathing apparatusrequired by 5/4A.14.2.1.tions of 0 to 100% by volume. The detection equipment,

equipped with audible and visual alarms, should be capable 5/4A.14.2.4 Alternatively, the Administration may ac-of monitoring from each sampling head location sequen- cept a low-pressure air line system with hose connectiontially at intervals not exceeding 30 min. Alarms should suitable for use with the breathing apparatus required bybe activated when the vapour concentration reaches the 5/4A.14.2.1. This system should provide sufficient high-equivalent of 30% of the lower flammability limit in air or pressure air capacity to supply, through pressure reductionsuch other limit as may be approved by the Administration devices, enough low-pressure air to enable two men toin the light of particular cargo containment arrangements. work in a gas-dangerous space for at least 1 hour withoutCommon sampling lines to the detection equipment should using the air bottles of the breathing apparatus. Meansnot be fitted. should be provided for recharging the fixed air bottles

5/4A.13.6.12 In the case of toxic gases, hold spaces and and the breathing apparatus air bottles from a special airinterbarrier spaces should be provided with a permanently compressor suitable for the supply of high-pressure air ofinstalled piping system for obtaining gas samples from the required purity.the spaces. Gas from these spaces should be sampled and 5/4A.14.2.5 Protective equipment required in 5/4A.14.1analysed from each sampling head location by means of and safety equipment required in 5/4A.14.2.1 should befixed or portable equipment at intervals not exceeding 4 kept in suitable, clearly marked lockers located in readilyhours and in any event before personnel enter the space accessible places.and at 30 min intervals while they remain therein. 5/4A.14.2.6 The compressed air equipment should be in-

5/4A.13.6.13 Every ship should be provided with at least spected at least once a month by a responsible officer andtwo sets of portable gas detection equipment acceptable the inspection recorded in the ship’s log-book, and inspectedto the Administration and suitable for the products to be and tested by an expert at least once a year.carried.

5/4A.13.6.14 A suitable instrument for the measurement 5/4A.14.3 First-aid equipment (1 Oct. 1994)of oxygen levels in inert atmospheres should be provided. 5/4A.14.3.1 A stretcher which is suitable for hoisting an

injured person from spaces below deck should be kept in5/4A.14 Personnel Protection

a readily accessible location.

5/4A.14.3.2T Medical first-aid equipment including oxy-5/4A.14.1 Protective equipment gen resuscitation equipment and antidotes, if available, forSuitable protective equipment including eye protection products carried should be provided on board.should be provided for protection of crew members en- TReference is made to the Medical First Aid Guide for Use in Accidentsgaged in loading and discharging operations, taking into involving Dangerous Goods (MFAG) which includes the MFAG numbersaccount the character of the products. of products covered by the Code and the emergency procedures to be

applied in the event of an incident. MFAG numbers related to productscovered by the IGC Code are given in the table of minimum requirements5/4A.14.2 Safety equipmentin 5/4A.19.5/4A.14.2.1 Sufficient, but not less than two complete

sets of safety equipment in addition to the firemen’s outfits5/4A.14.4 Personnel protection requirements forrequired by 5/4A.11.6.1 each permitting personnel to enter

individual productsand work in a gas-filled space, should be provided.5/4A.14.4.1 Provisions of 5/4A.14.4 are applicable to5/4A.14.2.2 One complete set of safety equipment

ships carrying products for which those paragraphs areshould consist of:listed in column ‘‘h’’ in the table of 5/4A.19..1 one self-contained air-breathing apparatus not using

stored oxygen, having a capacity of at least 1,200ø of 5/4A.14.4.2 (1 Oct. 1994) Respiratory and eye protectionfree air; suitable for emergency escape purposes should be pro-

.2 protective clothing, boots, gloves and tight-fitting vided for every person on board subject to the following:goggles; .1.1 filter type respiratory protection is unacceptable;

.3 steel-cored rescue line with belt; and .1.2 self-contained breathing apparatus should normally

.4 explosion-proof lamp. have a duration of service of at least 15 min;.2 emergency escape respiratory protection should not5/4A.14.2.3 (1 Oct. 1994) An adequate supply of com-

pressed air should be provided and should consist either of: be used for fire-fighting or cargo handling purposesand should be marked to that effect;.1 one set of fully charged spare air bottles for each

breathing apparatus required by 5/4A.14.2.1; .3 two additional sets of the above respiratory and eyeprotection should be permanently located in the navi-a special air compressor suitable for the supply of

high-pressure air of the required purity; and gating bridge.


5/4A.14.4.3 Suitably marked decontamination showers quired in 5/4A.8.2, an additional pressure relievingsystem complying with 5/4A.8.3 should be fitted.and an eyewash should be available on deck in convenient

locations. The showers and eyewash should be operable 5/4A.15S.1.4.2 Intrepertation of 5/4A.8.3.1. and 5/in all ambient conditions. 4A.15.1.4.2 (IMO)

The words ‘‘to prevent the tank from becoming liquid5/4A.14.4.4 In ships of cargo capacity of 2,000 m3 andover, two complete sets of safety equipment should be full’’ contained in 5/4A.8.3.1 and 5/4A.15.1.4.2 have the

following meaning: At no time during the loading, transportprovided in addition to the equipment required by 5/5A.11.6.1 and 5/4A.14.2.1. At least three spare charged or unloading of the cargo including fire conditions will the

tank be more than 98% liquid full, except as permitted byair bottles should be provided for each self-contained air-breathing apparatus required in this paragraph. 5/4A.15.1.3. These requirements, along with those of 5/

4A.8.2.17, are intended to ensure that the pressure relief5/4A.14.4.5 Personnel should be protected against thevalves remain in the vapour phase, since their design andeffects of a major cargo release by the provision of a spacecapacity are based on such a condition.within the accommodation area designed and equipped to

the satisfaction of the Administration.5/4A.14.4.6 For certain highly dangerous products, 5/4A.15.2 Information to be provided to the master

The maximum allowable loading limits for each cargo tankcargo control rooms should be of the gas-safe type only.should be indicated for each product which may be carried,

5/4A.15 Filling Limits for Cargo Tanks for each loading temperature which may be applied andfor the applicable maximum reference temperature, on a

5/4A.15.1 General list to be approved by the Administration. Pressures at5/4A.15.1.1 No cargo tanks should be more than 98% which the pressure relief valves, including those valves

liquid full at the reference temperature, except as permit- required by 5/4A.8.3, have been set should also be statedted by 5/4A.15.1.3. on the list. A copy of the list should be permanently kept

5/4A.15.1.2 The maximum volume to which a cargo tank on board by the master.may be loaded is determined by the following formula.

5/4A.16 Use of Cargo as Fuel (1 Oct. 1994)VL = 0.98 V

rR

rL

where: 5/4A.16.1 GeneralVL = maximum volume to which the tank may be loaded 5/4A.16.1.1 Methane (LNG) is the only cargo whoseV = volume of the tank vapour or boil-off gas may be utilized in machinery spacesrR = relative density of cargo at the reference temperature of Category A and in such spaces may be utilized only inrL = relative density of cargo at the loading temperature boilers, inert gas generators, combustion engines and gas

and pressure. turbines.5/4A.16.1.2 These provisions do not preclude the use5/4A.15.1.3 The Administration may allow a higher fill-

of gas fuels for auxiliary services in other locations provideding limit than the limit of 98% specified in 5/4A.15.1.1that such other services and locations are specially consid-and 5/4A.15.1.2 at the reference temperature, taking intoered by the Administration.account the shape of the tank, arrangements of pressure

relief valves, accuracy of level and temperature gauging 5/4A.16S.1.3 Plans and specifications covering the en-and the difference between the loading temperature and tire installation with all of the accessories are to be submit-the temperature corresponding to the vapour pressure of ted (see 4/1.5.2) and are to include: (ABS)the cargo at the set pressure of the pressure relief valves,

General arrangementprovided the conditions specified in 5/4A.8.2.17 are main-Vapor and gas piping including details of all special valvestained.

and fittings5/4A.15.1.4 For the purpose of 5/4A.15 only, ‘‘referenceGas compressorstemperature’’ means:Gas heaters.1 the temperature corresponding to the vapour pres-Gas storage pressure vesselssure of the cargo at the set pressure of the pressureSchematic-wiring diagramrelief valves when no cargo vapour pressure/tempera-Details of all electrical equipmentture control as referred to in 5/4A.7 is provided;Electric bonding arrangement.2 the temperature of the cargo upon termination ofOperating instruction manualloading, during transport, or at unloading, whichever

is the greatest, when a cargo vapour pressure/temper-5/4A.16.2 Arrangement of machinery spaces ofature control as referred to in 5/4A.7 is provided. If

category Athis reference temperature would result in the cargotank becoming liquid full before the cargo reaches a 5/4A.16.2.1 Spaces in which gas fuel is utilized should

be fitted with a mechanical ventilation system and shouldtemperature corresponding to the vapour pressure ofthe cargo at the set pressure of the relief valves re- be arranged in such a way as to prevent the formation


of dead spaces. Such ventilation should be particularly ventilation system and continuous gas detection should beprovided to indicate leaks and to shut down the gas fueleffective in the vicinity of electrical equipment and machin-

ery or of other equipment and machinery which may gener- supply to the machinery space in accordance with 5/4A.16.3.10. The master gas fuel valve required by 5/ate sparks. Such a ventilation system should be separated

from those intended for other spaces. 4A.16.3.7 should close automatically if the required air flowis not established and maintained by the exhaust ventilation5/4A.16.2.2 Gas detectors should be fitted in thesesystem. The ventilated hood or casing should be installedspaces, particularly in the zones where air circulation isor mounted to permit the ventilating air to sweep acrossreduced. The gas detection system should comply with thethe gas utilization unit and be exhausted at the top of therequirements of 5/4A.13.ventilation hood or casing.5/4A.16.2.3 Electrical equipment located in the double

5/4A.16S.3.4 (ABS)wall pipe or duct specified in 5/4A.16.3.1 should be of theVentilation equipment for the vented hood is to be capableintrinsically safe type.of changing the air at least once in two minutes and in nocase permit a pressure less than atmospheric in way of the5/4A.16.3 Gas fuel supplyburners.5/4A.16.3.1 Gas fuel piping should not pass through

5/4A.16.3.5 The ventilation inlet and discharge for theaccommodation spaces, service spaces or control stations.required ventilation systems should be respectively fromGas fuel piping may pass through or extend into otherand to a safe location.spaces provided they fulfil one of the following:

5/4A.16.3.6 Each gas utilization unit should be provided.1 the gas fuel piping should be a double wall pipingwith a set of three automatic valves. Two of these valvessystem with the gas fuel contained in the inner pipe.should be in series in the gas fuel pipe to the consumingThe space between the concentric pipes should beequipment. The third valve should be in a pipe that vents,pressurized with inert gas at a pressure greater thanto a safe location in the open air, that portion of the gasthe gas fuel pressure. Suitable alarms should be pro-fuel piping that is between the two valves in series. Thesevided to indicate a loss of inert gas pressure betweenvalves should be arranged so that failure of the necessarythe pipes; orforced draft, loss of flame on boiler burners, abnormal.2 the gas fuel piping should be installed within a venti-pressure in the gas fuel supply line, or failure of the valvelated pipe or duct. The air space between the gascontrol actuating medium will cause the two gas fuel valvesfuel piping and inner wall of this pipe or duct shouldwhich are in series to close automatically and the ventbe equipped with mechanical exhaust ventilation hav-valve to open automatically. Alternatively, the functioning a capacity of at least 30 air changes per hour. Theof one of the valves in series and the vent valve can beventilation system should be arranged to maintain aincorporated into one valve body so arranged that, whenpressure less than the atmospheric pressure. The fanone of the above conditions occurs, flow to the gas utiliza-motors should be placed outside the ventilated pipetion unit will be blocked and the vent opened. The threeor duct. The ventilation outlet should be placed in ashut-off valves should be arranged for manual reset.position where no flammable gas-air mixture may be

5/4A.16.3.7 A master gas fuel valve that can be closedignited. The ventilation should always be in operationfrom within the machinery space should be provided withinwhen there is gas fuel in the piping. Continuous gasthe cargo area. The valve should be arranged so as todetection should be provided to indicate leaks andclose automatically if leakage of gas is detected, or loss ofto shut down the gas fuel supply to the machineryventilation for the duct or casing or loss of pressurizationspace in accordance with 5/4A.16.3.10. The masterof the double wall gas fuel piping occurs.gas fuel valve required by 5/4A.16.3.7 should close

automatically if the required air flow is not established 5/4A.16.3.8 Gas fuel piping in machinery spaces shouldand maintained by the exhaust ventilation system. comply with 5/4A.5.2 through 5/4A.5.5 as far as found

applicable. The piping should, as far as practicable, have5/4A.16.3.2 If a gas leak occurs, the gas fuel supplywelded joints. Those parts of the gas fuel piping, whichshould not be restored until the leak has been found andare not enclosed in a ventilated pipe or duct according torepaired. Instructions to this effect should be placed in a5/4A.16.3.1 and are on the open deck outside the cargoprominent position in the machinery spaces.area should have full penetration butt welded joints and5/4A.16.3.3 The double wall piping system or the venti-should be fully radiographed.lated pipe or duct provided for the gas fuel piping should

5/4A.16.3.9 Provision should be made for inerting andterminate at the ventilation hood or casing required by 5/gas-freeing that portion of the gas fuel piping system lo-4A.16.3.4.cated in the machinery space.5/4A.16.3.4 A ventilation hood or casing should be pro-

vided for the areas occupied by flanges, valves, etc., and 5/4A.16.3.10 Gas detection systems provided in accord-ance with the requirements of 5/4A.16.3.1 and 5/4A.16.3.4for the gas fuel piping, at the gas fuel utilization units,

such as boilers, diesel engines or gas turbines. If this venti- should comply with 5/4A.13.6.2 and 5/4A.13.6.4 through5/4A.13.6.8 as applicable; they should activate the alarmlation hood or casing is not served by the exhaust ventila-

tion fan serving the ventilated pipe or duct as specified in at 30% of the lower flammable limit and shut down themaster gas fuel valve referred to in 5/4A.16.3.7 before the5/4A.16.3.1.2, then it should be equipped with an exhaust


gas concentration reaches 60% of the lower flammable It should be possible to change over easily and quicklyfrom gas fuel operation to oil fuel operation. Gas nozzleslimit.should be fitted in such a way that gas fuel is ignited by5/4A.16S.3 (No text—1 Oct. 1994)the flame of the oil fuel burner. A flame scanner shouldbe installed and arranged to assure that gas flow to the5/4A.16.4 Gas make-up plant and related storageburner is cut off unless satisfactory ignition has been estab-tanks (1 Oct. 1994)lished and maintained. On the pipe of each gas burner5/4A.16.4.1 All equipment (heaters, compressors, filters,a manually operated shut-off valve should be fitted. Anetc.) for making-up the gas for its use as fuel, and theinstallation should be provided for purging the gas supplyrelated storage tanks should be located in the cargo areapiping to the burners by means of inert gas or steam, afterin accordance with 5/4A.3.1.5.4. If the equipment is in anthe extinguishing of these burners.enclosed space, the space should be ventilated according

5/4A.16.5.5 Alarm devices should be fitted in order toto 5/4A.12.1 and be equipped with a fixed fire extinguishingmonitor a possible decrease in liquid fuel oil pressure orsystem according to 5/4A.11.5 and with a gas detectiona possible failure of the related pumps.system according to 5/4A.13.6, as applicable.

5/4A.16.5.6 Arrangements should be made that, in case5/4A.16.4.2 The compressors should be capable of beingof flame failure of all operating burners for gas or oil orremotely stopped from a position which is always easilyfor a combination thereof, the combustion chambers of theaccessible, and also from the engine room. In addition, theboilers are automatically purged before relighting. Ar-compressors should be capable of automatically stoppingrangements should also be made to enable the boilers towhen the suction pressure reaches a certain value de-be manually purged and these arrangements should be topending on the set pressure of the vacuum relief valves ofthe satisfaction of the Administration.the cargo tanks. The automatic shut-down device of the

compressors should have a manual resetting. Volumetric 5/4A.16S.5 Boiler Casings (ABS)compressors should be fitted with pressure relief valves When the boilers are fitted with a double casing, care is

to be exercised to preclude the possibility of gases leakingdischarging into the suction line of the compressor. Thesize of the pressure relief valves should be determined in into and being trapped in pockets of the inner casing. Gas-

detection probes within the casing and explosion-reliefsuch a way that, with the delivery valve kept closed, themaximum pressure does not exceed by more than 10% panels on the outer casing are to be provided.the maximum working pressure. The requirements of 5/ 5/4A.16S.6 Boiler Burners (ABS)4A.5.6.1.3 apply to these compressors. .1 Firing Condition The burners are to maintain com-

5/4A.16.4.3 If the heating medium for the gas fuel evap- plete and stable combustion under all operating conditionsorator or heater is returned to spaces outside the cargo including the minimum rate of firing, or during any suddenarea it should first go through a degassing tank. The degass- change in gas firing rate between maximum and mini-ing tank should be located in the cargo area. Provisions mum rates.should be made to detect and alarm the presence of gas .2 Valve Marking Important valves are to be plainlyin the tank. The vent outlet should be in a safe position marked to indicate the service controlled. Detailed op-and fitted with a flame screen. erating instructions are to be posted, including a sequence

5/4A.16.4.4 Piping and pressure vessels in the gas fuel of valve operations, where this information is necessary forconditioning system should comply with 5/4A.5. effective emergency action.

5/4A.16S.4 (No Text—1 Oct. 1994)5/4A.16.6 Special requirements for gas fired internal

combustion engines and gas fired turbines5/4A.16.5 Special requirements for main boilers (1(1 Oct. 1994)Oct. 1994)

Special provisions for gas fuelled internal combustion en-5/4A.16.5.1 Each boiler should have a separate uptake.gines and for gas turbines will be considered by the Admin-5/4A.16.5.2 A system suitable to ensure the forcedistration in each case.draught in the boilers should be provided. The particulars

of such a system should be to the satisfaction of the Admin- 5/4A.16S.8 Additional Requirements for Internal-istration. combustion Engines and Gas Turbines

5/4A.16.5.3 Combustion chambers of boilers should be (ABS)of suitable form such as not to present pockets where gas Internal-combustion engines are to comply with the follow-may accumulate. ing additional requirements detailed in 5/4A.16S.9 through

5/4A.16.5.4 The burner systems should be of dual type, 5/4A.16S.17. Gas turbines are also to comply with thesesuitable to burn either oil fuel or gas fuel alone or oil and additional requirements as applicable; however specialgas fuel simultaneously. Only oil fuel should be used during consideration will be given to alternative arrangements.manoeuvring and port operations unless automatic transferfrom gas to oil burning is provided in which case the 5/4A.16S.9 General (ABS)

Main propulsion units are to be of the compression-igni-burning of a combination of oil and gas or gas alone maybe permitted provided the system is demonstrated to the tion, dual-fuel type using pilot-oil fuel ignition and ar-

ranged for rapid changeover to oil fuel.satisfaction of the Administration.


5/4A.16S.10 Gas and Air Supply (ABS) 5/4A.16S.14 Engine Exhaust Systems (ABS)Each cylinder is to have a separate gas supply fitted with If the engine exhaust system is not designed to withstand

damage resulting from the ignition of unburned fuel, con-a shut-off valve. Means are to be provided to exclude gasfrom starting air if the engine is air-started. Air intakes are sideration is to be given to the fitting of explosion-relief

valves. The explosion-relief valves are to be of the return-not to be located where gases or vapors could be introducedinto the engine or turbine through the intake. seating type. The arrangement and location of the valves

is to minimize the dangers from emission of flame.

5/4A.16S.11 Crankcase Ventilation (ABS) 5/4A.16S.15 Machinery-space Ventilation (ABS)In addition to the requirements of 4/4.11.2, Adequate ventilation of the machinery space is to be pro-consideration is to be given to the following. vided. Because of the design of the engine and its gas1 Ventilation To prevent accumulation of gas the crank- piping system, it may be necessary to provide a mechani-case ventilation will be subject to special consider- cally-vented hood. This vented hood is to exhaust to a safeation. Arrangements are to be made so that any blow- location in the atmosphere through a flame arrester. Noby gas may readily reach the vent. The crankcase vent electric equipment is to be fitted within the hood exceptis to be led to a safe location in the atmosphere through that which is certified safe.a flame arrester.2 Explosion Relief Valves The present Rule require-

5/4A.16S.16 Operating Instructions (ABS)ments for explosion relief valves are based on the lowInstructions for starting, operation, and routine mainte-pressure expected to develop through the ignition ofnance are to be posted conspicuously on or near each gas-fuel or lubricating oil vapors. Since the pressures duefired unit.to the ignition of the blow-by gas may be considerably

greater, consideration is to be given to increasing the5/4A.16S.17 Requirements for Automatic or Remoterelief-valve areas. Also, since the detonation pressure

Control of Propulsion Machinery (ABS)depends on the length of flame travel, it may be neces-(1994)sary to provide one or more relief valves in way of

Propulsion machinery using methane as fuel and intendedeach crank throw. The area of the relief valves andfor automatic operations or operations from a remote con-their location will be subject to special considerationtrol station are to comply with the applicable requirementsin each case.in Section 4/11, in particular 4/11.7.15d.3 Warning Notice The warning notice required by 4/

4.11.5 is to include a caution that the crankcase is not5/4A.17 Special Requirementsto be opened until adequate precautions have been

taken to insure that no gas remains trapped in the5/4A.17.1 General (1 Oct. 1994)crankcase.The provisions of this chapter are applicable where refer-ence is made in column ‘‘i’’ in the table of 5/4A.19. These

5/4A.16S.12 Engine Protective Devices (ABS) are requirements additional to the general requirements.1 Automatic Shut-Off Valves The two series gas fuel of the Code.

valves required by paragraph 5/4A.16.2 are to auto-matically shut off the flow of gas in case the unit stops 5/4A.17.2 Materials of construction (1 Oct. 1994)from any cause. Materials which may be exposed to cargo during normal

.2 Internal-combustion Engines In addition to the pro- operations should be resistant to the corrosive action oftective devices required by Section 4/4, means are the gases. In addition, the following materials ofto be provided for shutting off the fuel supply to the construction for cargo tanks, and associated pipelines,engine from a readily accessible location outside of valves, fittings and other items of equipment should notthe machinery space. be used for certain products as specified in column ‘‘i ’’

.3 Gas Turbines In addition to the protective devices in the table of 5/4A.19:required by Section 4/3, the gas turbines are to be .1 mercury, copper and copper-bearing alloys, and zinc;fitted with an automatic shut-down device for high .2 copper, silver, mercury, magnesium and other ace-exhaust temperatures. tylide-forming metals;

.3 aluminium and aluminium-bearing alloys;

.4 copper, copper alloys, zinc and galvanized steel;5/4A.16S.13 Regulators (ABS)

.5 aluminium, copper and alloys of either;When the gas pressure on the upstream side of a regulator

.6 copper and copper-bearing alloys with greater thanexceeds 350 mm (14 in.) of H2O, a relief valve is to be1% copper.installed on the downstream side of the regulator. This

relief valve is to discharge to a safe location in the atmo-5/4A.17.3 Independent tankssphere through a flame arrester. The capacity of the relief

valve is to be adequate to vent the volume of gas that 5/4A.17.3.1 Products should be carried in independenttanks only.would pass through the regulator if that device should fail.


5/4A.17.3.2 Products should be carried in type C inde- poses of this paragraph, dry air is air which has a dewpointof −46C or below at atmospheric pressure.pendent tanks and the provisions of 5/4A.7.1.3 apply. The

design pressure of the cargo tank should take into accountany padding pressure or vapour discharge unloading 5/4A.17.8 Inhibitionpressure. Care should be taken to ensure that the cargo is sufficiently

inhibited to prevent polymerization at all times during the5/4A.17.4 Refrigeration systems voyage. Ships should be provided with a certificate from

the manufacturer stating:5/4A.17.4.1 Only the indirect system described in 5/.1 name and amount of inhibitor added;4A.7.2.4.2 should be used..2 date inhibitor was added and the normally expected5/4A.17.4.2 For a ship engaged in the carriage of prod-

duration of its effectiveness;ucts which readily form dangerous peroxides, recondensed.3 any temperature limitations affecting the inhibitor;cargo should not be allowed to form stagnant pockets of.4 the action to be taken should the length of the voyageuninhibited liquid. This may be achieved either by:

exceed the effective lifetime of the inhibitors..1 using the indirect system described in 5/4A.7.2.4.2with the condenser inside the cargo tank; or

.2 using the direct system or combined system de- 5/4A.17.9 Permanently installed toxic gas detectorsscribed in 5/4A.7.2.4.1 and .3 respectively, or the 5/4A.17.9.1 Gas sampling lines should not be led into orindirect system described in 5/4A.7.2.4.2 with the through gas-safe spaces. Alarms referred to in 5/4A.13.6.7condenser outside the cargo tank, and designing the should be activated when the vapour concentration reachescondensate system to avoid any places in which liquid the threshold limiting value.could collect and be retained. Where this is impossi- 5/4A.17.9.2 The alternative of using portable equipmentble inhibited liquid should be added upstream of such in accordance with 5/4A.13.6.9 should not be permitted.a place.

5/4A.17.4.3 If the ship is to carry consecutively products 5/4A.17.10 Flame screens on vent outletsas specified in 5/4A.17.4.2 with a ballast passage between, Cargo tank vent outlets should be provided with readilyall uninhibited liquid should be removed prior to the ballast renewable and effective flame screens or safety heads ofvoyage. If a second cargo is to be carried between such an approved type when carrying a cargo referenced to thisconsecutive cargoes, the reliquefaction system should be section. Due attention should be paid in the design of flamethoroughly drained and purged before loading the second screens and vent heads to the possibility of the blockage ofcargo. Purging should be carried out using either inert gas these devices by the freezing of cargo vapour or by icing upor vapour from the second cargo, if compatible. Practical in adverse weather conditions. Ordinary protection screenssteps should be taken to ensure that polymers or peroxides should be fitted after removal of the flame screens.do not accumulate in the cargo system.

5/4A.17.11 Maximum allowable quantity of cargo per5/4A.17.5 Deck cargo pipingtankOne hundred per cent radiography of all butt welded

When carrying a cargo referenced to this section, the quan-joints in cargo piping exceeding 75 mm in diameter istity of the cargo should not exceed 3,000 m3 in any one tank.required.

5/4A.17.12 Submerged electric cargo pumps5/4A.17.6 Exclusion of air from vapour spacesThe vapour space of cargo tanks equipped with submergedAir should be removed from the cargo tanks andelectric motor pumps should be inerted to a positive pressureassociated piping before loading and then subsequentlyprior to loading, during carriage and during unloading ofexcluded by:flammable liquids..1 introducing inert gas to maintain a positive pressure.

Storage or production capacity of the inert gas should5/4A.17.13 Ammonia (1 Oct. 1994)be sufficient to meeting normal operating requirements

and relief valve leakage. The oxygen content of inert 5/4A.17.13.1 Anhydrous ammonia may cause stress cor-gas should at no time be greater than 0.2% by vol- rosion cracking in containment and process systems madeume or of carbon manganese steel or nickel steel. To minimize the

.2 control of cargo temperatures such that a positive risk of this occurring, measures detailed in 5/4A.17.13.2 topressure is maintained at all times. 5/4A.17.13.8 should be taken as appropriate.

5/4A.17.13.2 Where carbon manganese steel is used,cargo tanks, process pressure vessels and cargo piping5/4A.17.7 Moisture control

For gases which are non-flammable and may become corro- should be made of fine grained steel with a specified mini-mum yield strength not exceeding 355 N/mm2 and withsive or react dangerously with water, moisture control

should be provided to ensure that cargo tanks are dry before an actual yield strength not exceeding 440 N/mm2. Oneof the following constructional or operational measuresloading and that during discharge, dry air or cargo vapour

is introduced to prevent negative pressures. For the pur- should also be taken:


.1 lower strength material with a specified minimum 5/4A.17.14.1.3 Parts of tanks protruding above the up-per deck should be provided with protection against ther-tensile strength not exceeding 410 N/mm2 should be

used; or mal radiation taking into account total engulfment by fire..2 cargo tanks, etc., should be post weld stress relief 5/4A.17.14.1.4 Each tank should be provided with two

heat treated; or pressure relief valves. A bursting disc of appropriate mate-.3 carriage temperature should be maintained prefera- rial should be installed between the tank and the pressure

bly at a temperature close to the product’s boiling relief valves. The rupture pressure of the bursting discpoint of −33°C but in no case at a temperature above should be 1 bar lower than the opening pressure of the−20°C; or pressure relief valve, which should be set at the design

.4 the ammonia should contain not less than 0.1% w/w vapour pressure of the tank but not less than 13.5 barwater. gauge. The space between the bursting disc and the relief

valve should be connected through an excess flow valve5/4A.17.13.3 If carbon manganese steels with higheryield properties are used other than those specified in 5/ to a pressure gauge and a gas detection system. Provision

should be made to keep this space at or near the atmo-4A.17.3.2, the completed cargo tanks, piping, etc. shouldbe given a post weld stress relief heat treatment. spheric pressure during normal operation.

5/4A.17.14.1.5 Outlets from pressure relief valves5/4A.17.13.4 Process pressure vessels and piping of thecondensate part of the refrigeration system should be given should be arranged in such a way as to minimize the hazards

on board the ship as well as to the environment. Leakagea post-weld stress relief heat treatment when made ofmaterials mentioned in 5/4A.17.13.1 from the relief valves should be led through the absorption

plant to reduce the gas concentration as far as possible.5/4A.17.13.5 The tensile and yield properties of theThe relief valve exhaust line should be arranged at thewelding consumables should exceed those of the tank orforward end of the ship to discharge outboard at deck levelpiping material by the smallest practical amount.with an arrangement to select either port or starboard5/4A.17.13.6 Nickel steel containing more than 5%side, with a mechanical interlock to ensure that one linenickel and carbon manganese steel not complying with theis always open.requirements of 5/4A.17.13.2 and 5/4A.17.13.3 are particu-

5/4A.17.14.1.6 The Administration and the port Admin-larly susceptible to ammonia stress corrosion cracking andistration may require that chlorine is carried in refrigeratedshould not be used for containment and piping systemsstate at a specified maximum pressure.for the carriage of this product.

5/4A.17.14.2 Cargo piping systems5/4A.17.13.7 Nickel steel containing not more than 5%5/4A.17.14.2.1 Cargo discharge should be performed bynickel may be used provided the carriage temperature

means of compressed chlorine vapour from shore, dry aircomplies with the requirements specified in 5/4A.17.13.2.3.or another acceptable gas or fully submerged pumps. The5/4A.17.13.8 In order to minimize the risk of ammoniapressure in the vapour space of the tank during dischargingstress corrosion cracking, it is advisable to keep the dis-should not exceed 10.5 bar gauge. Cargo discharge com-solved oxygen content below 2.5 ppm/w/w. This can bestpressors on board ships should not be accepted by thebe achieved by reducing the average oxygen content inAdministration.the tanks prior to the introduction of liquid ammonia to

5/4A.14.2.2 The design pressure of the cargo piping sys-less than the values given as a function of the carriagetem should be not less than 21 bar gauge. The internaltemperature T in the table below:diameter of the cargo pipes should not exceed 100 mm.T (°C) O2(%v/v)Only pipe bends should be accepted for compensation of

−30 and below 0.90 pipeline thermal movement. The use of flanged joints−20 0.50 should be restricted to a minimum, and when used the−10 0.28 flanges should be of the welding neck type with tongue

0 0.16 and groove.10 0.105/4A.17.14.2.3 Relief valves of the cargo piping system20 0.05

should discharge to the absorption plant (see also 5/30 0.034A.8.2.16).

Oxygen percentages for intermediate temperatures may 5/4A.17.14.3 Materialsbe obtained by direct interpolation. 5/4A.17.14.3.1 The cargo tanks and cargo piping sys-

tems should be made of steel suitable for the cargo andfor a temperature of −40°C, even if a higher transport5/4A.17.14 Chlorinetemperature is intended to be used.5/4A.17.14.1 Cargo containment system

5/4A.17.14.3.2 The tanks should be thermally stress re-5/4A.17.14.1.1 The capacity of each tank should not ex-lieved. Mechanical stress relief should not be accepted asceed 600 m3 and the total capacity of all cargo tanks shouldan equivalent.not exceed 1,200 m3.

5/4A.17.14.4 Instrumentation—safety devices5/4A.17.14.1.2 The tank design vapour pressure shouldnot be less than 13.5 bar (see also 5/4A.7.1.3 and 5/ 5/4A.17.14.4.1 The ship should be provided with a chlo-

rine absorbing plant with connections to the cargo piping4A.17.3.2).


system and the cargo tanks. The absorbing plant should 5/4A.17.16 Ethylene oxidebe capable of neutralizing at least 2% of the total cargo 5/4A.17.16.1 For the carriage of ethylene oxide the re-capacity at a reasonable absorption rate. quirements of 5/4A.17.20 apply, with the additions and

modifications as given in this section.5/4A.17.14.4.2 During the gas-freeing on cargo tanks,vapors should not be discharged to the atmosphere. 5/4A.17.16.2 Deck tanks should not be used for the

carriage of ethylene oxide.5/4A.17.14.4.3 (1 Oct. 1994) A gas detecting system5/4A.17.16.3 Stainless steels types 416 and 442 as wellshould be provided capable of monitoring chlorine concen-

as cast iron should not be used in ethylene oxide cargotrations of at least 1 ppm by volume. Suction points shouldcontainment and piping systems.be located:

.1 near the bottom of the hold spaces; 5/4A.17.16.4 Before loading, tanks should be thoroughly

.2 in the pipes from the safety relief valves; and effectively cleaned to remove all traces of previous

.3 at the outlet from the gas absorbing plant; cargoes from tanks and associated pipework, except where

.4 at the inlet to the ventilation systems for the accom- the immediate prior cargo has been ethylene oxide, pro-modation, service and machinery spaces and control pellent oxide or mixtures of these products. Particular carestations; should be taken in the case of ammonia in tanks made of

.5 on deck at the forward end, in the middle and at the steel other than stainless steel.after end of the cargo area. (Only required to be used 5/4A.17.16.5 Ethylene oxide should be discharged onlyduring cargo handling and gas-freeing operations.) by deepwell pumps or inert gas displacement. The arrange-

The gas detection system should be provided with an audi- ment of pumps should comply with 5/4A.17.20.5.3.ble and visual alarm with a set point of 5 ppm. 5/4A.17.16.6 Ethylene oxide should be carried refriger-

5/4A.17.14.4.4 Each cargo tank should be fitted with a ated only and maintained at temperatures of less than 30°C.high-pressure alarm giving an audible alarm at a pressure 5/4A.17.16.7 Pressure relief valves should be set at aequal to 10.5 bar gauge. pressure of not less than 5.5 bar gauge. The maximum set

5/4A.17.14.5 Personnel protection pressure should be specially approved by the Adminis-In addition to the requirements given in 5/4A.14 the follow- tration.ing requirements should be met: 5/4A.17.16.8 The protective padding of nitrogen gas as

.1 The enclosed space required by 5/4A.14.4.5 should required by 5/4A.17.20.15 should be such that the nitrogenbe easily and quickly accessible from the open deck concentration in the vapour space of the cargo tank willand from accommodation spaces and should be capa- at no time be less than 45% by volume.ble of being rapidly closed gastight. Access to this 5/4A.17.16.9 Before loading and at all times when thespace from the deck and from the accommodation cargo tank contains ethylene oxide liquid or vapour, thespaces should be by means of an air-lock. The space cargo tank should be inerted with nitrogen.should be so designed as to accommodate the entire 5/4A.17.16.10 The water spray system required by para-crew of the ship and be provided with a source of graph 5/4A.17.20.17 and that required by 5/4A.11.3 shoulduncontaminated air for a period of not less than 4 operate automatically in a fire involving the cargo contain-hours. One of the decontamination showers required ment system.by 5/4A.14.4.3 should be located near the air-lock to 5/4A.17.16.11 A jettisoning arrangement should be pro-the space. vided to allow the emergency discharge of ethylene oxide

.2 A compressor and the necessary equipment for filling in the event of uncontrollable self-reaction.the air bottles should be provided.

.3 One set of oxygen therapy equipment should be car- 5/4A.17.17 Isopropylamine and monoethylamineried in the space referred to in 5/4A.17.14.5.1. Separate piping systems should be provided as defined

5/4A.17.14.6 Filling limits for cargo tanks in 5/4A.1.3.32.5/4A.17.14.6.1 The requirements of 5/4A.15.1.4.2 do not

apply when it is intended to carry chlorine. 5/4A.17.18 Methyl acetylene-propadiene mixtures5/4A.17.18.1 Methyl acetylene-propadiene mixtures5/4A.17.14.6.2 The chlorine content of the gas in the

should be suitably stabilized for transport. Additionally,vapour space of the cargo tank after loading should beupper limits of temperature and pressure during the re-greater than 80% by volume.frigeration should be specified for the mixtures.

5/4A.17.18.2 Examples of acceptable, stabilized compo-5/4A.17.15 Diethyl ether and vinyl ethyl ether sitions are:

5/4A.17.15.1 The cargo should be discharged only by .1 Composition 1deepwell pumps or by hydraulically operated submerged .1.1 maximum methyl acetylene to propadiene molar ratiopumps. These pumps should be of a type designed to avoid of 3 to 1;liquid pressure against the shaft gland. .1.2 maximum combined concentration of methyl acetylene

and propadiene of 65 mol per cent;5/4A.17.15.2 Inert gas displacement may be used of dis-charging cargo from type C independent tanks provided .1.3 minimum combined concentration of propane, butane,

and isobutane of 24 mol per cent, of which at leastthe cargo system is designed for the expected pressure.


one third (on a molar basis) must be butanes and one vent lines and any other possible connections, such ascommon inert gas supply lines.third propane; and

.1.4 maximum combined concentration of propylene andbutadiene of 10 mol per cent. 5/4A.17.19 Nitrogen

Materials of construction and ancillary equipment such as.2 Composition 2insulation should be resistant to the effects of high oxygen.2.1 maximum methyl acetylene and propadiene combinedconcentrations caused by condensation and enrichment atconcentration of 30 mol per cent;the low temperatures attained in parts of the cargo system..2.2 maximum methyl acetylene concentration of 20 molDue consideration should be given to ventilation in suchper cent;areas where condensation might occur to avoid the stratifi-

.2.3 maximum propadiene concentration of 20 mol per cation of oxygen-enriched atmosphere.cent;

.2.4 maximum propylene concentration of 45 mol per cent; 5/4A.17.20 Propylene oxide and mixtures of ethylene

.2.5 maximum butadiene and butylenes combined concen- oxide-propylene oxide with ethylene oxidetration of 2 mol per cent; content of not more than 30% by weight

.2.6 minimum saturated C4 hydrocarbon concentration of 5/4A.17.20.1 Products transported under the provisions4 mol per cent; and of this section should be acetylene-free.

.2.7 minimum propane concentration of 25 mol per cent. 5/4A.17.20.2.1 Unless cargo tanks are properly cleaned,these products should not be carried in tanks which have5/4A.17.18.3 Other compositions may be accepted pro-contained as one of the three previous cargoes any productvided the stability of the mixture is demonstrated to theknown to catalyze polymerization, such as:satisfaction of the Administration.

.1 anhydrous ammonia and ammonia solutions;5/4A.17.18.4 A ship carrying methyl acetylene-propa-

.2 amines and amine solutions;diene mixtures should preferably have an indirect refriger-

.3 oxidizing substances (e.g. chlorine).ation system as specified in 5/4A.7.2.4.2. Alternatively, a5/4A.17.20.2.2 Before loading, tanks should be thor-ship not provided with indirect refrigeration may utilize

oughly and effectively cleaned to remove all traces of previ-direct vapour compression refrigeration subject to pressureous cargoes from tanks and associated pipework, exceptand temperature limitations depending on the composi-where the immediate prior cargo has been propylene oxidetion. For the example compositions given in 5/4A.17.18.2,or ethylene oxide-propylene oxide mixtures. Particular carethe following features should be provided:should be taken in the case of ammonia in tanks made of.1 A vapour compressor that does not raise the temper-steel other than stainless steel.ature and pressure of the vapour above 60°C and

5/4A.17.20.2.3 In all cases, the effectiveness of cleaning17.5 bar gauge during its operation, and that doesprocedures for tanks and associated pipework should benot allow vapour to stagnate in the compressorchecked by suitable testing or inspection to ascertain thatwhile it continues to run.no traces of acidic or alkaline materials remain that might.2 Discharge piping from each compressor stage orcreate a hazardous situation in the presence of theseeach cylinder in the same stage of a reciprocatingproducts.compressor should have:

5/4A.17.20.2.4 Tanks should be entered and inspected.2.1 two temperature-actuated shutdown switches set toprior to each initial loading of these products to ensureoperate at 60°C or less;freedom from contamination, heavy rust deposits and any

.2.2 a pressure-actuated shutdown switch set to operate visible structural defects. When cargo tanks are in continu-at 17.5 bar gauge or less; and ous service for these products, such inspections should be

.2.3 a safety relief valve set to relieve at 18.0 bar gauge performed at intervals of not more than 2 years.or less. 5/4A.17.20.2.5 Tanks for the carriage of these products

.3 The relief valve required by 5/4A.17.18.4.2.3 should should be of steel or stainless steel construction.vent to a mast meeting the requirements of 5/ 5/4A.17.20.2.6 Tanks which have contained these prod-4A.8.2.9, 5/4A.8.2.10, 5/4A.8.2.13 and 5/4A.8.2.14 ucts may be used for other cargoes after thorough cleaningand should not relieve into the compressor suc- of tanks and associated pipework systems by washing ortion line. purging.

.4 An alarm that sounds in the cargo control position 5/4A.17.20.3.1 All valves, flanges, fittings and accessoryand in the navigating bridge when a high-pressure equipment should be of a type suitable for use with theseswitch, or a high-temperature switch operates. products and should be constructed of steel or stainless

steel or other material acceptable to the Administration.5/4A.17.18.5 The piping system, including the cargo re-frigeration system, for tanks to be loaded with methyl acety- The chemical composition of all material used should be

submitted to the Administration for approval prior to fabri-lene-propadiene mixtures should be either independent(as defined in 5/4A.1.3.20) or separate (as defined in 5/ cation. Discs or disc faces, seats and other wearing parts

of valves should be made of stainless steel containing not4A.1.3.32) from piping and refrigeration systems for othertanks. This segregation applies to all liquid and vapour less than 11% chromium.


5/4A.17.20.3.2 Gaskets should be constructed of materi- 5/4A.17.20.11 Tanks for the carriage of propylene oxidewith a design vapour pressure of less than 0.6 bar andals which do not react with, dissolve in, or lower the autoig-

nition temperature of these products and which are fire- tanks for the carriage of ethylene oxide-propylene oxidemixtures with a design vapour pressure of less than 1.2resistant and possess adequate mechanical behaviour. The

surface presented to the cargo should be polytetrafluoro- bar should have a cooling system to maintain the cargobelow the reference temperature. For reference tempera-ethylene (PTFE) or materials giving a similar degree of

safety by their inertness. Spirally-wound stainless steel ture see 5/4A.15.1.4.1.with a filler of PTFE or similar fluorinated polymer may 5/4A.17.20.12 Pressure relief valve settings should notbe accepted by the Administration. be less than 0.2 bar gauge and for type C independent

5/4A.17.20.3.3 Insulation and packing if used should be cargo tanks not greater than 7.0 bar gauge for the carriageof a material which does not react with, dissolve in, or of propylene oxide and not greater than 5.3 bar gauge forlower the autoignition temperature of these products. the carriage of ethylene oxide-propylene oxide mixtures.

5/4A.17.20.3.4 The following materials are generally 5/4A.17.20.13.1 The piping system for tanks to befound unsatisfactory for gaskets, packing and similar uses in loaded with these products should be completely separatecontainment systems for these products and would require from piping systems for all other tanks, including emptytesting before being approved by the Administration: tanks, and from all cargo compressors. If the piping system

.1 Neoprene or natural rubber if it comes into contact for the tanks to be loaded with these products is not inde-with the products; pendent as defined in 5/4A.1.3.20 the required piping sepa-

.2 Asbestos or binders used with asbestos; ration should be accomplished by the removal of spool

.3 Materials containing oxides of magnesium, such as pieces, valves, or other pipe sections and the installationmineral wools. of blank flanges at these locations. The required separation

5/4A.17.20.4 Filling and discharge piping should extend applies to all liquid and vapour piping, liquid and vapourto within 100 mm of the bottom of the tank or any sump. vent lines and any other possible connections such as com-

mon inert gas supply lines.5/4A.17.20.5.1 The products should be loaded and dis-charged in such a manner that venting of the tanks to 5/4A.17.20.13.2 The products should be transportedatmosphere does not occur. If vapour return to shore is used only in accordance with cargo handling plans that haveduring tank loading, the vapour return system connected to been approved by the Administration. Each intended load-a containment system for the product should be independent ing arrangement should be shown on a separate cargoof all other containment systems. handling plan. Cargo handling plans should show the entire

5/4A.17.20.5.2 During discharging operations, the pres- cargo piping system and the locations for installation ofsure in the cargo tank should be maintained above 0.07 blank flanges needed to meet the above piping separationbar gauge. requirements. A copy of each approved cargo handling

plan should be kept on board the ship. The International5/4A.17.20.5.3 The cargo should be discharged only byCertificate of Fitness for the Carriage of Liquefied Gasesdeepwell pumps, hydraulically operated submergedin Bulk should be endorsed to include reference to thepumps, or inert gas displacement. Each cargo pump shouldapproved cargo handling plans.be arranged to ensure that the product does not heat signifi-

cantly if the discharge line from the pump is shut off or 5/4A.17.20.13.3 Before each initial loading of these prod-otherwise blocked. ucts and before every subsequent return to such service,

5/4A.17.20.6 Tanks carrying these products should be certification verifying that the required piping separationvented independently of tanks carrying other products. has been achieved should be obtained from a responsibleFacilities should be provided for sampling the tank con- person acceptable to the port Administration and carriedtents without opening the tank to atmosphere. on board the ship. Each connection between a blank flange

and pipeline flange should be fitted with a wire and seal5/4A.17.20.7 Cargo hoses used for transfer of these prod-by the responsible person to ensure that inadvertent removalucts should be marked ‘‘FOR ALKYLENE OXIDE TRANS-of the blank flange is impossible.FER ONLY’’.

5/4A.17.20.8 Hold spaces should be monitored for these 5/4A.17.20.14 The maximum allowable tank filling lim-products. Hold spaces surrounding type A and B indepen- its for each cargo tank should be indicated for each loadingdent tanks should also be inerted and monitored for oxygen. temperature which may, be applied and for the applicableThe oxygen content of these spaces should be maintained maximum reference temperature, on a list to be approvedbelow 2%. Portable sampling equipment is satisfactory. by the Administration. A copy of the list should be perma-

nently kept on board by the master.5/4A.17.20.9 Prior to disconnecting shore-lines, the pres-sure in liquid and vapour lines should be relieved through 5/4A.17.20.15 The cargo should be carried under a suit-suitable valves installed at the loading header. Liquid and able protective padding of nitrogen gas. An automatic nitro-vapour from these lines should not be discharged to atmo- gen make-up system should be installed to prevent thesphere. tank pressure falling below 0.07 bar gauge in the event

of product temperature fall due to ambient conditions or5/4A.17.20.10 Tanks should be designed for the maxi-mum pressure expected to be encountered during loading, malfunctioning of refrigeration system. Sufficient nitrogen

should be available on board to satisfy the demand of thecarriage or unloading of cargo.


automatic pressure control. Nitrogen of commercially pure 5/4A.18.1.2 Products required to be inhibited should berefused if the certificate required by 5/4A.17.8 is not sup-quality (99.9% by volume) should be used for padding. A

battery of nitrogen bottles connected to the cargo tanks plied.through a pressure reduction valve satisfies the intention 5/4A.18.1.3 A copy of this Code or national regulationsof the expression ‘‘automatic’’ in this context. incorporating the provisions of this Code should be on board

5/4A.17.20.16 The cargo tank space should be tested every ship covered by this Code.prior to and after loading to ensure that the oxygen contentis 2% by volume or less. 5/4A.18.2 Compatibility

5/4A.17.20.17 (1 Oct. 1994) A water spray system of 5/4A.18.2.1 The master should ascertain that the quan-sufficient capacity should be provided to blanket effectively tity and characteristics of each product to be loaded arethe area surrounding the loading manifold, the exposed within the limits indicated in the International Certificatedeck piping associated with product handling and the tank of Fitness for the Carriage of Liquefied Gases in Bulk anddomes. The arrangement of piping and nozzles should be in the Loading and Stability information booklet providedsuch as to give a uniform distribution rate of 10ø/m2 per for in 5/4A.2.2.5 and that products are listed in the Interna-minute. This water spray system should be capable of both tional Certificate of Fitness for the Carriage of Liquefiedlocal and remote manual operation and the arrangement Gases in Bulk as required under Section 3 of the Certificate.should ensure that any spilled cargo is washed away. Re- 5/4A.18.2.2 Care should be taken to avoid dangerousmote manual operation should be arranged such that re- chemical reactions if cargoes are mixed. This is of particularmote starting of pumps supplying water spray system and significance in respect of:remote operation of any normally closed valves in the sys-tem can be carried out from a suitable location outside .1 tank cleaning procedures required between successivethe cargo area, adjacent to the accommodation spaces and cargoes in same tank; andreadily accessible and operable in the event of fire in the .2 simultaneous carriage of cargoes which react whenareas protected. Additionally, a water hose with pressure mixed. This should be permitted only if the completeto the nozzle, when ambient temperatures permit, should cargo systems including, but not limited to, cargo pipe-be connected ready for immediate use during loading and work, tanks, vent systems and refrigeration systemsunloading operations. are separated as defined in 5/4A1.3.32.

5/4A.18.3 Personnel trainingT

5/4A.17.21 Vinyl chloride5/4A.18.3.1 Personnel involved in cargo operationsIn cases where polymerization of vinyl chloride is pre-

should be adequately trained in handling procedures.vented by addition of an inhibitor, 5/4A.17.8 is applicable.5/4A.18.3.2 All personnel should be adequately trainedIn cases where no or insufficient inhibitor has been added,

in the use of protective equipment provided on board andany inert gas used for the purposes of 5/4A.17.6 shouldhave basic training in the procedure, appropriate to theircontain not more oxygen than 0.1%. Before loading isduties, necessary under emergency conditions.started, inert gas samples from the tanks and piping should

5/4A.18.3.3 Officers should be trained in emergency pro-be analysed. When vinyl chloride is carried, a positivecedures to deal with conditions of leakage, spillage or firepressure should always be maintained in the tanks, alsoinvolving the cargo and a sufficient number of them shouldduring ballast voyages between successive carriages.be instructed and trained in essential first aid for the cargoescarried.

5/4A.18 Operating Requirements5/4A.18.4 Entry into spaces

5/4A.18.1 Cargo information 5/4A.18.4.1 Personnel should not enter cargo tanks, hold5/4A.18.1.1 (1 Oct. 1994) Information should be on board spaces, void spaces, cargo handling spaces or other enclosed

and available to all concerned, giving the necessary data spaces where gas may accumulate, unless:for the safe carriage of cargo. Such information should

.1 the gas content of the atmosphere in such space isinclude for each product carried:determined by means of fixed or portable equipment.1 a full description of the physical and chemical proper-to ensure oxygen sufficiency and the absence of toxicties necessary for the safe containment of the cargo;atmosphere; or.2 action to be taken in the event of spills or leaks;

.3 counter-measures against accidental personal contact;

.4 fire-fighting procedures and fire-fighting media;T Reference is made to the provisions of the International Convention.5 procedures for cargo transfer, gas-freeing, ballasting,

on Standards of Training, Certification and Watchkeeping for Seafarers,tank cleaning and changing cargoes; 1978, and in particular to the ‘‘Mandatory minimum requirements for

.6 special equipment needed for the safe handling of the the training and qualifications of masters, officers and ratings of liquefiedparticular cargo; gas tankers’’-regulation V/ 3, chapter V of the Annex to that Convention

.7 minimum allowable inner hull steel temperatures; and and to resolution 12 of the International Conference on Training andCertification of Seafarers, 1978..8 emergency procedures.


.2 personnel wear breathing apparatus and other neces-sary protective equipment and the entire operation is

3600U

LR(s)

under the close supervision of a responsible officer.

5/4A.18.4.2 Personnel entering any space designed as where:gas-dangerous on a ship carrying flammable productsshould not introduce any potential source of ignition into U = ullage volume at operating signal level (m3)the space unless it has been certified gas-free and is main- LR = maximum loading rate agreed between ship andtained in that condition. shore facility (m3/hr).

5/4A.18.4.3.1 For internal insulation tanks, special fireprecautions should be taken in the event of hot work carried The loading rate should be adjusted to limit surge pressureout in the vicinity of the tanks. For this purpose, gas ab- on valve closure to an acceptable level taking into accountsorbing the de-absorbing characteristics of the insulation the loading hose or arm, the ship and the shore pipingmaterial should be taken into account. systems where relevant.

5/4A.18.4.3.2 For internal insulation tanks, repairsshould be carried out in accordance with the proceduresprovided for in paragraph 5/4A.4.4.7.6.

5/4A.18.8.9 Additional operating requirements5/4A.18.5 Carriage of cargo at low temperatureAdditional operating requirements will be found in the5/4A.18.5.1 When carrying cargoes at low temperature:following paragraphs of the Code:

.1 if provided, the heating arrangements associated with5/4A.3.8.4, 5/4A.3.8.5, 5/4A.7.1.1.5, 5/4A.8.2.5, 5/cargo containment systems should be operated in such4A.8.2.7, 5/4A.9.4.2, 5/4A.12.1.1, 5/4A.12.1.10, 5/a manner as to ensure that the temperature does not4A.13.1.4, 5/4A.14.2.5, 5/4A.14.2.6, 5/4A.14.3.1, 5/fall below that for which the material of the hull struc-4A.15.1, 5/4A.15.2, 5/4A.16.2.2, 5/4A.17.4.2, 5/4A.17.6, 5/ture is designed;4A.17.7, 5/4A.17.12, 5/4A.17.13, 5/4A.17.14, 5/ 4A.17.15,.2 loading should be carried out in such a manner as to5/4A.17.16, 5/4A.17.17, 5/4A.17.18, 5/4A.17.20.ensure that unsatisfactory temperature gradients do

not occur in any cargo tank, piping, or other ancillaryequipment; and 5/4A.19 Summary of Minimum Requirements

.3 when cooling down tanks from temperatures at or Explanatory notes to the summary of minimumnear ambient, the cool-down procedure laid down for requirements (1 Oct. 1994)that particular tank, piping and ancillary equipment UN Numbers The UN numbers as listed inshould be followed closely. the table of 19 are intended

for information only.5/4A.18.6 Protective equipment Vapour detection F — Flammable vapourPersonnel should be made aware of the hazards associated required (column f) detectionwith the cargo being handled and should be instructed to T — Toxic vapour de-act with care and use the appropriate protective equipment tectionas mentioned in 5/4A.14.1 during cargo handling. O — Oxygen analyser

F + T — Flammable and toxic5/4A.18.7 Systems and controls vapour detectionCargo emergency shutdown and alarm systems involved in Gauging—types I — Indirect or closed,cargo transfer should be tested and checked before cargo permitted (column g) as described in 5/handling operations begin. Essential cargo handling con- 4A.13.2.2.1 and .2trols should also be tested and checked prior to transfer C — Indirect, or closed,operations. as described in 5/

4A.13.2.2.1, .2 and5/4A.18.8 Cargo transfer operations .3

5/4A.18.8.1 Transfer operations including emergency R — Indirect, closed orprocedures should be discussed between ship personnel restricted, as de-and the personnel responsible at the shore facility prior to scribed in 5/commencement and communications maintained through- 4A.13.2.2.1, .2, .3out the transfer operations. and .4

Refrigerant gases Non-toxic and non-5/4A.18.8.2 The closing time of the valve referred to in5/4A.13.3.1 (i.e. time from shutdown signal initiation to flammable gases

such as:complete valve closure) should not be greater than:


Unless otherwise specified, gas mixtures containing less than 5% total acetylenes may betransported with no further requirements than those provided for the major components.MFAG numbers are provided for information on the emergency procedures to be appliedin the event of an incident involving the products covered by the IGC Code. Where anyof the products listed are carried at low temperature from which frostbite may occur,MFAG no. 620 is also applicable.


ab

cd

ef

gh

i

Sp

ecia

lre

qu

irem

ents

Pro

du

ctn

am

e

UNnumber

ShipType

IndependentTankTypeCRequired

ControlofVapourSpaceWithinCargoTanks

VapourDetection

Gauging

MFAGTableNo.

Ace

tald

ehyd

e10

892G

/2P

G—

Iner

tF

+T

C30

014

.4.3

,14.

4.4,

17.4

.1,1

7.6.

1

Am

mon

ia,a

nhyd

rous

1005

2G/2

PG

——

TC

725

14.4

.2,1

4.4.

3,14

.4.4

,17.

2.1,

17.1

3

But

adie

ne10

102G

/2P

G—

—F

R31

017

.2.2

,17.

4.2,

17.4

.3,1

7.6,

17.8

But

ane

1011

2G/2

PG

——

FR

310

But

ane-

prop

ane

mix

ture

s10

11/

2G/2

PG

——

FR

310

1978

But

ylen

es10

122G

/2P

G—

—F

R31

0

Chl

orin

e10

171G

Yes

Dry

TI

740

14.4

,17.

3.2,

17.4

.1,1

7.5,

17.7

,17.

9,17

.14

Die

thyl

ethe

r*11

552G

/2P

G—

Iner

tF

+T

C33

014

.4.2

,14.

4.3,

17.2

.6,1

7.3.

1,17

.6.1

,17.

10,1

7.11

,17.

15

Dim

ethy

lam

ine

1032

2G/2

PG

——

F+

TC

320

14.4

.2,1

4.4.

3,14

.4.4

,17.

2.1

Eth

ane

1961

2G—

—F

R31

0

Eth

ylch

lori

de10

372G

/2P

G—

—F

+T

R34

0

Eth

ylen

e10

382G

——

FR

310

Eth

ylen

eox

ide

1040

1GYe

sIn

ert

F+

TC

365

14.4

.2,1

4.4.

3,14

.4.4

,14.

4.6,

17.2

.2,1

7.3.

2,17

.4.1

,17.

5,17

.6.1

,17

.16

Eth

ylen

eox

ide-

prop

ylen

eox

ide

mix

ture

sw

ithet

hyle

neox

ide

2983

2G/2

PG

—In

ert

F+

TC

365

14.4

.3,1

7.3.

1,17

.4.1

,17.

6.1,

17.1

0,17

.11,

17.2

0co

nten

tof

not

mor

eth

an30

%by

wei

ght*

Isop

rene

*12

182G

/2P

G—

—F

R31

014

.4.3

,17.

8,17

.10,

17.1

2

*T

his

carg

ois

cove

red

also

byth

eIB

CC

ode.

The

pref

ix5/

4Ais

tobe

adde

dt

the

refe

renc

epa

ragr

aphs

inco

lum

n‘‘i

’’(1

Oct

.1994).


ab

cd

ef

gh

i

Sp

ecia

lre

qu

irem

ents

Pro

du

ctn

am

e

UNnumber

ShipType

IndependentTankTypeCRequired

ControlofVapourSpaceWithinCargoTanks

VapourDetection

Gauging

MFAGTableNo.

Isop

ropy

lam

ine*

1221

2G/2

PG

——

F+

TC

320

14.4

.2,1

4.4.

3,17

.2.4

,17.

10,1

7.11

,17.

12,1

7.17

Met

hane

(LN

G)

1972

2G—

—F

C62

0

Met

hyl

acet

ylen

e-pr

opad

iene

mix

ture

s10

602G

/2P

G—

—F

R31

017

.18

Met

hyl

brom

ide

1062

1GYe

s—

F+

TC

345

14.4

,17.

2.3,

17.3

.2,1

7.4.

1,17

.5,1

7.9

Met

hyl

chlo

ride

1063

2G/2

PG

——

F+

TC

340

17.2

.3

Mon

oeth

ylam

ine*

1036

2G/2

PG

——

F+

TC

320

14.4

.2,1

4.4.

3,14

.4.4

,17.

2.1,

17.3

.1,1

7.10

,17.

11,1

7.12

,17.

17

Nitr

ogen

2040

3G—

—O

C62

017

.19

Pen

tane

s(a

llis

omer

s)*

1265

2G/2

PG

——

FR

310

14.4

.4,1

7.10

,17.

12

Pen

tene

(all

isom

ers)

*12

652G

/2P

G—

—F

R31

014

.4.4

,17.

10,1

7.12

Pro

pane

1978

2G/2

PG

——

FR

310

Pro

pyle

ne10

772G

/2P

G—

—F

R31

0

Pro

pyle

neox

ide*

1280

2G/2

PG

—In

ert

F+

TC

365

14.4

.3,1

7.3.

1,17

.4.1

,17.

6.1,

17.1

0,17

.11,

17.2

0

Ref

rige

rant

gase

s(s

eeno

tes)

—3G

——

—R

350

Sulp

hur

diox

ide

1079

1GYe

sD

ryT

C63

514

.4,1

7.3.

2,17

.4.1

,17.

5,17

.7,1

7.9

Vin

ylch

lori

de10

862G

/2P

G—

—F

+T

C34

014

.4.2

,14.

4.3,

17.2

.2,1

7.2.

3,17

.3.1

,17.

6,17

.21

Vin

ylet

hyl

ethe

r*13

022G

/2P

G—

Iner

tF

+T

C33

014

.4.2

,14.

4.3,

17.2

.2,1

7.3.

1,17

.6.1

,17.

8,17

.10,

17.1

1,17

.15

Vin

ylid

ene

chlo

ride

*13

032G

/2P

G—

Iner

tF

+T

R34

014

.4.2

,14.

4.3,

17.2

.5,1

7.6.

1,17

.8,1

7.10

,17.

11

*T

his

carg

ois

cove

red

also

byth

eIB

CC

ode.

The

pref

ix5/

4Ais

tobe

adde

dt

the

refe

renc

epa

ragr

aphs

inco

lum

n‘‘i

’’(1

OC

T’9

4).


carriage of noxious liquid substances falling in to categoryPart B Chemical CarriersA, B or C and identified as such by an entry of ‘‘A, B orC’’ in column c.5/4B.1S.1 Special Construction Requirements

5/4B.1.1.3 (1 July 1994) For a product proposed for car-a. Material Hull structural material is to be in accord-riage in bulk, but not listed in 5/4B.17 or 18, the Adminis-ance with Sections 3/2 and 2/1.tration* and port Administrations involved in such carriageb. Cold Deformation Materials subjected to cold defor-should prescribe the preliminary suitable conditions formation or strain are to be dealt with as may be requiredthe carriage, having regard to the criteria for hazard evalua-to maintain the specific impact properties. For formedtion of bulk chemicals. The Organization should be notifiedmaterial see 2/3.3.7.of the conditions for consideration for inclusion of thec. Welding Details are to be in accordance with Sectionproduct in the Code. For the evaluation of the pollution2/3.hazard of such a product and assignment of its pollutioncategory, the procedure specified in regulation 3(4) of

5/4B.1S.2 Test Agenda (1994) Annex II of MARPOL 73/78 must be followed.The agenda for the testing of tanks required by this sectionis to be submitted for review. Also by Section 1/2. The 5/4B.1.2 Hazardstests are to be witnessed by a Surveyor. In addition, for Hazards of products covered by the Code include:hydrostatic testing of pressure vessel type cargo tanks, see 5/4B.1.2.1 Fire hazard defined by flashpoint, boiling4/2.39.2. For phosphorus tanks, see 5/4B.15.7.2. point, flammability limits and autoignition temperature of

5/4B.1S.3 International Certificate of Fitness the chemical.When the vessel is issued an International Certificate of 5/4B.1.2.2 Health hazard defined by:Fitness For The Carriage of Dangerous Chemicals in Bulk .1 irritant or toxic effect on the skin or on the mucousby the Country of Registry or its agents other than the membranes of the eyes, nose, throat and lungs in theBureau, such certificate will be accepted as evidence of gas or vapour state combined with vapour pressure; orcompliance with the following requirements of this section. .2 irritational effects on the skin in the liquid state; or

.3 toxic effect, taking into account values of5/4B.2.2 Freeboard and intact stability LD50 oral: a dose which is lethal to 50% of the test5/4B.2.5 Damage assumptions subjects when administered orally;5/4B.2.7 Flooding assumptions

LD50 skin: a dose which is lethal to 50% of the test5/4B.2.8 Standard of damagesubjects when administered to the skin;5/4B.2.9 Survival requirements

5/4B.11.1 Structural fire protection requirements. LD50: the concentration which is lethal by inhalationto 50% of the test subjects.

On all other vessels, the Bureau will review the data5/4B.1.2.3 Water pollution hazard defined by humanand plans for compliance with these requirements.

toxicity, water solubility, volatility, odour or taste, and rela-When authorized by the Country of Registry and upontive density.the request of the Owners of a classed vessel or one in-

5/4B.1.2.4 Air pollution hazard defined by:tended to be classed, the Bureau will review the plans,.1 emergency exposure limit (E.E.L.) or LC50;data, etc. and survey the vessel for compliance of these.2 vapour pressure;Rules and issue an International Certificate of Fitness For.3 solubility in water;the Carriage of Dangerous Chemicals in Bulk in addition.4 relative density of liquid;to the classification indicated in 5/4.1S.1..5 vapour density.5/4B.1S.4 Petroleum Products5/4B.1.2.5 Reactivity hazard defined by reactivity with:Where it is intended to carry petroleum products on a.1 other products; orchemical carrier, a procedure manual is to be submitted.2 water; orfor review showing the procedure to be followed for the.3 the product itself (including polymerization).change from a chemical product to a petroleum product5/4B.1.2.6 Marine pollution hazard as defined by:and vice versa..1 bioaccumulation with attendant risk to aquatic life or5/4B.1S.5 Surveys

human health or cause tainting to seafood;See 1/3.22 for survey requirements for vessels in service.2 damage to living resources;intended to carry chemicals in bulk..3 hazard to human health; and5/4B.1.1.2A For the purpose of the 1974 SOLAS Con-.4 reduction of amenities.vention, the Code does not apply to ships which are en-

gaged in the carriage of products included in 5/4B.17 solely5/4B.1.3 Definitionson the basis of their pollution characteristics and identifiedThe following definitions apply unless expresslyas such by an entry of ‘‘P’’ only in column d.provided otherwise. (Additional definitions are given in

5/4B.1.1.2B For the purposes of MARPOL 73/78, the individual chapters).Code applies only to chemical tankers as defined in regula-tion 1(1) of Annex II thereof, which are engaged in the *‘‘Adminstration’’ means ‘‘Flag State Adminstration.’’


5/4B.1.3.1 Accommodation spaces are those spaces used 5/4B.1.3.13 Flashpoint is the temperature in degreesCelsius at which a product will give off enough flammablefor public spaces, corridors, lavatories, cabins, offices, hos-

pitals, cinemas, games and hobbies rooms, barber shops, vapour to be ignited. Values given in the Code are ‘‘closedcup test’’ determined by an approved flashpoint apparatus.pantries containing no cooking appliances and similar

spaces. Public spaces are those portions of the accommoda- 5/4B.1S.3.13 ‘‘Gravity tank.’’ see 5/4B.4.1.3.tion spaces which are used for halls, dining rooms, lounges 5/4B.1.3.14 Hold space is the space enclosed by theand similar permanently enclosed spaces. ship’s structure in which an independent cargo tank is

5/4B.1.3.2.1 Administration means the Government of situated.the State whose flag the ship is entitled to fly. 5/4B.1.3.15 Independent means that a piping or venting

For the purpose of classification, the term ‘‘Administra- system, for example, is in no way connected to anothertion’’ unless otherwise specified, is to be read as the ‘‘Bu- system and that there are no provisions available for thereau’’. See 5/4.1S.2. potential connection to other systems.

5/4B.1.3.2.2 Port administration means the appropriate 5/4B.1S.3.15a ‘‘International Certificate of Fitness’’authority of the country in the port of which the ship is means an International Certificate of Fitness for Carriageloading or unloading. of Dangerous Chemicals in Bulk issued under the ‘‘Interna-5/4B.1.3.3 Boiling point is the temperature at which a tional Code for the Construction and Equipment of Ships

product exhibits a vapour pressure equal to the atmo- Carrying Dangerous Chemicals in Bulk,’’ adopted by thespheric pressure. Maritime Safety Committee of IMO.

5/4B.1.3.4 Breadth (B) means the maximum breadth of 5/4B.1S.3.15b ‘‘Independent tank.’’ see 5/4B.4.1.1the ship, measured amidships to the moulded line of the

5/4B.1S.3.15c ‘‘Integral tank.’’ see 5/4B.4.1.2frame in a ship with a metal shell and to the outer surface5/4B.1.3.16 Length (L) means 96% of the total lengthof the hull in a ship with a shell of any other material. The

on a waterline at 85% of the least moulded depth measuredbreadth (B) should be measured in metres.from the top of the keel, or the length from the foreside5/4B.1.3.5 Cargo area is that part of the ship that con-of the stem to the axis of the rudder stock on that waterline,tains cargo tanks, slop tanks, cargo pump-rooms includingif that be greater. In ships designed with a rake of keel,pump-rooms, cofferdams, ballast or void spaces adjacentthe waterline on which this length is measured should beto cargo tanks or slop tanks and also deck areas throughoutparallel to the designed waterline. The length (L) shouldthe entire length and breadth of the part of the ship overbe measured in metres.the above-mentioned spaces. Where independent tanks

5/4B.1.3.17 Machinery spaces of category A are thoseare installed in hold spaces, cofferdams, ballast or voidspaces and trunks to such spaces which contain:spaces at the after end of the aftermost hold space or at

.1 internal combustion machinery used for main propul-the forward end of the forwardmost hold space are ex-sion; orcluded from the cargo area.

.2 internal combustion machinery used for purposes5/4B.1.3.6 Cargo pump-room is a space containingother than main propulsion where such machinerypumps and their accessories for the handling of the prod-has in the aggregate a total power output of not lessucts by the Code.than 375 kW; or5/4B.1.3.7 Cargo service spaces are spaces within the

.3 any oil-fired boiler or oil fuel unit.cargo area used for workshops, lockers and store-rooms ofmore than 2 m2 in area, used for cargo-handling equipment. 5/4B.1.3.18 Machinery spaces are all machinery spaces

of category A and all other spaces containing propelling5/4B.1.3.8 Cargo tank is the envelope designed to con-machinery, boilers, oil fuel units, steam and internal com-tain the cargo.bustion engines, generators and major electrical machin-5/4B.1.3.9 Chemical tanker is a cargo ship constructedery, oil filling station, refrigerating, stabilizing, ventilationor adapted and used for the carriage in bulk of any liquidand air-conditioning machinery, and similar spaces, andproduct listed in 5/4B.17.trunks to such spaces.5/4B.1.3.10 Cofferdam is the isolating space between

5/4B.1.3.18A MARPOL 73/78 means the Internationaltwo adjacent steel bulkheads or decks. This space may beConvention for the Prevention of Pollution from Ships,a void space or a ballast space.1973, as modified by the Protocol of 1978 relating thereto.5/4B.1.3.11 Control stations are those spaces in which

5/4B.1.3.18B Noxious liquid substance means any sub-ship’s radio or main navigating equipment or the emer-stance designated in appendix II to Annex II of MARPOLgency source of power is located or where the fire-re-73/78 or provisionally assessed under the provisions ofcording or fire-control equipment is centralized. This doesregulation 3(4) of that Annex as falling into category A, B,not include special fire-control equipment which can beC or D.most practically located in the cargo area.

5/4B.1.3.12 Flammability limits are the conditions de- 5/4B.1.3.19 Oil fuel unit is the equipment used for thepreparation of oil fuel for delivery to an oil-fired boiler, orfining the state of fuel-oxidant mixture at which application

of an adequately strong external ignition source is only just equipment used for the preparation for delivery of heatedoil to an internal combustion engine, and includes any oilcapable of producing flammability in a given test apparatus.


pressure pumps, filters and heaters dealing with oil at a ballast space, oil fuel tank, cargo pump-room, pump-room,or any space in normal use by personnel.pressure of more than 1.8 bar gauge.

5/4B.1.3.20 Organization is the International MaritimeOrganization (IMO). 5/4B.1.4 Equivalents

5/4B.1.4.1 Where the Code requires that a particular5/4B.1.3.21 Permeability of a space means the ratio offitting, material, appliance, apparatus, item of equipmentthe volume within that space which is assumed to be occu-or type thereof should be fitted or carried in a ship, or thatpied by water to the total volume of that space.any particular provision should be made, or any procedure5/4B.1S.3.21 ‘‘Pressure tank.’’ see 5/4B.4.1.4or arrangement should be complied with, the Administra-5/4B.1.3.22 Pump-room is a space, located in the cargotion may allow any other fitting, material, appliance, appa-area, containing pumps and their accessories for the han-ratus, item of equipment or type thereof to be fitted ordling of ballast and oil fuel.carried, or any other provision, procedure or arrangement5/4B.1.3.23 Relative density of liquid is the ratio of theto be made in that ship, if it is satisfied by trial thereof ormass of a volume of a product to the mass of an equalotherwise that such fitting, material, appliance, apparatus,volume of fresh water. For a product of limited solubility, item of equipment or type thereof or that any particularthe relative density indicates whether it floats on water provision, procedure or arrangement is at least as effective

or sinks. as that required by the Code. However, the Administration5/4B.1.3.24 Separate means that a cargo piping system may not allow operational methods or procedures to be

or cargo vent system, for example, is not connected to made an alternative to a particular fitting, material, appli-another cargo piping or cargo vent system. This separation ance, apparatus, item of equipment, or type thereof, whichmay be achieved by the use of design or operational meth- are prescribed by the Code, unless such substitution isods. Operational methods should not be used within a specifically allowed by the Code.cargo tank and should consist of one of the following types: 5/4B.1.4.2 When the Administration so allows any fit-

.1 removing spool pieces or valves and blanking the ting, material, appliance, apparatus, item of equipment, orpipe ends; type thereof, or provision, procedure, or arrangement, or

.2 arrangement of two spectacle flanges in series with novel design or application to be substituted thereafter, itprovisions for detecting leakage into the pipe between should communicate to the Organization the particularsthe two spectacle flanges. thereof together with a report on the evidence submitted

5/4B.1.3.25 Service areas are those spaces used for gal- so that the Organization may circulate the same to otherleys, pantries containing cooking appliances, lockers, mail Contracting Governments to the 1974 SOLAS Conventionand specie rooms, store-rooms, workshops other than those and Parties to MARPOL 73/78 for the information of theirforming part of the machinery spaces and similar spaces officers.and trunks to such spaces. (Also see 5/4A.1S.3.33)

5/4B.1.3.26 1974 SOLAS Convention means the Inter- 5/4B.1.5 Surveys and certificationnational Convention for the Safety of Life at Sea, 1974. 5/4B.1.5.1 Survey procedure

5/4B.1.3.27 1983 SOLAS amendments means the 5/4B.1.5.1.1 The survey of ships, so far as regards theamendments to the 1974 SOLAS Convention adopted by enforcement of the provisions of the regulations and grant-the Maritime Safety Committee of the Organization at its ing of exemptions therefrom, should be carried out byforty-eighth session on 17 June 1983 by resolution officers of the Administration. The Administration may,MSC.6(48). however, entrust the surveys either to surveyors nominated

5/4B.1.3.27A Standards for Procedures and Arrange- for the purpose or to organizations recognized by it.ments means the Standards for Procedures and Arrange- 5/4B.1.5.1.2 The Administration nominating surveyorsments for the Discharge of Noxious Liquid Substances or recognizing organizations to conduct surveys should, as acalled for by Annex II of MARPOL 73/ 78 adopted by the minimum, empower any nominated surveyor or recognizedMarine Environment Protection Committee at its twenty- organization to:second session by resolution MEPC 18(22) as may be .1 require repairs to a ship; andamended by the Organization. .2 carry out surveys if requested by the port State au-

5/4B.1.3.28 Vapour density or the relative density of thorityT concerned.vapour is the ratio of the mass of a volume of vapour gas The Administration should notify the Organization of(with no air present) to the mass of an equal volume of air the specific responsibilities and conditions of the authorityat the same pressure and temperature. Vapour density delegated to nominated surveyors or recognized organiza-below or above 1 indicates whether the vapour or gas is tions for circulation to the Contracting Governments.lighter or heavier than air. 5/4B.1.5.1.3 When a nominated surveyor or recognized

5/4B.1.3.29 Vapour pressure is the equilibrium pressure organization determines that the condition of the ship orof the saturated vapour above the liquid expressed in bars its equipment does not correspond substantially with theabsolute at a specified temperature.

5/4B.1.3.30 Void space is an enclosed space in the cargo T Port State authority has the meaning as presented in chapter 1, regula-tion 19 of the 1978 Protocol to the 1974 SOLAS Convention.area external to a cargo tank, other than a hold space,


particulars of the certificate or is such that the ship is not spects satisfactory for the service for which the shipis intended. Such a survey should be endorsed in thefit to proceed to sea without danger to the ship, or personsInternational Certificate of Fitness for the Carriageon board, such surveyor or organization should immedi-of Dangerous Chemicals in Bulk.ately ensure that corrective action is taken and should in

.5 An additional survey, either general or partial ac-due course notify the Administration. If such correctivecording to the circumstances, should be made whenaction is not taken the relevant certificate should be with-required after an investigation prescribed in 5/drawn and the Administration should be notified immedi-4B.1.5.3.3, or whenever any important repairs or re-ately; and, if the ship is in a port of another Contractingnewals are made. Such a survey should ensure thatGovernment, the port State authority concerned shouldthe necessary repairs or renewals have been effec-also be notified immediately.tively made, that the material and workmanship of5/4B.1.5.1.4 In every case, the Administration shouldsuch repairs or renewals are satisfactory; and that theguarantee the completeness and efficiency of the survey,ship is fit to proceed to sea without danger to theand should undertake to ensure the necessary arrange-ship or persons on board.ments to satisfy this obligation.

5/4B.1.5.3 Maintenance of conditions after survey5/4B.1.5.2 Survey Requirements5/4B.1.5.3.1 The condition of the ship and its equipment5/4B.1.5.2.1 The structure, equipment, fittings, arrange-

should be maintained to conform with the provisions ofments and material (other than items in respect of whichthe Code to ensure that the ship will remain fit to proceeda Cargo Ship Safety Construction Certificate, Cargo Shipto sea without danger to the ship or persons on board.Safety Equipment Certificate and Cargo Ship Safety Radio-

5/4B.1.5.3.2 After any survey of the ship under 5/telegraphy Certificate or Cargo Ship Safety Radioteleph-4B.1.5.2 has been completed, no change should be madeony Certificate are issued) of a chemical tanker should bein the structure, equipment, fittings, arrangements andsubjected to the following surveys:material covered by the survey, without the sanction of.1 An initial survey before the ship is put in service orthe Administration, except by direct replacement.before the International Certificate of Fitness for the

5/4B.1.5.3.3 Whenever an accident occurs to a ship orCarriage of Dangerous Chemicals in Bulk is issueda defect is discovered, either of which affects the safety offor the first time, which should include a completethe ship or the efficiency or completeness of its life-savingexamination of its structure, equipment, fittings, ar-appliances or other equipment, the master or owner ofrangements and material in so far as the ship is cov-the ship should report at the earliest opportunity to theered by the Code. This survey should be such as toAdministration, the nominated surveyor or recognized or-ensure that the structure, equipment, fittings, ar-ganization responsible for issuing the relevant certificate,rangements and material fully comply with the appli-who should cause investigations to be initiated to deter-cable provisions of the Code.mine whether a survey, as required by 5/4B.1.5.2.5 is nec-.2 A periodical survey at intervals specified by the Ad-essary. If the ship is in a port of another Contracting Gov-ministration, but not exceeding 5 years which shouldernment, the master or owner should also reportbe such as to ensure that the structure, equipment,immediately to the port State authority concerned andfittings, arrangements and material comply with thethe nominated surveyor or recognized organization shouldapplicable provisions of the Code.ascertain that such a report has been made..3 A minimum of one intermediate survey during the

5/4B.1.5.4 Issue of International Certificate of Fitnessperiod of validity of the International Certificate of5/4B.1.5.4.1 A certificate called an International Certifi-Fitness for the Carriage of Dangerous Chemicals in

cate of Fitness for the Carriage of Dangerous ChemicalsBulk. In cases where only one such intermediatein Bulk, the model form of which is set out in the appendix,survey is carried out in any one certificate validityshould be issued after an initial or periodical survey to aperiod, it should be held not before 6 months priorchemical tanker engaged in international voyages whichto, nor later than 6 months after, the halfway datecomplies with the relevant requirements of the Code.of the certificate’s period of validity. Intermediate

5/4B.1.5.4.2 The certificate issued under provisions ofsurveys should be such as to ensure that the safetythis section should be available on board for inspection atequipment, and other equipment, and associatedall times.pump and piping systems comply with the applicable

provisions of the Code and are in good working order. 5/4B.1.5.5 Issue or endorsement of International Certif-Such surveys should be endorsed on the International icate of Fitness by another GovernmentCertificate of Fitness for the Carriage of Dangerous 5/4B.1.5.5.1 A Party to the 1974 SOLAS ConventionChemicals in Bulk. and to MARPOL 73/78 may, at the request of another

.4 A mandatory annual survey within 3 months before Party, cause a ship entitled to fly the flag of the other Stateor after the anniversary date of the International Cer- to be surveyed and, if satisfied that the requirements oftificate of Fitness for the Carriage of Dangerous the Code are complied with, issue or authorize the issueChemicals in Bulk which should include a general of the certificate to the ship, and, where appropriate, en-examination to ensure that the structure, equipment, dorse or authorize the endorsement of the certificate on

board the ship in accordance with the Code. Any certificatefittings, arrangements and materials remain in all re-


so issued should contain a statement to the effect that it cant preventive measures to preclude an escape ofhas been issued at the request of the Government of the such cargo.State whose flag the ship is entitled to fly.1 .3 A type 3 ship is a chemical tanker intended to trans-

port 5/4B.17 products with sufficiently severe envi-5/4B.1.5.6 Duration and validity of the Internationalronmental and safety hazards which require a moder-Certificate of Fitnessate degree of containment to increase survival5/4B.1.5.6.1 An International Certificate of Fitness forcapability in a damaged condition.the Carriage of Dangerous Chemicals in Bulk should be

Thus a type 1 ship is a chemical tanker intended for theissued for a period specified by the Administration whichtransportation of products considered to present the great-should not exceed 5 years from the date of the initial surveyest overall hazard and type 2 and type 3 for products ofor the periodical survey.progressively lesser hazards. Accordingly, a type 1 ship5/4B.1.5.6.2 No extension of the 5 year period of theshould survive the most severe standard of damage and itscertificate should be permitted.cargo tanks should be located at the maximum prescribed5/4B.1.5.6.3 The certificate should cease to be valid:distance inboard from the shell plating..1 if the surveys are not carried out within the period

specified by 5/4B.1.5.2; 5/4B.2.1.3 The ship type required for individual prod-.2 upon transfer of the ship to the flag of another State. ucts is indicated in column ‘‘e’’ in the table of 5/4B.17.

A new certificate should only be issued when the 5/4B.2.1.4 If a ship is intended to carry more than oneGovernment issuing the new certificate is fully satis- product listed in 5/4B.17, the standard of damage shouldfied that the ship is in compliance with the require- correspond to that product having the most stringent shipments of 5/4B.1.5.3.1 and 1.5.3.2. Where a transfer type requirement. The requirements for the location ofoccurs between Contracting Governments, the Gov- individual cargo tanks, however, are those for ship typesernment of the State whose flag the ship was formerly related to the respective products intended to be carried.entitled to fly should, if requested within 12 monthsafter the transfer has taken place, as soon as possibletransmit to the Administration copies of the certifi-

5/4B.2.2 Freeboard and intact stabilitycates carried by the ship before the transfer and, ifavailable, copies of the relevant survey reports. 5/4B.2.2.1 Ships subject to the Code may be assigned

the minimum freeboard permitted by the InternationalConvention on Load Lines in force. However, the draught5/4B.2 Ship Survival CapabilityT and Location ofassociated with the assignment should not be greater thanCargo Tanksthe maximum draught otherwise permitted by this Code.

5/4B.2.2.2 The stability of the ship in all seagoing condi-5/4B.2.1 Generaltions should be to a standard which is acceptable to the5/4B.2.1.1 Ships subject to the Code should survive theAdministration.normal effects of flooding following assumed hull damage

caused by some external force. In addition, to safeguard 5/4B.2.2.3 When calculating the effect of free surfacesthe ship and the environment, the cargo tanks of certain of consumable liquids for loading conditions it should betypes of ships should be protected from penetration in the assumed that, for each type of liquid, at least one transversecase of minor damage to the ship resulting, for example, pair or a single centre tank has a free surface and the tankfrom contact with a jetty or tug, and given a measure of or combination of tanks to be taken in account should beprotection from damage in the case of collision or stranding, those where the effect of free surfaces is the greatest. Theby locating them at specified minimum distances inboard free surface effect in undamaged compartments should befrom the ship’s shell plating. Both the damage to be as- calculated by a method acceptable to the Administration.sumed and the proximity of the cargo tanks to the ship’s

5/4B.2.2.4 Solid ballast should not normally be used inshell should be dependent upon the degree of hazard pre-double bottom spaces in the cargo area. Where, however,sented by the products to be carried.because of stability considerations, the fitting of solid bal-5/4B.2.1.2 Ships subject to the Code should be designed last in such spaces becomes unavoidable, then its disposi-to one of the following standards:tion should be governed by the need to ensure that the.1 A type 1 ship is a chemical tanker intended to trans-impact loads resulting from bottom damage are not directlyport 5/4B.17 products with very severe environmen-transmitted to the cargo tank structure.tal and safety hazards which require maximum pre-

5/4B.2.2.5 The master of the ship should be suppliedventive measures to preclude an escape of such cargo.with a loading and stability information booklet. This book-.2 A type 2 ship is a chemical tanker intended to trans-let should contain details of typical service and ballastport 5/4B.17 products with appreciably severe envi-conditions, provisions for evaluating other conditions ofronmental and safety hazards which require signifi-loading and a summary of the ship’s survival capabilities.In addition, the booklet should contain sufficient informa-T Reference is made to the Guidelines for the Uniform Application oftion to enable the master to load and operate the ship inthe Survival Requirements of the Bulk Chemical Code and the Gas

Carrier Code. See Annex A. a safe and seaworthy manner.


.1.3 Vertical upwards without limit5/4B.2.3 Shipside discharges below the freeboarddeck extent:

from the5/4B.2.3.1 The provision and control of valves fitted tomoulded linedischarges led through the shell from spaces below theof thefreeboard deck or from within the superstructures andbottom shelldeckhouses on the freeboard deck fitted with weathertightplating atdoors should comply with the requirements of the relevantcentrelineregulation of the International Convention on Load Lines

in force, except that the choice of valves should be lim-.2 Bottom For 0.3L from Any other partited to:

damage: the forward of the ship.1 one automatic nonreturn valve with a positive meansperpendicularof closing from above the freeboard deck; orof the ship.2 where the vertical distance from the summer load

waterline to the inboard end of the discharge pipe.2.1 Longitudinal 1/3L2/3 or 14.5 1/3L2/3 or 5 m,exceeds 0.01L, two automatic nonreturn valves with-

extent: m, whichever is whichever isout positive means of closing, provided that the in-less lessboard valve is always accessible for examination un-

der service conditions..2.2 Transverse B/6 or 10 m, B/6 or 5 m,5/4B.2.3.2 For the purpose of this chapter ‘‘summer

extent: whichever is whichever iswaterline’’ and ‘‘freeboard deck’’, have the meanings asless lessdefined in the International Convention on Load Lines

in force..2.3 Vertical B/15 or 6 m, B/15 or 6 m,5/4B.2.3.3 The automatic nonreturn valves referred to

extent: whichever is whichever isin 5/4B.2.3.1.1 and 5/4B.2.3.1.2 should be of a type accept-less measured less measuredable to the Administration and should be fully effective infrom the from thepreventing admission of water into the ship, taking intomoulded line of moulded line ofaccount the sinkage, trim and heel in survival requirementsthe bottom the bottomin 5/4B.2.9.shell plating at shell plating atcentreline (see centreline (see

5/4B.2.4 Conditions of loading 5/4B.2.6.2) 5/4B.2.6.2)Damage survival capability should be investigated on

5/4B.2.5.2 If any damage of a lesser extent than thethe basis of loading information submitted to themaximum damage specified in 5/4B.2.5.1 would result in aAdministration for all anticipated conditions of loadingmore severe condition, such damage should be considered.and variations in draught and trim. Ballast conditions

where the chemical tanker is not carrying products5/4.B.2.6 Location of cargo tankscovered by the Code, or is carrying only residues of

5/4B.2.6.1 Cargo tanks should be located at the follow-such products, need not be considered.ing distances inboard:

.1 Type 1 ships: from the side shell plating not less5/4B.2.5 Damage assumptions than the transverse extent of damage specified in 5/

5/4B.2.5.1 The assumed maximum extent of damage 4B.2.5.1.1.2 and from the moulded line of the bottomshould be: shell plating at centreline not less than the vertical

extent of damage specified in 5/4B.2.5.1.2.3 and no-.1 Side damage: where less than 760 mm from the shell plating. This

requirement does not apply to the tanks for diluted.1.1 Longitudinal 1/3L2/3 or 14.5 m, whichever is lessslops arising from tank washing.extent:

.2 Type 2 ships: from the moulded line of the bottomshell plating at centreline not less than the vertical.1.2 Transverse B/5 or 11.5 m, whichever is lessextent of damage specified in 5/4B.2.5.1.2.3 and no-extent:where less than 760 mm from the shell plating. Thismeasuredrequirement does not apply to the tanks for dilutedinboard fromslops arising from tank washing.the ship’s

.3 Type 3 ships: no requirement.side at rightangles to the 5/4B.2S.6.1 Interpretation of 5/4B.2.6.1 (IMO)centreline at Any cargo tank may be used for holding contaminated

cargo pump-room bilge water and cargo tank washingsthe level ofthe summer irrespective of the cargo tank location requirements of 5/

4B.2.6.load line


5/4B.2.6.2 Except for type 1 ships, suction wells in- FIGURE 5/4B.1stalled in cargo tanks may protrude into the vertical extent Longitudinal extent of damage toof bottom damage specified in 5/4B.2.5.1.2.3 provided that superstructure (5/4B.2.7.8 and 2.8.1)such wells are as small as practicable and the protrusionbelow the inner bottom plating does not exceed 25% ofthe depth of the double bottom or 350 mm whichever isless. Where there is no double bottom, the protrusion ofthe suction well of independent tanks below the upperlimit of bottom damage should not exceed 350 mm. Suctionwells installed in accordance with this paragraph may beignored in determining the compartments affected bydamage.

5/4B.2S.6.2 Interpretation of 5/4B.2.6.2 (IMO)The area of suction well should not be greater than thatrequired to accommodate equipment such as cargo pumps,suction pipes, valves, associated heating coils, etc., and to stability to meet the requirements of 5/4B.2.9 and sufficientensure efficient flow and the necessary access for cleaning residual stability should be maintained during all stagesand maintenance. where equalization is used. Spaces which are linked by

ducts of large cross-sectional area may be considered tobe common.5/4B.2.7 Flooding assumptions

5/4B.2.7.7 If pipes, ducts, trunks or tunnels are situated5/4B.2.7.1 The requirements of 5/4B.2.9 should be con-within the assumed extent of damage penetration, as de-firmed by calculations which take into consideration thefined in 5/4B.2.5, arrangements should be such that pro-design characteristics of the ship; the arrangements, config-gressive flooding cannot thereby extend to compartmentsuration and contents of the damaged compartments; theother than those assumed to be flooded for each case ofdistribution, relative densities and the free surface effectsdamage.of liquids; and the draught and trim for all conditions of

5/4B.2.7.8 The buoyancy of any superstructure directlyloading.above the side damage should be disregarded. The un-5/4B.2.7.2 The permeabilities of spaces assumed to beflooded parts of superstructures beyond the extent of dam-damaged should be as follows:age, however, may be taken into consideration provided

Spaces Permeabilities that:Appropriated to stores 0.60 .1 they are separated from the damaged space by water-Occupied by accommodation 0.95 tight divisions and the requirements of 5/4B.2.9.3 inOccupied by machinery 0.85 respect of these intact spaces are complied with; andVoids 0.95 .2 openings in such divisions are capable of being closedIntended for consumable liquids 0 to 0.95T

by remotely operated sliding watertight doors andIntended for other liquids 0 to 0.95T

unprotected openings are not immersed within theT The permeability of partially filled compartments should be consistent minimum range of residual stability required in 5/with the amount of liquid carried in the compartment. 4B.2.9; however the immersion of any other openings

capable of being closed weathertight may be per-5/4B.2.7.3 Wherever damage penetrates a tank con-mitted.taining liquids it should be assumed that the contents are

5/4B.2S.7 Interpretation of 5/4B.2.7.8 and 5/4B.2.8.1completely lost from that compartment and replaced by(IMO)salt water up to the level of the final plane of equilibrium.The longitudinal extent of damage to superstructure in the5/4B.2.7.4 Every watertight division within the maxi-instance of side damage to a machinery space aft under 5/mum extent of damage defined in 5/4B.2.5.1 and consid-4B.2.8.1 should be the same as the longitudinal extent ofered to have sustained damage in positions given in 5/the side damage to the machinery space (see figure 5/4B.2.8.1 should be assumed to be penetrated. Where dam-4B.1).age less than the maximum is being considered in accord-

ance with 5/4B.2.5.2, only watertight divisions or combina-tions of watertight divisions within the envelope of such 5/4B.2.8 Standard of damagelesser damage should be assumed to be penetrated. 5/4B.2.8.1 Ships should be capable of surviving the

5/4B.2.7.5 The ship should be so designed as to keep damage indicated in 5/4B.2.5 with the flooding assump-unsymmetrical flooding to the minimum consistent with tions in 5/4B.2.7 to the extent determined by the ship’sefficient arrangements. type according to the following standards: (See 5/4B.2S.7)

.1 A type 1 ship should be assumed to sustain damage5/4B.2.7.6 Equalization arrangements requiring me-chanical aids such as valves or cross-levelling pipes, if anywhere in its length;

.2 A type 2 ship of more than 150 m in length shouldfitted, should be considered for the purpose of reducingan angle of heel or attaining the minimum range of residual be assumed to sustain damage anywhere in its length;


FIGURE 5/4B.2Damage to stepped machinery space forward bulkhead (Damages are notsimultaneous) (5/4B.2.8.1.3 and 2.8.1.5)

.3 A type 2 ship of 150 m in length or less should be 5/4B.2.9 Survival requirementsassumed to sustain damage anywhere in its length 5/4B.2.9.1 Ships subject to the Code should be capableexcept involving either of the bulkheads bounding a of surviving the assumed damage specified in 5/4B.2.5 tomachinery space located aft; the standard provided in 5/4B.2.8 in a condition of stable

.4 A type 3 ship of more than 225 m in length should equilibrium and should satisfy the following criteria.be assumed to sustain damage anywhere in its length; 5/4B.2.9.2 In any stage of flooding:

.5 A type 3 ship of 125 m in length or more but not .1 the waterline, taking into account sinkage, heel andexceeding 225 m in length should be assumed to trim, should be below the lower edge of any openingsustain damage anywhere in its length except involv- through which progressive flooding or downfloodinging either of the bulkheads bounding a machinery may take place. Such openings should include airspace located aft; pipes and openings which are closed by means of

.6 A type 3 ship below 125 m in length should be as- weathertight doors or hatch covers and may excludesumed to sustain damage anywhere in its length ex- those openings closed by means of watertight man-cept involving damage to the machinery space when hole covers and watertight flush scuttles, small water-located aft. However, the ability to survive the flood- tight cargo tank hatch covers which maintain the highing of the machinery space should be considered by integrity of the deck, remotely operated watertightthe Administration. sliding doors, and sidescuttles of the non-opening

5/4B.2S.8 Interpretation of 5/4B.2.8.1.3 and 5/ type;4B.2.8.1.5 (IMO) .2 the maximum angle of heel due to unsymmetricalThe concept of a stepped machinery space forward bulk- flooding should not exceed 25°, except that this anglehead is already implied in 5/4B.3.2.1 and in regulation II- may be increased to 30° if no deck immersion occurs;2/56 of the 1974 SOLAS Convention as amended. For

.3 the residual stability during intermediate stages ofdamage stability considerations when such a bulkhead con-flooding should be to the satisfaction of the Adminis-tains a step more than 3 m in length, damage should betration. However, it should never be significantly lesstreated as shown in figure 5/4B.2.than that required by 5/4B.2.9.3.5/4B.2.8.2 In the case of small type 2 and type 3 ships

5/4B.2.9.3 At final equilibrium after flooding:which do not comply in all respects with the appropriaterequirements of 5/4B.2.8.1.3 and 5/4B.2.8.1.6, special dis- .1 the righting lever curve should have a minimum

range of 20° beyond the position of equilibrium inpensation may only be considered by the Administrationprovided that alternative measures can be taken which association with a maximum residual righting lever

of at least 0.1 m within the 20° range; the area undermaintain the same degree of safety. The nature of thealternative measures should be approved and clearly stated the curve within this range should not be less than

0.0175 m.rad. Unprotected openings should not beand be available to the port Administration. Any such dis-pensation should be duly noted on the International Certif- immersed within this range unless the space con-

cerned is assumed to be flooded. Within this range,icate of Fitness.


the immersion of any of the openings listed in 5/ FIGURE 5/4B.34B.2.9.2.1 and other openings capable of being closed Segregation of mutually hazardousweathertight may be permitted; and reactive cargoes (5/ 4B.3.1.2.1, 5/.2 the emergency source of power should be capable of

4B.15.16.2.3 and 5/4B.4)operating.5/4B.2S.9 Interpretation of 5/4B.2.9.3.1 (IMO)

The 20° range may be measured from any angle commenc-ing between the position of equilibrium and the angle of25° (or 30° if no deck immersion occurs).

5/4B.3 Ship Arrangements

5/4B.3.1 Cargo segregation5/4B.3.1.1 Unless expressly provided otherwise, tanks

containing cargo or residues of cargo subject to the Codeshould be segregated from accommodation, service andmachinery spaces and from drinking water and stores forhuman consumption by means of a cofferdam, void space,cargo pump-room, pump-room, empty tank, oil fuel tankor other similar space.

5/4B.3.1.2 Cargoes, residues of cargoes or mixtures con-taining cargoes which react in a hazardous manner withother cargoes, residues or mixtures, should:

.1 be segregated from such other cargoes by means ofa cofferdam, void space, cargo pump-room, pump-room, empty tank, or tank containing a mutually com-patible cargo;

.2 have separate pumping and piping systems whichshould not pass through other cargo tanks containingsuch cargoes, unless encased in a tunnel; and

.3 have separate tank venting systems.5/4B.3S.1.1 Interpretation of 5/4B.3.1.2, 5/

4B.15.16.2.3 and 5/4B.15.16.2.4 (IMO)A cruciform joint (see figure 5/4B.3) can be considered a‘‘double barrier for the purpose of segregation as follows:

.1 between mutually hazardous reactive cargoes;

.2 between water reactive cargoes and water.5/4B.3.1.3 Cargo piping should not pass through any

accommodation, service or machinery space other thancargo pump-rooms or pump-rooms.

5/4B.3S.1.2 Interpretation of 5/4B.3.1.3 (IMO)The siting of cargo piping is considered to be adequatelycovered by 5/4B.3.7

service and machinery spaces and control stations in rela-5/4B.3.1.4 Cargoes subject to the Code should not be tion to cargo piping and cargo vent systems.

carried in either the fore or aft peak tank. 5/4B.3S.2.1 Interpretation of 5/4B.3.2.2 (IMO)5/4B.3.2 Accommodation, service and machinery Compliance with other relevant paragraphs of the Code

spaces and control stations and in particular with 5/4B.3.2.3, 5/4B.3.7, 5/4B.8.2.2, 5/5/4B.3.2.1 No accommodation or service spaces or con- 4B.12.1.5 and 5/4B.15.12 where applicable would also en-

trol stations should be located within the cargo area except sure compliance with this paragraph.over a cargo pump-room recess or pump-room recess that 5/4B.3.2.3 Entrances, air inlets and openings to accom-complies with regulation II-2/ 56 of the 1983 SOLAS modation, service and machinery spaces and control sta-amendments and no cargo or slop tank should be aft of tions should not face the cargo area. They should be locatedthe forward end of any accommodation. on the end bulkhead not facing the cargo area and/or on

5/4B.3.2.2 In order to guard against the danger of haz- the outboard side of the superstructure or deckhouse at aardous vapours, due consideration should be given to the distance of at least 4% of the length (L) of the ship but

not less than 3 m from the end of the superstructure orlocation of air intakes and openings into accommodation,


deckhouse facing the cargo area. This distance, however, 5/4B.3.3.4 Normal access ladders should not be fittedvertical and should incorporate platforms at suitable inter-need not exceed 5 m. No doors should be permitted within

the limits mentioned above, except that doors to those vals.Tspaces not having access to accommodation and service 5/4B.3.3.5 Means should be provided to deal with drain-spaces and control stations, such as cargo control stations age and any possible leakage from cargo pumps and valvesand store-rooms may be permitted by the Administration. in cargo pump-rooms. The bilge system serving the cargoWhere such doors are fitted, the boundaries of the space pump-room should be operable from outside the cargoshould be insulated to ‘‘A-60’’ standard. Bolted plates for pump-room. One or more slop tanks for storage of contami-removal of machinery may be fitted within the limits speci- nated bilge water or tank washings should be provided. Afied above. Wheelhouse doors and wheelhouse windows shore connection with a standard coupling or other facili-may be located within the limits specified above so long ties should be provided for transferring contaminated liq-as they are so designed that a rapid and efficient gas and uids to on-shore reception facilities. (Also see 5/4B.2S.6.1)vapour tightening of the wheelhouse can be ensured. Win- 5/4B.3.3.6 Pump discharge pressure gauges should bedows and sidescuttles facing the cargo area and on the provided outside the cargo pump-room.sides of the superstructures and deckhouses within the 5/4B.3.3.7 Where machinery is driven by shafting pass-limits specified above should be of the fixed (non-opening) ing through a bulkhead or deck, gastight seals with efficienttype. Such sidescuttles in the first tier on the main deck lubrication or other means of ensuring the permanence ofshould be fitted with inside covers of steel or equivalent the gas seal should be fitted in way of the bulkhead or deck.material. 5/4B.3S.3.2 Interpretation of 5/4B.3.3.7 (IMO)

5/4B.3S.2.2 Interpretation of 5/4B.3.2.3 (IMO) Lubrication or other means of ensuring permanence ofAir outlets are subject to the same requirements as air gastight seals should be effected from outside the cargoinlets and air intakes. This interpretation also applies to 5/ pump-room.4B.3.2.2, 5/4B.3.7.4, 5/4B.8.2.3, 5/4B.15.12.1.3 and 5/4B.19.3.8. 5/4B.3.4 Access to spaces in the cargo areaAccess facing the cargo area or in prohibited zones

5/4B.3S.4.1 Interpretation of 5/4B.3.4 (IMO)should be restricted to stores for cargo-related and safetyAlthough fuel oil tanks are not included in the definitionequipment, cargo control stations and emergency showers.of ‘‘cargo area’’ where such tanks are adjacent to cargoFor all chemical tankers regardless of the cargo to betanks the requirements of 5/4B.3.4 are applicable.carried, where a deckhouse is substituted for a superstruc-

5/4B.3.4.1 Access to cofferdams, ballast tanks, cargoture and liquid could flow along the sides of the house,tanks and other spaces in the cargo area should be directthe house front should be continued to the sides of thefrom the open deck and such as to ensure their completeship in the form of a sill or a separate spillage barrierinspection. Access to double bottom spaces may be throughshould be arranged as described in regulation II-2/56.6 ofa cargo pump-room, pump-room, deep cofferdam, pipethe 1974 SOLAS Convention, as amended. Also see 5/tunnel or similar compartments, subject to consideration4B.3S.7.of ventilation aspects.

5/4B.3S.4.2 Interpretation of 5/4B.3.4.1 (IMO)To take care of restrictions in the movement of personnel5/4B.3.3 Cargo pump-roomsand to limit the time needed for a possible emergency5/4B.3.3.1 Cargo pump-rooms should be so arranged as escape, two separate means of access should be provided into ensure: double bottom tanks and similar spaces where obstructions.1 unrestricted passage at all times from any ladder plat- impede movement. The two accesses should be as widelyform and from the floor; and separated as practicable..2 unrestricted access to all valves necessary for cargo The provision of only one access may be approved inhandling for a person wearing the required personnel special circumstances if the ability to readily traverse theprotective equipment. space or to remove an injured person can be proved to

5/4B.3S.3.1 Interpretation of 5/4B.3.3.1 (IMO) the satisfaction of the Administration.In general a cargo pump-room should be provided with 5/4B.3.4.2 For access through horizontal openings,one set of access/escape ladders. Where it is envisaged hatches or manholes, the dimensions should be sufficientthat personnel are normally employed in a pump-room or to allow a person wearing a self-contained air-breathingthe pump-room is unusually large, the Administration may apparatus and protective equipment to ascend or descendrequire an additional means of escape. Two doorways from any ladder without obstruction and also to provide a clearthe pump-room house, emerging above the weather deck opening to facilitate the hoisting of an injured person fromare preferable. the bottom of the space. The minimum clear opening

5/4B.3.3.2 Permanent arrangements should be made for should be not less than 600 mm by 600 mm.hoisting an injured person with a rescue line while avoidingany projecting obstacles. T Reference is made to the Recommendation on Safe Access to and

5/4B.3.3.3 Guard railings should be installed on all lad- Working in Large Tanks (resolution A.272(VIII)) as amended by resolutionA.330(IX).ders and platforms.


5/4B.3.5.3 Bilge pumping arrangements for cargoFIGURE 5/4B.4pump-rooms, pump-rooms, void spaces, slop tanks, doubleDischarge arrangement ofbottom tanks and similar spaces should be situated entirelypermanent ballast tanks sited within the cargo area except for void spaces, double bottom

immediately adjacent to cargo tanks and ballast tanks where such spaces are separatedfrom tanks containing cargo or residues of cargo by a doubletanks (5/4B.3.5.1)bulkhead.

5/4B.3S.5.3 Interpretation of 5/4B.3.5.3 (IMO)The relaxation at the end of the paragraph should be limitedto spaces not enclosing piping which may contain cargo.

5/4B.3.6 Pump and pipeline identificationProvisions should be made for the distinctive marking of

pumps, valves and pipelines to identify the service andtanks which they serve.

5/4B.3.4.3 For access through vertical openings, or5/4B.3.7 Bow or stern loading and unloadingmanholes providing passage through the length and

arrangementsbreadth of the space, the minimum clear opening shouldbe not less than 600 mm by 800 mm, at a height of not 5/4B.3.7.1 Subject to the approval of the Administration,more than 600 mm from the bottom shell plating unless cargo piping may be fitted to permit bow or stern loadinggratings or other footholds are provided. and unloading. Portable arrangements should not be per-

mitted.5/4B.3.4.4 Smaller dimensions may be approved by theAdministration in special circumstances, if the ability to 5/4B.3.7.2 Bow or stern loading and unloading linestraverse such openings or to remove an injured person can should not be used for the transfer of products requiredbe proved to the satisfaction of the Administration. to be carried in type 1 ships. Bow and stern loading and

unloading lines should not be used for the transfer of car-goes emitting toxic vapours required to comply with 5/

5/4B.3.5 Bilge and ballast arrangements 4B.15.12.1, unless specifically approved by the Adminis-5/4B.3.5.1 Pumps, ballast lines, vent lines and other tration.

similar equipment serving permanent ballast tanks should 5/4B.3.7.3 In addition to 5/4B.5.1, the following provi-be independent of similar equipment serving cargo tanks sions apply:and of cargo tanks themselves. Discharge arrangements .1 The piping outside the cargo area should be fitted atfor permanent ballast tanks sited immediately adjacent to least 760 mm inboard on the open deck. Such pipingcargo tanks should be outside machinery spaces and accom- should be clearly identified and fitted with a shutoffmodation spaces. Filling arrangements may be in the ma- valve at its connection to the cargo piping systemchinery spaces provided that such arrangements ensure within the cargo area. At this location, it should alsofilling from tank deck level and nonreturn valves are fitted. be capable of being separated by means of a remov-

5/4B.3S.5.1 Interpretation of 5/4B.3.5.1 (IMO) able spool piece and blank flanges when not in use.An eductor situated in the cargo area using water power .2 The shore connection should be fitted with a shutofffrom the machinery spaces is acceptable for discharge pur- valve and a blank flange.poses provided a non-return valve and means of separation .3 The piping should be full penetration butt welded,are fitted in the supply line and the supply line is above and fully radiographed. Flange connections in thedeck level. A non-return valve and means of separation piping should only be permitted within the cargoshould be located outside the machinery space. (see figure area and at the shore connection.5/4B.4) .4 Spray shields should be provided at the connections

5/4B.3.5.2 Filling of ballast in cargo tanks may be ar- specified in .1 as well as collecting trays of sufficientranged from deck level by pumps serving permanent ballast capacity with means for the disposal of drainage.tanks, provided that the filling line has no permanent con- .5 The piping should be self-draining to the cargo areanection to cargo tanks or piping and that nonreturn valves and preferably into a cargo tank. Alternative arrange-are fitted. ments for draining the piping may be accepted by

the Administration.5/4B.3S.5.2 Interpretation of 5/4B.3.5.2 (IMO)The filling arrangement may consist of a portable spool .6 Arrangements should be made to allow such piping

to be purged after use and maintained gas-safe whenpiece or flexible hose plus an isolating valve on the inletto the cargo tank. This isolating valve is in addition to the not in use. The vent pipes connected with the purge

should be located in the cargo area. The relevantrequired non-return valve. Consideration should be givento the arrangement of in-tank piping and the creation of connections to the piping should be provided with a

shutoff valve and blank flange.static electricity.


5/4B.3.7.4 Entrances, air inlets and openings to accom- be stressed in the same manner and by the same loadswhich stress the contiguous hull structure and which ismodation, service and machinery spaces and control sta-

tions should not face the cargo shore connection location normally essential to the structural completeness of theship’s hull.of bow or stern loading and unloading arrangements. They

should be located on the outboard side of the superstruc- 5/4B.4.1.3 Gravity tank means a tank having a designpressure not greater than 0.7 bar gauge at the top of theture or deckhouse at a distance of at least 4% of the length

of the ship but not less than 3 m from the end of the house tank. A gravity tank may be independent or integral. Agravity tank should be constructed and tested accordingfacing the cargo shore connection location of the bow or

stern loading and unloading arrangements. This distance, to the standards of the Administration taking account ofthe temperature of carriage and relative density of thehowever, need not exceed 5 m. Sidescuttles facing the

shore connection location and on the sides of the super- cargo.5/4B.4.1.4 Pressure tank means a tank having a designstructure or deckhouse within the distance mentioned

above should be of the fixed (non-opening) type. In addi- pressure greater than 0.7 bar gauge. A pressure tank shouldbe an independent tank and should be of a configurationtion, during the use of the bow or stern loading and un-

loading arrangements, all doors, ports and other openings permitting the application of pressure vessel design criteriaaccording to the standards of the Administration.on the corresponding superstructure or deckhouse side

should be kept closed. Where, in the case of small ships,compliance with 5/4B.3.2.3 and this paragraph is not possi- 5/4B.4S.1a Integral Tanks (ABS) (1994)ble, the Administration may approve relaxations from the Tankers designed for the carriage of chemical cargoes inabove requirements. integral tanks are to be designed and constructed in

5/4B.3.7.5 Air pipes and other openings to enclosed accordance with these Rules. The scantlings of the tankspaces not listed in 5/4B.3.7.4 should be shielded from any boundaries, plating, stiffeners, etc. are to be not lessspray which may come from a burst hose or connection. than required by Section 5/2 as modified below.

5/4B.3.7.6 Escape routes should not terminate within1 PV Valve Setting Where integral tanks are fitted withthe coamings required by 5/4B.3.7.7 or within a distance

pressure/vacuum relief valves in tank venting system,of 3 m beyond the coamings.the valves are to be set within 0.7 bar (0.71 kgf/ cm2,5/4B.3.7.7 Continuous coamings of suitable height 10.2 psi) above atmospheric and 0.07 bar (0.07 kgf/

should be fitted to keep any spills on deck and away from cm2, 1.0 psi) below atmospheric.the accommodation and service areas.

2 Scantling Head The scantling head h in m (ft) is to be5/4B.3S.7 Interpretation of 5/4B.3.7.7 (IMO)taken as the greater of hn or ho as defined below.The expression ‘‘suitable height’’ should mean the height

a Normal Head (hn)of coaming to be of approximately 150 mm, however no-hn = pht + ha m (ft)where less than 50 mm above upper edge of sheer strake.

where5/4B.3.7.8 Electrical equipment within the coamings re-quired by 5/4B.3.7.7 or within a distance of 3 m beyond the p= 1.0 where the specific gravity of liquid is 1.05 or lesscoamings should be in accordance with the requirements of = specific gravity of the liquid where it is in excess5/4B.10. of 1.05

5/4B.3.7.9 Fire-fighting arrangements for the bow or ht= the distance in m (ft) from the lower edge of the platestern loading and unloading areas should be in accordance or the middle of the area supported to the top of thewith 5/4B.11.3.16. tank at side

5/4B.3.7.10 Means of communication between the cargo ha= the greater of ha1 or ha2 and not less than the distancecontrol station and the cargo shore connection location in m (ft) to the top of the hatch.should be provided and certified safe, if necessary. Provi- ha1= 0.02L for 61m (200ft.) < L ≤ 122 m (400 ft.)sion should be made for the remote shutdown or cargo = 2.44m (8 ft) for L > 122 m (400 ft.)pumps from the cargo shore connection location. ha2= 9.95 pv (9.75 pv, 2.25 pv)

pv= pressure-vacuum valve pressure setting in bar (kgf/5/4B.4 Cargo Containment cm2, psi)

5/4B.4.1 Definitions b Overflow condition ho5/4B.4.1.1 Independent tank means a cargo containmentenvelope which is not contiguous with, or part of, the hull ho= (2/3)(p hs + 9.95 ps) m (ps in bar)

= (2/3)(p hs + 9.75 ps) m (ps in kgf/cm2)structure. An independent tank is built and installed so asto eliminate whenever possible (or in any event to mini- = (2/3)(p hs + 9.75 ps) m (ps in psi)

wheremize) its stressing as a result of stressing or motion ofthe adjacent hull structure. An independent tank is not hs= head in m (ft) to the spill valve or rupture disk

ps= relieving pressure in bar (kgf/cm2, psi)of spill valveessential to the structural completeness of the ship’s hull.5/4B.4.1.2 Integral tank means a cargo containment en- or rupture disc.

Where no spill valve or rupture disc is fitted, hs is tovelope which forms part of the ship’s hull and which may


b = allowance for bending (mm). The value of b shouldbe taken to the highest point the liquid may rise andps may be taken as zero. be chosen so that the calculated stress in the bend,

due to internal pressure only, does not exceed the3 Liquid Level Control Provision is to be made to guard allowable stress. Where such justification is not given,

against liquid rising to a height that would exceed theb should be not less than:

above and this may be done using high level alarms,overflow control systems, or spill valves together with

b =Dto

2.5r(mm)gauging and tank filling procedures.

5/4B.4S.1b Independent Gravity Tanks with1 PV Valve Setting Where independent gravity tanksr = mean radius of the bend (mm).are fitted with pressure/vacuum relief valves in tankc = corrosion allowance (mm). If corrosion or erosionventing system, the valves are to be set within 0.7 bar is expected, the wall thickness of piping should be(0.71 kgf/cm2, 10.2 psi) above atmospheric, and 0.07 increased over that required by the other design re-bar (0.07 kgf/cm2, 1.0 psi) below atmospheric. quirements.2 Scantling Head and Liquid Level Control Independenta = negative manufacturing tolerance for thickness (%).gravity tanks are to comply with the requirements in

5/4B.5.1.2 The design pressure P in the formula for to5.4B.4S.1a except that where piping arrangements arein 5/4B.5.1.1 is the maximum gauge pressure to which thesuch that the independent tank cannot be filled withsystem may be subjected in service, taking into accountballast water, p need not be taken in excess of thethe highest set pressure on any relief valve on the system.actual specific gravity of the liquid.

5/4B.5.1.3 Piping and piping system components whichAdditionally, h2 is not to be less than 2.4m (7.9ft) forare not protected by a relief valve, or which may be isolatedphosphorus tanks. See 5/4B.15.7.2from their relief valve, should be designed for at least the5/4B.4S.1c Carriage of Heated Cargoesgreatest of:Where cargoes are to be carried at high temperatures,

.1 for piping systems or components which may containconsideration is to be given to loading arrangement ofsome liquid, the saturated vapour pressure at 45 C;heated cargoes, temperature distribution and thermal

.2 the pressure setting of the associated pump dischargestresses induced by heating (See also 5/4B.7 and 5/relief valve;4B.16.6).

.3 the maximum possible total pressure head at the out-let of the associated pumps when a pump discharge5/4B.4.2 Tank type requirements for individualrelief valve is not installed.products

5/4B.5.1.4 The design pressure should not be less thanRequirements for both installation and design of tank10 bar gauge except for open-ended lines where it shouldtypes for individual products are shown in column ‘‘f’’ inbe not less than 5 bar gauge.the table of 5/4B.17.

5/4B.5.1.5 For pipes, the allowable stress to be consid-5/4B.5 Cargo Transfer ered in the formula for to in 5/4B.5.1.1 is the lower of the

following values:5/4B.5.1 Piping scantlings

5/4B.5.1.1 Subject to the conditions stated in 5/4B.5.1.4 Rm

Aor

Re

Bthe wall thickness (t) of pipes should not be less than:where:

t =to + b + c

1 −a

100

(mm) Rm = specified minimum tensile strength at ambient tem-perature (N/ mm2)

Re = specified minimum yield stress at ambient tempera-ture (N/ mm2). If the stress-strain curve does notwhere:show a defined yield stress, the 0.2% proof stressto = theoretical thicknessapplies.

to = PD/(20 Ke + P ) (mm) A and B should have values of at leastA = 2.7 and B = 1.8with5/4B.5.1.6.1 The minimum wall thickness should be inP = design pressure (bar) referred to in 5/4B.5.1.2

accordance with Recognized StandardsD = outside diameter (mm)K = allowable stress (N/mm2) referred to in 5/4B.5.1.5 5/4B.5.1.6.2 Where necessary for mechanical strength

to prevent damage, collapse, excessive sag or buckling ofe = efficiency factor; equal to 1.0 for seamless pipes andfor longitudinally or spirally welded pipes, delivered pipes due to weight of pipes and content and to superim-

posed loads from supports, ship deflection or other causes,by manufacturers approved for making welded pipeswhich are considered by the Administration as equiv- the wall thickness should be increased over that required

by 5/4B.5.1.1 or, if this is impracticable or would causealent to seamless pipes. In other cases the e value isto be determined by the Administration depending excessive local stresses, these loads should be reduced,

protected against or eliminated by other design methods.on the manufacturing process and testing procedure.


5/4B.5.1.6.3 Flanges, valves and other fittings should be 5/4B.5.4 Test requirements for pipingto a standard acceptable to the Administration, taking into 5/4B.5.4.1 The test requirements of this section applyaccount the design pressure defined under 5/4B.5.1.2. (Also to piping inside and outside cargo tanks. However, thesee 4/6.11.2 and 4/6.15) Administration may accept relaxations from these require-

ments for piping inside cargo tanks and open-ended piping.5/4B.5.1.6.4 For flanges not complying with a standardthe dimensions for flanges and associated bolts should be 5/4B.5.4.2 After assembly, each cargo piping systemto the satisfaction of the Administration. (Also see 4/6.11.2 should be subject to a hydrostatic test to at least 1.5 timesand 4/6.15) the design pressure. When piping systems or parts of sys-

tems are completely manufactured and equipped with allfittings, the hydrostatic test may be conducted prior to5/4B.5.2 Piping fabrication and joining detailsinstallation aboard the ship. Joints welded on board should5/4B.5.2.1 The requirements of this section apply tobe hydrostatically tested to at least 1.5 times the designpiping inside and outside the cargo tanks. However, thepressure.Administration may accept relaxations from these require-

5/4b.5.4.3 After assembly on board, each cargo pipingments for open-ended piping and for piping inside cargosystem should be tested for leaks to a pressure dependingtanks except for cargo piping serving other cargo tanks.on the method applied.5/4B.5.2.2 Cargo piping should be joined by welding

except:.1 for approved connections to shutoff valves and expan- 5/4B.5.5 Piping arrangements

sion joints; and 5/4B.5.5.1 Cargo piping should not be installed under.2 for other exceptional cases specifically approved by deck between the outboard side of the cargo containment

the Administration. spaces and the skin of the ship unless clearances required5/4B.5S.2 Interpretation of 5/4B.5.2.2.2 (IMO) for damage protection (see 5/4B.2.6) are maintained; but

Cargo piping should be welded except for necessary such distances may be reduced where damage to the pipeflanged connections to valves, expansion joints (as permit- would not cause release of cargo provided that the clear-ted in 5/4B.5.2.2.1), spool pieces and similar fittings or ance required for inspection purposes is maintained.where required for coating, lining, fabrication, inspection 5/4B.5.5.2 Cargo piping, located below the main deck,or maintenance. may run from the tank it serves and penetrate tank bulk-

5/4B.5.2.3 The following direct connections of pipe heads or boundaries common to longitudinally or transver-lengths, without flanges may be considered: sally adjacent cargo tanks, ballast tanks, empty tanks,

.1 Butt welded joints with complete penetration at the pump-rooms or cargo pump-rooms provided that insideroot may be used in all applications. the tank it serves it is fitted with a stop valve operable

.2 Slip-on welded joints with sleeves and related weld- from the weather deck and provided cargo compatibilitying having dimensions satisfactory to the Administra- is assured in the event of piping failure. As an exception,tion should only be used for pipes with an external where a cargo tank is adjacent to a cargo pump-room, thediameter of 50 mm or less. This type of joint should stop valve operable from the weather deck may be situatednot be used when crevice corrosion is expected to on the tank bulkhead on the cargo pump-room side, pro-occur vided an additional valve is fitted between the bulkhead

.3 Screwed connections acceptable to the Administra- valve and the cargo pump. The Administration may, how-tion should only be used for accessory lines and in- ever, accept a totally enclosed hydraulically operated valvestrumentation lines with external diameters of 25 mm located outside the cargo tank, provided that the valve is:or less. .1 designed to preclude the risk of leakage;

5/4B.5.2.4 Expansion of piping should normally be al- .2 fitted on the bulkhead of the cargo tank which itlowed for by the provision of expansion loops or bends in serves;the piping system. .3 suitably protected against mechanical damage;

.1 Bellows may be specially considered by the Adminis- .4 fitted at a distance from the shell, as required fortration in each case. damage protection; and

.2 Slip joints should not be used. .5 operable from the weather deck.5/4B.5.2.5 Welding, post weld heat treatment and non- 5/4B.5S.5 Interpretation of 5/4B.5.5.2.1 (IMO)

destructive testing should be performed in accordance with The intent is to guard against the hazard of cargo leakingRecognized Standards. past a valve gland into the space where the valve is located.

5/4B.5.5.3 In any cargo pump-room where a pump5/4B.5.3 Flange connections serves more than one tank, a stop valve should be fitted

in the line to each tank.5/4B.5.3.1 Flanges should be of the welded neck, slip-on or socket welded type. However, socket welded type 5/4B.5.5.4 Cargo piping installed in pipe tunnels shouldflanges should not be used in nominal size above 50 mm. also comply with the requirements of 5/4B.5.5.1 and 5/

4B.5.5.2. Pipe tunnels should satisfy all tank requirements5/4B.5.3.2 Flanges should comply with standards ac-ceptable to the Administration as to their type, manufacture for construction, location and ventilation and electrical haz-

ard requirements. Cargo compatibility should be assuredand test.


in the event of a piping failure. The tunnel should not have The hose temperature during this prototype test shouldbe the intended extreme service temperature. Hoses usedany other openings except to the weather deck and cargo

pump-room or pump-room. for prototype testing should not be used for cargo service.Thereafter, before being placed in service, each new length5/4B.5.5.5 Cargo piping passing through bulkheadsof cargo hose produced should be hydrostatically tested atshould be so arranged as to preclude excessive stresses atambient temperature to a pressure not less than 1.5 timesthe bulkhead and should not utilize flanges bolted throughits specified maximum working pressure but not more thanthe bulkhead.two-fifths of its bursting pressure. The hose should bestencilled or otherwise marked with its specified maximum5/4B.5.6 Cargo transfer control systemsworking pressure and, if used in other than ambient tem-5/4B.5.6.1 For the purpose of adequately controlling theperature services, its maximum and minimum service tem-cargo, cargo transfer systems should be provided with:perature as applicable. The specified maximum working.1 one stop valve capable of being manually operatedpressure should not be less than 10 bar gauge.on each tank filling and discharge line, located near

the tank penetration; if an individual deepwell pump5/4B.6 Materials of Constructionis used to discharge the contents of a cargo tank, a

stop valve is not required on the discharge line of5/4B.6.1 Generalthat tank;

.2 one stop valve at each cargo hose connection; 5/4B.6.1.1 Structural materials used for tank construc-

.3 remote shutdown devices for all cargo pumps and tion, together with associated piping, pumps, valves, ventssimilar equipment. and their jointing materials, should be suitable at the tem-

perature and pressure for the cargo to be carried to the5/4B.5S.6 Interpretation of 5/4B.5.6.1.1 (IMO)satisfaction of the Administration. Steel is assumed to beThe provisions of 5/4B.5.6.1.1 are not intended to be addi-the normal material of construction.tional to those of 5/4B.5.5.2 and 5/4B.5.5.3 for cargo piping

below deck. 5/4B.6.1.2 Where applicable the following should betaken into account in selecting the material of construction:5/4B.5.6.2 The controls necessary during transfer or

.1 notch ductility at the operating temperature;transport of cargoes covered by the Code other than in

.2 corrosive effect of the cargo;cargo pump-rooms which have been dealt with elsewhere

.3 possibility of hazardous reactions between the cargoin the Code should not be located below the weather deck.and the material of construction; and5/4B.5.6.3 For certain products additional cargo transfer

.4 suitability of linings;control requirements are shown in column ‘‘o’’ in the tableof 5/4B.17.

5/4B.5S.6.4 (1994) Where provided, remote or auto- 5/4B.6.2 Special requirements for materialsmatic cargo transfer control systems are to comply with 4/ 5/4B.6.2.1 For certain products special requirements11.27. (ABS) apply in respect of materials indicated by symbols in col-

umn ‘‘m’’ in the table of 5/4B.17, as stipulated in 5/4B.6.2.2,5/4B.5.7 Ship’s cargo hoses 5/4B.6.2.3 and 5/4B.6.2.4.

5/4B.5.7.1 Liquid and vapour hoses used for cargo trans- 5/4B.6.2.2 The following materials of constructionfer should be compatible with the cargo and suitable for should not be used for tanks, pipelines, valves, fittings andthe cargo temperature. other equipment, which may come into contact with the

5/4B.5S.7 Interpretation of 5/4B.5.7.1 (IMO) products of their vapour where referred to in column ‘‘m’’This paragraph applies to cargo hoses carried on board the in the table of 5/4B.17:vessel and ‘‘compatibility with the cargo’’ means that: N1 Aluminium, copper, copper alloys, zinc, galvanized

.1 the cargo hose does not lose its mechanical strength steel and mercury.or deteriorate unduly when in contact with the N2 Copper, copper alloys, zinc and galvanized steel.cargo, and N3 Aluminium, magnesium, zinc, galvanized steel and

.2 the cargo hose material does not affect the cargo in lithium.a hazardous way. N4 Copper and copper-bearing alloys.

Consideration must be given to internal and external N5 Aluminium, copper and alloys of either.surfaces with respect to the above where hoses may be N6 Copper, silver, mercury, magnesium and other ace-used as an integral part of, or connected to emergency tylide-forming metals and their alloys.cargo pumps and submerged in the cargo tank. N7 Copper and copper-bearing alloys with greater than

1% copper.5/4B.5.7.2 Hoses subject to tank pressure or the dis-N8 Aluminium, zinc, galvanized steel and mercury.charge pressure of pumps should be designed for a bursting

pressure not less than 5 times the maximum pressure the 5/4B.6S.2 Interpretation of 5/4B.6.2.2 & 5/4B.6.2.4hose will be subjected to during cargo transfer. (IMO)

Cargo pump-room structure, fittings and equipment other5/4B.5.7.3 Each new type of cargo hose, complete withend fittings, should be prototype tested to a pressure not than electrical apparatus, which are normally only exposed

to vapours from the pump-room bilges are not subject toless than 5 times its specified maximum working pressure.


the requirements of these paragraphs. Electrical items are for individual substances as shown in column ‘‘j’’ inthe table of 5/4B.17.subject to 5/4B.6.2.3.

.2 A restricted temperature measuring device is subject5/4B.6.2.3 Materials normally used in electrical appara-to the definition for a restricted gauging device intus, such as copper, aluminium and insulation, should as5/4B.13.1.1.2, e.g., a portable thermometer loweredfar as practicable be protected, e.g. by encapsulation, toinside a gauge tube of the restricted type.prevent contact with vapours of products where referred

.3 A closed temperature measuring device is subject toto by Z in column ‘‘m’’ in the table of 5/4B.17.the definition for closed gauging device in 5/5/4B.6.2.4 The following materials of construction4B.13.1.1.3, e.g. a remote-reading thermometer ofwhich may come into contact with certain products or theirwhich the sensor is installed in the tank.vapour should be used for tanks, pipelines, valves, fittings

.4 When overheating or overcooling could result in aand other equipment, where referred to in column ‘‘m’’ indangerous condition, an alarm system which monitorsthe table of 5/4B.17 as follows: (See 5/4B 6S.2)the cargo temperature should be provided. (See alsoY1 Steel covered with a suitable protective lining oroperational requirements in 5/4B.16.6)coating, aluminum or stainless steel.

5/4B.7.1.6 When products for which 5/4B.15.12, 5/Y2 Aluminium or stainless steel for product concentra-4B.15.12.1 or 5/4B.15.12.3 are listed in column ‘‘o’’ in thetions of 98% or more.table of 5/4B.17 are being heated or cooled, the heatingY3 Special acid-resistant stainless steel for product con-or cooling medium should operate in a circuit:centrations of less than 98%.

.1 which is independent of other ship’s services, exceptY4 Solid austenitic stainless steel.for another cargo heating or cooling system, andY5 Steel covered with suitable protective lining or coat-which does not enter the machinery space; oring or stainless steel.

.2 which is external to the tank carrying toxic prod-5/4B.6.2.5 Materials of construction having a meltingucts; orpoint below 925°C, e.g. aluminium and its alloys, should

.3 where the medium is sampled to check for the pres-not be used for external piping involved in cargo handlingence of cargo before it is recirculated to other servicesoperations on ships intended for the carriage of productsof the ship or into the machinery space. The samplingwith flashpoints not exceeding 60°C (closed cup test) unlessequipment should be located within the cargo areaso specified in column ‘‘m’’ in the table of 5/4B.17. Shortand be capable of detecting the presence of any toxiclengths of external pipes connected to cargo tanks may becargo being heated or cooled. Where this method ispermitted by the Administration if they are provided withused, the coil return should be tested not only atfire-resistant insulation.the commencement of heating or cooling of a toxicproduct, but also on the first occasion the coil isused subsequent to having carried an unheated or5/4B.7 Cargo Temperature Controluncooled toxic cargo.

5/4B.7S.1.6.3 Interpretation of 5/4B.7.1.6.3 (ABS)5/4B.7.1 GeneralThe sampling equipment may be of portable or fixed type.5/4B.7.1.1 When provided, any cargo heating or cooling

systems should be constructed, fitted and tested to thesatisfaction of the Administration. Materials used in the 5/4B.7.2 Additional requirementsconstruction of temperature control systems should be suit- For certain products, additional requirements containedable for use with the product intended to be carried. in 5/4B.15 are shown in column ‘‘o’’ in the table of 5/ 4B.17.

5/4B.7.1.2 Heating or cooling media should be of a typeapproved for use with the specific cargo. Consideration 5/4B.8 Cargo Tank Venting and Gas-Freeingshould be given to the surface temperature of heating Arrangements (1 July 1994)coils or ducts to avoid dangerous reactions from localizedoverheating or overcooling of cargo. (See also 5/4B.15.13.6.)

5/4B.8.1 Application5/4B.7.1.3 Heating or cooling systems should be pro-5/4B.8.1.1 This subsection 5/4B.8 applies to ships con-vided with valves to isolate the system for each tank and

structed on or after 1 January 1994.to allow manual regulation of flow.5/4B.8.1.2 Ships constructed before 1 January 19945/4B.7.1.4 In any heating or cooling system, means

should comply with the requirements of subsection 5/4B.8should be provided to ensure that, when in any conditionwhich were in force prior to the above date.other than empty, a higher pressure can be maintained

5/4B.8.1.3 For the purpose of the requirements in thiswithin the system than the maximum pressure head thatsubsection, the term ‘‘ship constructed’’ is as defined incould be exerted by the cargo tank contents on the system.regulation II-1/1.3.1 of the 1974 SOLAS Convention as5/4B.7.1.5 Means should be provided for measuring theamended.cargo temperature.

.1 The means for measuring the cargo temperature 5/4B.8.1.4 Ships constructed on or after 1 July 1986but before 1 January 1994 which fully comply with theshould be of restricted or closed type, respectively,

when a restricted or closed gauging device is required requirements of the Code applicable at that time may be


regarded as complying with the requirements of regulation Code, should be similarly lined or coated, or constructedof corrosion-resistant material.II-2/59 of SOLAS 74.

5/4B.8.2.6 The master should be provided with the max-5/4B.8.1.5 For ships to which the Code applies, theimum permissible loading and unloading rates for eachrequirements of this subsection should apply in lieu oftank or group of tanks consistent with design of the ventingregulation II-2/59.1 and 59.2 of the 1974 SOLAS Conven-systems.tion, as amended.

5/4B.8.3 Types of tank vent systems5/4B.8.2 Cargo Tank Venting 5/4B.8.3.1 An open tank venting system is a system

which offers no restriction except for friction losses to the5/4B.8.2.1 All cargo tanks should be provided with afree flow of cargo vapours to and from the cargo tanksventing system appropriate to the cargo being carried andduring normal operations. An open venting system maythese systems should be independent of the air pipes andconsist of individual vents from each tank, or such individ-venting systems of all other compartments of the ship.ual vents may be combined into a common header orTank venting systems should be designed so as to minimizeheaders, with due regard to cargo segregation. In no casethe possibility of cargo vapour accumulating about theshould shutoff valves be fitted either to the individual ventsdecks, entering accommodation, service and machineryor to the header.spaces and control stations and, in the case of flammable

vapours entering or collecting in spaces or areas containing 5/4B.8.3.2 A controlled tank venting system is a systemin which pressure and vacuum relief valves or pressure/sources of ignition. Tank venting systems should be ar-

ranged to prevent entrance of water into the cargo tanks vacuum valves are fitted to each tank to limit the pressureor vacuum in the tank. A controlled venting system mayand at the same time, vent outlets should direct the vapour

discharge upwards in the form of unimpeded jets. consist of individual vents from each tank or such individualvents, on the pressure side only as may be combined into5/4B.8.2.2 The venting systems should be connected toa common header or headers with due regard to cargothe top of each cargo tank and as far as practicable thesegregation. In no case should shutoff valves be fitted eithercargo vent lines should be self-draining back to the cargoabove or below pressure or vacuum relief valve or pressure/tanks under all normal operational conditions of list andvacuum valves. Provision may be made for bypassing atrim. Where it is necessary to drain venting systems abovepressure or vacuum relief valve or pressure/vacuum valvethe level of any pressure/vacuum valve, capped or pluggedunder certain operating conditions provided that the re-drain cocks should be provided.quirement of 5/4B.8.3.5 is maintained and that there is5/4B.8.2.3 Provision should be made to ensure that thesuitable indication to show whether or not the valve isliquid head in any tank does not exceed the design headbypassed.of that tank. Suitable high-level alarms, overflow control

5/4B.8.3.3 The position of vent outlets of a controlledsystems or spill valves, together with gauging and tanktank venting system should be arranged:filling procedures may be accepted for this purpose. Where

.1 at a height of not less than 6 m above the weatherthe means of limiting cargo tank overpressure includes andeck or above a raised walkway if fitted within 4 mautomatic closing valve, the valve should comply with theof the raised walkway:appropriate provisions of 5/4B.15.19.

.2 at a distance of at least 10 m measured horizontally5/4B.8S.1 Interpretation of 5/4B.8.2.3 (IMO)from the nearest air intake or opening to accommoda-When large amounts of drainage from vent lines is envis-tion, service and machinery spaces and ignitionaged provision for a hose connection to a drain line drainingsources.to a suitable slop tank should be provided.

5/4B.8.3.4 The vent outlet height referred to in 5/5/4B.8.2.4 Tank venting systems should be designed4B.8.3.3.1 may be reduced to 3 m above the deck or aand operated so as to ensure that neither pressure norraised walkway, as applicable, provided that high velocityvacuum crated in the cargo tanks during loading or un-venting valves of a type approved by the Administrationloading exceeds tank design parameters. The main factorsdirecting the vapour/air mixture upwards in an unimpededto be considered in the sizing of a tank venting system arejet with an exit velocity of at least 30 m/s are fitted.as follows:

5/4B.8.3.5 Controlled tank venting systems fitted to.1 design loading and unloading rate;tanks to be used for cargoes having a flashpoint not ex-.2 gas evolution during loading: this should be takenceeding 60°C (closed cup test) should be provided withaccount of by multiplying the maximum loading ratedevices to prevent the passage of flame into the cargoby a factor of at least 1.25;tanks. The design, testing and locating of the devices should.3 density of the cargo vapour mixture;comply with the requirements of the Administration which.4 pressure loss in vent piping and across valves andshould contain at least the standards adopted by the Orga-fittings;nization.T.5 pressure/vacuum settings of relief devices.

5/4B.8.2.5 Tank vent piping connected to cargo tanks T Reference is made to the Revised Standards for the Design, Testingof corrosion-resistant material, or to tanks which are lined and Locating of Devices to Prevent the Passage of Flame into Cargo

Tanks in Tankers (MSC/Circ.373/Rev.1).or coated to handle special cargoes, as required by the


5/4B.8.3.6 In designing venting systems and in the se- .3 flow characteristics of fans to be used;.4 the pressure losses created by ducting, piping, cargolection of devices to prevent the passage of flame for incor-

poration into the tank venting system, due attention should tank inlets and outlets;.5 the pressure achievable in the fan driving mediumbe paid to the possibility of the blockage of these systems

and fittings by, for example, the freezing of cargo vapour, (e.g., water or compressed air);.6 the densities of the cargo vapour/air mixtures for thepolymer build up, atmospheric dust or icing up in adverse

weather conditions. In this context it should be noted that range of cargoes to be carried.flame arresters and flame screens are more susceptible to 5/4B.8S.2 Interpretation of 5/4B.8 (IMO)blockage. Provisions should be made such that the system Proposal for Venting Arrangements on Board Chemicaland fittings may be inspected, operationally checked, Tankerscleaned or renewed as applicable. The following arrangement may be accepted as providing a

level of protection equivalent to that requested by SOLAS, regula-5/4B.8.3.7 Reference in 5/4B.8.3.1 and 5/4B.8.3.2 to thetion II-2/59.1.5 and contained in the annex to MSC/Circ.373/use of shutoff valves in the vent lines should be interpretedRev.1. The arrangement may be used on non-inerted or inertedto extend to all other means of stoppage, including specta-cargo tanks with vent pipe sizes up to and including 100 mm incle blanks and blank flanges.diameter.1 Piping systems referred to in 5/4B.8 may be provided with the5/4B.8.4 Venting requirements for individualfollowing;products

.1 pressure/vacuum valves with the following characteristics:Venting requirements for individual products are shown— constructed in accordance with the appropriate sectionsin column ‘‘g’’ and additional requirements in column

of MSC/Circ.373/Rev. 1 excluding the type test proce-‘‘o’’ in the table of 5/4B.17.dures for flame arresting capabilities:

— opening overpressure of at least 0.18 bar;5/4B.8.5 Cargo tank gas-freeingTT

.2 a flame-arresting device fitted at the pipe outlet which has5/4B.8.5.1 The arrangements for gas-freeing cargo tanks been tested for flashback in accordance with paragraph 3.2.2

used for cargoes other than those for which open venting and, where applicable, paragraph 2.5.4 of MSC/Circ.373/is permitted should be such as to minimize the hazards Rev.1;due to the dispersal of flammable or toxic vapours in the .3 the vacuum side of the valve to be protected with a flames-atmosphere and to flammable or toxic vapour mixtures in creen as defined in MSC/Circ.373/Rev.1 or a device testeda cargo tank. Accordingly, gas-freeing operations should for flashback.be carried out such that vapour is initially discharged: 2 It should be ensured that when the valve is open a minimum

.1 through the vent outlets specified in 5/4B.8.3.3 and flow velocity of at least 10 m/sec is maintained at the outlet of5/4B.8.3.4; or the assembly above the flame-arresting device.

.2 through outlets at least 2 m above the cargo tank5/4B.9 Environmental Controldeck level with a vertical efflux velocity of at least

30 m/s maintained during the gas freeing operation; or5/4B.9.1 General.3 through outlets at least 2 m above the cargo tank

5/4B.9.1.1 Vapour spaces within cargo tanks and, indeck level with a vertical efflux velocity of at leastsome cases, spaces surrounding cargo tanks may be re-20 m/s which are protected by suitable devices toquired to have specially controlled atmospheres.prevent the passage of flame.

5/4B.9.1.2 There are four different types of control forWhen the flammable vapour concentration at the outletscargo tanks, as follows:has been reduced to 30% of the lower flammable limit and

.1 Inerting — by filling the cargo tank and associatedin the case of a toxic product the vapour concentrationpiping systems and, where specified in 5/4B.15, thedoes not present a significant health hazard, gas freeingspaces surrounding the cargo tanks, with a gas ormay thereafter be continued at cargo tank deck level.vapour which will not support combustion and which5/4B.8.5.2 The outlets referred to in 5/4B.8.5.1.2 and 5/will not react with the cargo, and maintaining that4B.8.5.1.3 may be fixed or portable pipes.condition.5/4B.8.5.3 In designing a gas-freeing system in confor-

.2 Padding — by filling the cargo tank and associatedmity with 5/4B.8.5.1 particularly in order to achieve thepiping systems with a liquid, gas or vapour whichrequired exit velocities of 5/4B.8.5.1.2 and 5/4B.8.5.1.3,separates the cargo from the air, and maintaining thatdue consideration should be given to the following:condition..1 materials of construction of system;

.3 Drying — by filling the cargo tank and associated.2 time to gas-free;piping systems with moisture-free gas or vapour witha dewpoint of −40°C or below at atmospheric pres-TT Reference is made to the Revised Factors to be taken into Considerationsure, and maintaining that condition.when Designing Cargo Tanks Venting and Gas-Freeing Arrangements

.4 Ventilation — forced or natural.(MSC/Circ.450/Rev.1) and to the Revised Standards for the Design, Test-5/4B.9.1.3 Where inerting or padding of cargo tanks ising and Locating of Devices to Prevent the Passage of Flame into Cargo

Tanks in Tankers (MSC/Circ.373/Rev.1). required:


.1 An adequate supply of inert gas for use in filling operational requirements contained in the Guidelines forand discharging the cargo tanks should be carried or Inert Gas Systems.T

4 Tankers carrying petroleum products having a flashpointshould be manufactured on board unless a shore sup-ply is available. In addition, sufficient inert gas should exceeding 60°C (closed cup test) as determined by an ap-

proved flashpoint apparatus shall comply with the provi-be available on the ship to compensate for normallosses during transportation. sions of part C, except that in lieu of the fixed fire-extin-

guishing system required in regulation 53 they shall be.2 The inert gas system on board the ship should beable to maintain a pressure of at least 0.07 bar gauge fitted with a fixed deck foam system which shall comply

with the provisions of regulation 61.within the containment system at all times. In addi-tion, the inert gas system should not raise the cargo 5 The requirements for inert gas systems of regulation 60

need not be applied to:tank pressure to more than the tank’s relief valvesetting. .1 chemical tankers constructed before, on or after 1 July

1986 when carrying cargoes described in paragraph 1,.3 Where padding is used, similar arrangements for sup-ply of the padding medium should be made as re- provided that they comply with the requirements for

inert gas systems on chemical tankers developed byquired for inert gas in .1 and .2..4 Means should be provided for monitoring ullage the OrganizationT; or

.2 chemical tankers constructed before 1 July 1986,spaces containing a gas blanket to ensure that thecorrect atmosphere is being maintained. when carrying crude oil or petroleum products, pro-

vided that they comply with the requirements for.5 Inerting or padding arrangements or both, whereused with flammable cargoes, should be such as to inert gas systems on chemical tankers carrying petro-

leum products developed by the OrganizationTT; orminimize the creation of static electricity during theadmission of the inerting medium. .3 gas carriers constructed before, on or after 1 July

1986 when carrying cargoes described in paragraph 1,5/4B.9.1.4 Where drying is used and dry nitrogen isprovided that they are fitted with cargo tank inertingused as the medium, similar arrangements for supply ofarrangements equivalent to those specified in para-the drying agent should be made to those required ingraph 5.1 or 5.2; or5/4B.9.1.3. Where drying agents are used as the drying

.4 chemical tankers and gas carriers when carrying flam-medium on all air inlets to the tank, sufficient mediummable cargoes other than crude oil or petroleum prod-should be carried for the duration of the voyage, takingucts such as cargoes listed in chapters VI and VII ofinto consideration the diurnal temperature range and thethe Code for the Construction and Equipment ofexpected humidity.Ships Carrying Dangerous Chemicals in Bulk or5/4B.9S.1 Amendments to SOLAS (IMO)chapters 17 and 18 of the International Code forSOLAS has been amended by MSC.13 (57) and comes intothe Construction and Equipment of Ships Carryingforce on 1 February 1992 which revises the requirementsDangerous Chemicals in Bulk:on inert gas systems on some liquefied gas carriers and

.4.1 if constructed before 1 July 1986; orchemical carriers and the revised text of Regulations II-2/

.4.2 if constructed on or after 1 July 1986, provided that55 to read as follows:the capacity of tanks used for their carriage does notexceed 3,000 m3 and the individual nozzle capacitiesof tank washing machines do not exceed 17.5 m3/h andRegulation 55

Application the total combined throughput from the number ofmachines in use in a cargo tank at any one time does1 Unless expressly provided otherwise, this part shall

apply to tankers carrying crude oil and petroleum products not exceed 110 m3/h.having a flashpoint not exceeding 60°C (closed cup test),

5/4B.9S.1.1 Inert Gas Systems on Chemical Carriersas determined by an approved flashpoint apparatus, and a(IACS) (1996)Reid vapour pressure which is below atmospheric pressure

In addition to 5/4B.9S.1, the following reqirements applyand other liquid products having a similar fire hazard.where an inert gas system based on oil fired inert gas2. Where liquid cargoes other than those referred to ingenerators is fitted on board chemical tankers. Otherparagraph 1 or liquefied gases which introduce additionalsources of inert gas will be specially considered.fire hazards are intended to be carried, additional safety

measures shall be required to the satisfaction of the Admin-5/4B.9S.1.1.1 Alternative to Water Sealistration, having due regard to the provisions of the Interna-As an alternative to the water seal in the inert gas line ontional Bulk Chemical Code, the Bulk Chemical Code, thedeck, an arrangement consising of two shut-off valves inInternational Gas Carrier Code and the Gas Carrier Code,

as appropriate. T Reference is made to Regulation for Inert Gas Systems on Chemical3. This paragraph applies to all ships which are combina- Tankers adopted by the Organization by resolution A.567(14). Seetion carriers. Such ships shall not carry solid cargoes unless Annex E.all cargo tanks are empty of oil and gas-freed or unless the TT Reference is made to Interim Regulation for Inert Gas Systems onarrangements provided in each case are to the satisfaction Chemical Tankers Carrying Petroleum Products, adopted by the Organi-

zation by resolution A.473(XII). See Annex D.of the Administration and in accordance with the relevant


series with a venting valve in between may be accepted by the relevent authorities recognized by the Administra-tion for operation in the flammable atmosphere concerned,provided:as indicated in column ‘‘i’’ in the table of 5/4B.17.a the operation of the valve is automatically executed

5/4B.10.1.6 Absence of information on temperatureand signal(s) for opening/closing are taken from theclass and apparatus group in column ‘‘i’’ in the table of 5/process directly, e.g. inert gas flow or differential pres-4B.17 means that data are not currently available, andsure; andthis should not be confused with the non-flammable (NF)b alarm for faulty operation of the valves is provided, e.g.notation describing some substances. For guidance, indica-the operational status of ‘‘Blower stop’’ and ‘‘supplytion is given if the flashpoint of a substance is in excess ofvalve(s) open’’ is an alarm condition.60°C (closed cup test). In the case of heated cargo, carriagec the valves are to be arranged to automatically closeconditions might need to be established and the require-upon loss of power.ments of 5/4B.10.2.2 applied.

5/4B.9S.1.1.2 Additional Requirements5/4B.10.2 Hazardous locations and types ofThe requirements in 4/6.72.11a, f and hl are to be

equipment and wiringcomplied with.5/4B.10.2.1 The restrictions in this section do not pre-

clude the use of intrinsically safe systems and circuits in5/4B.9.2 Environmental control requirements forall hazardous locations including cargo piping. It is particu-individual productslarly recommended that intrinsically safe systems and cir-The required types of environmental control for certaincuits are used for measurement, monitoring, control andproducts are shown in column ‘‘h’’ in the table of 5/communication purposes.4B.17.

5/4B.10.2.2 Cargoes with a flashpoint exceeding 60°C5/4B.10 Electrical Installations (closed cup test):

.1 Cargo tanks and cargo piping are the only hazardous5/4B.10.1 General locations for such cargoes which have no qualification

in column ‘‘o’’ in the table of 5/4B.17. Submerged5/4B.10.1.1 The provisions of this chapter are applicablecargo pump motors and their associated cables may,into ships carrying cargoes which are inherently, or due toexceptional circumstances for a specific cargo or fortheir reaction with other substances, flammable or corro-a clearly defined range of cargoes, be permitted bysive to the electrical equipment, and should be applied inthe Administration, due consideration having beenconjunction with applicable electrical requirements of partgiven to the chemical and physical characteristicsD, chapter II-1 of the 1983 SOLAS amendments.of the products. Arrangements should be made to5/4B.10.1.2.1 Electrical installations should be such asprevent the energizing of motors and cables in flam-to minimize the risk of fire and explosion from flammablemable gas-air mixtures and to de-energize the motorsproducts. Electrical installations complying with this chap-and cables in the event of low liquid level. Such ater should not be considered a source of ignition for theshutdown should be indicated by an alarm at thepurposes of 5/4B.8.2.2.3, having regard to 5/4B.10.1.4.cargo control station.5/4B.10.1.2.2 Where the specific cargo is liable to dam-

.2 Where electrical equipment is located in a cargoage the materials normally used in electrical apparatus,pump-room, due consideration should be given to thedue consideration should be given to the particular charac-use of types of apparatus which ensure the absence ofteristics of the materials chosen for conductors, insulation,arcs or sparks and hot spots during normal operation,metal parts, etc. as far as necessary, these componentsor which are of a certified safe type.should be protected to prevent contact with gases or va-

.3 Where the cargo is heated to within 15°C of its flash-pours liable to be encountered.point value, the cargo pump-room should be consid-5/4B.10.1.3 The Administration should take appropriateered as a hazardous area as well as areas within 3 msteps to ensure uniformity in the implementation and theof openings from tanks where the cargo is so heated,application of the provisions of this chapter in respect ofand within 3 m of the entrance or ventilation openingselectrical installationsT.to cargo pump-rooms. Electrical equipment installed5/4B.10.1.4 Electrical equipment and wiring should notwithin these locations should be of a certified safebe installed in the hazardous locations referred to in 5/type.4B.10.2, unless essential for operational purposes, when

.4 Where the cargo is heated above its flashpoint value,the exceptions listed in 5/4B.10.2.3 are permitted.the requirements of 5/4B.10.2.3 are applicable.5/4B.10.1.5 Where electrical equipment is installed in

5/4B.10.2.3 For cargoes with a flashpoint not exceedinghazardous locations, as permitted in this chapter, it should60°C (closed cup test) without qualification in column ‘‘o’’be to the satisfaction of the Administration and certifiedin the table of 5/4B.17, the hazardous locations are givenbelow. In addition to intrinsically safe systems and circuits,T Reference is made to the Recommendations published by the Interna-the only electrical installations permitted in hazardous loca-tional Electrotechnical Commission and in particular to Publication

92-502. tions are the following:


.1 Cargo tanks and cargo piping: 5/4B.10S.2 Interpretation of 5/4B.10.2.3.5 (IMO)For this purpose the length of the cargo area on open deckNo additional electrical equipment is permitted.to be measured is to extend between the forward bulkhead.2 Void spaces adjacent to, above or below integralof the foremost cargo tank and the after bulkhead of thetanks.aftermost cargo tank or when independent tanks are fitted.2.1 Through runs of cables. Such cables should be in-the forward bulkhead of the foremost hold space and thestalled in heavy gauge steel pipes with gastightafter bulkhead of the aftermost hold space.joints. Expansion bends should not be fitted in such

.6 Enclosed or semi-enclosed spaces in which pipesspaces.containing cargoes are located; enclosed or semi-.2.2 Electrical depth sounding or log devices and im-enclosed spaces immediately above cargo tanks (e.g.pressed current cathodic protection system anodesbetween decks) or having bulkheads above and inor electrodes. These devices should be housed inline with cargo tank bulkheads; enclosed or semi-gastight enclosures; associated cables should beenclosed spaces immediately above cargo pump-protected as referred to in 5/4B.10.2.3.2.1.rooms or above vertical cofferdams adjoining cargo.3 Hold spaces containing independent cargo tanks:tanks, unless separated by a gastight deck and suit-.3.1 Through runs of cable without any additional pro-ably ventilated; and compartments for cargo hoses:tection.

.6.1 Lighting fittings of a certified safe type. The lighting.3.2 Lighting fittings with pressurized enclosure or ofsystem should be divided between at least twothe flameproof type. The lighting system should bebranch circuits. All switches and protective devicesdivided between at least two branch circuits. Allshould interrupt all poles or phases and should beswitches and protective devices should interrupt alllocated in a non-hazardous location.poles or phases and should be located in a non-

.6.2 through runs of cables.hazardous location.

.7 Enclosed or semi-enclosed spaces having a direct.3.3 Electrical depth sounding or log devices and im-opening into any hazardous location referred topressed current cathodic protection system anodesabove should have electrical installations complyingor electrodes. These devices should be housed inwith the requirements for the space or zone intogastight enclosures.which the opening leads..4 Cargo pump-rooms and pump-rooms in the cargo

area:5/4B.10.3 Bonding.4.1 Lighting fittings with pressurized enclosures or ofIndependent cargo tanks should be electrically bondedthe flameproof type. The lighting system should beto the hull. All gasketed cargo pipe joints and hosedivided between at lest two branch circuits. Allconnections should be electrically bonded.switches and all protective devices should interrupt

all poles or phases and should be located in a non-hazardous location. 5/4B.10.4 Electrical requirements for individual

.4.2 Electrical motors for driving cargo pumps and any productsElectrical requirements for individual products areassociated auxiliary pumps should be separatedshown in column ‘‘i’’ in the table of 5/4B.17.from these spaces by a gastight bulkhead or deck.

Flexible couplings, or other means of maintainingalignment, should be fitted to the shafts between the 5/4B.11 Fire Protection and Fire Extinctiondriven equipment and its motors, and in addition,glands should be provided to the satisfaction of the 5/4B.11.1 ApplicationAdministration where the shafts pass through the 5/4B.11.1.1 The requirements for tankers in chapter II-bulkhead or deck. Such electrical motors should be 2 of the 1983 SOLAS amendments should apply to shipslocated in a compartment having positive pressure covered by the Code, irrespective of tonnage, includingventilation. ships of less than 500 tons gross tonnage, except that:

.4.3 Flameproof general alarm audible indicator. .1 regulations 60, 61, 62 and 63 should not apply;

.5 Zones on open deck, or semi-enclosed spaces on .2 regulation 56.2, i.e. the requirements for location ofopen deck, within 3 m of any cargo tank outlet, gas the main cargo control station, need not apply;or vapour outlet, cargo pipe flange, cargo valve or .3 regulation 4, as applicable to cargo ships, and regula-entrance and ventilation opening to cargo pump- tion 7 should apply as they would apply to tankersrooms; cargo area on open deck over all cargo tanks of 2,000 tons gross tonnage and over;and cargo tank holds, including all ballast tanks and .4 the provisions of 5/4B.11.3 should apply in lieu of

regulation 61; andcofferdams within the cargo tank block, to the full.5 the provisions of 5/4B.11.2 should apply in lieu ofwidth of the ship, plus 3 m for and aft and up to a

regulation 63.height of 2.4 m above the deck:.5.1 equipment of a certified safe type, adequate for 5/4B.11.1.2 (1 July 1994) Notwithstanding the provi-

open deck use; sions of 5/4B.11.1.1, ships engaged solely in the carriageof products which are non-flammable (entry NF in column.5.2 through runs of cables.


‘‘i’’ of the table of minimum requirements) need not comply cargoes will be carried which are not suited to extinguish-ment by carbon dioxide or halogenated hydrocarbons. Thewith part D of chapter II-2 of the 1983 SOLAS amend-

ments, provided that they comply with part C of that chap- International Certificate of Fitness for the Carriage of Dan-gerous Chemicals in Bulk should reflect this conditionalter, except that regulation 53 need not apply to such ships

and 5/4B.11.2 and 5/4B.11.3 hereunder need not apply. requirement.5/4B.8.11.1.3 (1 July 1994) For ships engaged solely in

the carriage of products with flashpoint above 60°C (entry 5/4B.11.3 Cargo areaT

‘‘yes’’ in column ‘‘i’’ of the table of minimum requirements) 5/4B.11.3.1 Every ship should be provided with a fixedrequirements of chapter II-2 of the 1983 SOLAS amend- deck foam system in accordance with the requirements ofments may apply as specified in regulation II-2/55.4 in lieu 5/4B.11.3.2 to 5/4B.11.3.12.of the provisions of 5/4B.11. 5/4B.11.3.2 Only one type of foam concentrate should

be supplied, and it should be effective for the maximum5/4B.11.2 Cargo pump-rooms possible number of cargoes intended to be carried. For

5/4B.11.2.1 The cargo pump-room of any ship should be other cargoes for which foam is not effective or is incompat-provided with a fixed fire-extinguishing system as follows: ible, additional arrangements to the satisfaction of the Ad-

.1 a carbon dioxide system as specified in regulation II- ministration should be provided. Regular protein foams2/5.1 and .2 of the 1983 SOLAS amendments. A notice should not be used.should be exhibited at the controls stating that the 5/4B.11.3.3 The arrangements for providing foamsystem is only to be used for fire-extinguishing and should be capable of delivering foam to the entire cargonot for inerting purposes, due to the electrostatic tanks deck area as well as into any cargo tank, the deck ofignition hazard. The alarms referred to in regulation which is assumed to be ruptured.II-2/ 5.1.6 of the 1983 SOLAS amendments should 5/4B.11.3.4 The deck foam system should be capable ofbe safe for use in a flammable cargo vapour-air mix- simple and rapid operation. The main control station forture. For the purpose of this requirement, an extin- the system should be suitably located outside of the cargoguishing system should be provided which would be area, adjacent to the accommodation spaces and readilysuitable for machinery spaces. However, the amount accessible and operable in the event of fires in the areasof gas carried should be sufficient to provide a quan- protected.tity of free gas equal to 45% of the gross volume of 5/4B.11.3.5 The rate of supply foam solution should notthe cargo pump-room in all cases; or be less than the greatest of the following.

.2 a halogenated hydrocarbon system as specified in .1 2 ø/min per square metre of the cargo tanks decksregulation II-2/5.1 and .3 of the 1983 SOLAS amend- area, where cargo tanks deck area means the maxi-ments. A notice should be exhibited at the controls mum breadth of the ship times the total longitudinalstating that the system is only to be used for fire- extent of the cargo tank spaces;extinguishing and not for inerting purposes, due to .2 20 ø/min per square metre of the horizontal sectionalthe electrostatic ignition hazard. The alarms referred area of the single tank having the largest such area;to in regulation II-2/5.1.6 of the 1983 SOLAS amend- .3 10 ø/min per square metre of the area protected byments should be safe for use in a flammable cargo the largest monitor, such area being entirely forwardvapour-air mixture. For the purpose of this require- of the monitor, but not less than 1,250 ø/min. Forment, an extinguishing system should be provided ships of less than 4,000 tonnes deadweight, the mini-which would be suitable for machinery spaces but mum capacity of the monitor should be to the satisfac-utilizing the following minimum design quantities tion of the Administration.based on the gross volume of the cargo pump-room: 5/4B.11S.3.1 Interpretation of 5/4B.11.3.5.3 and 5/

4B.11.3.7 (IMO)For ships of less than 4000 tonnes deadweight the mini-mum capacity of a monitor should be 1000 ø/min and theapplication rate should be at least 10 ø/min/m2, of thesurface to be protected.

5/4B.11.3.6 Sufficient foam concentrate should be sup-plied to ensure at least 30 min of foam generation whenusing the highest of the solution rates stipulated in 5/

5/4B.11.2.2 Cargo pump-rooms of ships which are dedi- 4B.11.3.5.1, 5/4B.11.3.5.2 and 5/4B.11.3.5.3.cated to the carriage of a restricted number of cargoes 5/4B.11.3.7 Foam from the fixed foam system shouldshould be protected by an appropriate fire-extinguishing be supplied by means of monitors and foam applicators.system approved by the Administration.

5/4B.11.2.3 A fire-extinguishing system consisting of ei- T Reference is made to MSC/Circ. 314 which provides guidance forther a fixed pressure water-spray system or a high-expan- calculating the capacity of foam systems for chemical tankers and maysion foam system could be provided for a cargo pump- be used in applying the requirements for extinguishing media of the

Code. (See Annex C).room if it can be demonstrated to the Administration that


At least 50% of the foam rate required in 5/4B.11.3.5.1 or 4B.11.3.7 and one additional applicator meeting the re-quirements of 5/4B.11.3.10. The additional monitor should5/4B.11.3.5.2 should be delivered from each monitor. The

capacity of any monitor should be at least 10 ø/min of foam be located to protect the bow or stern loading and un-loading arrangements. The area of the cargo line forwardsolution per square metre of deck area protected by that

monitor, such area being entirely forward of the monitor. or aft of the cargo area should be protected by the above-mentioned applicator.Such capacity should be not less than 1,250 ø/min. For

ships of less than 4,000 tonnes deadweight, the minimumcapacity of the monitor should be to the satisfaction of the 5/4B.11.4 Special requirementsAdministration. (See 5/4B.11S.3.1) ‘‘Fire-extinguishing media determined to be effective for

5/4B.11.3.8 The distance from the monitor to the far- certain products are listed in column ‘‘1’’ in the table ofthest extremity of the protected area forward of that moni- 5/4B.17’’.tor should not be more than 75% of the monitor throw instill air conditions.

5/4B.12 Mechanical Ventilation in the Cargo Area5/4B.11.3.9 A monitor and hose connection for a foamFor ships to which the Code applies, the requirements ofapplicator should be situated both part and starboard at thethis chapter replace the requirements of regulation II-2/poop front or accommodation spaces facing the cargo area.59.3 of the 1983 SOLAS amendments. However, for prod-5/4B.11.3.10 Applicators should be provided for flexibil-ucts addressed under 5/4B.11.1.2 and 5/4B.11.1.3, exceptity of action during fire-fighting operations and to coveracids and products for which 5/4B.15.17 apply, regulationareas screened from the monitors. The capacity of anyII-2/59.3 of the 1983 SOLAS Amendments may apply inapplicator should not be less than 400 ø/ min and thelieu of the provisions of 5/4B.12.applicator throw in still air conditions should be not less

than 15 m. The number of foam applicators provided shouldbe not less than four. The number and disposition of foam 5/4B.12.1 Spaces normally entered during cargomain outlets should be such that foam from at least two handling operationsapplicators can be directed to any part of the cargo tanks 5/4B.12.1.1 Cargo pump-rooms and other encloseddeck area. spaces which contain cargo handling equipment and simi-

5/4B.11.3.11 Valves should be provided in the foam lar spaces in which work is performed on the cargo shouldmain, and in the fire main where this is an integral part of be fitted with mechanical ventilation systems, capable ofthe deck foam system, immediately forward of any monitor being controlled from outside such spaces.position to isolate damaged sections of those mains. 5/4B.12.1.2 Provision should be made to ventilate such

5/4B.11.3.12 Operation of a deck foam system at its spaces prior to entering the compartment and operatingrequired output should permit the simultaneous use of the the equipment and a warning notice requiring the use ofminimum required number of jets of water at the required such ventilation should be placed outside the com-pressure from the fire main. partment.

5/4B.11S.3.2 Interpretation of 5/4B.11.3.12 (IMO) 5/4B.12.1.3 Mechanical ventilation inlets and outletsThe simultaneous use of the minimum number of jets of should be arranged to ensure sufficient air movementwater should be possible on deck over the full length of through the space to avoid the accumulation of toxic orthe ship, in the accommodation, service spaces, control flammable vapours or both (taking into account their va-spaces and machinery spaces. pour densities) and to ensure sufficient oxygen to provide

5/4B.11.3.13 Ships which are dedicated to the carriage a safe working environment, but in no case should theof a restricted number of cargoes should be protected by ventilation system have a capacity of less than 30 changesalternative provisions to the satisfaction of the Administra- of air per hour based upon the total volume of the space.tion when they are just as effective for the products con- For certain products, increased ventilation rates for cargocerned as the deck foam system required for the generality pump-rooms are prescribed in 5/4B.15.17.of flammable cargoes. 5/4B.12.1.4 Ventilation systems should be permanent

5/4B.11.3.14 Suitable portable fire-extinguishing equip- and should normally be of the extraction type. Extractionment for the products to be carried should be provided from above and below the floor plates should be possible. Inand kept in good operating order. rooms housing motors, driving cargo pumps, the ventilation

should be of the positive pressure type.5/4B.11S.3.3 Interpretation of 5/4B.11.3.14 (IMO)The capacity of portable fire-extinguishing equipment 5/4B.12.1.5 Ventilation exhaust ducts from spacesshould be as specified in the 1974 SOLAS Convention, as within the cargo area should discharge upwards in locationsamended. at least 10 m in the horizontal direction from ventilation

intakes and openings to accommodation, service and ma-5/4B.11.3.15 Where flammable cargoes are to be carriedchinery spaces and control stations and other spaces out-all sources of ignition should be excluded from hazardousside the cargo area.locations referred to in 5/4B.10.2.

5/4B.11.3.16 Ships fitted with bow or stern loading and 5/4B.12.1.6 Ventilation intakes should be so arranged asto minimize the possibility of recycling hazardous vapoursunloading arrangements should be provided with one addi-

tional foam monitor meeting the requirements of 5/ from any ventilation discharge opening.


5/4B.12.1.7 Ventilation ducts should not be led through blowers should be clear of personnel access openings, andshould comply with 5/4B.12.1.8.accommodation, service and machinery spaces or other

similar spaces.5/4B.12.1.8 Electric motors driving fans should be 5/4B.13 Instrumentation

placed outside the ventilation ducts if the carriage of flam-mable products is intended. Ventilation fans and fan ducts, 5/4B.13.1 Gaugingin way of fans only, for hazardous locations referred to in 5/4B.13.1.1 Cargo tanks should be fitted with one of the5/4B.10 should be of nonsparking construction defined as: following types of gauging devices:

.1 impellers or housing of nonmetallic construction, due .1 Open device — which makes use of an opening inregard being paid to the elimination of static elec- the tanks and may expose the gauger to the cargo ortricity; its vapour. An example of this is the ullage opening.

.2 impellers and housing of nonferrous materials; .2 Restricted device — which penetrates the tank and

.3 impellers and housing of austenitic stainless steel; and which, when in use, permits a small quantity of cargo

.4 ferrous impellers and housing with not less than 13 vapour or liquid to be exposed to the atmosphere.mm design tip clearance. When not in use, the device is completely closed.

Any combination of an aluminium or magnesium alloy fixed The design should ensure that no dangerous escapeor rotating component and a ferrous fixed or rotating com- of tank contents (liquid or spray) can take place inponent, regardless of tip clearance, is considered a sparking opening the device.hazard and should not be used in these places. 5/4B.13S.1 Interpretation of 5/4B.13.1.1.2 (IACS)

5/4B.12S.1.8 Nonsparking Fans (IACS/ABS) (1993) A restricted device could be a sounding pipe with insideSee 5/4A.12S.1.9 diameter not exceeding 200 mm, with vapour tight cover.

5/4B.12.1.9 Sufficient spare parts should be carried for .3 Closed device — which penetrates the tank, buteach type of fan on board, required by this chapter. which is part of a closed system and keeps tank con-

5/4B.12.1.10 Protection screens of not more than 13 tents from being released. Examples are the float-mm square mesh should be fitted in outside openings of type systems, electronic probe, magnetic probe andventilation ducts. protected sight glass. Alternatively an indirect device

5/4B.12S.1.10 Protection Screen (ABS) (1993) See 5/ which does not penetrate the tank shell and which4A.12S.1.11 is independent of the tank may be used. Examples

are weighing of cargo, pipe flow meter.5/4B.13.1.2 Gauging devices should be independent of5/4B.12.2 Pump-rooms and other enclosed spaces

normally entered the equipment required under 5/4B.15.19.Pump-rooms and other enclosed spaces normally 5/4B.13.1.3 Open gauging and restricted gaugingentered, which are not covered by 5/4B.12.1.1, should should be allowed only where:be fitted with mechanical ventilation systems, capable of .1 open venting is allowed by the Code; orbeing controlled from outside such spaces and .2 means are provided for relieving tank pressure beforecomplying with the requirements of 5/4B.12.1.3, except the gauge is operated.that the capacity should not be less than 20 changes of 5/4B.13.1.4 Types of gauging for individual products areair per hour, based upon the total volume of the space. shown in column ‘‘j’’ in the table of 5/4B.17.Provision should be made to ventilate such spaces prior 5/4B.13S.2 Interpretation of 5/4B.13.1.1 and 5/4B.15.19to entering. (IMO)

5/4B.12S.2 Interpretation of 5/4B.12.2 (IMO) In almost all cases a code cargo which requires a high levelA pump-room is subject to this paragraph whether or not alarm and overflow control also requires a closed gaugingcontrol for pumps and valves is fitted external to the pump- device.room. A cargo tank containing such a product therefore re-

quires three sensors:.1 level gauging5/4B.12.3 Spaces not normally entered

Double bottoms, cofferdams, duct keels, pipe tunnels, hold .2 high level alarm.3 overflow controlspaces and other spaces where cargo may accumulate,

should be capable of being ventilated to ensure a safe The sensing elements for .1, .2 and .3 should be separatedalthough sensors for .2 and .3 (reed switches, float cham-environment when entry into the spaces is necessary.

Where a permanent ventilation system is not provided bers, electronic devices, etc.) may be contained in thesame tube.for such spaces, approved means of portable mechanical

ventilation should be provided. Where necessary owing to Electronic, pneumatic, hydraulic circuits required forsensors .1, .2 and .3 should be independent of each otherthe arrangement of spaces, for instance hold spaces, essen-

tial ducting for such ventilation should be permanently such that a fault on any one will not render either of theothers inoperative.installed. For permanent installations, the capacity of eight

air changes per hour should be provided and for portable Where processing units are used to give digital or visualindication such as in a bridge space the independency ofsystems the capacity of 16 air changes per hour. Fans or


circuitry should be maintained at least beyond this point. ment and equipment which has not been used since undergo-ing a thorough cleaning process. The Administration may,The power should be supplied from distribution boards.

Where a control room or a bridge space containing a however, approve storage rooms for such equipment withinaccommodation spaces if adequately segregated from livingmodular unit is envisaged, separate level indication and

visual alarms must be provided for each of the functions spaces such as cabins, passageways, dining rooms, bath-rooms, etc..1, .2 or .3. An audible alarm must also be provided but

since this is not directional it need not be separate. An 5/4B.14S.1 Interpretation of 5/4B.14.1.2 (IMO)audible alarm must also be arranged in the cargo area. Lockers for work clothes and protective equipment whichWhere there is no control room an audible and visual alarm are not new or have not undergone a thorough cleaningshould be arranged at the cargo control station. process should not open directly into accommodation

Testing of sensors should be arranged from outside the spaces.tanks although entry into product clean tanks is not pre- 5/4B.14.1.3 Protective equipment should be used in anycluded. operation which may entail danger to personnel.

Simulation testing of electronic circuits or circuits whichare self-monitoring is acceptable. 5/4B.14.2 Safety equipment

5/4B.14.2.1 Ships carrying cargoes for which 5/4B.15.12, 5/4B.15.12.1 or 5/4B.15.12.3 is listed in column5/4B.13.2 Vapour detection‘‘m’’ in the table of 5/4B.17 should have on board sufficient5/4B.13.2.1 Ships carrying toxic or flammable productsbut not less than three complete sets of safety equipmentor both should be equipped with at least two instrumentseach permitting personnel to enter a gas-filled compartmentdesigned and calibrated for testing for the specific vapoursand perform work there for at lest 20 min. Such equipmentin question. If such instruments are not capable of testingshould be in addition to that required by regulation II-2/for both toxic concentrations and flammable concentra-17 of the 1983 SOLAS amendments.tions, then two separate sets of instruments should be

5/4B.14.2.2 One complete set of safety equipment shouldprovided.consist of:5/4B.13.2.2. Vapour detection instruments may be por-

table or fixed. If a fixed system is installed, at least one .1 one self-contained air-breathing apparatus (not usingportable instrument should be provided. stored oxygen);

5/4B.13.2.3 When toxic vapour detection equipment is .2 protective clothing, boots, gloves and tight-fittingnot available for some products which require such detec- goggles;tion, as indicated in column ‘‘i’’ in the table of 5/4B.17, the .3 fireproof lifeline with belt resistant to the cargoes car-Administration may exempt the ship from the requirement, ried; andprovided an appropriate entry is made on the International .4 explosion-proof lamp.Certificate of Fitness for the Carriage of Dangerous Chemi- 5/4B.14.2.3 For the safety equipment required in 5/cals in Bulk. When granting such an exemption, the Admin- 4B.14.2.1, all ships should carry the following, either:istration should recognize the necessity for additional

.1 one set of fully charged spare air bottles for eachbreathing air supply and an entry should be made on thebreathing apparatus;International Certificate of Fitness for the Carriage of Dan-

.2 a special air compressor suitable for the supply ofgerous Chemicals in Bulk drawing attention to the provi-high-pressure air of the required purity;sions of 5/4B.14.2.4 and 5/4B.16.4.2.2.

.3 a charging manifold capable of dealing with sufficient5/4B.13.2.4 Vapour detection requirements for individ-spare breathing apparatus air bottles for the breathingual products are shown in column ‘‘k’’ in the table of 5/apparatus; or4B.17.

.4 fully charged spare air bottles with a total free aircapacity of at least 6,000 ø for each breathing appara-

5/4B.14 Personnel Protectiontus on board in excess of the requirements of regulationII-2/17 of the 1983 SOLAS amendments.

5/4B.14.1 Protective Equipment5/4B.14.2.4 A cargo pump-room on ships carrying car-

5/4B.14.1.1 For the protection of crew members who aregoes which are subject to the requirements of 5/4B.15.18

engaged in loading and discharging operations, the shipor cargoes for which in column ‘‘i’’ in the table of 5/4B.17

should have on board suitable protective equipment con-toxic vapour detection equipment is required but is not

sisting of large aprons, special gloves with long sleeves,available should have either:

suitable footwear, coveralls of chemical-resistant material,and tight-fitting goggles or face shield or both. The protec- .1 a low-pressure line system with hose connections suit-

able for use with the breathing apparatus requiredtive clothing and equipment should cover all skin so thatno part of the body is unprotected. by 5/4B.14.2.1. This system should provide sufficient

high-pressure air capacity to supply, through pressure5/4B.14.1.2 Work clothes and protective equipmentshould be kept in easily accessible places and in special reduction devices, enough low-pressure air to enable

two men to work in a gas-dangerous space for at leastlockers. Such equipment should not be kept within accom-modation spaces, with the exception of new, unused equip- 1 hour without using the air bottles of the breathing


apparatus. Means should be provided for recharging should be provided by the manufacturer, and kept onboard, specifying:the fixed air bottles and breathing apparatus air bottles

from a special air compressor suitable for the supply .1 name and amount of stabilizer added;.2 date stabilizer was added and duration of effec-of high-pressure air of the required purity; or

.2 an equivalent quantity of spare bottled air in lieu of tiveness;.3 any temperature limitations qualifying the stabilizer’sthe low-pressure air line.

effective lifetime;5/4B.14S.2 Interpretation of 5/4B.14.2.4.2 (IMO).4 the action to be taken should the length of voyageThe equivalent quantity of spare bottled air in lieu of the

exceed the effective lifetime of the stabilizer.low-pressure air line should be at least 4800 litres.5/4B.14.2.5 At least one set of safety equipment as re-

5/4B.15.2 Ammonium nitrate solution, 93% or lessquired by 5/4B.14.2.2 should be kept in a suitable clearly5/4B.15.2.1 The ammonium nitrate solution should con-marked locker in a readily accessible place near the cargo

pump-room. The other sets of safety equipment should also tain at least 7% by weight of water. The acidity (pH) ofbe kept in suitable, clearly marked, easily accessible, places. the cargo when diluted with ten parts of water to one part

5/4B.14.2.6 The breathing apparatus should be inspected of cargo by weight should be between 5.0 and 7.0. Theat least once a month by a responsible officer, and the solution should not contain more than 10 ppm chlorideinspection recorded in the ship’s log-book. The equipment ions, 10 ppm ferric ions, and should be free of other con-should be inspected and tested by an expert at least once taminants.a year. 5/4B.15.2.2 Tanks and equipment for ammonium nitrate

5/4B.14.2.7 A stretcher which is suitable for hoisting an solution should be independent of tanks and equipmentinjured person up from spaces such as the cargo pump- containing other cargoes or combustible products. Equip-room should be placed in a readily accessible location. ment which may in service, or when defective, release

5/4B.14.2.8 (1 July 1994) Ships intended for the carriage combustible products into the cargo, e.g. lubricants, shouldof certain cargoes should be provided with suitable respira- not be used. Tanks should not be used for seawater ballast.tory and eye protection sufficient for every person on board

5/4B.15.2.3 Except where expressly approved by thefor emergency escape purposes, subject to the following:

Administration, ammonium nitrate solutions should not betransported in tanks which have previously contained other.1 filter type respiratory protection is unacceptable.cargoes unless tanks and associated equipment have been.2 self-contained breathing apparatus should have nor-cleaned to the satisfaction of the Administration.mally at least a duration of service of 15 min;

.3 emergency escape respiratory protection should not 5/4B.15.2.4 The temperature of the heat exchangingbe used for fire-fighting or cargo handling purposes medium in the tank heating system should not exceedand should be marked to that effect. 160°C. The heating system should be provided with a

Individual cargoes to which the provisions of this paragraph control system to keep the cargo at a bulk mean tempera-apply are indicated in column ‘‘n’’ in the table of 5/4B.17. ture of 140°C. High-temperature alarms at 145°C and

5/4B.14.2.9 The ship should have on board medical first- 150°C and a low-temperature alarm at 125°C should beaid equipment including oxygen resuscitation equipment provided. Where the temperature of the heat exchangingand antidotes for cargoes carried. medium exceeds 160°C an alarm should also be given.

5/4B.14.2.10 Suitably marked decontamination showers Temperature alarms and controls should be located on theand an eyewash should be available on deck in convenient navigating bridge.locations. The showers and eyewash should be operable in 5/4B.15.2.5 If the bulk mean cargo temperature reachesall ambient conditions. 145°C, a cargo sample should be diluted with ten parts of

5/4B.14S.2.10 Interpretation of 5/4B.14.2.10 (ABS) distilled or demineralized water to one part of cargo byIn general, as a minimum, a decontamination shower and weight and the acidity (pH) should be determined byan eyewash are provided at the front of the after house or means of a narrow range indicator paper or stick. Aciditysuperstructure on the main deck, port and starboard. (pH) measurements should then be taken every 24 hours.

If the acidity (pH) is found to be below 4.2, ammonia gasshould be injected into the cargo until the acidity (pH) of5/4B.15 Special Requirements5.0 is reached.

5/4B.15.2.6 A fixed installation should be provided toThe provisions of this chapter are applicable whereinject ammonia gas into the cargo. Controls for this systemspecific reference is made in column ‘‘m’’ in the tableshould be located on the navigation bridge. For this pur-of chapter 17. These requirements are additional topose, 300 kg of ammonia per 1,000 tonnes of ammoniumthe general requirements of the Code.nitrate solution should be available on board.5/4B.15.1 Acetone cyanohydrin and lactonitrile

5/4B.15S.2.1 Interpretation of 5/4B.15.2.6 (IMO)solution (80% or less)For the purpose of injecting ammonia the cargo may beAcetone cyanohydrin and lactonitrile solution (80% orcirculated by means of the cargo pump. Gaseous ammonialess) should be stabilized with an inorganic acid to

prevent decomposition. A certificate of stabilization may be injected into the circulating cargo.


FIGURE 5/4B.5Water flushed seal in chemicalpump (5/4B.15.2.7)

5/4B.15.2.7 Cargo pumps should be of the centrifugal 5/4B.15.3.4 A standard ullage opening should be pro-deepwell type or of the centrifugal type with water vided for emergency sounding.flushed seals. 5/4B.15.3.5 Cargo piping and vent lines should be inde-

5/4B.15S.2.2 Interpretation of 5/4B.15.2.7 (IMO) pendent of piping and vent lines used for other cargo.The seal for the centrifugal pump should be a stuffing box

5/4B.15.3.6 Pumps may be used for discharging cargo,provided with a lantern ring. Fresh water under pressureprovided they are of the deepwell or hydraulically drivenshould be injected into the stuffing box at the location ofsubmersible types. The means of driving a deepwell pumpthe lantern ring (see Figure 5/4B.5).should not present a source of ignition for carbon disul-5/4B.15.2.8 Vent piping should be fitted with approvedphide and should not employ equipment that may exceedweatherhoods to prevent clogging. Such weatherhoodsa temperature of 80°C.should be accessible for inspection and cleaning.

5/4B.15.3.7 If a cargo discharge pump is used, it should5/4B.15.2.9 Hot work on tanks, piping and equipmentbe inserted through a cylindrical well extending from thewhich have been in contact with ammonium nitrate solu-tank top to a point near the tank bottom. A water padtion should only be done after all traces of ammoniumshould be formed in this well before attempting pumpnitrate have been removed, inside as well as outside.removal unless the tank has been certified as gas-free.

5/4B.15.3.8 Water or inert gas displacement may be5/4B.15.3 Carbon disulphideused for discharging cargo, provided the cargo system is5/4B.15.3.1 Provision should be made to maintain a wa- designed for the expected pressure and temperature.ter pad in the cargo tank during loading, unloading and

5/4B.15.3.9 Safety relief valves should be of stainlesstransit. In addition, an inert gas pad should be maintainedsteel construction.in the ullage space during transit.

5/4B.15.3.2 All openings should be in the top of the 5/4B.15.3.10 Because of its low ignition temperaturetank, above the deck. and close clearances required to arrest its flame propaga-

tion, only intrinsically safe systems and circuits are permit-5/4B.15.3.3 Loading lines should terminate near thebottom of the tank. ted in the hazardous locations described in 5/4B.10.2.3.


5/4B.15.4 Diethyl ether should also be located on the navigating bridge. The visibleand audible alarms should be activated if the oxygen con-5/4B.15.4.1 Unless inerted, natural ventilation shouldcentration in these void spaces exceeds 30% by volume.be provided for the voids around the cargo tanks whileTwo portable oxygen monitors should also be available asthe vessel is under way. If a mechanical ventilation systemback-up systems.is installed, all blowers should be of nonsparking construc-

tion. Mechanical ventilation equipment should not be lo- 5/4B.15.5.8 As a safeguard against uncontrolled decom-cated in the void spaces surrounding the cargo tanks. position, a cargo jettisoning system should be installed

to discharge the cargo overboard. The cargo should be5/4B.15.4.2 Pressure relief valve settings should not beless than 0.2 bar gauge for gravity tanks. jettisoned if the temperature rise of the cargo exceeds a

rate of 2°C per hour over a 5 hour period or when the5/4B.15.4.3 Inert gas displacement may be used for dis-temperature in the tank exceeds 40°C.charging cargo from pressure tanks provided the cargo

system is designed for the expected pressure. 5/4B.15.5.9 Cargo tank venting systems should havepressure/vacuum relief valves for normal controlled vent-5/4B.15.4.4 In view of the fire hazard, provision should

be made to avoid any ignition source or heat generation ing, and rupture discs or a similar device for emergencyventing, should tank pressure rise rapidly as a result ofor both in the cargo area.uncontrolled decomposition. Rupture discs should be sized5/4B.15.4.5 Pumps may be used for discharging cargo,on the basis of tank design pressure, tank size and antici-provided that they are of a type designed to avoid liquidpated decomposition rate.pressure against the shaft gland or are of a hydraulically

operated submerged type and are suitable for use with the 5/4B.15.5.10 A fixed water-spray system should be pro-cargo. vided for diluting and washing away any concentrated hy-

drogen peroxide solution spilled on deck. The areas cov-5/4B.15.4.6 Provision should be made to maintain theinert gas pad in the cargo tank during loading, unloading ered by the water-spray should include the manifold/hose

connections and the tank tops of those tanks designatedand transit.for carrying hydrogen peroxide solutions. The minimumapplication rate should satisfy the following criteria:5/4B.15.5 Hydrogen peroxide solutions

.1 The product should be diluted from the original con-Hydrogen peroxide solutions over 60% but not overcentration to 35% by weight within 5 minutes of70% by weight.the spill.

5/4B.15.5.1 Hydrogen peroxide solutions over 60% but .2 The rate and estimated size of the spill should benot over 70% should be carried in dedicated ships only based upon maximum anticipated loading and dis-and no other cargoes should be carried. charge rates, the time required to stop flow of cargo

5/4B.15.5.2 Cargo tanks and associated equipment in the event of tank overfill or a piping/hose failure,should be either pure aluminium (99.5%) or solid stainless and the time necessary to begin application of dilutionsteel (304L, 316, 316L or 316Ti), and passivated in accord- water with actuation at the cargo control location orance with approved procedures. Aluminium should not on the navigating bridge.be used for piping on deck. All nonmetallic materials of 5/4B.15S.5 Interpretation of 5/4B.15.5.10.2 (IMO)construction for the containment system should neither Piping/hose failure should be assumed to be total.be attacked by hydrogen peroxide nor contribute to its 5/4B.15.5.11 Hydrogen peroxide solutions should be sta-decomposition. bilized to prevent decomposition. A certificate of stabiliza-

5/4B.15.5.3 Pump-rooms should not be used for cargo tion should be provided by the manufacturer, and kept ontransfer operations. board, specifying:

5/4B.15.5.4 Cargo tanks should be separated by coffer-dams from oil fuel tanks or any other space containing .1 name and amount of stabilizer added;flammable or combustible materials. .2 date stabilizer was added and duration of effec-

5/4B.15.5.5 Tanks intended for the carriage of hydrogen tiveness;peroxide should not be used for seawater ballast. .3 any temperature limitations qualifying the stabilizer’s

effective lifetime;5/4B.15.5.6 Temperature sensors should be installed atthe top and bottom of the tank. Remote temperature read- .4 the action to be taken should the length of voyageouts and continuous monitoring should be located on the exceed the effective lifetime of the stabilizer.navigating bridge. If the temperature in the tanks rises 5/4B.15.5.12 Only those hydrogen peroxide solutionsabove 35°C, visible and audible alarms should be activated which have a maximum decomposition rate of 1% per yearon the navigating bridge. at 25°C should be carried. Certification from the shipper

that the product meets this standard should be presented5/4B.15.5.7 Fixed oxygen monitors (or gas samplingto the master and kept on board. A technical representativelines) should be provided in void spaces adjacent to tanksof the manufacturer should be on board to monitor theto detect leakage of the cargo into these spaces. Remotetransfer operations and have the capability to test the stabil-readouts, continuous monitoring (if gas sampling lines areity of the hydrogen peroxide. He should certify to the masterused, intermittent sampling is satisfactory) and visible and

audible alarms similar to those for the temperature sensors that the cargo has been loaded in a stable condition.


5/4B.15.5.13 Protective clothing that is resistant to hy- jettisoned if the temperature rise of the cargo exceeds adrogen peroxide solutions should be provided for each rate of 2°C per hour over a 5 hour period or when thecrew member involved in cargo transfer operations. Protec- temperature in the tank exceeds 40°C.tive clothing should include nonflammable coveralls, suit- 5/4B.15.5.21 Cargo tank venting systems with filtrationable gloves, boots and eye protection. should have pressure vacuum relief valves for normal con-

trolled venting, and a device for emergency venting, shouldHydrogen peroxide solutions over 8% but not over 60%tank pressure rise rapidly as a result of an uncontrolledby weightdecomposition rate, as stipulated in 5/4B.15.5.20. These5/4B.15.5.14 The ship’s shell plating should not formventing systems should be designed in such a manner thatany boundaries of tanks containing this product.there is no introduction of seawater into the cargo tank even5/4B.15.5.15 Hydrogen peroxide should be carried inunder heavy sea conditions. Emergency venting should betanks thoroughly and effectively cleaned of all traces ofsized on the basis of tank design pressure and tank size.previous cargoes and their vapours or ballast. Procedures

5/4B.15.5.22 A fixed water-spray system should be pro-for inspection, cleaning, passivation and loading of tanksshould be in accordance with MSC/Circ. 394. A certificate vided for diluting and washing away any concentrated solu-should be on board the passivation requirement may be tion spilled on deck. The areas covered by the water-spraywaived by an Administration for domestic shipments of should include the manifold/ hose connections and theshort duration. Particular care in this respect is essential tank tops of those tanks designated for the carriage ofto ensure the safe carriage of hydrogen peroxide. hydrogen peroxide solutions. The minimum application

.1 When hydrogen peroxide is carried no other cargoes rate should satisfy the following criteria:should be carried simultaneously. .1 The product should be diluted from the original con-

.2 Tanks which have contained hydrogen peroxide may centration to 35% by weight within 5 minutes ofbe used for other cargoes after cleaning in accordance the spill.with the procedures outlined in MSC/Circ. 394. .2 The rate and estimated size of the spill should be

.3 Consideration in design should provide minimum in- based upon maximum anticipated loading and dis-ternal tank structure, free draining, no entrapment charge rates, the time required to stop flow of theand ease of visual inspection. cargo in the event of tank overfill or a piping/hose

5/4B.15.5.16 Cargo tanks and associated equipment failure, and the time necessary to begin applicationshould be either pure aluminium (99.5%) or solid stainless of dilution water with actuation at the cargo controlsteel of types suitable for use with hydrogen peroxide (e.g., location or on the navigating bridge.304, 304L, 316, 316L, 316Ti). Aluminium should not be 5/4B.15.5.23 Hydrogen peroxide should be stabilized toused for piping on deck. All nonmetallic materials of con- prevent decomposition. A certificate of stabilization shouldstruction for the containment system should neither be

be provided by the manufacturer, and kept on board, speci-attacked by hydrogen peroxide nor contribute to its decom-

fying:position. .1 name and amount of stabilizer added;

5/4B.15.5.17 Cargo tanks should be separated by a cof- .2 date stabilizer was added and duration of effec-ferdam from fuel oil tanks or any other space containing

tiveness;materials incompatible with hydrogen peroxide. .3 any temperature limitations qualifying the stabilizer’s

5/4B.15.5.18 Temperature sensors should be installed effective lifetime;at the top and bottom of the tank. Remote temperature .4 the action to be taken should the product becomereadouts and continuous monitoring should be located on unstable during the voyage.the navigating bridge. If the temperature in the tank rises 5/4B.15.5.24 Only those hydrogen peroxide solutionsabove 35°C, visible and audible alarms should activate on

which have a maximum decomposition rate of 1% per yearthe navigating bridge.

at 25°C should be carried. Certification from the shipper5/4B.15.5.19 Fixed oxygen monitors (or gas sampling that the product meets this standard should be presented

lines) should be provided in void spaces adjacent to tanksto the master and kept on board. A technical representative

to detect leakage of the cargo into these spaces. The en-of the manufacturer should be on board to monitor the

hancement of flammability by oxygen enrichments shouldtransfer operations and have the capability to test the stabil-

be recognized. Remote readouts, continuous monitoringity of the hydrogen peroxide. He should certify to the master(if gas sampling lines are used, intermittent sampling isthat the cargo has been loaded in a stable condition.satisfactory) and visible and audible alarms similar to those

5/4B.15.5.25 Protective clothing that is resistant to hy-for the temperature sensors should also be located on thedrogen peroxide should be provided for each crew membernavigating bridge. The visible and audible alarms activateinvolved in cargo transfer operations. Protective clothingif the oxygen concentration in these void spaces exceedsshould include coveralls that are nonflammable, suitable30% by volume. Two portable oxygen monitors should alsogloves, boots and eye protection.be available as back-up systems.

5/4B.15.5.26 During transfer of hydrogen peroxide the5/4B.15.5.20 As a safeguard against uncontrolled de-related piping system should be separated from all othercomposition, a cargo jettisoning system should be installed

to discharge the cargo overboard. The cargo should be systems. Cargo hoses used for transfer of hydrogen peroxide


should be marked ‘‘FOR HYDROGEN PEROXIDE ventilation which should be capable of being sealed offquickly in an emergency.TRANSFER ONLY’’.

5/4B.15.7.10 Loading and discharge of phosphorusshould be governed by a central system on the ship which,5/4B.15.6 Motor fuel anti-knock compoundsin addition to incorporating high-level alarms, should en-(containing lead alkyls)sure that no overflow of tanks is possible and that such5/4B.15.6.1 Tanks used for these cargoes should not beoperations can be stopped quickly in an emergency fromused for the transportation of any other cargo except thoseeither ship or shore.commodities to be used in the manufacture of motor fuel

5/4B.15.7.11 During cargo transfer, a water hose on deckanti-knock compounds containing lead alkyls.should be connected to a water supply and kept flowing5/4B.15.6.2 If a cargo pump-room is located on deckthroughout the operation so that any spillage of phosphoruslevel according to 5/4B.15.18, the ventilation arrangementsmay be washed down with water immediately.should be in compliance with 5/4B.15.17.

5/4.15.7.12 Ship-to-shore loading and discharge con-5/4B.15.6.3 Entry into cargo tanks used for the transpor-nections should be of a type approved by the Adminis-tation of these cargoes is not permitted unless approved bytration.the Administration.

5/4B.15.6.4 Air analysis should be made for lead contentto determine if the atmosphere is satisfactory prior to

5/4B.15.8 Propylene oxide and mixtures of ethyleneallowing personnel to enter the cargo pump-room or voidoxide/ propylene oxide with an ethylenespaces surrounding the cargo tank.oxide content of not more than 30% byweight5/4B.15.7 Phosphorus, yellow or white

5/4B.15.8.1 Products transported under the provisions5/4B.15.7.1 Phosphorus should, at all times, be loaded,of this section should be acetylene free.carried and discharged under a water pad of 760 mm mini-

5/4B.15.8.2 Unless cargo tanks are properly cleaned,mum depth. During discharge operations, arrangementsthese products should not be carried in tanks which haveshould be made to ensure that water occupies the volumecontained as one of the three previous cargoes any productsof phosphorus discharged. Any water discharged from aknown to catalyst polymerization, such as:phosphorus tank should be returned only to a shore instal-

.1 mineral acids (e.g. sulfuric, hydrochloric, nitric);lation.

.2 carbonxylic acids and anhydrides (e.g. formic, acetic);5/4B.15.7.2 Tanks should be designed and tested to aminimum equivalent water head of 2.4 m above the top .3 halogenated carboxylic acids (e.g. chloracetic);of the tank, under designed loading conditions, taking into .4 sulphonic acids (e.g. benzene sulphonic);account the depth, relative density and method of loading .5 caustic alkalis (e.g. sodium hydroxide, potassium hy-and discharge of the phosphorus. droxide);

5/4B.15.7.3 Tanks should be so designed as to minimize .6 ammonia and ammonia solutions;the interfacial area between the liquid phosphorus and its .7 amines and amine solutions;water pad. .8 oxidizing substances.

5/4B.15.7.4 A minimum ullage space of 1% should be5/4B.15.8.3 Before loading, tanks should be thoroughlymaintained above the water pad. The ullage space should

and effectively cleaned, to remove all traces of previousbe filled with inert gas or naturally ventilated by two cowledcargoes from tanks and associated pipework, except wherestandpipes terminating at different heights but at leastthe immediately prior cargo has been propylene oxide or6 m above the deck and at least 2 m above the pumpethylene oxide/propylene oxide mixtures. Particular carehouse top.should be taken in the case of ammonia in tanks made of5/4B.15.7.5 All openings should be at the top of cargosteel other than stainless steel.tanks, and fittings and joints attached thereto should be of

5/4B.15.8.4 In all cases, the effectiveness of cleaning pro-materials resistant to phosphorus pentoxide.cedures for tanks and associated pipework should be5/4B.15.7.6 Phosphorus should be loaded at a tempera-checked by suitable testing or inspection, to ascertain thatture not exceeding 60°C.no traces of acidic or alkaline materials remain that might5/4B.15.7.7 Tank heating arrangements should be exter-create a hazardous situation in the presence of thesenal to tanks and have a suitable method of temperatureproducts.control to ensure that the temperature of the phosphorus

5/4B.15.8.5 Tanks should be entered and inspected priordoes not exceed 60°C. A high-temperature alarm shouldto each initial loading of these products to ensure freedombe fitted.from contamination, heavy rust deposits and visible struc-5/4B.15.7.8 A water drench system acceptable to thetural defects. When cargo tanks are in continuous serviceAdministration should be installed in all void spaces sur-for these products, such inspections should be performedrounding the tanks. The system should operate automati-at intervals of not more than two years.cally in the event of an escape of phosphorus.

5/4B.15.7.9 Void spaces referred to in 5/4B.15.7.8 5/4B.15.8.6 Tanks for the carriage of these productsshould be of steel or stainless steel construction.should be provided with effective means of mechanical


5/4B.15.8.7 Tanks for the carriage of these products may Facilities should be provided for sampling the tank con-be used for their cargoes after thorough cleaning of tanks tents without opening the tank to atmosphere.and associated pipework systems by washing or purging. 5/4B.15.8.17 Cargo hoses used for transfer of these prod-

ucts should be marked ‘‘FOR ALKYLENE OXIDE TRANS-5/4B.15.8.8 All valves, flanges, fittings and accessoryFER ONLY’’.equipment should be of a type suitable for use with the

products and should be constructed of steel or stainless 5/4B.15.8.18 Cargo tanks, void spaces and other en-steel or other material acceptable to the Administration. closed spaces, adjacent to an integral gravity cargo tankThe chemical composition of all material used should be carrying propylene oxide, should either contain a compati-submitted to the Administration for approval prior to fabri- ble cargo (those cargoes specified in 5/4B.15.8.2 are exam-cation. Discs or disc faces, seats and other wearing parts ples of substances considered incompatible) or be inertedof valves should be made of stainless steel containing not by injection of a suitable inert gas. Any hold space in whichless than 11% chromium. an independent cargo tank is located should be inerted.

5/4B.15.8.9 Gaskets should be constructed of materials Such inerted spaces and tanks should be monitored forwhich do not react with, dissolve in, or lower the autoigni- these products and oxygen. The oxygen content of thesetion temperature of, these products and which are fire- spaces should be maintained below 2%. Portable samplingresistant and possess adequate mechanical behaviour. The equipment is satisfactory.surface presented to the cargo should be polytetrafluore- 5/4B.15.8.19 In no case should air be allowed to enterthylene (PTFE), or materials giving a similar degree of the cargo pump or piping system while these products aresafety by their inertness. Spirally-wound stainless steel, contained within the system.with a filler of PTFE or similar fluorinated polymer, may 5/4B.15.8.20 Prior to disconnecting shore-lines, thebe accepted by the Administration. pressure in liquid and vapour lines should be relieved

5/4B.15.8.10 Insulation and packing, if used, should be through suitable valves installed at the loading header.of a material which does not react with, dissolve in, or Liquid and vapour from these lines should not be dis-lower the autoignition temperature of, these products. charged to atmosphere.

5/4B.15.8.11 The following materials are generally 5/4B.15.8.21 Propylene oxide may be carried in pres-found unsatisfactory for gaskets, packing and similar uses in sure tanks or in independent or integral gravity tanks.containment systems for these products and would require Ethylene oxide/propylene oxide mixtures should be carriedtesting before being approved by the Administration: in independent gravity tanks or pressure tanks. Tanks

.1 Neoprene or natural rubber, if it comes into contact should be designed for the maximum pressure expected towith the products. be encountered during loading, conveying and discharging

.2 Asbestos, or binders used with asbestos. cargo.

.3 Materials containing oxides of magnesium, such as 5/4B.15.8.22.1 Tanks for the carriage of propylene oxidemineral wools. with a design pressure less than 0.6 bar gauge and tanks

5/4B.15.8.12 Threaded joints should not be permitted for the carriage of ethylene oxide/propylene oxide mixturesin the cargo liquid and vapour lines. with a design pressure less than 1.2 bar gauge should have

5/4B.15.8.13 Filling and discharge piping should extend a cooling system to maintain the cargo below the referenceto within 100 mm of the bottom of the tank or any sump pit. temperature.

5/4B.15.8.14.1 The containment system for a tank con- 5/4B.15.8.22.2 The refrigeration requirement for tankstaining these products should have a valved vapour return with a design pressure less than 0.6 bar gauge may beconnection. waived by the Administration for ships operating in re-

5/4B.15.8.14.2 The products should be loaded and dis- stricted areas or on voyages of restricted duration, andcharged in such a manner that venting of the tanks to account may be taken in such cases of any insulation ofatmosphere does not occur. If vapour return to shore is the tanks. The area and times of year for which such car-used during tank loading, the vapour return system con-

riage would be permitted should be included in the condi-nected to a containment system for the product should betions of carriage of the International Certificate of Fitnessindependent of all other containment systems.for the Carriage of Dangerous Chemicals in Bulk.5/4B.15.8.14.3 During discharge operations, the pres-

5/4B.15.8.23.1 Any cooling system should maintain thesure in the cargo tank must be maintained above 0.07 barliquid temperature below the boiling temperature at thegauge.containment pressure. At least two complete cooling plants5/4B.15.8.15 The cargo may be discharged only byautomatically regulated by variations within the tanksdeepwell pumps, hydraulically operated submergedshould be provided. Each cooling plant should be completepumps, or inert gas displacement. Each cargo pump shouldwith the necessary auxiliaries for proper operation. Thebe arranged to ensure that the product does not heat signifi-control system should also be capable of being manuallycantly if the discharge line from the pump is shut off or

otherwise blocked. operated. An alarm should be provided to indicate malfunc-tioning of the temperature controls. The capacity of each5/4B.15.8.16 Tanks carrying these products should be

vented independently of tanks carrying other products. cooling system should be sufficient to maintain the temper-


ature of the liquid cargo below the reference temperatureTV L = 0.98 V 1rR

pL2of the system.

where VL = maximum volume to which the tank may be loaded5/4B.15.8.23.2 An alternative arrangement may consistV = volume of tankof three cooling plants, any two of which should be suffi-

pR = relative density of cargo at the reference tempera-cient to maintain the liquid temperatures below the refer-tureTence temperature.T

pL = relative density of cargo at the loading temperature5/4B.15.8.23.3 Cooling media which are separated from

and pressure.the products by a single wall only should be nonreactive

5/4B.15.8.26.3 The maximum allowable tank filling lim-with the products.its for each cargo tank should be indicated for each loading5/4B.15.8.23.4 Cooling systems requiring compressiontemperature which may be applied, and for the applicableof the products should not be used.maximum reference temperature, on a list to be approved

5/4B.15.8.24 Pressure relief valve settings should not by the Administration. A copy of the list should be perma-be less than 0.2 bar gauge and for pressure tanks not greater nently kept on board by the master.than 7.0 bar gauge for the carriage of propylene oxide and 5/4B.15.8.27 The cargo should be carried under a suit-not greater than 5.3 bar gauge for the carriage of propylene able protective padding of nitrogen gas. An automatic nitro-oxide/ethylene oxide mixtures. gen make-up system should be installed to prevent the

tank pressure falling below 0.07 bar gauge in the event5/4B.15.8.25.1 The piping system for tanks to be loadedof product temperature fall due to ambient conditions orwith these products should be separated (as defined in 5/maloperation of refrigeration systems. Sufficient nitrogen4B.1.3.24) from piping systems for all other tanks, includingshould be available on board to satisfy the demand of theempty tanks. If the piping system for the tanks to be loadedautomatic pressure control. Nitrogen of commercially pureis not independent (as defined in 5/4B.1.3.15), the requiredquality (99.9% by volume) should be used for padding. Apiping separation should be accomplished by the removalbattery of nitrogen bottles connected to the cargo tanksof spool pieces, valves, or other pipe section, and the instal-through a pressure reduction valve satisfies the intentionlation of blank flanges at these locations. The requiredof the expression ‘‘automatic’’ in this context.separation applies to all liquid and vapour piping, liquid

5/4B.15.8.28 The cargo tank vapour space should beand vapour vent lines and any other possible connections,tested prior to and after loading to ensure that the oxygensuch as common inert gas supply lines.content is 2% by volume or less.

5/4B.15.8.25.2 These products may be transported only 5/4B.15.8.29 (1 July 1994) A water-spray system of suffi-in accordance with cargo handling plans that have been cient capacity should be provided to blanket effectivelyapproved by the Administration. Each intended loading the area surrounding the loading manifold, the exposedarrangement should be shown on a separate cargo handling deck piping associated with product handling, and the tankplan. Cargo handling plans should show the entire cargo domes. The arrangement of piping and nozzles should bepiping system and the locations for installation of blank such as to give a uniform distribution rate of 10 ø/m2 min.flanges needed to meet the above piping separation re- Remote manual operation should be arranged such thatquirements. A copy of each approved cargo handling plan remote starting of pumps supplying the water spray systemshould be maintained on board the ship. The International and remote operation of any normally closed valves in theCertificate of Fitness for the Carriage of Dangerous Chemi- system can be carried out from a suitable location outsidecals in Bulk should be endorsed to include reference to the cargo area, adjacent to the accommodation spaces andthe approved cargo handling plans. readily accessible and operable in the event of fire in the

5/4B.15.8.25.3 Before each initial loading of these prod- areas protected. The water-spray system should be capableucts and before every subsequent return to such service, of both local and remote manual operation, and the arrange-certification verifying that the required piping separation ment should ensure that any spilled cargo is washed away.has been achieved should be obtained from a responsible Additionally, a water hose with pressure to the nozzle,

when atmospheric temperatures permit, should be con-person acceptable to the Port Administration and carriednected ready for immediate use during loading and un-on board the ship. Each connection between a blank flangeloading operations.and a pipeline flange should be fitted with a wire and seal

5/4B.15.8.30 A remotely operated, controlled closing-by the responsible person to ensure that inadvertent removalrate, shutoff valve should be provided at each cargo hoseof the blank flange is impossible.connection used during cargo transfer.5/4B.15.8.26.1 No cargo tanks should be more than 98%

liquid full at the reference temperatureT.5/4B.15.9 Sodium chlorate solution, 50% or less5/4B.15.8.26.2 The maximum volume to which a cargo

5/4B.15.9.1 Tanks and associated equipment which havetank should be loaded is:contained this product may be used for other cargoes afterthorough cleaning by washing or purging.

5/4B.15.9.2 In the event of spillage of this product, allT See 5/4B.15.8.22.1T See 5/4B.15.8.22.1 spilled liquid should be thoroughly washed away without


delay. To minimize fire risk, spillage should not be allowed 5/4B.15.12 Toxic productsto dry out. 5/4B.15.12.1 Exhaust openings of tank vent systems

should be located:.1 at a height of B/3 or 6 m, whichever is greater, above5/4B.15.10 Sulphur liquid

the weather deck or, in the case of a deck tank, the5/4B.15.10.1 Cargo tank ventilation should be providedaccess gangway;to maintain the concentration of hydrogen sulphide below

.2 not less than 6 m above the fore and aft gangway, ifone half of its lower explosive limit throughout the cargofitted within 6 m of the gangway; andtank vapour space for all conditions of carriage, i.e. below

.3 15 m from any opening or air intake to any accommo-1.85% by volume.dation and service spaces;5/4B.15.10.2 Where mechanical ventilation systems are

.4 the vent height may be reduced to 3 m above theused for maintaining low gas concentrations in cargo tanks,deck or fore and aft gangway, as applicable, providedan alarm system should be provided to give warning if thehigh-velocity vent valves of a type approved by thesystem fails.Administration, directing the vapour-air mixture up-5/4B.15.10.3 Ventilation systems should be so designed wards in an unimpeded jet with an exit velocity ofand arranged as to preclude depositing of sulphur within at least 30 m/s, are fitted.the system.

5/4B.15.12.2 Tank venting systems should be provided5/4B.15.10.4 Openings to void spaces adjacent to cargo with a connection for a vapour return line to the shoretanks should be so designed and fitted as to prevent the installation.entry of water, sulphur or cargo vapour.5/4B.15S.12 Interpretation of 5/4B.15.12.2 (IACS)5/4B.15.10.5 Connections should be provided to permit Tank venting systems should be provided with a stop valvesampling and analysing of vapour in void spaces. for vapour return line to shore.

5/4B.15.10.6 Cargo temperature controls should be pro- 5/4B.15.12.3 Products should:vided to ensure that the temperature of the sulphur does .1 not be stowed adjacent to oil fuel tanks;not exceed 155°C. .2 have separate piping systems; and.3 have tank vent systems separate from tanks containing

5/4B.15.11 Acids nontoxic products.5/4B.15.11.1 The ship’s shell plating should not form (See also 5/4B.3.7.2)

any boundaries of tanks containing mineral acids. 5/4B.15.12.4 Cargo tank relief valve settings should be5/4B.15.11.2 Proposals for lining steel tanks and related a minimum of 0.2 bar gauge.

piping systems with corrosion-resistant materials may beconsidered by the Administration. The elasticity of the 5/4B.15.13 Cargoes protected by additiveslining should not be less than that of the supporting bound- (1 July 1994)ary plating. 5/4B.15.13.1 Certain cargoes, with a reference in col-

5/4B.15.11.3 Unless constructed wholly of corrosion-re- umn ‘‘o’’ in the table of 5/4B.17, by the nature of theirsistant materials or fitted with an approved lining, the chemical make-up tend, under certain conditions of tem-plating thickness should take into account the corrosivity perature, exposure to air or contact with a catalyst, toof the cargo. undergo polymerization, decomposition, oxidation or other

5/4B.15.11.4 Flanges of the loading and discharge mani- chemical changes. Mitigation of this tendency is carriedfold connections should be provided with shields, which out by introducing small amounts of chemical additivesmay be portable, to guard against the danger of the cargo into the liquid cargo or by controlling the cargo tank envi-being sprayed; and in addition, drip trays should also be ronment.provided to guard against leakage on to the deck. 5/4B.15.13.2 Ships carrying these cargoes should be so

5/4B.15.11.5 Because of the danger of evolution of hy- designed as to eliminate from the cargo tanks and cargodrogen when these substances are being carried, the elec- handling system any material of construction or contami-trical arrangements should comply with 5/4B.10.2.3.1, 5/ nants which could act as a catalyst or destroy the inhibitor.4B.10.2.3.2, 5/4B.10.2.3.3, 5/4B.10.2.3.4, 5/4B.10.2.3.6 and 5/4B.15.13.3 Care should be taken to ensure that these5/4B.10.2.3.7. The certified safe type equipment should be cargoes are sufficiently protected to prevent deleterioussuitable for use in hydrogen-air mixtures. Other sources chemical change at all times during the voyage. Ships car-of ignition should not be permitted in such spaces. rying such cargoes should be provided with a certificate

5/4B.15.11.6 Substances subjected to the requirements of protection from the manufacturer, and kept during theof this section should be segregated from oil fuel tanks, in voyage, specifying:addition to the segregation requirements in 5/4B.3.1.1. .1 the name and amount of additive present;

5/4B.15.11.7 Provision should be made for suitable ap- .2 whether the additive is oxygen dependent;paratus to detect leakage of cargo into adjacent spaces. .3 date additive was put in the product and duration of

effectiveness;5/4B.15.11.8 The cargo pump-room bilge pumping anddrainage arrangements should be of corrosion-resistant ma- .4 any temperature limitations qualifying the additive’s

effective lifetime; andterials.


.5 the action to be taken should the length of voyage 5/4B.15.14.4 Connections should be provided for re-turning expelled gases to shore during loading.exceed the effective lifetime of the additive.

5/4B.15.13.4 Ships using the exclusion of air as the 5/4B.15S.14 Interpretation of 5/4B.14.14.4 (IACS)method of preventing oxidation of the cargo should comply Tank venting systems should be provided with a stop valvewith 5/4B.9.1.3. for vapour return line to shore.

5/4B.15.13.5 A product containing an oxygen dependent 5/4B.15.14.5 Each tank should be provided with a pres-additive should be carried without inertion (in tanks of a sure gauge which indicates the pressure in the vapoursize not greater than 3,000 m3). Such cargoes should not space above the cargo.be carried in a tank requiring inertion under the require- 5/4B.15.14.6 Where the cargo needs to be cooled, ther-ments of SOLAS chapter II-2. mometers should be provided at the top and bottom of

5/4B.15.13.6 Venting systems should be of a design that each tank.eliminates blockage from polymer build-up. Venting equip- 5/4B.15.14.7.1 No cargo tanks should be more than 98%ment should be of a type that can be checked periodically liquid full at the reference temperature (R).for adequacy of operation. 5/4B.15.14.7.2 The maximum volume (VL) of cargo to be

loaded in a tank should be:5/4B.15S.13 Interpretation of 5/4B.15.13.6 (IMO)Internal obstructions should be avoided beyond the re-quirement for pressure vacuum valves and flame screens VL = 0.98V 1pR

pL2

which should be accessible for inspection and mainte-nance. where V = volume of the tank

5/4B.15.13.7 Crystallization or solidification of cargoes pR = relative density of cargo at the reference tempera-

normally carried in the molten state can lead to depletion ture (R)

of inhibitor in parts of the tanks contents. Subsequent pL = relative density of cargo at the loading temperature

remelting can thus yield pockets of uninhibited liquid, with R = reference temperature is the temperature at which

the accompanying risk of dangerous polymerization. To the vapour pressure of the cargo corresponds to the

prevent this, care should be taken to ensure that at no time set pressure of the pressure relief valve.

are such cargoes allowed to crystallize or solidify, either5/4B.15.14.7.3 The maximum allowable tank filling lim-wholly or partially, in any part of the tank. Any required

its for each cargo tank should be indicated for each loadingheating arrangements should be such as to ensure that intemperature which may be applied, and for the applicableno part of the tank does cargo become overheated to suchmaximum reference temperature, on a list approved byan extent that any dangerous polymerization can be initi-the Administration. A copy of the list should be permanentlyated. If the temperature from steam coils would inducekept on board by the master.overheating, an indirect low-temperature heating system

should be used.5/4B.15.15 Cargoes with low ignition temperature

and wide flammability range (1 July 1994)5/4B.15.14 Cargoes with a vapour pressure greater(Text deleted)than 1.013 bar absolute at 37.8°C

5/4B.15.14.1 For a cargo referenced in column ‘‘o’’ inthe table of 5/4B.17 to this section, a mechanical refrigera- 5/4B.15.16 Cargo contaminationtion system should be provided unless the cargo system is 5/4B.15.16.1 Where column ‘‘o’’ in the table of 5/4B.17designed to withstand the vapour pressure of the cargo at refers to this section, alkaline or acidic materials, such as45°C. Where the cargo system is designed to withstand the caustic soda or sulfuric acid, should not be allowed tovapour pressure of the cargo at 45°C, and no refrigeration contaminate the cargo.system is provided, a notation should be made in the condi- 5/4B.15.16.2 Where column ‘‘o’’ in the table of 5/4B.17tions of carriage on the International Certificate of Fitness refers to this section water should not be allowed to contami-for the Carriage of Dangerous Chemicals in Bulk to indi- nate this cargo. In addition, the following provisions apply:cate the required relief valve setting for the tanks. .1 Air inlets to pressure/vacuum relief valves of tanks

5/4B.15.14.2 A mechanical refrigeration system should containing the cargo should be situated at least 2 mmaintain the liquid temperature below the boiling temper- above the weather deck.ature at the cargo tank design pressure. .2 Water or steam should not be used as the heat transfer

media in a cargo temperature control system required5/4B.15.14.3 When ships operate in restricted areas andat restricted times of the year, or on voyages of limited by 5/4B.7.

.3 The cargo should not be carried in cargo tanks adja-duration, the Administration involved may agree to waiverequirements for a refrigeration system. A notation of any cent to permanent ballast or water tanks unless the

tanks are empty and dry. (See 5/4B.3S.1.1)such agreement, listing geographic area restrictions andtimes of the year, or voyage duration limitations, should be .4 The cargo should not be carried in tanks adjacent to

slop tanks or cargo tanks containing ballast or slopsincluded in the conditions of carriage on the InternationalCertificate for the Carriage of Dangerous Chemicals in or other cargoes containing water which may react

in a dangerous manner. Pumps, pipes or vent linesBulk.


serving such tanks should be separate from similar should be permitted only when specific approval hasbeen obtained from the Administration and the portequipment serving tanks containing the cargo. Pipe-

lines from slop tanks or ballast lines should not pass Administrations concerned.5/4B.15.19.8 The loading rate (LR) of the tank shouldthrough tanks containing the cargo unless encased in

a tunnel. (See 5/4B.3S.1.1) not exceed:

5/4B.15.17 Increased ventilation requirements LR =3600 U

t(m3/h)

For certain products, the ventilation system as describedin 5/4B.12.1.3 should have a minimum capacity of atleast 45 changes of air per hour based upon the total where U = ullage volume (m3) at operating signal level;

volume of space. The ventilation system exhaust ducts t = time (s) needed from the initiating signal to fully stop-

should discharge at least 10 m away from openings into ping the cargo flow into the tank, being the sum of

accommodation spaces, work areas or other similar times needed for each step in sequential operations

spaces, and intakes to ventilation systems, and at least 4 such as operator’s responses to signals, stopping

m above the tank deck. pumps and closing valves;

and should also take into account the pipeline system design5/4B.15.18 Special cargo pump-room requirements

pressure.For certain products, the cargo pump-room should belocated on the deck level or cargo pumps should be

5/4B.15.20 Octyl nitrates, all isomerslocated in the cargo tank. The Administration may give5/4B.15.20.1special consideration to cargo pump-rooms below deck.

The carriage temperature of the cargo should be main-5/4B.15S.18 Interpretation of 5/4B.15.18 (IMO)tained below 100°C to prevent the occurrence of a self-No circumstances can be foreseen where an Administrationsustaining, exothermic decomposition reaction.might allow any relaxation.

5/4B.15.20.25/4B.15.19 Overflow control (See 5/4B.3S.2)The cargo may not be carried in independent pressure5/4B.15.19.1 The provisions of this section are applica-vessels permanently affixed to the vessel’s deck unless:ble where specific reference is made in column ‘‘o’’ in the

.1 the tanks are sufficiently insulated from fire; andtable of 5/4B.17, and are in addition to the requirements

.2 the vessel has a water deluge system for the tanksfor gauging devices.such that the cargo temperature is maintained below5/4B.15.19.2 In the event of a power failure on any100°C and the temperature rise in the tanks does notsystem essential for safe loading, an alarm should be givenexceed 1.5°C/hour for a fire of 650°C.to the operators concerned.

5/4B.15.21 Temperature sensors (1 July 1994)5/4B.15.19.3 Loading operations should be terminatedTemperature sensors should be used to monitor the cargoat once in the event of any system essential for safe loadingpump temperature to detect overheating due to pumpbecoming inoperative.failures.5/4B.15.19.4 Level alarms should be capable of being

tested prior to loading.5/4B.16 Operational RequirementsT5/4B.15.19.5 The high-level alarm system required un-

der 5/4B.15.19.6 should be independent of the overflow5/4B.16.1 Maximum allowable quantity of cargo percontrol system required by 5/4B.15.19.7 and should be

tankindependent of the equipment required by 5/4B.13.1.5/4B.16.1.1 The quantity of a cargo required to be car-5/4B.15.19.6 Cargo tanks should be fitted with a visual

ried in a type 1 ship should not exceed 1,250 m3 in anyand audible high-level alarm which complies with 5/one tank.4B.15.19.1 to 5/4B.15.19.5 and which indicates when the

5/4B.16.1.2 The quantity of cargo required to be carriedliquid level in the cargo tank approaches the normal fullin a type 2 ship should not exceed 3,000 m3 in any one tank.condition.

5/4B.16.1.3 Tanks carrying liquids at ambient tempera-5/4B.15.19.7 A tank overflow control system requiredtures should be so loaded as to avoid the tank becomingby this section should:liquid-full during the voyage, having due regard to the.1 come into operation when the normal tank loadinghighest temperature which the cargo may reach.procedures fail to stop the tank liquid level exceeding

the normal full condition;5/4B.16.2 Cargo Information.2 give a visual and audible tank overflow alarm to the

5/4B.16.2.1 A copy of this Code, or national regulationsship’s operator; andincorporating the provision of this Code, should be on board.3 provide an agreed signal for sequential shutdown ofevery ship covered by this Code.onshore pumps or valves or both and of the ship’s

valves. The signal, as well as the pump and valveshutdown, may be dependent on operator’s interven- T Attention is also drawn to the operation guidelines contained in the

ICS Tanker Safety Guide (Chemicals).tion. The use of shipboard automatic closing valves


5/4B.16.2.2 Any cargo offered for bulk shipment should 5/4B.16.3 Personnel TrainingTT

5/4B.16.3.1 All personnel should be adequately trainedbe indicated in the shipping documents by the correct tech-in the use of protective equipment and have basic trainingnical name. Where the cargo is a mixture, an analysis indi-in the procedures appropriate to their duties, necessarycating the dangerous components contributing significantlyunder emergency conditions.to the total hazard of the product should be provided, or

5/4B.16.3.2 Personnel involved in cargo operationsa complete analysis if this is available. Such an analysisshould be adequately trained in handling procedures.should be certified by the manufacturer or by an indepen-

5/4B.16.3.3 Officers should be trained in emergency pro-dent expert acceptable to the Administration.cedures to deal with conditions of leakage, spillage or fire5/4B.16.2.3 Information should be on board, and avail-involving the cargo, and a sufficient number of them shouldable to all concerned, giving the necessary data for the safebe instructed and trained in essential first aid for cargoescarriage of the cargo. Such information should include acarried.cargo stowage plan to be kept in an accessible place, indicat-

ing all cargo on board, including each dangerous chemical5/4B.16.4 Opening of and entry into cargo tankscarried:

5/4B.16.4.1 During handling and carriage of cargoes.1 a full description of the physical and chemical proper-producing flammable or toxic vapours, or both, or whenties, including reactivity necessary for the safe con-ballasting after the discharge of such cargo, or when loadingtainment of the cargo;or unloading cargo, cargo tank lids should always be kept.2 action to be taken in the event of spills or leaks;closed. With any hazardous cargo, cargo tank lids, ullage.3 countermeasures against accidental personal contact;and sighting ports and tank washing access covers should.4 fire-fighting procedures and fire-fighting media;be open only when necessary..5 procedures for cargo transfer, tank cleaning, gas-free-

5/4B.16.4.2 Personnel should not enter cargo tanks, voiding and ballasting;spaces around such tanks, cargo handling spaces or other.6 for those cargoes required to be stabilized or inhibitedenclosed spaces unless:in accordance with 5/4B.15.1, 5/4B.15.5.11 or 5/

4B.15.13.3, the cargo should be refused if the certifi- .1 the compartment is free of toxic vapours and not defi-cate required by these paragraphs is not supplied. cient in oxygen; or

5/4B.16.2.4 If sufficient information necessary for the .2 personnel wear breathing apparatus and other neces-safe transportation of the cargo is not available, the cargo sary protective equipment, and the entire operation isshould be refused. under the close supervision of a responsible officer.

5/4B.16.2.5 Cargoes which evolve highly toxic impercep- 5/4B.16.4.3 Personnel should not enter such spaces whentible vapours should not be transported unless perceptible the only hazard is of a purely flammable nature, exceptadditives are introduced into the cargo. under the close supervision of a responsible officer.

5/4B.16.2.6 Where column ‘‘o’’ in the table of 5/4B.17refers to this paragraph, the cargo’s viscosity at 20°C should 5/4B.16.5 Stowage of cargo samplesbe specified on a shipping document and if the cargo’s 5/4B.16.5.1 Samples which have to be kept on boardviscosity exceeds 25 mPa.s at 20°C, the temperature at should be stowed in a designated space situated in the cargowhich the cargo has a viscosity of 25mPa.s should be speci- area or, exceptionally, elsewhere, subject to the approvalfied in the shipping document. of the Administration.

5/4B.16.2.7 Where column ‘‘o’’ in the table of 5/4B.17 5/4B.16.5.2 The stowage space should be:refers to this paragraph, the cargo’s viscosity at 20°C should

.1 cell-divided in order to avoid shifting the bottles at sea;be specified on a shipping document and if the cargo’s

.2 made of material fully resistant to the different liquidsviscosity exceeds 60 mPa.s at 20°C the temperature at which

intended to be stowed; andthe cargo has a viscosity of 60 mPa.s should be specified .3 equipped with adequate ventilation arrangements.in the shipping document.

5/4B.16.5.3 Samples which react with each other dan-5/4B.16.2.8 Where column ‘‘o’’ in the table of 5/4B.17

gerously should not be stowed close to each other.refers to this paragraph and the possibility exists that it will 5/4B.16.5.4 Samples should not be retained on boardbe unloaded within a Special AreaT, the cargo’s viscosity longer than necessary.at 20°C should be specified on a shipping document and if 5/4B.16.6 Cargoes not to be exposed to excessive heatthe cargo’s viscosity exceeds 25 mPa.s at 20°C the tempera- 5/4B.16.6.1 Where the possibility exists of a dangerousture at which the cargo has a viscosity of 25 mPa.s should reaction of a cargo such as polymerization, decomposition,be specified in the shipping document. thermal instability or evolution of gas, resulting from local

5/4B.16.2.9 Where column ‘‘o’’ in the table of 5/4B.17refers to this paragraph, the cargo’s melting point should TT Reference is made to the provisions of the International Convention onbe indicated in the shipping document. Standards of Training, Certification and Watchkeeping for Seafarers, 1978,

and in particular to the ‘‘Mandatory minimum requirements for the trainingand qualifications of masters, officers and ratings of chemical tankers’’—regula-tion V/2, chapter V of the Annex to that Convention and to resolution 11 ofT Special Areas are defined in regulation 1(7) of Annex II to MARPOL

73/78. the International Conference on Training and Certification of Seafarers, 1978.


overheating of the cargo in either the tank or associated 5/4B.17 Summary of Minimum Requirements (1 July1994)pipelines, such cargo should be loaded and carried ade-

quately segregated from other products whose temperature Mixtures of noxious liquid substances presenting pollutionhazards only and which are provisionally assessed underis sufficiently high to initiate a reaction of such cargo (see

5/4B.7.1.5.4). regulation 3(4) of Annex II of MARPOL 73/78, may becarried under the requirements of the Code applicable to5/4B.16.6.2 Heating coils in tanks carrying this product

should be blanked off or secured by equivalent means. the appropriate position of the entry in 5/4B.17 for noxiousliquids not otherwise specified.5/4B.16.6.3 Heat-sensitive products should not be car-

ried in deck tanks which are not insulated.Explanatory Notes

Product name The product names are not identical with the5/4B.16.7 Additional operational requirements(column a) names given in previous issues of the Code, orThe Code contains additional operational requirements

the BCH Code (for explanation see index ofin:chemicals).

5/4B.3.1.1 5/4B.13.2.4 5/4B.15.8.4 5/4B.15.8.26.3UN number The number relating to each product shown in5/4B.3.1.2.1 5/4B.14 5/4B.15.8.5 5/4B.15.8.27

(column b) the recommendations proposed by the United5/4B.3.1.2.2 5/4B.15.1 5/4B.15.8.7 5/4B.15.8.28Nations Committee of Experts on the5/4B.3.1.4 5/4B.15.3.1 5/4B.15.8.14.2 5/4B.15.8.29Transport of Dangerous Goods. UN numbers,5/4B.3.5.2 5/4B.15.3.7 5/4B.15.8.14.3 5/4B.15.9where available, are given for information only.5/4B.3.7.4 5/4B.15.3.8 5/4B.15.8.16 5/4B.15.10.1

5/4B.7.1.2 5/4B.15.4.6 5/4B.15.8.17 5/4B.15.11.4Pollution category The letter A, B, C or D means the pollution5/4B.7.1.6.3 5/4B.15.5 5/4B.15.8.18 5/4B.15.11.6

(column c) category assigned to each product under5/4B.9.1.4 5/4B.15.6.1 5/4B.15.8.19 5/4B.15.12.3.1Annex II of MARPOL 73/78. ‘‘III’’ means the5/4B.9.2 5/4B.15.6.3 5/4B.15.8.20 5/4B.15.13product was evaluated and found to fall5/4B.11.3.2 5/4B.15.6.4 5/4B.15.8.23.3 5/4B.15.14.7.1

5/4B.11.4 5/4B.15.7.1 5/4B.15.8.23.4 5/4B.15.14.7.2 outside the categories A, B, C or D.5/4B.12.1.2 5/4B.15.7.6 5/4B.15.8.25.1 5/4B.15.14.7.3 Pollution category in brackets indicates that5/4B.12.2 5/4B.15.7.11 5/4B.15.8.25.2 5/4B.15.16 the product is provisionally categorized and5/4B.13.2.1 5/4B.15.8.1 5/4B.15.8.25.3 5/4B.15.19.8 that further data are necessary to complete the5/4B.13.2.2 5/4B.15.8.2 5/4B.15.8.26.1 evaluation of their pollution hazards. Until the5/4B.13.2.3 5/4B.15.8.3 5/4B.15.8.26.2

hazard evaluation is completed, the pollutioncategory assigned is used.

5/4B.16A Additional Measures for the Protection ofHazards S means that the product is included in thethe Marine Environment

(column d) Code because of its safety hazards;P means that the product is included in the

5/4B.16A.1 General Code because of its pollution hazards; and5/4B.16A.1.1 The requirements of this chapter apply to S/P means that the product is included in the

Code because of both its safety and pollutionships carrying products noted as category A, B or C noxioushazards.liquid substances in 5/4B.17.

Ship type 1 = ship type 1 (5/4B.2.1.2)(column e) 2 = ship type 2 (5/4B.2.1.2)5/4B.16A.2 Condition of carriage

3 = ship type 3 (5/4B.2.1.2)5/4B.16A.2.1 The condition of carriage of productsTank type 1 = independent tank (5/4B.4.1.1)listed in the International Certificate of Fitness for the

(column f) 2 = integral tank (5/4B.4.1.2)Carriage of Dangerous Chemicals in Bulk should reflectG = gravity tank (5/4B.4.1.3)the requirements of regulation 5A of Annex II of MARPOLP = pressure tank (5/4B.4.1.4)73/78.

Tank vents Open: open venting5/4B.16A.2.2 A category B substance with a melting(column g) Cont: controlled ventingpoint equal to or greater than 15°C should not be carried

SR: safety relief valvein a cargo tank any boundary of which is formed by a ship’sTank environmental Inert: inerting (5/4B.9.1.2.1)shell plating and should only be carried in a cargo tankcontrolT Pad: liquid or gas (5/4B.9.1.2.2)fitted with a cargo heating system.

(column h) Dry: drying (5/4B.9.1.2.3)Vent: natural or forced (5/4B.9.1.2.4)

5/4B.16A.3 Procedures and arrangements manualElectrical T1 to T6 temperature classesTT5/4B.16A.3.1 Each ship should be provided with a Pro-equipment IIA, IIB or IIC apparatus groupsTT

cedures and Arrangements Manual developed for the ship (column i) NF: non-flammable product (5/in accordance with the provisions of the Standards for 4B.10.1.6)the Procedures and Arrangements and approved by theAdministration. T ‘‘No’’ indicates nil requirements.

5/4B.16A.3.2 Each ship should be fitted with equipment TT Temperature classes and apparatus groups as defined in Internationaland arrangements identified in its Procedures and Arrange- Electrotechnical Commission Publication 79 (part 1, appendix D, parts

4, 8 and 12). A blank indicates that data are currently not available.ments Manual.


Yes: flashpoint exceeding 60°C(closed cup test) (5/4B.10.1.6)

No: flashpoint not exceeding60°C (closed cup test) (5/4B.10.1.6)

Gauging O: open gauging (5/4B.13.1.1.1)(column j) R: restricted gauging (5/4B.13.1.1.2)

C: closed gauging (5/4B.13.1.1.3)I: indirect gauging (5/4B.13.1.1.3)

Vapour detectionT F: flammable vapours(column k) T: toxic vapours

Fire protection A: alcohol-resistant foam or multi-(column 1) purpose foam

B: regular foam, encompasses all foamsthat are not of an alcohol-resistanttype, including fluoroprotein andaqueous-film-forming foam (AFFF)

C: water-sprayD: dry chemicalTTT

No: no special requirements under thisCode

Materials of N: see 5/4B.6.2.2construction Z: see 5/4B.6.2.3

(column m) Y: see 5/4B.6.2.4A blank indicates no special guidance givenfor materials of construction

Respiratory and E: see 5/4B.14.2.8eye protection

(column n)

TTT Dry chemical powder systems when used may require an additionalwater system for boundary cooling. This is normally provided in sufficientquantities by the standard fire main system required by regulation II-2/4 of the 1974 SOLAS Convention as amended.


Minimum Requirements


ab

cd

ef

gh

i′i′′

i′′′

jk

lm

no

Ele

ctri

cal

Eq

uip

men

t

Sp

ecia

lre

qu

irem

ents

Pro

du

ctn

am

e(S

eeC

hap

ter

5/4

B.1

5)

UNnumber

PollutionCategory

Hazards

ShipType

TankType

TankVent

TankEnvironmentalControl

Class

Group

Flashpoint60°C

Guaging

VapourDetection

FireProtection

MaterialsofConstruction

RespiratoryandEyeProtection

15.1

1.2

to15

.11.

4,15

.11.

6to

Ace

ticac

idD

S3

2GC

ont.

No

T1

IIA

No

RF

AY1

,ZE

15.1

1.8,

15.1

9.6

15.1

1.2

to15

.11.

4,15

.11.

6to

Ace

tican

hydr

ide

1715

DS

22G

Con

t.N

oT

2II

AN

oR

F-T

AY1

E15

.11.

8,15

.19.

6

15.1

,15.

12,1

5.17

,15.

18,1

5.19

,A

ceto

necy

anoh

ydri

n15

41A

S/P

22G

Con

t.N

oT

1II

AYe

sC

TA

Y1E

16.6

Ace

toni

trile

1648

III

S2

2GC

ont.

No

T2

IIA

No

RF

-TA

No

15.1

2,15

.19.

6

15.1

2.3,

15.1

3,15

.16.

1,15

.19.

6,A

cryl

amid

eso

lutio

n(5

0%or

less

)20

74D

S2

2GO

pen

No

NF

CN

oN

oN

o16

.6.1

Acr

ylic

acid

2218

DS

32G

Con

t.N

oT

2II

AN

oR

F-T

AY1

No

15.1

3,15

.19.

6,16

.6.1

Acr

ylon

itrile

1093

BS/

P2

2GC

ont.

No

T1

IIB

No

CF

-TA

N3,

ZE

15.1

2,15

.13,

15.1

7,15

.19

Adi

poni

trile

2205

DS

32G

Con

t.N

oII

BYe

sR

TA

No

Ala

chlo

rte

chni

cal

(90%

orm

ore)

BS/

P3

2GO

pen

No

Yes

ON

oA

,CY1

No

15.1

9.6,

16.2

.6,1

6.2.

9,16

A.2

.2

Alc

ohol

(C12

-C15

)pol

y(1-

6)et

hoxy

late

sA

P2

2GO

pen

No

Yes

ON

oA

No

15.1

9.6

Alc

ohol

(C12

-C15

)pol

y(7-

19)e

thox

ylat

esB

P3

2GO

pen

No

Yes

ON

oA

No

15.1

9.6,

16.2

.6

Alc

ohol

(C12

-C15

)po

ly(2

0+)e

thox

ylat

esC

P3

2GO

pen

No

Yes

ON

oA

No

Alc

ohol

(C6-

C17

)(sec

onda

ry)p

oly(

3-6)

AP

22G

Ope

nN

oYe

sO

No

AN

o15

.19.

6et

hoxy

late

s

Alc

ohol

(C6-

C17

)(sec

onda

ry)p

oly(

7-12

)B

P3

2GO

pen

No

Yes

ON

oA

No

15.1

9.6,

16.2

.6,1

6.2.

9et

hoxy

late

s

Alk

anes

(C6-

C9)

(C)

P3

2GC

ont.

No

No

RF

AN

o15

.19.

6

Alk

aryl

poly

ethe

rs(C

9-C

20)

BP

32G

Ope

nN

oYe

sO

No

A,B

No

15.1

9.6,

16.2

.6

Alk

ylac

ryla

te-v

inyl

pyri

dine

copo

lym

erC

P3

2GC

ont.

No

No

RF

AN

o15

.19.

6in

tolu

ene

Alk

ylbe

nzen

e/-i

ndan

e/-i

nden

em

ixtu

reA

P2

2GO

pen

No

Yes

ON

oA

No

15.1

9.6

(C12

-C17

tota

lca

rbon

)

Alk

yl(C

3-C

4)be

nzen

esA

P3

2GC

ont.

No

No

RF

AN

o15

.19.

6

Alk

yl(C

5-C

8)be

nzen

esA

P2

2GO

pen

No

Yes

ON

oA

No

15.1

9.6


Alk

ylbe

nzen

esu

lpho

nic

acid

2586

,258

4C

S/P

32G

Ope

nN

oYe

sO

No

AN

o16

.2.7

,16.

2.8

Alk

ylbe

nzen

esu

lpho

nic

acid

,sod

ium

CP

32G

Ope

nN

oN

FO

No

No

No

16.2

.7,1

6.2.

8,16

.2.9

salt

solu

tion

Alk

yl(C

7-C

9)ni

trat

esB

S/P

22G

Ope

nN

oYe

sO

No

A,B

No

15.1

9.6,

15.2

0,16

.6

Ally

lal

coho

l10

98B

S/P

22G

Con

t.N

oT

2II

BN

oC

F-T

AE

15.1

2,15

.17,

15.1

9

Ally

lch

lori

de11

00B

S/P

22G

Con

t.N

oT

2II

AN

oC

F-T

AE

15.1

2,15

.17,

15.1

9

Alu

min

ium

chlo

ride

(30%

orle

ss)/

DS

31G

Con

t.N

oN

FR

TN

oE

(f)15

.11

Hyd

roch

lori

cac

id(2

0%or

less

)so

lutio

n

2-(2

-Am

inoe

thox

y)et

hano

l30

55D

S3

2GO

pen

No

Yes

ON

oA

,DN

2N

o15

.19.

6

Am

inoe

thyl

etha

nola

min

e(D

)S

32G

Ope

nN

oT

2II

AYe

sO

No

AN

1N

o

N-A

min

oeth

ylpi

pera

zine

2815

DS

32G

Con

t.N

oYe

sR

TA

N2

No

15.1

9.6

2-A

min

o-2-

met

hyl-

1-pr

opan

ol(9

0%or

DS

32G

Ope

nN

oYe

sO

No

AN

1N

ole

ss)

Am

mon

iaaq

ueou

s(2

8%or

less

)26

72(m

)C

S/P

32G

Con

t.N

oN

FR

TA

,B,C

N4

E(a

)

Am

mon

ium

bisu

lphi

teSo

lutio

n(7

0%or

DS

32G

Con

t.N

oN

FR

TN

oY5

No

15.1

6.1,

16.6

less

)

Am

mon

ium

nitr

ate

solu

tion

(93%

or15

.2,1

5.11

.4,1

5.11

.6,1

5.18

,D

S2

1GO

pen

No

NF

ON

oN

oY4

No

less

)15

.19.

6

Am

mon

ium

sulp

hide

solu

tion

(45%

or15

.12,

15.1

6.1,

15.1

7,15

.19,

2683

BS/

P2

2GC

ont.

No

No

CF

-TA

N1

Ele

ss)

16.6

Am

mon

ium

thio

cyan

ate

(25%

orle

ss)/

Am

mon

ium

thio

sulp

hate

(20%

orle

ss)

(C)

P3

2GO

pen

No

NF

ON

oN

oN

oso

lutio

n

Am

mon

ium

thio

sulp

hate

solu

tion

(C)

P3

2GO

pen

No

NF

ON

oN

oN

o16

.2.9

(60%

orle

ss)

Am

ylac

etat

e(a

llis

omer

s)11

04C

P3

2GC

ont.

No

No

RF

AN

o15

.9.6

Ani

line

1547

CS/

P2

2GC

ont.

No

T1

IIA

Yes

CT

AN

o15

.12,

15.1

7,15

.19

Avi

atio

nal

kyla

tes

(C8

para

ffins

and

iso-

(C)

P3

2GC

ont.

No

No

RF

BN

o15

.19.

6pa

raffi

nsB

PT

95—

120°

C)

(bb)

Ben

zene

and

mix

ture

sha

ving

10%

1114

(t)C

S/P

32G

Con

t.N

oT

1II

AN

oC

F-T

A,B

No

15.1

2.1,

15.1

7,15

.19.

6,16

.2.9

benz

ene

orm

ore*

Ben

zene

sulp

hony

lch

lori

de22

25D

S3

2GC

ont.

No

Yes

RT

A,D

N1

No

15.1

9.6

Ben

zyl

acet

ate

CP

32G

Ope

nN

oYe

sO

No

AN

o

Ben

zyl

alco

hol

CP

32G

Ope

nN

oYe

sO

No

AN

o

Ben

zyl

chlo

ride

1738

BS/

P2

2GC

ont.

No

T1

IIA

Yes

CT

A,B

E15

.12,

15.1

3,15

.17,

15.1

9

But

ene

olig

omer

BP

32G

Ope

nN

oYe

sO

No

AN

o15

.19.

6

But

ylac

etat

e(a

llis

omer

s)C

P3

2GC

ont.

No

No

RF

AN

o15

.19.

6

But

ylac

ryla

te(a

llis

omer

s)B

S/P

22G

Con

t.N

oT

2II

BN

oR

F-T

AN

o15

.13,

15.1

9.6,

16.6

.1,1

6.6.

2

But

ylam

ine

(all

isom

ers)

CS/

P2

2GC

ont.

No

No

RF

-TA

N1

E15

.12,

15.1

7,15

.19.

6

The

pref

ix5/

4B.i

sto

bead

ded

toth

ere

fere

nce

para

grap

hsin

colu

mn

‘‘o’’.

*For

mix

ture

sco

ntai

ning

noot

her

com

pone

nts

with

safe

tyha

zard

san

dw

here

the

pollu

tion

cate

gory

isC

orle

ss.


ab

cd

ef

gh

i′i′′

i′′′

jk

lm

no

Ele

ctri

cal

Eq

uip

men

t

Sp

ecia

lre

qu

irem

ents

Pro

du

ctn

am

e(S

eeC

hap

ter

5/4

B.1

5)

UNnumber

PollutionCategory

Hazards

ShipType

TankType

TankVent


Class

Group

Flashpoint60°C

Guaging

VapourDetection

FireProtection



But

ylbe

nzen

e(a

llis

omer

s)27

09A

P3

2GC

ont.

No

No

RF

AN

o15

.19.

6

But

ylbe

nzyl

phth

alat

eA

P2

2GO

pen

No

Yes

ON

oA

No

15.1

9.6

But

ylbu

tyra

te(a

llis

omer

s)B

P3

2GC

ont.

No

No

RF

AN

o15

.19.

6

But

yl/D

ecyl

/Cet

yl/E

icos

ylm

etha

cryl

ate

DS

32G

Con

t.N

oYe

sR

No

A,D

No

15.1

3,16

.6.1

,16.

6.2

mix

ture

15.8

.1to

.7,.

12,.

13,.

16to

.19,

1,2-

But

ylen

eox

ide

3022

CS/

P3

2GC

ont.

Iner

tT

2II

BN

oR

FA

,CZ

No

.21,

.25,

.27,

.29,

15.1

9.6

n-B

utyl

ethe

r11

49C

S/P

32G

Con

t.In

ert

T4

IIB

No

RF

-TA

No

15.4

.6,1

5.12

,15.

19.6

But

ylm

etha

cryl

ate

DS

32G

Con

t.N

oII

AN

oR

F-T

A,D

No

15.1

3,16

.6.1

,16.

6.2

n-B

utyl

prop

iona

te19

14C

P3

2GC

ont.

No

No

RF

AN

o15

.19.

6

But

yral

dehy

de(a

llis

omer

s)C

S/P

32G

Con

t.N

oT

3II

AN

oR

F-T

AN

o15

.16.

1,15

.19.

6

15.1

1.2

to15

.11.

4,15

.11.

6to

But

yric

acid

2820

DS

32G

Con

t.N

oYe

sR

No

AY1

No

15.1

1.8

Cal

cium

alky

l(C

9)ph

enol

sulp

hide

/A

P2

2GO

pen

No

Yes

ON

oA

,BN

o15

.19.

6po

lyol

efin

phos

phor

osul

phid

em

ixtu

re

Cal

cium

hypo

chlo

rite

solu

tion

(15%

orC

S/P

32G

Con

t.N

oN

FR

No

No

N5

No

15.1

6.1

less

)

Cal

cium

hypo

chlo

rite

solu

tion

(mor

eB

S/P

32G

Con

t.N

oN

FR

No

No

N5

No

15.1

6.1,

15.1

9.6

than

15%

)

Cal

cium

long

chai

nal

kyl

salic

ylat

eC

P3

2GO

pen

No

Yes

ON

oA

,BN

o16

.2.7

,16.

2.8

(C13

+)

Cam

phor

oil

BS/

P2

2GC

ont.

No

IIA

No

RF

A,B

No

15.1

9.6

Car

bolic

oil

AS/

P2

2GC

ont.

No

Yes

CF

-TA

No

15.1

2,15

.19

Pad

+C

arbo

ndi

sulp

hide

1131

BS/

P2

1GC

ont.

T6

IIC

No

CF

-TC

E15

.3,1

5.12

,15.

19In

ert

Car

bon

tetr

achl

orid

e18

46B

S/P

32G

Con

t.N

oN

FC

TN

oZ

E15

.12,

15.1

7,15

.19.

6

Cas

hew

nut

shel

loi

l(u

ntre

ated

)D

S3

2GC

ont.

No

Yes

RT

A,B

No

Cet

yl/E

icos

ylm

etha

cryl

ate

mix

ture

III

S3

2GO

pen

No

Yes

ON

oA

,DN

o15

.13,

16.6

.1,1

6.6.

2

15.1

1.2,

15.1

1.4,

15.1

1.6

toC

hlor

oace

ticac

id(8

0%or

less

)17

50C

S/P

22G

Con

t.N

oN

FC

No

No

Y5N

o15

.11.

8,15

.12.

3,15

.19,

16.2

.9

Chl

orin

ated

para

ffins

(C10

-C13

)A

P1

2GO

pen

No

Yes

ON

oA

No

15.1

9


Chl

orob

enze

ne11

34B

S/P

32G

Con

t.N

oT

1II

AN

oR

F-T

A,B

No

15.1

9.6

Chl

orof

orm

1888

BS/

P3

2GC

ont.

No

NF

RT

No

E15

.12,

15.1

9.6

Chl

oroh

ydri

ns(c

rude

)(D

)S

22G

Con

t.N

oII

AN

oC

F-T

AN

o15

.12,

15.1

9

4-C

hlor

o-2-

met

hylp

heno

xyac

etic

acid

,(C

)P

32G

Ope

nN

oN

FO

No

No

N1

No

dim

ethy

lam

ine

salt

solu

tion

15.1

2,15

.17,

15.1

8,15

.19,

o-C

hlor

onitr

oben

zene

1578

BS/

P2

2GC

ont.

No

Yes

CT

A,B

,DN

o16

.2.6

,16.

2.9,

16A

.2.2

15.1

1.2

to15

.11.

4,15

.11.

6to

2-or

3-C

hlor

opro

pion

icac

id25

11(n

)(C

)S/

P3

2GO

pen

No

Yes

ON

oA

Y1N

o15

.11.

8,16

.2.7

to16

.2.9

15.1

1.2

to15

.11.

8,15

.12,

Chl

oros

ulph

onic

acid

1754

CS/

P1

2GC

ont.

No

NF

CT

No

E15

.16.

2,15

.19

m-C

hlor

otol

uene

2238

BS/

P3

2GC

ont.

No

No

RF

-TA

,BN

o15

.19.

6

o-C

hlor

otol

uene

2238

AS/

P3

2GC

ont.

No

No

RF

-TA

,BN

o15

.19.

6

p-C

hlor

otol

uene

2238

BS/

P2

2GC

ont.

No

No

RF

-TA

,BN

o15

.19.

6,16

.2.9

Chl

orot

olue

nes

(mix

edis

omer

s)22

38A

S/P

22G

Con

t.N

oN

oR

F-T

A,B

No

15.1

9.6

Coa

lta

rA

S/P

22G

Con

t.N

oT

2II

AYe

sR

No

B,D

No

15.1

9.6

Coa

lta

rna

phth

aso

lven

tB

S/P

32G

Con

t.N

oT

3II

AN

oR

F-T

A,D

No

15.1

9.6

Coa

lta

rpi

tch

(mol

ten)

DS

31G

Con

t.N

oT

2II

AYe

sR

No

B,D

No

15.1

9.6

Cob

alt

naph

then

ate

inso

lven

tna

phth

aA

S/P

22G

Con

t.N

oN

oR

F-T

A,D

No

15.1

9.6

Coc

onut

oil

fatt

yac

idC

P3

2GO

pen

No

Yes

ON

oA

No

16.2

.7,1

6.2.

8,16

.2.9

Cre

osot

e(c

oal

tar)

AS/

P2

2GO

pen

No

T2

IIA

Yes

ON

oA

,DN

o15

.19.

6

Cre

osot

e(w

ood)

AS/

P2

2GO

pen

No

T2

IIA

Yes

ON

oA

,DN

o15

.19.

6

Cre

sols

(all

isom

ers)

2076

AS/

P2

2GO

pen

No

T1

IIA

Yes

ON

oA

,BN

o15

.19.

6

Cre

sylic

acid

,dep

heno

lized

AS/

P2

2GO

pen

No

Yes

ON

oA

,BN

o15

.19.

6

Cre

sylic

acid

,sod

ium

salt

solu

tion

AS/

P2

2GO

pen

No

Yes

ON

oN

oN

8N

o15

.19.

6

Cro

tona

ldeh

yde

1143

AS/

P2

2GC

ont.

No

T3

IIB

No

RF

-TA

E15

.12,

15.1

6.1,

15.1

7,15

.19.

6

1,5,

9-C

yclo

dode

catr

iene

AS/

P1

2GC

ont.

No

Yes

RT

AN

2N

o15

.13,

15.1

9,16

.6.1

,16.

6.2

Cyc

lohe

ptan

e(b

b)22

41(C

)P

32G

Con

t.N

oN

oR

FA

No

15.1

9.6

Cyc

lohe

xane

(bb)

1145

CP

32G

Con

t.N

oN

oR

FA

No

15.1

9.6,

16.2

.9

Cyc

lohe

xano

ne19

15D

S3

2GO

pen

No

T2

IIA

No

RF

-TA

N5

No

15.1

9.6

Cyc

lohe

xano

ne,c

yclo

hexa

nol

mix

ture

DS

32G

Con

t.N

oYe

sR

F-T

AN

5N

o

Cyc

lohe

xyl

acet

ate

2243

(B)

P3

2GC

ont.

No

No

RF

AN

o15

.19.

6

Cyc

lohe

xyla

min

e23

57C

S/P

32G

Con

t.N

oT

3II

AN

oR

F-T

A,C

N1

No

15.1

9.6

1,3-

Cyc

lope

ntad

iene

dim

er(m

olte

n)B

P2

2GC

ont.

No

No

RF

AN

o15

.19.

6,16

.2.6

,16.

2.9,

16A

.2.2

The

pref

ix5/

4B.i

sto

bead

ded

toth

ere

fere

nce

para

grap

hsin

colu

mn

‘‘o’’.


ab

cd

ef

gh

i′i′′

i′′′

jk

lm

no

Ele

ctri

cal

Eq

uip

men

t

Sp

ecia

lre

qu

irem

ents

Pro

du

ctn

am

e(S

eeC

hap

ter

5/4

B.1

5)

UNnumber

PollutionCategory

Hazards

ShipType

TankType

TankVent


Class

Group

Flashpoint60°C

Guaging

VapourDetection

FireProtection



Cyc

lope

ntan

e(b

b)11

46(C

)P

32G

Con

t.N

oN

oR

FA

No

15.1

9.6

Cyc

lope

nten

e22

46(B

)P

32G

Con

t.N

oN

oR

FA

No

15.1

9.6

p-C

ymen

e(b

b)20

46C

P3

2GC

ont.

No

No

RF

AN

o15

.19.

6

Dec

anoi

cac

idC

P3

2GO

pen

No

Yes

ON

oA

No

16.2

.7,1

6.2.

8,16

.2.9

Dec

ene

BP

32G

Con

t.N

oN

oR

FA

No

15.1

9.6

Dec

ylac

etat

e(B

)P

32G

Ope

nN

oYe

sO

No

AN

o15

.9.6

Dec

ylac

ryla

teA

S/P

22G

Ope

nN

oT

3II

AYe

sO

No

A,C

,DN

2N

o15

.13,

15.1

9.6,

16.6

.1,1

6.6.

2

Dec

ylal

coho

l(a

llis

omer

s)B

P3

2GO

pen

No

Yes

ON

oA

No

15.1

9.6,

16.2

.9(s

)

Dec

ylox

ytet

rahy

dro-

thio

phen

edi

oxid

eA

S/P

22G

Con

t.N

oYe

sR

TA

No

15.1

9.6

Dib

utyl

amin

eC

S/P

32G

Con

t.N

oT

2II

AN

oR

F-T

A,C

,DN

4N

o15

.19.

6

Dib

utyl

hydr

ogen

phos

phon

ate

BP

32G

Ope

nN

oYe

sO

No

AN

o15

.19.

6,16

.2.6

Dib

utyl

phth

alat

eA

P2

2GO

pen

No

Yes

ON

oA

No

15.1

9.6

15.1

9.6,

16.2

.6(x

),16

.2.9

(y),

Dic

hlor

oben

zene

s(a

llis

omer

s)B

S/P

22G

Con

t.N

oT

1II

AYe

sR

TA

,B,D

N5

No

16A

.2.2

(z)

1,1-

Dic

hlor

oeth

ane

2362

DS

32G

Con

t.N

oT

2II

AN

oR

F-T

AE

15.1

9.6

Dic

hlor

oeth

ylet

her

BS/

P2

2GC

ont.

No

T2

IIA

No

RF

-TA

N5

No

15.1

9.6

1,6

Dic

hlor

ohex

ane

BS/

P2

2GC

ont.

No

No

RT

A,B

No

15.1

9.6

2,2-

Dic

hlor

oiso

prop

ylet

her

2490

CS/

P2

2GC

ont.

No

Yes

RT

A,C

,DN

5N

o15

.12,

15.1

7,15

.19

Dic

hlor

omet

hane

1593

DS

32G

Con

t.N

oT

1II

AYe

sR

TN

oN

o

2,4-

Dic

hlor

ophe

nol

2021

AS/

P2

2GC

ont.

Dry

Yes

RT

AN

1N

o15

.19.

6

2,4-

Dic

hlor

ophe

noxy

acet

icac

id,

AS/

P3

2GO

pen

No

NF

ON

oN

oN

1N

o15

.19.

6di

etha

nola

min

esa

ltso

lutio

n

2,4-

Dic

hlor

ophe

noxy

acet

icac

id,

dim

ethy

lam

ine

salt

solu

tion

(70%

orA

S/P

32G

Ope

nN

oN

FO

No

No

N1

No

15.1

9.6

less

)

2,4-

Dic

hlor

ophe

noxy

acet

icac

id,

AS/

P3

2GO

pen

No

NF

ON

oN

oN

1N

o15

.19.

6tr

iisop

ropa

nola

min

esa

ltso

lutio

n

1,1

Dic

hlor

opro

pane

CS/

P2

2GC

ont.

No

No

RF

-TA

,BZ

No

15.1

2,15

.19.

6

1,2-

Dic

hlor

opro

pane

1279

CS/

P2

2GC

ont.

No

T1

IIA

No

RF

-TA

,BZ

No

15.1

2,15

.19.

6

1,3-

Dic

hlor

opro

pane

DS

22G

Con

t.N

oT

1II

AN

oR

F-T

A,B

No

15.1

2,15

.19.

6


1,3-

Dic

hlor

opro

pene

2047

BS/

P2

2GC

ont.

No

T2

IIA

No

CF

-TA

,BE

15.1

2,15

.17,

15.1

8,15

.19

Dic

hlor

opro

pene

/Dic

hlor

opro

pane

BS/

P2

2GC

ont.

No

No

CF

-TA

,B,D

E15

.12,

15.1

7,15

.18,

15.1

9m

ixtu

res

15.1

1.2,

15.1

1.4,

15.1

1.6

to2,

2-D

ichl

orop

ropi

onic

acid

DS

32G

Con

t.D

ryYe

sR

No

AY5

No

15.1

1.8

Die

than

olam

ine

DS

32G

Ope

nN

oT

1II

AYe

sO

No

AN

2N

o

Die

thyl

amin

e11

54C

S/P

32G

Con

t.N

oT

2II

AN

oR

F-T

AN

1E

15.1

2,15

.19.

6

Die

thyl

amin

oeth

anol

2686

CS/

P3

2GC

ont.

No

T2

IIA

No

RF

-TA

,CN

1N

o15

.19.

6

2,6-

Die

thyl

anili

neC

S/P

32G

Ope

nN

oYe

sO

No

B,C

,DN

4N

o15

.19.

6,16

.2.9

Die

thyl

benz

ene

2049

AP

32G

Con

t.N

oN

oR

FA

No

15.1

9.6

Die

thyl

enet

riam

ine

2079

DS

32G

Ope

nN

oT

2II

AYe

sO

No

AN

2N

o

Die

thyl

ethe

r11

55II

IS

21G

Con

t.In

ert

T4

IIB

No

CF

-TA

N7

E15

.4,1

5.14

,15.

19

Di(2

-eth

ylhe

xyl)p

hosp

hori

cac

id19

02C

S/P

32G

Ope

nN

oYe

sO

No

A,D

N2

No

Die

thyl

phth

alat

eC

P3

2GO

pen

No

Yes

ON

oA

No

Die

thyl

sulp

hate

1594

(B)

S/P

22G

Con

t.N

oYe

sC

TA

N3

No

15.1

9.6

Dig

lyci

dyl

ethe

rof

bisp

heno

lA

BP

32G

Ope

nN

oYe

sO

No

AN

o15

.19.

6,16

.2.6

Dig

lyci

dyl

ethe

rof

bisp

heno

lF

BP

32G

Ope

nN

oYe

sO

No

AN

o15

.19.

6,16

.2.6

Di-

n-he

xyl

adip

ate

BP

32G

Ope

nN

oYe

sO

No

AN

o15

.19.

6

Diis

obut

ylam

ine

2361

(C)

S/P

22G

Con

t.N

oN

oR

F-T

A,C

,DN

1N

o15

.12.

3,15

.19.

6

Diis

obut

ylen

e20

50B

P3

2GC

ont.

No

No

RF

AN

o15

.19.

6

Diis

obut

ylph

thal

ate

BP

32G

Ope

nN

oYe

sO

No

AN

o15

.19.

6,16

.2.6

Diis

opro

pano

lam

ine

CS/

P3

2GO

pen

No

T2

IIA

Yes

ON

oA

N2

No

16.2

.7,1

6.2.

8,16

.2.9

Diis

opro

pyla

min

e11

58C

S/P

22G

Con

t.N

oT

2II

AN

oC

F-T

AN

2E

15.1

2,15

.19

Diis

opro

pylb

enze

ne(a

llis

omer

s)A

P2

2GO

pen

No

Yes

ON

oA

No

15.1

9.6

N,N

-Dim

ethy

lace

tam

ide

solu

tion

(40%

DS

32G

Con

t.N

oYe

sR

TB

N4

No

15.1

2.1,

15.1

7or

less

)

Dim

ethy

lad

ipat

eB

P3

2GO

pen

No

Yes

ON

oA

No

15.1

9.6,

16.2

.9

Dim

ethy

lam

ine

solu

tion

(45%

orle

ss)

1160

CS/

P3

2GC

ont.

No

T2

IIA

No

RF

-TA

,C,D

N1

No

15.1

2,15

.19.

6

Dim

ethy

lam

ine

solu

tion

(gre

ater

than

1160

CS/

P2

2GC

ont.

No

No

CF

-TA

,C,D

N1

E15

.12,

15.1

7,15

.19

45%

but

not

grea

ter

than

55%

)

Dim

ethy

lam

ine

solu

tion

(gre

ater

than

1160

CS/

P2

2GC

ont.

No

No

CF

-TA

,C,D

N1

E15

.12,

15.1

4,15

.17,

15.1

955

%bu

tno

tgr

eate

rth

an65

%)

N,N

-Dim

ethy

lcyc

lohe

xyla

min

e22

64C

S/P

22G

Con

t.N

oN

oR

F-T

A,C

N1

No

15.1

2,15

.17,

15.1

9.6

Dim

ethy

leth

anol

amin

e20

51D

S3

2GC

ont.

No

T3

IIA

No

RF

-TA

,DN

2N

o15

.19.

6

Dim

ethy

lform

amid

e22

65D

S3

2GC

ont.

No

T2

IIA

No

RF

-TA

,DN

o15

.19.

6

Dim

ethy

lgl

utar

ate

CP

32G

Ope

nN

oYe

sO

No

AN

o

The

pref

ix5/

4B.i

sto

bead

ded

toth

ere

fere

nce

para

grap

hsin

colu

mn

‘‘o’’.


ab

cd

ef

gh

i′i′′

i′′′

jk

lm

no

Ele

ctri

cal

Eq

uip

men

t

Sp

ecia

lre

qu

irem

ents

Pro

du

ctn

am

e(S

eeC

hap

ter

5/4

B.1

5)

UNnumber

PollutionCategory

Hazards

ShipType

TankType

TankVent


Class

Group

Flashpoint60°C

Guaging

VapourDetection

FireProtection



Dim

ethy

lhy

drog

enph

osph

ite(B

)S/

P3

2GC

ont.

No

Yes

RT

A,D

No

15.1

2.1

Dim

ethy

loc

tano

icac

id(C

)P

32G

Ope

nN

oYe

sO

No

AN

o16

.2.8

,16.

2.9

Dim

ethy

lph

thal

ate

CP

32G

Ope

nN

oYe

sO

No

AN

o

Dim

ethy

lsu

ccin

ate

CP

32G

Ope

nN

oYe

sO

No

AN

o16

.2.9

Din

itrot

olue

ne(m

olte

n)16

00A

S/P

22G

(o)

Con

t.N

oYe

sC

TA

No

15.1

2,15

.17,

15.1

9,15

.21

1,4-

Dio

xane

1165

DS

22G

Con

t.N

oT

2II

BN

oC

F-T

AN

o15

.12,

15.1

9

Dip

ente

ne20

52C

P3

2GC

ont.

No

No

RF

AN

o15

.19.

6

Dip

heny

lA

P1

2GO

pen

No

Yes

ON

oB

No

15.1

9

Dip

heny

lam

ine

reac

tion

prod

uct

with

(A)

S/P

12G

Ope

nN

oYe

s0

No

AN

o15

.19

2,2,

4-T

rim

ethy

lpen

tene

Dip

heny

lam

ines

,alk

ylat

edA

P2

2GO

pen

No

Yes

0N

oA

No

15.1

9.6

Dip

heny

l/Dip

heny

let

her

mix

ture

sA

P1

2GO

pen

No

Yes

ON

oB

No

15.1

9

Dip

heny

let

her

AP

32G

Ope

nN

oYe

sO

No

AN

o15

.19.

6

Dip

heny

leth

er/D

iphe

nyl

phen

ylet

her

AP

32G

Ope

nN

oYe

sO

No

AN

o15

.19.

6m

ixtu

re

A,B

,C(c

),15

.12,

15.1

6.2,

15.1

7,15

.19.

6,D

iphe

nylm

etha

nedi

isoc

yana

te24

89(B

)S/

P2

2GC

ont.

Dry

Yes

(b)

CT

(b)

N5

No

D16

.2.6

,16.

2.9,

16A

.2.2

Dip

heny

lol

prop

ane-

epic

hlor

ohyd

rin

BP

32G

Ope

nN

oYe

sO

No

AN

o15

.19.

6,16

.2.6

resi

ns

Di-

n-pr

opyl

amin

e23

83C

S/P

32G

Con

t.N

oN

oR

F-T

AN

2N

o15

.12.

3,15

.19.

6

Dod

ecen

e(a

llis

omer

s)(B

)P

32G

Ope

nN

oYe

sO

No

AN

o15

.19.

6

Dod

ecyl

alco

hol

BP

32G

Ope

nN

oYe

sO

No

AN

o15

.19.

6,16

.2.6

,16.

2.9,

16A

.2.2

Dod

ecyl

amin

e/T

etra

decl

yam

ine

mix

ture

AS/

P2

2GC

ont.

No

Yes

RT

A,D

N2

No

15.1

9.6

Dod

ecyl

dim

ethy

lam

ine/

Tet

rade

cyA

S/P

22G

Ope

nN

oYe

sO

No

B,C

,DN

4N

o15

.9.6

Idim

ethy

lam

ine

mix

ture

Dod

ecyl

diph

enyl

ethe

rdi

sulp

hona

teA

S/P

22G

Ope

nN

oN

FO

No

No

No

15.1

9.6

solu

tion

Dod

ecyl

met

hacr

ylat

eII

IS

32G

Ope

nN

oYe

sO

No

AN

o15

.13

Dod

ecyl

/Pen

tade

cyl

met

hacr

ylat

eII

IS

32G

Ope

nN

oYe

sO

No

A,D

No

15.1

3,16

.6.1

,16.

6.2

mix

ture


Dod

ecyl

phen

olA

P1

2GO

pen

No

Yes

ON

oA

No

15.1

9

Dri

lling

brin

es(c

onta

inin

gZ

inc

salts

)B

P3

2GO

pen

No

Yes

ON

oN

oN

o15

.19.

6

Epi

chlo

rohy

drin

2023

AS/

P1

2GC

ont.

No

IIB

No

CF

-TA

E15

.12,

15.1

7,15

.19

Eth

anol

amin

e24

91D

S3

2GO

pen

No

T2

IIA

Yes

OF

-TA

N2

No

2-E

thox

yeth

ylac

etat

e11

72C

P3

2GC

ont.

No

No

RF

AN

o15

.19.

6

Eth

ylac

ryla

te19

17A

S/P

22G

Con

t.N

oT

2II

BN

oR

F-T

AE

15.1

3,15

.19.

6,16

.6.1

,16.

6.2

Eth

ylam

ine

1036

(C)

S/P

21G

Con

t.N

oT

2II

AN

oC

F-T

C,D

N2

E15

.12,

15.1

4,15

.19.

6

Eth

ylam

ine

solu

tions

(72%

orle

ss)

2270

(C)

S/P

22G

Con

t.N

oN

oC

F-T

A,C

N1

E15

.12,

15.1

4,15

.17,

15.1

9

Eth

ylam

ylke

tone

2271

CP

32G

Con

t.N

oN

oR

FA

No

15.1

9.6

Eth

ylbe

nzen

e11

75B

P3

2GC

ont.

No

No

RF

AN

o15

.19.

6

N-E

thyl

buty

lam

ine

(C)

S/P

32G

Con

t.N

oN

oR

F-T

AN

1N

o15

.12.

3,15

.19.

6

Eth

ylbu

tyra

te11

80C

P3

2GC

ont.

No

No

RF

AN

o15

.19.

6

Eth

ylcy

cloh

exan

e(b

b)(C

)P

32G

Con

t.N

oN

oR

FA

No

15.1

9.6

N-E

thyl

cycl

ohex

ylam

ine

DS

32G

Con

t.N

oN

oR

F-T

AN

1N

o15

.19.

6

Eth

ylen

ech

loro

hydr

in11

35C

S/P

22G

Con

t.N

oT

2II

AN

oC

F-T

A,D

E15

.12,

15.1

7,15

.19

Eth

ylen

ecy

anoh

ydri

n(D

)S

32G

Ope

nN

oII

BYe

sO

No

AN

o

Eth

ylen

edia

min

e16

04C

S/P

22G

Con

t.N

oT

2II

AN

oR

F-T

AN

2N

o15

.19.

6,16

.2.9

Eth

ylen

edi

brom

ide

1605

BS/

P2

2GC

ont.

No

NF

CT

No

E15

.12,

15.1

9.6,

16.2

.9

Eth

ylen

edi

chlo

ride

1184

BS/

P2

2GC

ont.

No

T2

IIA

No

RF

-TA

,BN

4N

o15

.19

Eth

ylen

egl

ycol

buty

let

her

acet

ate

(C)

P3

2GO

pen

No

Yes

ON

oA

No

Eth

ylen

egl

ycol

diac

etat

eC

P3

2GO

pen

No

Yes

ON

oA

No

Eth

ylen

egl

ycol

met

hyl

ethe

rac

etat

eC

P3

2GO

pen

No

Yes

ON

oA

No

Eth

ylen

egl

ycol

mon

oalk

ylet

hers

DS

32G

Con

t.N

oN

oR

FA

No

15.1

9.6

Eth

ylen

eox

ide/

Pro

pyle

neox

ide

mix

ture

with

anE

thyl

ene

oxid

eco

nten

tof

not

2983

CS/

P2

1GC

ont.

Iner

tT

2II

BN

oC

F-T

A,C

No

15.8

,15.

12,1

5.14

,15.

19m

ore

than

30%

inw

eigh

t

Eth

yl-3

-eth

oxyp

ropi

onat

eC

P3

2GC

ont.

No

No

RN

oA

No

15.1

9.6

2-E

thyl

hexy

lac

ryla

teB

S/P

32G

Ope

nN

oT

3II

BYe

sO

No

AN

o15

.13,

15.1

9.6,

16.6

.1,1

6.6.

2

2-E

thyl

hexy

lam

ine

2276

BS/

P2

2GC

ont.

No

No

RF

-TA

N2

No

15.1

2,15

.19.

6

Eth

ylid

ene

norb

orne

neB

S/P

32G

Con

t.N

oN

oR

F-T

A,D

N4

No

15.1

2.1,

15.1

6.1,

15.1

9.6

Eth

ylm

etha

cryl

ate

2277

(D)

S3

2GC

ont.

No

T2

IIA

No

RF

-TA

,DN

o15

.13,

15.1

9.6,

16.6

.1,1

6.6.

2

o-E

thyl

phen

ol(A

)S/

P3

2GO

pen

No

T1

IIA

Yes

ON

oB

No

15.1

9.6

2-E

thyl

-3-p

ropy

lacr

olei

n(A

)S/

P3

2GC

ont.

No

IIA

No

RF

-TA

No

15.1

9.6

Eth

ylto

luen

e(B

)P

32G

Con

t.N

oN

oR

FA

No

15.1

9.6

Fer

ric

chlo

ride

solu

tions

2582

CS/

P3

2GO

pen

No

NF

ON

oN

oN

o15

.11,

15.1

9.6,

16.2

.9

Fer

ric

nitr

ate/

Nitr

icac

idso

lutio

nC

S/P

22G

Con

t.N

oN

FR

TN

oE

15.1

1,15

.19

The

pref

ix5/

4B.i

sto

bead

ded

toth

ere

fere

nce

para

grap

hsin

colu

mn

‘‘o’’.


ab

cd

ef

gh

i′i′′

i′′′

jk

lm

no

Ele

ctri

cal

Eq

uip

men

t

Sp

ecia

lre

qu

irem

ents

Pro

du

ctn

am

e(S

eeC

hap

ter

5/4

B.1

5)

UNnumber

PollutionCategory

Hazards

ShipType

TankType

TankVent


Class

Group

Flashpoint60°C

Guaging

VapourDetection

FireProtection



Flu

oros

ilici

cac

id(2

0-30

%)

inw

ater

1778

CS/

P3

1GC

ont.

No

NF

RT

No

E15

.11

solu

tion

1198

(d),

For

mal

dehy

deso

lutio

ns(4

5%or

less

)C

S/P

32G

Con

t.N

oT

2II

BN

oR

F-T

AE

(e)

15.1

6.1,

15.1

9.6,

16.2

.922

09

15.1

1.2

to15

.11.

4,15

.11.

6to

For

mic

acid

1779

DS

32G

Con

t.N

oT

1II

AN

oR

T(v

)A

Y2,Y

3E

15.1

1.8,

15.1

9.6

Fum

aric

addu

ctof

rosi

n,w

ater

BP

32G

Ope

nN

oYe

sO

No

No

No

15.1

9.6,

16.2

.6di

sper

sion

Fur

fura

l11

99C

S/P

32G

Con

t.N

oT

2II

BN

oR

F-T

AN

o15

.16.

1,15

.19.

6

Fur

fury

lal

coho

l28

74C

P3

2GO

pen

No

Yes

ON

oA

No

Glu

tara

ldeh

yde

solu

tions

(50%

orle

ss)

DS

32G

Ope

nN

oN

FO

No

No

No

15.1

6.1

Gly

cidy

les

ter

ofC

10tr

ialk

ylac

etic

acid

BP

32G

Ope

nN

oYe

sO

No

AN

o15

.19.

6

Hep

tane

(all

isom

ers)

(bb)

1206

(C)

P3

2GC

ont.

No

No

RF

AN

o15

.19.

6

Hep

tano

l(a

llis

omer

s)(q

)C

P3

2GC

ont.

No

No

RF

AN

o15

.19.

6

Hep

tene

(all

isom

ers)

(bb)

CP

32G

Con

t.N

o.N

oR

FA

No

15.1

9.6

Hep

tyl

acet

ate

(B)

P3

2GO

pen

No

Yes

ON

oA

No

15.1

9.6

Hex

amet

hyle

nedi

amin

eso

lutio

n17

83C

S/P

32G

Con

t.N

oYe

sR

TA

N2

No

15.1

9.6,

16.2

.9

Hex

amet

hyle

neim

ine

2493

CS/

P2

2GC

ont.

No

No

RF

-TA

,CN

1N

o15

.19.

6

Hex

ane

(all

isom

ers)

(bb)

1208

(C)

P3

2GC

ont.

No

No

RF

AN

o15

.19.

6

Hex

ene

(all

isom

ers)

(bb)

(C)

P3

2GC

ont.

No

No

RF

AN

o15

.19.

6

Hex

ylac

etat

e12

33B

P3

2GC

ont.

No

No

RF

AN

o15

.19.

6

Hyd

roch

lori

cac

id17

89D

S3

1GC

ont.

No

NF

RT

No

E(f)

15.1

1

Hyd

roge

npe

roxi

deso

lutio

ns(o

ver

8%15

.5.1

4to

15.5

.26,

15.1

8,20

14,2

984

CS/

P3

2GC

ont.

No

NF

CN

oN

oN

obu

tno

tov

er60

%)

15.1

9.6

Hyd

roge

npe

roxi

deso

lutio

ns(o

ver

60%

2015

CS/

P2

2GC

ont.

No

NF

CN

oN

oN

o15

.5.1

to15

.5.1

3,15

.19.

6bu

tno

tov

er70

%)

15.1

2,15

.13,

15.1

9.6,

16.6

.1,

2-H

ydro

xyet

hyl

acry

late

BS/

P2

2GC

ont.

No

Yes

CT

AN

o16

.6.2

2-H

ydro

xy-4

-(m

ethy

lthio

)but

anoi

cac

idC

P3

2GO

pen

No

Yes

ON

oA

No

16.2

.7,1

6.2.

8

Isop

horo

nedi

amin

e22

89D

S3

2GC

ont.

No

Yes

RT

AN

2N

o


Isop

horo

nedi

isoc

yana

te22

90B

S/P

22G

Con

t.D

ryYe

sC

TA

,B,D

N5

No

15.1

2,15

.16.

2,15

.17,

15.1

9.6

15.1

3,15

.14,

15.1

9.6,

16.6

.1,

Isop

rene

1218

CS/

P3

2GC

ont.

No

T3

IIB

No

RF

BN

o16

.6.2

Isop

ropa

nola

min

eC

S/P

32G

Ope

nN

oT

2II

AYe

sO

F-T

AN

2N

o16

.2.8

,16.

2.9

Isop

ropy

lam

ine

1221

CS/

P2

2GC

ont.

No

T2

IIA

No

CF

-TC

,DN

2E

15.1

2,15

.14,

15.1

9

Isop

ropy

lcyc

lohe

xane

(bb)

(C)

P3

2GC

ont.

No

No

RF

AN

o15

.19.

6,16

.2.7

,16.

2.8

Isop

ropy

let

her

1159

DS

32G

Con

t.In

ert

No

RF

AN

o15

.4.6

,15.

13.3

,15.

19.6

15.1

,15.

12,1

5.17

,15.

18,1

5.19

,L

acto

nitr

ileso

lutio

n(8

0%or

less

)B

S/P

21G

Con

t.N

oYe

sC

TA

,C,D

Y1E

16.2

.6,1

6.6

Lau

ric

acid

BP

32G

Ope

nN

oYe

sO

No

AN

o15

.19.

6,16

.2.6

,16.

2.9,

16A

.2.2

Lau

ryl

poly

gluc

ose

(50%

orle

ss)

(B)

P3

2GO

pen

No

Yes

ON

oN

oN

o15

.9.6

,16.

2.6,

16.2

.9,1

6A.2

.2

Liq

uid

chem

ical

was

tes

AS/

P2

2GC

ont.

No

No

CF

-TA

E15

.12,

15.1

9.6,

20.5

.1

Lon

gch

ain

alka

ryl

poly

ethe

r(C

11-C

20)

CP

32G

Ope

nN

oYe

sO

No

A,B

No

16.2

.7,1

6.2.

8

Lon

gch

ain

poly

ethe

ram

ine

inal

kyl

CP

32G

Con

t.N

oN

oR

FA

No

15.1

9.6,

16.2

.7,1

6.2.

8(C

2-C

4)be

nzen

es

Lon

gch

ain

poly

ethe

ram

ine

inar

omat

icC

P3

2GC

ont.

No

No

RF

AN

o15

.19.

6,16

.2.7

,16.

2.8

solv

ent

Mag

nesi

umlo

ngch

ain

alky

lsa

licyl

ate

CP

32G

Ope

nN

oYe

sO

No

A,B

No

16.2

.7,1

6.2.

8(C

11+

)

Mal

eic

anhy

drid

e22

15D

S3

2GC

ont.

No

Yes

RN

oA

(g),C

No

Mer

capt

oben

zoth

iazo

l,so

dium

salt

BS/

P3

2GO

pen

No

NF

ON

oN

oN

1N

o15

.19.

6,16

.2.9

solu

tion

Mes

ityl

oxid

e12

29D

S3

2GC

ont.

No

T2

IIB

No

RF

-TA

No

15.1

9.6

Met

amso

dium

solu

tion

AS/

P3

2GO

pen

No

NF

ON

oN

oN

1N

o15

.19.

6

Met

hacr

ylic

acid

2531

DS

32G

Con

t.N

oYe

sR

TA

Y1N

o15

.13,

16.6

.1

Met

hacr

ylic

resi

nin

ethy

lene

dich

lori

deB

S/P

22G

Con

t.N

oT

2II

AN

oR

F-T

A,B

N4

No

15.1

9,16

.2.6

Met

hacr

ylon

itrile

3079

DS

22G

Con

t.N

oN

oC

F-T

AN

4,Z

E15

.12,

15.1

3,15

.17,

15.1

9

Met

hyl

acry

late

1919

BS/

P2

2GC

ont.

No

T1

IIB

No

RF

-TA

E15

.13,

15.1

9.6,

16.6

.1,1

6.6.

2

Met

hyla

min

eso

lutio

ns(4

2%or

less

)12

35C

S/P

22G

Con

t.N

oN

oC

F-T

A,C

,DN

1E

15.1

2,15

.17,

15.1

9

Met

hyla

myl

acet

ate

1233

(C)

P3

2GC

ont.

No

No

RF

AN

o15

.19.

6

Met

hyla

myl

alco

hol

2053

(C)

P3

2GC

ont.

No

No

RF

AN

o15

.19.

6

Met

hyl

buty

rate

1237

(C)

P3

2GC

ont.

No

No

RF

AN

o15

.19.

6

Met

hylc

yclo

hexa

ne(b

b)22

96(C

)P

32G

Con

t.N

oN

oR

FA

No

15.1

9.6

Met

hylc

yclo

pent

adie

nedi

mer

(B)

P3

2GC

ont.

No

No

RF

BN

o15

.19.

6

Met

hyl

diet

hano

lam

ine

DS

32G

Ope

nN

oYe

sO

No

AN

2N

o

2-M

ethy

l-6-

ethy

lan

iline

CS/

P3

2GO

pen

No

Yes

ON

oA

,DN

o

2-M

ethy

l-5-

ethy

lpy

ridi

ne23

00(B

)S/

P3

2GO

pen

No

IIA

Yes

ON

oA

,DN

4N

o15

.19.

6

Met

hyl

form

ate

1243

DS

22G

Con

t.N

oN

oR

F-T

AE

15.1

2,15

.14,

15.1

9

The

pref

ix5/

4B.i

sto

bead

ded

toth

ere

fere

nce

para

grap

hsin

colu

mn

‘‘o’’.


ab

cd

ef

gh

i′i′′

i′′′

jk

lm

no

Ele

ctri

cal

Eq

uip

men

t

Sp

ecia

lre

qu

irem

ents

Pro

du

ctn

am

e(S

eeC

hap

ter

5/4

B.1

5)

UNnumber

PollutionCategory

Hazards

ShipType

TankType

TankVent


Class

Group

Flashpoint60°C

Guaging

VapourDetection

FireProtection



Met

hyl

hept

ylke

tone

BP

32G

Con

t.N

oN

oR

FA

No

15.1

9.6

2-M

ethy

l-2-

hydr

oxy-

3-bu

tyne

III

S3

2GC

ont.

No

IIA

No

RF

-TA

,B,D

N6

No

15.1

9.6

Met

hyl

met

hacr

ylat

e12

47D

S2

2GC

ont.

No

T2

IIA

No

RF

-TA

No

15.1

3,15

.19.

6,16

.6.1

,16.

6.2

Met

hyl

naph

thal

ene

(mol

ten)

AS/

P2

2GC

ont.

No

Yes

RN

oA

,DN

o15

.19.

6

2-M

ethy

lpyr

idin

e23

13D

S2

2GC

ont.

No

No

CF

AN

4N

o15

.12.

3,15

.19.

6

3-M

ethy

lpyr

idin

e23

13C

S/P

22G

Con

t.N

oN

oC

FA

,CN

4N

o15

.12.

3,15

.19

4-M

ethy

lpyr

idin

e23

13D

S2

2GC

ont.

No

No

CF

-TA

N4

No

15.1

2.3,

15.1

9,16

.2.9

Met

hyl

salic

ylat

e(B

)P

32G

Ope

nN

oYe

sO

No

AN

o15

.19.

6

alph

a-M

ethy

lsty

rene

2303

AS/

P3

2GC

ont.

No

T1

IIB

No

RF

-TA

,D**

*N

o15

.13,

15.1

9.6,

16.6

.1,1

6.6.

2

Mor

phol

ine

2054

DS

32G

Con

t.N

oT

2II

AN

oR

FA

N2,

ZN

o15

.19.

6

Mot

orfu

elan

ti-kn

ock

com

poun

ds16

49A

S/P

11G

Con

t.N

oT

4II

AN

oC

F-T

A,C

E15

.6,1

5.12

,15.

18,1

5.19

(con

tain

ing

lead

alky

ls)

Nap

htha

lene

(mol

ten)

2304

AS/

P2

2GC

ont.

No

T1

IIA

Yes

RN

oA

,DN

o15

.19.

6

Nap

then

icac

ids

AP

22G

Ope

nN

oYe

sO

No

AN

o15

.19.

6

Neo

deca

noic

acid

CP

32G

Ope

nN

oYe

sO

No

AN

o16

.2.8

Nitr

atin

gac

id(m

ixtu

reof

sulp

huri

can

d17

96(C

)S/

P2

2GC

ont.

No

NF

CT

No

E15

.11,

15.1

6.2,

15.1

7,15

.19

nitr

icac

ids)

Nitr

icac

id(le

ssth

an70

%)

2031

CS/

P2

2GC

ont.

No

NF

RT

No

E15

.11,

15.1

9

2031

,N

itric

acid

(70%

and

over

)C

S/P

22G

Con

t.N

oN

FC

TN

oE

15.1

1,15

.19

2032

(h)

15.1

2,15

.17,

15.1

8,15

.19,

Nitr

oben

zene

1662

BS/

P2

2GC

ont.

No

T1

IIA

Yes

CT

A,D

No

16.2

.9

15.1

2,15

.19.

6,16

.2.6

,16.

2.9,

o-N

itrop

heno

l(m

olte

n)16

63B

S/P

22G

Con

t.N

oYe

sC

TA

,DN

o16

A.2

.2

1-or

2-N

itrop

ropa

ne26

08D

S3

2GC

ont.

No

T2

IIB

No

RF

-TA

No

15.1

9.6

Nitr

opro

pane

(60%

)/Nitr

oeth

ane

(40%

)D

S3

2GC

ont.

No

No

RF

-TA

(u)

N4

No

15.1

9.6

mix

ture

(o-

orp-

)N

itrot

olue

nes

1664

BS/

P2

2GC

ont.

No

IIB

Yes

CT

A,B

No

15.1

2,15

.17,

15.1

9,16

.2.9

Non

ane

(all

isom

ers)

(bb)

1920

(C)

P3

2GC

ont.

No

No

RF

B,C

No

15.1

9.6

Non

ene

(all

isom

ers)

BP

32G

Con

t.N

oN

oR

FA

No

15.1

9.6


Non

ylA

ceta

te(C

)P

32G

Ope

nN

oYe

sO

No

AN

o15

.19.

6

Non

ylal

coho

l(a

llis

omer

s)C

P3

2GO

pen

No

Yes

ON

oA

No

Non

ylph

enol

AP

22G

Ope

nN

oYe

sO

No

AN

o15

.19.

6

15.1

9.6,

16.2

.6,1

6.2.

9,N

onyl

phen

olpo

ly(4

-12)

etho

xyla

tes

BP

32G

Ope

nN

oYe

sO

No

AN

o16

A.2

.2(a

a)

Nox

ious

liqui

d,N

.F,(

1)n.

o.s.

(trad

eA

P1

2GO

pen

No

Yes

ON

oA

No

15.1

9na

me

...,

cont

ains

...)

S.T

.1,C

at.A

*

Nox

ious

liqui

d,F

,(2)

n.o.

s.(tr

aden

ame

AP

12G

Con

t.N

oN

oR

FA

No

15.1

9..

.,co

ntai

ns..

.)S.

T.1

,Cat

.A*

Nox

ious

liqui

d,N

.F,(

3)n.

o.s.

(trad

enam

e..

.,co

ntai

ns..

.)S.

T.2

,A

P2

2GO

pen

No

Yes

ON

oA

No

15.1

9.6

Cat

.A*

Nox

ious

liqui

d,F

,(4)

n.o.

s.(tr

aden

ame

AP

22G

Con

t.N

oN

oR

FA

No

15.1

9.6

...,

cont

ains

...)

S.T

.2,C

at.A

*

Nox

ious

liqui

d,N

.F,(

5)n.

o.s.

(trad

enam

e..

.,co

ntai

ns..

.)S.

T.2

,B

P2

2GO

pen

No

Yes

ON

oA

No

15.1

9.6,

[16.

2.6,

16.2

.9]*

*C

at.B

*

Nox

ious

liqui

d,N

.F,(

6)n.

o.s.

15.1

9.6,

[16.

2.6]

**,1

6.2.

9,(tr

aden

ame

...,

cont

ains

...)

S.T

.2,

BP

22G

Ope

nN

oYe

sO

No

AN

o16

A.2

.2C

at.B

*,m

p15

°C+

Nox

ious

liqui

d,F

,(7)

n.o.

s.(tr

aden

ame

BP

22G

Con

t.N

oN

oR

FA

No

15.1

9.6,

[16.

2.6,

16.2

.9]*

*..

.,co

ntai

ns..

.)S.

T.2

,Cat

.B*

Nox

ious

liqui

d,F

,(8)

n.o.

s.(tr

aden

ame

15.1

9.6,

[16.

2.6]

**,1

6.2.

9,..

.,co

ntai

ns..

.)S.

T.2

,Cat

.B*,

mp

BP

22G

Con

t.N

oN

oR

FA

No

16A

.2.2

15°C

+

Nox

ious

liqui

d,N

.F,(

9)n.

o.s.

(trad

enam

e..

.,co

ntai

ns..

.)S.

T.3

,A

P3

2GO

pen

No

Yes

ON

oA

No

15.1

9.6

Cat

.A*

Nox

ious

liqui

d,F

,(10

)n.

o.s.

(trad

enam

eA

P3

2GC

ont.

No

No

RF

AN

o15

.19.

6..

.,co

ntai

ns..

.)S.

T.3

,Cat

.A*

Nox

ious

liqui

d,N

.F,(

11)

n.o.

s.(tr

aden

ame

...,

cont

ains

...)

S.T

.3,

BP

32G

Ope

nN

oYe

sO

No

AN

o15

.19.

6,[1

6.2.

6,16

.2.9

]**

Cat

.B*

Nox

ious

liqui

d,N

.F,(

12)

n.o.

s.15

.9.6

,[16

.2.6

]**,

16.2

.9,

(trad

enam

e..

.,co

ntai

ns..

.)S.

T.3

,B

P3

2GO

pen

No

Yes

ON

oA

No

16A

.2.2

Cat

.B*,

mp

15°C

+

The

pref

ix5/

4B.i

sto

bead

ded

toth

ere

fere

nce

para

grap

hsin

colu

mn

‘‘o’’.

*In

case

ofa

spec

ific

n.o.

s.ca

rgo

asse

ssed

asfa

lling

with

inth

isn.

o.s.

grou

pth

atis

carr

ied

ona

ship

,thi

sen

try,

incl

udin

gth

eca

rgo’

str

ade

nam

ean

don

eor

two

prin

cipl

eco

mpo

nent

s,sh

ould

bepr

ovid

edin

the

ship

ping

docu

men

t.A

bbre

viat

ions

used

mea

n:

N.F

:F

lash

poin

tex

ceed

ing

60°C

(clo

sed

cup

test

)S.

T.

Ship

type

F:

Fla

shpo

int

not

exce

edin

g60

°C(c

lose

dcu

pte

st)

Cat

.:P

ollu

tion

cate

gory

n.o.

s.:

not

othe

rwis

esp

ecifi

edm

.p.:

Mel

ting

poin

t**

For

high

visc

osity

orhi

ghm

eltin

gpo

int

carg

oes

***O

nly

cert

ain

alco

hol

resi

stan

tfo

ams

are

effe

ctiv

e.


ab

cd

ef

gh

i′i′′

i′′′

jk

lm

no

Ele

ctri

cal

Eq

uip

men

t

Sp

ecia

lre

qu

irem

ents

Pro

du

ctn

am

e(S

eeC

hap

ter

5/4

B.1

5)

UNnumber

PollutionCategory

Hazards

ShipType

TankType

TankVent


Class

Group

Flashpoint60°C

Guaging

VapourDetection

FireProtection



Nox

ious

liqui

d,F

,(13

)n.

o.s.

(trad

enam

eB

P3

2GC

ont.

No

No

RF

AN

o15

.19.

6,[1

6.2.

6,16

.2.9

]**

...,

cont

ains

...)

S.T

.3,C

at.B

*

Nox

ious

liqui

d,F

,(14

)n.

o.s.

(trad

enam

e15

.19.

6,[1

6.2.

6]**

,16.

2.9,

...,

cont

ains

...)

S.T

.3,C

at.B

*,m

pB

P3

2GC

ont.

No

No

RF

AN

o16

A.2

.215

°C+

Nox

ious

liqui

d,N

.F,(

15)

n.o.

s.(tr

aden

ame

...,

cont

ains

...)

S.T

.3,

CP

32G

Con

t.N

oYe

sO

No

AN

o[1

6.2.

7to

16.2

.9]*

*C

at.C

*

Nox

ious

liqui

d,F

,(16

)n.

o.s.

(trad

enam

eC

P3

2GC

ont.

No

No

RF

AN

o[1

6.2.

7to

16.2

.9]*

*..

.,co

ntai

ns..

.)S.

T.3

,Cat

.C*

Oct

ane

(all

isom

ers)

1262

(C)

P3

2GC

ont.

No

No

RF

AN

o15

.19.

6

Oct

anol

(all

isom

ers)

CP

32G

Ope

nN

oYe

sO

No

AN

o

Oct

ene

(all

isom

ers)

BP

32G

Con

t.N

oN

oR

FA

No

15.1

9.6

n-O

ctyl

acet

ate

CP

32G

Ope

nN

oYe

sO

No

AN

o

Oct

ylal

dehy

des

1191

(B)

P3

2GC

ont.

No

No

RF

AN

o15

.19.

6,16

.2.9

Ole

finm

ixtu

res

(C5-

C7)

(bb)

CP

32G

Con

t.N

oN

oR

FA

No

15.1

9.6

Ole

finm

ixtu

res

(C5-

C15

)B

P3

2GC

ont.

No

No

RF

AN

o15

.19.

6

alph

a-O

lefin

s(C

6-C

18)

mix

ture

sB

P3

2GC

ont.

No

No

RF

AN

o15

.19.

6,16

.2.6

,16.

2.9

15.1

1.2

to15

.11.

8,15

.12.

1,O

leum

1831

CS/

P2

2GC

ont.

No

NF

CT

No

E15

.16.

2,15

.17,

15.1

9,16

.2.7

,16

.2.8

Ole

ylam

ine

AS/

P2

2GC

ont.

No

Yes

RT

AN

o15

.19.

6

Pal

mke

rnel

acid

oil

CP

32G

Ope

nN

oYe

sO

No

A,B

No

16.2

.7to

16.2

.9

Par

alde

hyde

1264

CS/

P3

2GC

ont.

No

T3

IIB

No

RF

AN

o15

.19.

6,16

.2.9

Pen

tach

loro

etha

ne16

69B

S/P

22G

Con

t.N

oN

FR

TN

oN

o15

.12,

15.1

7,15

.19.

6

1,3-

Pen

tadi

ene

CS/

P3

2GC

ont.

No

No

RF

-TA

,BN

o15

.13,

15.1

9.6,

16.6

Pen

tane

(all

isom

ers)

(bb)

1265

(C)

P3

2GC

ont.

No

No

RF

AN

o15

.14,

15.1

9.6

Pen

tene

(all

isom

ers)

(bb)

CP

32G

Con

t.N

oN

oR

FA

No

15.1

4,15

.19.

6

n-P

enty

lpr

opio

nate

CP

32G

Con

t.N

oN

oR

FA

No

15.1

9.6

Per

chlo

roet

hyle

ne18

97B

S/P

32G

Con

t.N

oN

FR

TN

oN

o15

.12.

1,15

.12.

2,15

.19.

6


15.1

2,15

.19,

16.2

.7,1

6.2.

8,P

heno

l23

12C

S/P

22G

Con

t.N

oT

1II

AYe

sC

TA

No

16.2

.9

1-P

heny

l-1-

xyly

let

hane

(bb)

CP

32G

Ope

nN

oYe

sO

No

A,B

No

15.1

1.1

to15

.11.

4,15

.11.

6to

Pho

spho

ric

acid

1805

DS

32G

Ope

nN

oN

FO

No

No

No

15.1

1.8

Pad

+(v

ent

Pho

spho

rus,

yello

wor

whi

teA

S/P

11G

Con

t.N

o(k

)C

No

CE

15.7

,15.

19or in

ert)

Pht

halic

anhy

drid

e(m

olte

n)22

14C

S/P

32G

Con

t.N

oT

1II

AYe

sR

No

A,D

No

16.2

.7to

16.2

.9

alph

a-P

inen

eA

P3

2GC

ont.

No

No

RF

AN

o15

.19.

6

beta

-Pin

ene

2368

BP

32G

Con

t.N

oN

oR

FA

No

15.1

9.6

Pin

eoi

l12

72C

P3

2GO

pen

No

Yes

ON

oA

No

16.2

.7,1

6.2.

8

Pol

y(2+

)cyc

licar

omat

ics

AP

22G

Con

t.N

oYe

sR

No

A,D

No

15.1

9.6

Pol

yalk

yl(C

18-C

22)

acry

late

inX

ylen

eC

P3

2GC

ont.

No

No

RF

AN

o15

.19.

6,16

.2.7

,16.

2.8

Pol

yalk

ylen

eox

ide

poly

olC

P3

2GO

pen

No

Yes

ON

oA

No

16.2

.7,1

6.2.

8

Pol

yeth

ylen

epo

lyam

ines

(C)

S/P

32G

Ope

nN

oYe

sO

No

AN

2N

o16

.2.9

Pol

yfer

ric

sulp

hate

solu

tion

(C)

S/P

32G

Ope

nN

oN

FO

No

No

Y4N

o

Pol

ymet

hyle

nepo

lyph

enyl

isoc

yana

teD

S2

2GC

ont.

Dry

Yes

(b)

CT

(b)

AN

5N

o15

.12,

15.1

6.2,

15.1

9.6

Pol

yole

finam

ine

inal

kyl

(C2-

C4)

(C)

P3

2GC

ont.

No

No

RF

AN

o15

.19.

6,16

.2.7

,16.

2.8

benz

enes

Pol

yole

finam

ine

inar

omat

icso

lven

t(C

)P

32G

Con

t.N

oN

oR

FA

No

15.1

9.6,

16.2

.7,1

6.2.

8

Pol

yole

finph

osph

oros

ulph

ide—

bari

umC

P3

2GO

pen

No

Yes

ON

oA

,BN

o16

.2.7

,16.

2.8

deri

vativ

e(C

28-C

250)

Pot

assi

umch

lori

deso

lutio

n(1

0%or

CP

32G

Ope

nN

oN

FO

No

No

No

mor

e)

Pot

assi

umhy

drox

ide

solu

tion

1814

CS/

P3

2GO

pen

No

NF

ON

oN

oN

8N

o16

.2.9

Pot

assi

umol

eate

CP

32G

Ope

nN

oYe

sO

No

AN

o15

.19.

6

Pot

assi

umpo

lysu

lphi

de,P

otas

sium

(C)

S/P

32G

Ope

nN

oN

FO

No

No

N2

No

15.1

6.1,

15.1

9.6

this

ulph

ate

solu

tion

(41%

orle

ss)

n-P

ropa

nola

min

eC

S/P

32G

Ope

nN

oYe

sO

No

A,D

N2

No

16.2

.9

beta

-Pro

piol

acto

neD

S2

2GC

ont.

No

IIA

Yes

RT

AN

o

The

pref

ix5/

4B.i

sto

bead

ded

toth

ere

fere

nce

para

grap

hsin

colu

mn

‘‘o’’.

*In

case

ofa

spec

ific

n.o.

s.ca

rgo

asse

ssed

asfa

lling

with

inth

isn.

o.s.

grou

pth

atis

carr

ied

ona

ship

,thi

sen

try,

incl

udin

gth

eca

rgo’

str

ade

nam

ean

don

eor

two

prin

cipl

eco

mpo

nent

s,sh

ould

bepr

ovid

edin

the

ship

ping

docu

men

t.A

bbre

viat

ions

used

mea

n:

N.F

:F

lash

poin

tex

ceed

ing

60°C

(clo

sed

cup

test

)S.

T.

Ship

type

F:

Fla

shpo

int

not

exce

edin

g60

°C(c

lose

dcu

pte

st)

Cat

.:P

ollu

tion

cate

gory

n.o.

s.:

not

othe

rwis

esp

ecifi

edm

.p.:

Mel

ting

poin

t**

For

high

visc

osity

orhi

ghm

eltin

gpo

int

carg

oes


ab

cd

ef

gh

i′i′′

i′′′

jk

lm

no

Ele

ctri

cal

Eq

uip

men

t

Sp

ecia

lre

qu

irem

ents

Pro

du

ctn

am

e(S

eeC

hap

ter

5/4

B.1

5)

UNnumber

PollutionCategory

Hazards

ShipType

TankType

TankVent


Class

Group

Flashpoint60°C

Guaging

VapourDetection

FireProtection



Pro

pion

alde

hyde

1275

CS/

P3

2GC

ont.

No

No

RF

-TA

E15

.16.

1,15

.17,

15.1

9.6

15.1

1.2

to15

.11.

4,15

.11.

6to

Pro

pion

icac

id18

48D

S3

2GC

ont.

No

T1

IIA

No

RF

AY1

E15

.11.

8,15

.19.

6

Pro

pion

ican

hydr

ide

2496

CS/

P3

2GC

ont.

No

T2

IIA

Yes

RT

AY1

No

Pro

pion

itrile

2404

CS/

P2

1GC

ont.

No

T1

IIB

No

CF

-TA

,DE

15.1

2,15

.17,

15.1

8,15

.19

n-P

ropy

lam

ine

1277

CS/

P2

2GC

ont.

Iner

tT

2II

AN

oC

F-T

A,D

N2

E15

.12,

15.1

9

Pro

pylb

enze

ne(a

llis

omer

s)A

P3

2GC

ont.

No

No

RF

AN

o15

.19.

6

n-pr

opyl

chlo

ride

1278

DS

32G

Con

t.N

oN

oR

FA

,BN

o15

.19.

6

Pro

pyle

nedi

mer

(bb)

(C)

P3

2GC

ont.

No

No

RF

AN

o15

.19.

6

Pro

pyle

neox

ide

1280

CS/

P2

2GC

ont.

Iner

tT

2II

BN

oC

F-T

A,C

ZN

o15

.8,1

5.12

.1,1

5.14

,15.

19

Pro

pyle

nete

tram

er28

50B

P3

2GC

ont.

No

No

RF

AN

o15

.19.

6

Pro

pyle

netr

imer

2057

BP

32G

Con

t.N

oN

oR

FA

No

15.1

9.6

Pyr

idin

e12

82D

S3

2GC

ont.

No

T1

IIA

No

RF

AN

4N

o15

.19.

6

Ros

inB

P3

2GO

pen

No

Yes

ON

oA

No

15.1

9.6,

16.2

.6,1

6.2.

9,16

A.2

.2

Ros

inso

ap(d

ispr

opor

tiona

ted)

solu

tion

BP

32G

Ope

nN

oYe

sO

No

AN

o15

.19.

6

Sodi

umal

umin

ate

solu

tion

1819

DS

32G

Ope

nN

oN

FO

No

No

N1

No

Sodi

umbo

rohy

drid

e(1

5%or

less

)/C

S/P

32G

Ope

nN

oN

FO

No

No

N1

No

16.2

.7So

dium

hydr

oxid

eso

lutio

n

Sodi

umal

kyl

(C14

-C17

)B

P3

2GO

pen

No

NF

ON

oN

oN

o16

.2.6

Sulp

hona

tes

60-6

5%so

lutio

n

Sodi

umch

lora

teso

lutio

n(5

0%or

less

)24

28II

IS

32G

Ope

nN

oN

FO

No

No

No

15.9

,15.

16.1

,15.

19.6

Sodi

umdi

chro

mat

eso

lutio

n(7

0%or

CS/

P2

2GO

pen

No

NF

CN

oN

oN

2N

o15

.12.

3,15

.19

less

)

Sodi

umhy

drog

ensu

lphi

de(6

%or

less

)/B

P3

2GO

pen

No

NF

ON

oN

oN

o15

.19.

6So

dium

carb

onat

ed(3

%or

less

)so

lutio

n

Sodi

umhy

drog

ensu

lphi

teso

lutio

n(4

5%26

93D

S3

2GO

pen

No

NF

ON

oN

oN

oor

less

)

Ven

tor

Sodi

umhy

dros

ulph

ide

solu

tion

(45%

or29

49B

S/P

32G

Con

t.P

adN

FR

TN

oN

o15

.16.

1,15

.19.

6,16

.2.9

less

)(g

as)

Sodi

umhy

dros

ulph

ide/

Am

mon

ium

15.1

2,15

.14,

15.1

6.1,

15.1

7,B

S/P

22G

Con

t.N

oN

oC

F-T

AN

1E

sulp

hide

solu

tion

15.1

9,16

.6

Sodi

umhy

drox

ide

solu

tion

1824

DS

32G

Ope

nN

oN

FO

No

No

N8

No


Sodi

umhy

poch

lori

teso

lutio

n(1

5%or

1791

CS/

P3

2GC

ont.

No

NF

RN

oN

oN

5N

o15

.16.

1le

ss)

15.1

2.3.

1,15

.12.

3.2,

15.1

6.1,

Sodi

umni

trite

solu

tion

1500

BS/

P2

2GO

pen

No

NF

ON

oN

oN

o15

.19

Sodi

umpe

trol

eum

sulfo

nate

BS/

P2

2GO

pen

No

Yes

ON

oA

No

15.1

9.6,

16.2

.6

Sodi

umsi

licat

eso

lutio

nC

P3

2GO

pen

No

Yes

ON

oA

No

Sodi

umsu

phid

eso

lutio

n(1

5%or

less

)B

S/P

32G

Con

t.N

oN

FC

TN

oN

5N

o15

.16.

1,15

.19.

6,16

.2.9

Sodi

umsu

lphi

teso

lutio

n(2

5%or

less

)C

P3

2GO

pen

No

NF

ON

oN

oN

o15

.16.

1,15

.19.

6,16

.2.9

Sodi

umta

rtra

tes

and

mon

o-/d

i-su

ccin

ate

DS

32G

Ope

nN

oYe

sO

No

A,B

Y5N

oso

lutio

n

Sodi

umth

iocy

anat

e(5

6%or

less

)(B

)P

32G

Ope

nN

oYe

sO

No

No

No

15.1

9.6

solu

tion

Styr

ene

mon

omer

2055

BS/

P3

2GC

ont.

No

T1

IIA

No

RF

A,B

N4,

ZN

o15

.13,

15.1

9.6,

16.6

.1,1

6.6.

2

Sulp

hohy

droc

arbo

nlo

ngch

ain

(C18

+)

BP

32G

Ope

nN

oYe

sO

No

A,B

No

15.1

9.6,

16.2

.6al

kala

min

em

ixtu

re

Ven

tor

Sulp

hur

(mol

ten)

2448

III

S3

1GO

pen

Pad

T3

Yes

(1)

OF

-TN

oN

o15

.10

(gas

)

Sulp

huri

cac

id18

30C

S/P

32G

Ope

nN

oN

FO

No

No

No

15.1

1,15

.16.

2,16

.2.8

,16.

2.9

Sulp

huri

cac

id,s

pent

1832

CS/

P3

2GO

pen

No

NF

ON

oN

oN

o15

.11,

15.1

6.2,

16.2

.8,1

6.2.

9

Tal

loi

l(c

rude

and

dist

illed

)B

P3

2GO

pen

No

Yes

ON

oA

No

15.1

9.6,

16.2

.6,1

6.2.

9,16

A.2

.2

Tal

loi

l(fa

tty

acid

,bar

ium

salt)

BS/

P3

2GO

pen

No

Yes

ON

oA

No

15.1

9.6,

16.2

.6

Tal

loi

lfa

tty

acid

(res

inac

ids

less

than

(C)

P3

2GO

pen

No

Yes

ON

oA

No

16.2

.7to

16.2

.920

%)

Tal

loi

lso

ap(d

ispr

opor

tiona

ted)

solu

tion

BP

32G

Ope

nN

oYe

sO

No

AN

o15

.19.

6,16

.2.6

,16.

2.9

Tet

rach

loro

etha

ne17

02B

S/P

32G

Con

t.N

oN

FR

TN

oN

o15

.12,

15.1

7,15

.19.

6

Tet

raet

hyle

nepe

ntam

ine

2320

DS

32G

Ope

nN

oYe

sO

No

AN

1N

o

Tet

rahy

drof

uran

2056

DS

32G

Con

t.N

oT

3II

BN

oR

F-T

AN

o15

.19.

6

Tet

rahy

dron

apth

alen

e(b

b)C

P3

2GO

pen

No

Yes

ON

oA

No

Tet

ram

ethy

lben

zene

(all

isom

ers)

AP

32G

Ope

nN

oYe

sO

No

AN

o16

.2.9

,16A

.2.2

Tol

uene

(bb)

1294

CP

32G

Con

t.N

oN

oR

FA

No

15.1

9.6

15.1

2,15

.17,

15.1

9,16

.2.7

,T

olue

nedi

amin

e17

09C

S/P

22G

Con

t.N

oYe

sC

TA

,DN

1E

16.2

.9

A,C

(c),

15.1

2,15

.16.

2,15

.17,

15.1

9,T

olue

nedi

isoc

yana

te20

78C

S/P

22G

Con

t.D

ryT

1II

AYe

sC

F-T

N4

ED

16.2

.9

o-T

olui

dine

1708

CS/

P2

2GC

ont.

No

Yes

CT

AN

o15

.12,

15.1

7,15

.19

Tri

buty

lph

osph

ate

BP

32G

Ope

nN

oYe

sO

No

AN

o15

.19.

6

1,2,

4-T

rich

loro

benz

ene

2321

BS/

P2

2GC

ont.

No

Yes

RT

A,B

No

15.1

9.6,

16.2

.9,1

6A.2

.2

The

pref

ix5/

4B.i

sto

bead

ded

toth

ere

fere

nce

para

grap

hsin

colu

mn

‘‘o’’.


ab

cd

ef

gh

i′i′′

i′′′

jk

lm

no

Ele

ctri

cal

Eq

uip

men

t

Sp

ecia

lre

qu

irem

ents

Pro

du

ctn

am

e(S

eeC

hap

ter

5/4

B.1

5)

UNnumber

PollutionCategory

Hazards

ShipType

TankType

TankVent


Class

Group

Flashpoint60°C

Guaging

VapourDetection

FireProtection



1,1,

1-T

rich

loro

etha

ne28

31C

P3

2GO

pen

No

Yes

ON

oA

No

1,1,

2-T

rich

loro

etha

neC

S/P

32G

Con

t.N

oN

FR

TN

oN

o15

.12.

1,15

.19.

6

Tri

chlo

roet

hyle

ne17

10C

S/P

32G

Con

t.N

oT

2II

AYe

sR

TN

oN

o15

.12,

15.1

6.1,

15.1

7,15

.19.

6

1,2,

3-T

rich

loro

prop

ane

CS/

P2

2GC

ont.

No

Yes

CT

A,B

,DN

o15

.12,

15.1

7,15

.19

1,1,

2-T

rich

loro

-1,2

,2-T

riflu

oroe

than

eC

P3

2GO

pen

No

NF

ON

oN

oN

o

Tri

cres

ylph

osph

ate

(con

tain

ing

less

AP

22G

Ope

nN

oYe

sO

No

AN

o15

.19.

6th

an1%

orth

o-is

omer

)

Tri

cres

ylph

osph

ate

(con

tain

ing

1%or

2574

(j)A

S/P

12G

Con

t.N

oT

2II

AYe

sC

No

A,B

No

15.1

2.3,

15.1

9m

ore

orth

o-is

omer

)

Tri

deca

noid

acid

BP

32G

Ope

nN

oYe

sO

No

AN

o15

.19.

6,16

.2.6

,16.

2.9,

16A

.2.2

Tri

etha

nola

min

eD

S3

2GO

pen

No

IIA

Yes

ON

oA

N1

No

Tri

ethy

lam

ine

1296

CS/

P2

2GC

ont.

No

T2

IIA

No

RF

-TA

,CN

2E

15.1

2,15

.19.

6

Tri

ethy

lben

zene

AP

22G

Ope

nN

oYe

sO

No

AN

o15

.19.

6

Tri

ethy

lene

tetr

amin

e22

59D

S3

2GO

pen

No

T2

IIA

Yes

ON

oA

N1

No

Tri

ethy

lph

osph

ite23

23B

S/P

22G

Con

t.N

oN

oR

F-T

A,B

No

15.1

2.1,

15.1

9.6

Tri

isop

ropy

late

dph

enyl

phos

phat

esA

P2

2GO

pen

No

Yes

ON

oA

No

15.1

9.6

Tri

met

hyla

cetic

acid

DS

32G

Con

t.N

oYe

sR

No

AY1

No

15.1

1.2

to15

.11.

8

Tri

met

hyla

min

eso

lutio

n(3

0%or

less

)12

97C

S/P

22G

Con

t.N

oN

oC

F-T

A,C

N1

E15

.12,

15.1

4,15

.19,

16.2

.9

Tri

met

hylb

enze

nes

(all

isom

ers)

AP

32G

Con

t.N

oN

oR

FA

No

15.1

9.6

Tri

met

hylh

exam

ethy

lene

diam

ine

(2,2

,4-

2327

DS

32G

Ope

nN

oYe

sO

No

A,C

N1

No

15.1

9.6

and

2,4,

4-is

omer

s)

Tri

met

hylh

exam

ethy

lene

diis

ocya

nate

2328

BS/

P2

2GC

ont.

Dry

Yes

CT

A,C

(c)

No

15.1

2,15

.16.

2,15

.17,

15.1

9.6

(2,2

,4-

and

2,4,

4-is

omer

s)

2,2,

4-T

rim

ethy

l-1,

3-pe

ntan

edio

-1-1

-C

P3

2GO

pen

No

Yes

ON

oA

No

isob

utyr

ate

Tri

met

hyl

phos

phite

2329

S3

2GC

ont.

No

No

RF

-TA

,DN

o15

.12.

1,15

.16.

2,15

.19.

6

1,3,

5-T

riox

ane

DS

32G

Con

t.N

oN

oR

FA

,DN

o15

.19.

6

Tri

xyly

lph

osph

ate

AP

12G

Ope

nN

oYe

sO

No

AN

o15

.19

Tur

pent

ine

1299

BP

32G

Con

t.N

oN

oR

FA

No

15.1

9.6

Und

ecan

oic

acid

BP

32G

Ope

nN

oYe

sO

No

AN

o16

.2.6

,16.

2.9


1-U

ndec

ene

BP

32G

Ope

nN

oYe

sO

No

AN

o15

.19.

6

Und

ecyl

alco

hol

BP

32G

Ope

nN

oYe

sO

No

AN

o15

.19.

6,16

.2.9

,16A

.2.2

(r)

Ure

a/A

mm

oniu

mni

trat

eso

lutio

nC

S/P

32G

Con

t.N

oN

FR

TA

N4

No

(con

tain

ing

aqua

amm

onia

)

Val

eral

dehy

de(a

llis

omer

s)20

58C

S/P

32G

Con

t.In

ert

T3

IIB

No

RF

-TA

No

15.4

.6,1

5.16

.1,1

5.19

.6

Vin

ylac

etat

e13

01C

S/P

32G

Con

t.N

oT

2II

AN

oR

FA

No

15.1

3,15

.19.

6,16

.6.1

,16.

6.2

15.4

,15.

13,1

5.14

,15.

19,

Vin

ylet

hyl

ethe

r13

02C

S/P

21G

Con

t.In

ert

T3

IIB

No

CF

-TA

N6

E16

.6.1

,16.

6.2

15.1

3,15

.14,

15.1

9.6,

16.6

.1,

Vin

ylid

ene

chlo

ride

1303

DS

22G

Con

t.In

ert

T2

IIA

No

RF

-TB

N5

E16

.6.2

15.1

3,15

.16.

1,15

.19.

6,16

.6.1

,V

inyl

neod

ecan

oate

BS/

P3

2GO

pen

No

Yes

ON

oA

,BN

o16

.6.2

Vin

ylto

luen

e26

18A

S/P

32G

Con

t.N

oII

AN

oR

FA

,BN

1N

o15

.13,

15.1

9.6,

16.6

.1,1

6.6.

2

Whi

tesp

irit,

low

(15-

20%

)ar

omat

ic13

00(B

)P

22G

Con

t.N

oN

oR

FA

No

15.1

9.6

Xyl

enes

(bb)

1307

CP

32G

Con

t.N

oN

oR

FA

No

15.1

9.6,

16.2

.9(w

)

Xyl

enol

2261

BS/

P3

2GO

pen

No

IIA

Yes

ON

oA

,BN

o15

.19.

6,16

.2.9

,16A

.2.2

Zin

cal

kary

ldi

thio

phos

phat

e(C

7-C

16)

(C)

P3

2GO

pen

No

Yes

ON

oA

,BN

o16

.2.7

,16.

2.8

Zin

cal

kyl

dith

ioph

osph

ate

(C3-

C14

)B

P3

2GO

pen

No

Yes

ON

oA

,BN

o15

.19.

6,16

.2.6

The

pref

ix5/

4B.i

sto

bead

ded

toth

ere

fere

nce

para

grap

hsin

colu

mn

‘‘o’’.


a Applies to Ammonia aqueous, (28% or less) but not below 10%. m UN number 2672 refers to 10-35% ammonia solutions.

Ammonia aqueous (28% or less)Ammonia aqueous (28% or less)n UN number 2511 applies to 2-Chloropropionic acid only.b If the product to be carried contains flammable solvents such that

2- or 3-Chloropropionic acidthe flashpoint does not exceed 60°C c.c., then special electrical systemso Dinitrotoluene should not be carried in deck tanks.and the flammable vapour detector should be provided.

Dinitrotoluene (molten)Diphenyl methane diisocyanatePolymethylene polyphenyl isocyanate p (Deleted)

c Although water is suitable for extinguishing open air fires involving q Requirements are based on those isomers having a flashpoint of 60°Cchemicals to which this footnote applies, water should not be allowed

c.c. or less; some isomers have a flashpoint greater than 60°C c.c.,to contaminate closed tanks containing these chemicals because of

and therefore the requirements based on flammability would not applythe risk of hazardous gas generation.

to such isomers.Diphenylmethane diisocyanate

Heptanol (all isomers)Toluene diisocyanateTrimethylhexamethylene diisocyanate (2,2,4- and 2,4,4- r Reference 5/4B.16A.2.2 applies to 1-Undecyl alcohol only.

isomers)Undecyl alcohol

d UN number 1198 only applies if flashpoint is below 60°C c.c. s Applies to n-Decyl alcohol only.Formaldehyde solutions (45% or less)

Decyl alcohol (all isomers)e Applies to Formaldehyde solutions (45% or less), but not below 5%. t UN number 1114 applies to Benzene.

Formaldehyde solutions (45% or less)Benzene and mixtures having 10% benzene or more

f Applies to Hydrochloric acid not below 10%. u Dry chemicals should not be used as a fire-fighting medium.Aluminium chloride (30% or less)/Hydrochloric acid (20% or

Nitropropane (60%)/Nitroethane (40%) mixtureless) solution

Hydrochloric acid v Confined spaces should be tested for both Formic acid vapours andCarbon monoxide gas, a decomposition product.g Dry chemical cannot be used because of the possibility of an explosion.

Formic acidMaleic anhydride

w Applies to p-Xylene only.h UN number 2032 assigned to red fuming nitric acid.Xylenes

Nitric acid (70% and over)x Applies to p-isomer and mixtures containing p-isomer viscosity ofi UN number depends on boiling point of substance.

which is 25 mPa.s at 20°C.Polyethylene polyamines

Dichlorobenzenes (all isomers)Polymethylene polyphenyl isocyanate

y Applies to p-isomer and mixtures containing p-isomer melting pointj UN number assigned to this substance containing more than 3% ofof which is 0°C and above.

ortho-isomer.Dichlorobenzenes (all isomers)

Tricresyl phosphate (containing 1% or more ortho-isomer)z Applies to p-isomer and mixtures containing p-isomer melting pointk Phosphorus (yellow or white) is carried above its autoignition tempera-

of which is 15°C and above.ture and therefore flashpoint is not appropriate. Electrical equipmentrequirements may be similar to those for substances with a flashpoint Dichlorobenzenes (all isomers)above 60°C c.c. aa Applies only to products with melting point of 15°C and above.

Phophorus (yellow or white)Nonyl phenol poly(4-12)ethoxylates

l Sulphur (molten) has a flashpoint above 60°C c.c., however, electrical bb Applies to oil-like substances identified in accordance with the provi-equipment should be certified safe for gases evolved.

sions of the unified interpretation of regulation 14 of Annex II ofMARPOL 73/78 agreed by the MEPC.Sulphur (molten)


Explanatory Notes5/4B.18 List of Chemicals to Which the Code DoesNot Apply (1 July 1994)

Product name In some cases, the product names1 The following are chemicals which have been re-(column a) may not be identical with the names

viewed for their safety and pollution hazards and de- given in previous issues of the IBCtermined not to present hazards to such an extent as Code or the BCH Code (for expla-to warrant application of the Code. This may be used nation see index of chemicals).as a guide in considering bulk carriage of chemicals

UN number The number relating to each prod-whose hazards have not yet been evaluated.(column b) uct shown in the recommendations2 Although the chemicals listed in this subsection (5/

proposed by the United Nations4B.18) fall outside the scope of the Code, the attention Committee of Experts on theof Administrations is drawn to the fact that some safety Transport of Dangerous Goods.precautions may be needed for their safe transporta- UN numbers, where available, aretion. Accordingly, Administrations should prescribe given for information only.appropriate safety requirements.

Pollution category The letter D means the pollution3 Some chemicals are identified as falling into pollution(column c) category assigned to each productcategory D and, therefore, subject to certain opera-

under Annex II of MARPOL 73/tional requirements of Annex II of MARPOL 73/78. 78. ‘‘III’’ means the product was

4 Liquid mixtureswhich are provisionally assessed un- evaluated and found to fall outsideder regulation 3(4) of Annex II of MARPOL 73/78 as the categories A, B, C or D.falling into pollution category D, and which do not

Pollution category in brackets indi-present safety hazards, may be carried under the entrycates that the product is provi-for noxious liquids not otherwise specified in this sub-sionlly categorized and that further

section. Similarly, those mixtures provisionally as- data are necessary to complete thesessed as falling outside pollution category A, B, C, evaluation of their pollution haz-or D, and which do not present safety hazards, may ards. Until the hazard evaluation isbe carried under the entry for non-noxious liquids not completed, the pollution category

assigned is used.otherwise specified in this sub-section.

a b ca b c

UN Pollution

number Category for

Ammonium hydrogen phosphate so- — DoperationalProduct name

discharge lution(regulation 3 of

Ammonium polyphosphate solution — DAnnex II)

Acetone 1090 III Ammonium sulphate solution — D

Alcohols (C13+) — III n-Amyl alcohol 1105 D

Alcoholic beverages, n.o.s. 3065 III sec-Amyl alcohol 1105 D

Acrylonitrile-Styrene copolymer disper- — D tert-Amyl alcohol 1105 IIIsion in polyether polyol

Amyl alcohol, primary 1105 Dn-Alkanes (C10+) — III

Animal and fish oils, n.o.s. including: — DAlkenyl (C11+) amide — D Cod liver oil, Lanolin, Neatsfoot oil,

Pilchard oil, Sperm oilAlkyl (C8+) amine, alkenyl (C12+) acid es- — Dter mixture Animals and fish oils and distillates — D

acids, n.o.s. including: Animal acid oil,Alkyl (C9+) benzenes — IIIFish acid oil, Lard acid oil, Mixedacid oil, Mixed general acid oil,Alkyl dithiothiadiazole (C6–C24) — DMixed hard acid oil, Mixed soft acidoilAluminium sulphate solution — D

Aminoethyldiethanolamine/ — III Apple juice — IIIAminoethylethanolamine solution

Aryl polyolefin (C11–C50) — D2-Amino-2-hydroxymethyl-1,3- — III

propanediol solution (40% or less) Benzene tricarboxylic acid, trioctyl ester — III


a b ca b c

Diethylenetriamine pentaacetic acid, — IIIBrake fluid base mix: (Poly (2-8) alky- — Dlene (C2–C3) glycols/Polyalkylene (C2– pentasodium salt solutionC10) glycols monoalkyl (C1–C4) ethers

Di(2-ethylhexyl)adipate — Dand their borate esters)1

Diheptyl phthalate — IIIn-Butyl alcohol 1120 III

Dihexyl phthalate — IIIsec-Butyl alcohol 1120 III

1,4-Dihydro-9,10-dihydroxy antracene, — Dtert-Butyl alcohol 1120 IIIdisodium salt solution

Butylene glycol — DDiisobutyl ketone 1157 D

Butyl stearate — IIIDiisononyl adipate — D

gamma-Butyrolactone — DDiisooctyl phthalate — III

Calcium carbonate slurry — IIIDiisopropyl naphthalene (bb) — D

Calcium hydroxide slurry — DDimethyl polysiloxane — III

Calcium long chain alkaryl sulphonate — D2,2-Dimethylpropane-1,3-diol — (D)

(C11–C50)

Dinonyl phthalate — DCalcium long chain alkyl phenate sul- — D

phide (C8–C40) Dioctyl phthalate — III

Calcium long chain phenolic amine (C8– — III Dipropylene glycol — IIIC40)

Ditridecyl phthalate — DCalcium nitrate/Magnesium nitrate/Pot- — III

Diundecyl phthalate — Dassium chloride solution

Dodecane (all isomers) — IIIepsilon-Caprolactam (molten or aqueous — Dsolutions)

Dodecenyl succinic acid, dipotassium — (D)salt solutionChlorinated paraffins (C14–C17) (with — III

52% chlorine)Dodecyl benzene — III

Choline chloride solutions — D Dodecylxylene — III

Citric acid (70% or less) — D Drilling brines including: Calcium bro- — IIImide solution, Calcium chloride solu-Clay slurry — IIItion, Sodium chloride solution

Coal slurry — III2-Ethoxyethanol 1171 D

Coconut oil fatty acid methyl ester — DEthyl acetate 1173 D

Cyclohexanol — DEthyl acetoacetate — (D)

Decahydronaphthalene 1147 (D)Ethyl alcohol 1170 III

Dextrose solution — IIIEthylene carbonate — III

Diacetone alcohol 1148 DEthylenediamine tetraacetic acid, tetraso- — D

dium salt solutionDialkyl (C7–C13) phthalates — D

Ethylene glycol — DDiethylene glycol — D

Ethylene glycol acetate — (D)Diethylene glycol dibutyl ether — D

Ethylene glycol methyl butyl ether — DDiethylene glycol diethyl ether — III

Ethylene glycol phenyl ether — DDiethylene glycol phthalate — D

Ethylene glycol phenyl ether/Diethylene — Dglycol phenyl ether mixture1Use ‘‘Brake fluid base mix’’ as a proper name on the shipping document.


a b ca b c

Kaolin slurry — IIIEthylene-vinyl acetate copolymer — III(emulsion)

Lactic acid — D2-Ethylhexanoic acid — D

Lard — IIIEthyl propionate 1195 D

Latex:Carboxylated stryrene-butadiene co-Fatty acid (saturated C13+) — III

polymer — IIIFerric hydroxyethylethylene diamine tri- — D Styrene-butadiene rubber — III

acetic acid, trisodium salt solutionLatex, ammonia (1% or less) inhibited — D

Fish solubles2 — IIILignin sulphonic acid, sodium salt so- — III

Formamide — D lution

Glucose solution — III Long chain alkaryl sulphonic acid (C16– — DC60)Glycerine — III

Long chain alkylphenate/phenol sulfide — IIIGlycerine (83%), Dioxanedimethanol — D

(17% mixture) Magnesium chloride solution — III

Glycerol monooleate — D Magnesium hydroxide slurry — III

Glycerol polyalkoxylate — III Magnesium long chain alkarylsulphonate — D(C11–C50)

Glyceryl triacetate — (III)3-Methyoxy-1-butanol — III

Glycine, sodium salt solution — III3-Methoxybutyl acetate — D

Glyoxal solution (40% or less) — DMethyl acetate 1231 III

n-Heptanoic acid — DMethyl acetoacetate — D

Hexamethylenediamine adipate solution — DMethyl alcohol 1230 III(50% in water)

Methylamyl ketone 1110 DHexamethylene glycol — III

Methyl propyl ketone 1249 DHexamethylenetetramine solutions — D

N-Methyl-2-pyrrolidone — DHexanoic acid — D

N-Methylglucamine solution (70% or — IIIHexanol 2282 Dless)

Hexylene glycol — IIIMethyl butenol — (D)

N-(Hydroxyethyl)ethylenediamine tria- — DMethyl tert-butyl ether 2398 Dcetic acid, trisodium salt solution

Methyl butyl ketone — DIsoamyl alcohol 1105 D

Methyl butynol — DIsobutyl alcohol 1212 III

Methyl ethyl ketone 1193 IIIIsobutyl formate 2393 D

Methyl isobutyl ketone 1245 DIso- & cyclo-Alkanes (C10–C11) — D

3-Methyl-3-methoxy butanol — IIIIso- & cyclo-Alkanes (C12+) — III

3-Methyl-3-methoxy butyl acetate — IIIIsophorone — D

Molasses — IIIIsopropyl acetate 1220 III

Myrcene — DIsopropyl alcohol 1219 III

Naphthalene sulphonic acid/formalde- — Dhyde copolymer, sodium salt solution2Water-based fish meal products


a b ca b c

Polyolefin (molecular weight 300+) — IIINitrilotriacetic acid, trisodium salt so- — Dlution

Polyolefin amide alkeneamine (C28+) — DNonanoic acid (all isomers) — D

Polyolefin amide alkeneamine borate — DNonyl methacrylate monomer — (D) (C28–C250)

Noxious liquid, n.o.s. (17) — D Polyolefin amide alkeneamine molybde- — III(trade name ..........................................., num oxysulfidecontaining .............................. ) Cat. D3

Polyolefin amide alkeneamine polyol — DNon-noxious liquid, n.o.s. (18) — III

Polyolefin anhydride — D(trade name ...........................................,containing ................... ) Appendix III3

Polyolefin ester (C28–C250) — DOctanoic acid (all isomers) — D

Polyolefin phenolic amine (C28–C250) — DOctyl decyl adipate — III

Poly(20)oxyethylene soritan monooleate — IIIOlefins (C13+, all isomers) — III

Poly(5+)propylene — IIIOlefin/alkyl esther copolymer (molecular — D

Polypropylene glycol — Dweight 2000+)

Polysiloxane — IIIOleic acid — D

n-Propyl acetate 1276 DPalm oil fatty acid methyl ester — D

n-Propyl alcohol 1274 IIIPalm stearin — D

Propylene/butylene copolymer — IIIParaffin wax — III

Propylene glycol — IIIPentaethylenehexamine — D

Propylene glycol monalkyl ether — (D)Pentanoic acid — D

Propylene glycol methyl ether acetate — DPetrolatum — (III)

Sodium acetate solutions — (D)Polulnotenyl succinimide — D

Poly(2-8)alkylene glycol monoalkyl(C1– — D Sodium aluminosilicate slurry — IIIC6) ether

Sodium benzoate — DPoly(2-8)alkylene glycol monoalkyl(C1– — D

Sodium carbonate solution — DC6) ether acetate

Sodium poly(4+)acrylate solutions — IIIPolyaluminium chloride solution — III

Sodium sulphate solution — IIIPolybutene — III

Sorbitol solution — IIIPolyether (molecular weight 2000+) — D

Sulphohydrocarbon (C3–C88) — DPolyethylene glycol — III

Polyethylene glycol dimethyl ether — III Sulpholane — D

Polyglycerin, sodium salt solution (con- — III Tallow — Dtaining less than 3% sodium hy-

Tallow fatty acid — (D)droxide)

Tetraethylene glycol — IIIPolyglycerol — III

Tridecane — IIIPoly(4+)isobutylene — III

Tridecyl acetate — III3In case of a specific n.o.s. (not otherwise specified) cargo assessed as

Triethyl phosphate — Dfalling within this n.o.s. group that is carried on a ship, this entry, includingthe cargo’s trade name and one or two principle components, should be

Triethylene glycol — IIIprovided in the shipping document.


a b ca b c

Triisopropanolamine — III Vegetable acid oils and distillates, n.o.s. — Dincluding: Corn acid oil, Cottonseed

Trimethylol propane polyethyoxylate — Dacid oil, Dark mixed acid oil, Ground-

2,2,4-Trimethyl 1-1,3 pentanedioldiisobu- — III nut acid oil, Mixed acid oil, Mixedtyrate general acid oil, Mixed hard acid oil,

Mixed soft acid oil, Rapeseed acid oil,Tripropylene glycol — III

Safflower acid oil, Soya acid oil, Sun-flower seed acid oilUrea/Ammonium mono- and di-hydro- — (D)

gen phosphate/Potassium chloride so-Vegetable protein solution (hydrolysed) — IIIlution

Urea/Ammonium nitrate solution — D Water — III

Urea/Ammonium phosphate solution — D Waxes — D

Urea formaldehyde resin solution — IIIZinc alkenyl carboxamide — D

Urea solution — III

Vegetable oil, n.o.s. including: Beechnut — Doil, Castor oil, Cocoa butter, Coconutoil, Corn oil, Cottonseed oil, Ground-nut oil, Hazelnut oil, Linseed oil, Nut-meg butter, Oiticica oil, Olive oil,Palm nut oil, Palm oil, Peel oil (or-anges and lemons), Perilla oil, Poppyoil, Raising seed oil, Rape seed oil,Rice bran oil, Safflower oil, Salad oil,Sesame oil, Soya bean oil, Sunfloweroil, Tucum oil, Tung oil, Walnut oil.


5/4B.19 Requirements for Ships Engaged in the cent to cargo tanks and should be located within the cargoarea. The provisions of 5/4B.3.1 should apply to such tanksIncineration at Sea of Liquid Chemical

Waste and equipment to the same extent as they apply to cargotanks.5/4B.19.1 General

5/4B.19.3.3 Where necessary, oil fuel tanks and fuel5/4B.19.1.1 5/4B.1 to 16 apply to incinerator ships, aspumps directly feeding the incinerator burners during therelevant, and as supplemented or modified by the provi-process of pre-heating or supporting incineration may besions of this chapter.located outside the cargo area provided the oil fuel used5/4B.19.1.2 Information on the composition and thehas a flashpoint above 60°C (closed cup test). (See also 5/hazards of the waste to be incinerated should be made4B.19.5.3.)available to the Administration or port Administration, or

5/4B.19.3.4 Liquids which have been used for cleaningboth, as appropriate, which may prohibit carriage of thosecargo pipes and cargo tanks as well as for pump-roomwastes deemed to be too hazardous to be carried in bulk.Tdrainage should be stored in a slop tank in the cargo area,5/4B.19.1.3 The following additional definitions apply:for disposal in conformity with the technical guidelines.1 Incinerator space is a gastight space containing solelyannexed to the Dumping Convention. A cargo tank may bethe incinerator and its associated auxiliaries.used as a slop tank. Pumps used for handling contaminated.2 Incinerator blower space is a space containing thecleaning fluids should be located in the cargo area.blowers which supply combustion air to the incinera-

5/4B.19.3.5 Where necessary, compliance with 5/tor burners.4B.3.2.1 need not be required in so far as accommodation.3 Dumping Convention means the Convention on thespaces, service spaces, control stations and machineryPrevention of Marine Pollution by Dumping ofspaces other than those of category A may be permittedWastes and Other Matter at Sea, 1972.forward of the cargo area, subject to an equivalent standard.4 Cargo area is that part of the ship defined in 5/of safety and appropriate fire-extinguishing arrangements4B.1.3.5, excluding incinerators and chemical wastebeing provided to the satisfaction of the Administration.piping leading to the incinerators.

5/4B.19.3.6 If accommodation spaces, service spaces,5/4B.19.1.4 During the periodical and intermediate sur-control stations or machinery spaces other than those ofveys required under 5/4B.1.5.2.1.2 and .3, all cargo tankscategory A are located forward of the cargo area in accord-and the cargo piping system should be inspected for corro-ance with 5/4B.19.3.5, the requirements of 5/4B.3.2.3sion and the remaining thickness of material should beshould be applied by analogy; i.e. the specified distancesdetermined. Where severely corrosive wastes have beenshould be measured from the after end of a house locatedcarried, inspections of cargo tanks and the cargo pipingforward of the cargo area.system for corrosion should be held annually and the re-

maining thickness of materials determined during those 5/4B.19.3.7 The incinerator should be located outsidethe external perimeter of the cargo area. Alternative ar-inspections.rangements may, however, be considered by the Adminis-tration, provided an equivalent degree of safety is achieved.5/4B.19.2 Ship survival capability and location of

5/4B.19.3.8 The effect which combustion gases maycargo tankshave on adequate vision from the navigating bridge, on5/4B.19.2.1 Ships subject to this chapter should complyair intakes and openings into accommodation, service andwith type 2 ship standards and with the requirements formachinery spaces, and on deck working areas and passage-location of cargo tanks in type 2 ships.ways should be considered.5/4B.19.2.2 Waste mixtures containing substances

5/4B.19.3.9 Access to the incinerator space should bewhich would require a type 1 ship standard may be carriedfrom the open deck. However, the incinerator control roomin type 2 ships if solely for the purpose of incineration.and incinerator blower space may have direct access tothe incinerator space provided that these spaces have an

5/4B.19.3 Ship arrangements additional access from the open deck. Access openings of5/4B.19.3.1 Liquid chemical wastes should not be the incinerator space should be fitted with self-closing

stowed adjacent to oil fuel tanks except those tanks con- gastight doors.taining oil fuel to be used exclusively for incineration.

5/4B.19.4 Cargo containment and incinerator5/4B.19.3.2 Tanks and pumps, other than those de-standardsscribed in 5/4B.19.3.3, which may contain liquids and

which are to be used for the incineration process or for 5/4B.19.4.1 Integral gravity tanks may be used for haz-washing cargo pipes and cargo tanks may be located adja- ardous wastes.

5/4B.19.4.2 The incinerator including burners shouldbe designed and constructed to safety standards acceptableT The environmental aspects of incineration and dumping of wastes are

regulated by the Dumping Convention. In general, for incineration of to the AdministrationT. For materials of construction thewaste, a permit from the appropriate authority of the Contracting Party provisions of 5/4B.6.1 apply.to the Convention, where the loading port is situated, is required. Wherethe loading port is situated in a State not being a Contracting Party to T The standards set out by the Dumping Convention for the control of

incineration of wastes and other matter at sea should also be observed.the Convention, the Administration should issue a permit.


5/4B.19.4.3 The steel structure of the incinerator inwith a flashpoint not exceeding 60°C (closed cup test).Short lengths of external pipes connected to cargocluding supports and other fixtures should be designed for

the most unfavourable static angle of heel within the range tanks may be permitted by the Administration if theyare provided with fire-resistant insulation.of 0° to 30°, taking into account the dynamic loads due to

the ship’s motion. .3 In determining the scantlings of the cargo system thecorrosivity of the waste should be taken into account.5/4B.19.4.4 Suitable bricklining and insulation should

be provided to ensure that any temperature rise will notimpair the strength of the incinerator structure or the func- 5/4B.19.7 Tank vent systemstioning of the associated auxiliaries and instruments and 5/4B.19.7.1 The provisions for controlled venting sys-will not adversely affect personnel safety. tems—5/4B.8 and 5/4B.15.12 apply, except 5/4B.8.2.1 and

5/4B.19.4.5 Means should be provided for measuring 5/4B.15.12.3.the temperature on the outside furnace surfaces. Meansfor alarms should be provided to indicate when the temper- 5/4B.19.8 Cargo tank environmental controlature approved by the Administration is exceeded and the

5/4B.19.8.1 When the recirculating drop line does notprocess of incineration has to be stopped.terminate near the bottom of the cargo tank, the tank shouldbe inerted whenever wastes having a flashpoint not ex-5/4B.19.5 Cargo transfer ceeding 60°C (closed cup test) are being recirculated to it.

5/4B.19.5.1 The requirements of 5/4B.5.1 apply, except 5/4B.19.8.2 When washing machines using liquids hav-that cargo piping should as far as practicable be fitted in the ing a flashpoint not exceeding 60°C (closed cup test) arecargo area and that cargo piping leading to the incinerator employed, the cargo tank should be inerted.should:5/4B.19.8.3 The oxygen content of the atmosphere in.1 be fitted at least 760 mm inboard;

an inerted tank should not exceed 8% by volume in any.2 if outside the cargo area, be on the open deck;part of the tank..3 be clearly marked; and

5/4B.19.8.4 An audible and visual alarm should be pro-.4 be so designed as to allow draining and purging.vided to indicate when the pressure in the vapour space5/4B.19.5.2 Arrangements of the cargo piping and con-of an inerted cargo tank is less than 0.07 bar gauge.trols should be such as to preclude the discharge overboard

of wastes intended to be incinerated during normal cargo5/4B.19.9 Electrical installationhandling operations.

5/4B.19.1.1 In incinerator spaces, incinerator blower5/4B.19.5.3 Oil fuel cargo piping systems may be con-spaces, and adjacent spaces having direct access thereto,nected in front of the burners, provided that three-waythe lighting systems, telephone and public address systemscocks are installed and the oil fuel pipes are fitted withand general alarm systems should be of the certified safetwo screw-down nonreturn valves inside the incineratortype.space.

5/4B.19.9.2 All other electrical installations which are5/4B.19.5.4 Remote shutdown devices to cut out thefitted in the spaces referred to in 5/4B.19.9.1 should be ofsupply of waste and fuel for incineration should be fittedthe certified safe type unless the following conditions areat the control station and on the navigating bridge. Shutoffcomplied with:valves should be located in the cargo area. Where shutoff

.1 It is assured that the spaces are adequately ventilatedvalves are remotely controlled, provision for local manualprior to activating installations not of a certified safeoperation should be made, or a separate manually operatedtype. Interlocks should be provided between fansvalve should be fitted.and the switch gear of such installations to ensure5/4B.19.5.5 Flanges of the loading manifold connectionscompliance with this requirement.should be provided with shields, which may be portable,

.2 Installations not of a certified safe type should beto guard against the danger of the cargo being sprayed.automatically switched off in case of loss of the pres-Drip trays should also be provided.sure required by 5/4B.19.11.2.1 and 5/4B.19.11.3.1.A reasonable time delay may be permitted by the5/4B.19.6 Materials of constructionAdministration before these installations are5/4B.19.6.1 5/4B.6.2—special requirements for materi-switched off.als—is replaced by the following:

.3 Installations not of a certified safe type should comply.1 Aluminium, copper, copper alloys, zinc, galvanizedas a minimum with IP 55T or equivalent protection.steel or mercury should not be used for cargo tanks,

pipelines, valves, fittings and other equipment which5/4B.19.10 Fire protection and fire extinguishingmay come into contact with the liquid wastes or their

vapour. 5/4B.19.10.1 The incinerator space should be providedwith a fixed foam fire-extinguishing system complying with.2 Materials of construction having a melting point be-

low 925°C, e.g. aluminium and its alloys, should notbe used for external piping involved in cargo handling T Reference is made to the Recommendations published by the Interna-

tional Electrotechnical Commission and in particular to Publication 44.operations on ships intended for the carriage of wastes


regulation II-2/8 or II-2/9 of the 1983 SOLAS amendments. 5/4B.20.2 DefinitionsFor the purpose of this sub-section (5/4B.20):This system may be connected to the deck foam fire-extin-

guishing system. 5/4B.20.2.1 ‘‘Liquid chemical wastes’’ are substances,solutions or mixtures, offered for shipment, containing orcontaminated with one or more constituents which are5/4B.19.11 Mechanical ventilation in the cargo areasubject to the requirements of this Code and for which noand in the incinerator locationdirect use is envisaged but which are carried for dumping,5/4B.19.11.1 For cargo pump-rooms the provisions ofincineration or other methods of disposal other than at sea.5/4B.15.17— increased ventilation requirements—apply.

5/4B.20.2.2 ‘‘Transboundary movement’’ means mari-5/4B.19.11.2 The ventilation system of the incineratortime transport of wastes from an area under the nationalspace should be permanent, normally of the positive pres-jurisdiction of one country to or through an area undersure type and independent of all other air supply systems.the national jurisdiction of another country, or to or through.1 The air pressure should always be positive to thean area not under the national jurisdiction of any country,pressure within the furnace (see also 5/4B.19.9.2.2).provided at least two countries are concerned by the.2 A minimum capacity of 45 changes of air per hourmovement.should be provided based upon the total volume of

the incinerator space. 5/4B.20.3 ApplicabilityConsideration should be given to venting requirements 5/4B.20.3.1 The requirements of 5/4B.20 are applicableduring maintenance of burners. to the transboundary movement of liquid chemical wastes

5/4B.19.11.3 The ventilation system of the incinerator in bulk by seagoing ships and should be considered inblower space should be permanent, normally of the positive conjunction with all other requirements of this Code.pressure type and independent of other air supply systems. 5/4B.20.3.2 The requirements of 5/4B.20 do not apply.1 The air pressure should always be positive to the to:pressure within the furnace (see also 5/4B.19.9.2.2) .1 wastes derived from shipboard operations which are.2 A minimum capacity of 20 changes of air per hour covered by the requirements of MARPOL 73/78;should be provided based upon the total volume of .2 liquid chemical wastes carried by ships engaged inthe incinerator blower space. the incineration of such wastes at sea which are cov-

ered by 5/4B.19; and5/4B.19.12 Instrumentation and control .3 substances, solutions or mixtures containing or con-

taminated with radioactive materials which are sub-5/4B.19.12.1 Closed gauging devices described in 5/ject to the applicable requirements for radioactive4B.13.1.1.3 should be fitted and overflow control systemsmaterials.required in 5/4B.15.19 should be provided.

5/4B.19.12.2 Vapour detection instruments for toxic and5/4B.20.4 Permitted shipmentsflammable products described in 5/4B.13.2 should be

5/4B.20.4.1 Transboundary movement of wastes is per-fitted.mitted to commence only when:5/4B.19S.12.3 (1994) Where provided, incinerators in-

.1 notification has been sent by the competent authoritytended for automatic operations or operations from a re-of the country of origin, or by the generator or ex-mote control station are to comply with 4/11.15. (ABS)porter through the channel of the competent author-ity of the country of origin, to the country of final

5/4B.19.13 Personnel protection destination; and5/4B.19.13.1 The safety equipment described in 5/ .2 the competent authority of the country of origin, hav-

4B.14.2, including respiratory and eye protection for every ing received the written consent of the country ofperson on board described in 5/4B.14.2.8, should be pro- final destination stating that the wastes will be safelyvided. incinerated or treated by other methods of disposal,

has given authorization to the movement.5/4B.20 Transport of Liquid Chemical Wastes (1 July

5/4B.20.5 Documentation1994)

5/4B.20.5.1 In addition to the documentation specified5/4B.20.1 Preamble in 5/4B.16.2 ships engaged in transboundary movement

5/4B.20.1.1 Maritime transport of liquid chemical of liquid chemical wastes should carry on board a wastewastes could present a threat to human health and to the movement document issued by the competent authorityenvironment. of the country of origin.

5/4B.20.1.2 Liquid chemical wastes should, therefore,5/4B.20.6 Classification of liquid chemical wastesbe transported in accordance with relevant international

conventions and recommendations and, in particular,where it concerns maritime transport in bulk, with the 5/4B.20.6.1 For the purpose of the protection of the

marine environment all liquid chemical wastes transportedrequirements of this Code.


in bulk should be treated as Category A noxious liquid requirements for liquid chemical wastes specified in 5/substances, irrespective of the actual evaluated category. 4B.17, unless there are clear grounds indicating that the

hazards of the wastes would warrant:.1 carriage in accordance with the ship type 1 require-5/4B.20.7 Carriage and handling of liquid chemical

wastes ments; or.2 any additional requirements of this Code applicable

to the substance or, in case of a mixture, its constituent5/4B.20.7.1 Liquid chemical wastes should be carriedin ships and cargo tanks in accordance with the minimum presenting the predominant hazard.


SECTION 5/4 ANNEX A

Guidelines for the Uniform Application of theSurvival Requirements of the Bulk ChemicalCode and the Gas Carrier Code

(approved by the Maritime Safety Committeeat its forty-second session, 1980)

Preamble 2.4 The damage calculations should take account of:The following should be considered as guidelines for the pur- .1 tanks in way of the assumed damage filled with liquid at

pose of uniform application of the survival requirements of the increments of about 25% between empty and the maximumBulk Chemical Code and the Gas Carrier Code. Alternative meth- weight of liquid, or liquids, intended to be carried in theods to the suggested specific programme of calculations and pre- particular tanks under consideration;sentation, which demonstrate, to the Administration’s satisfaction, .2 the distribution of liquids in the adjacent tanks concernedcompliance with the applicable survival criteria, may be accepted. which will give the most severe result, taking into ac-

count trim;1 Alternative methods of calculation and presentation of ship .3 a number of draughts over the operating range, up to and

survival capability including the tropical freeboard mark. The fresh water free-.1 The parcel tanker will require a complete analysis of the boards need not be considered;

limiting survival characteristics over the full range of in- .4 the effect of damage involving the machinery space andtended loading conditions (as detailed in 2); adjacent tanks containing liquids over a number of draughts

.2 The dedicated service tanker will require approval of calcu- as in 2.4.3;lations based on service conditions proposed by the builder .5 the ship in either the departure or the arrival condition,or owner, in which the case the certificate of fitness should whichever will give the most severe result;be endorsed in respect of the conditions accepted; .6 the ship without trim and a sufficient number of trims cov-

ering the operating range, in order to permit interpolation..3 The inherently safe ship is one that will meet survival re-quirements with the ship assumed to be at a maximum 3 Particulars concerning survival capability calculations

3.1 The calculations should be based on moulded lines and in-draught and trim with all compartments within the extentof damage assumed to be empty with maximum vertical clude large appendages such as shaft bosses, skegs and bow

thrusters.centre of gravity (adjusted for free liquids).2 Minimum required metacentric height (GM) or maximum al- 3.2 The metacentric heights (GM), stability levers (GZ) and cen-

tre of gravity positions (KG) for judging the final survival condi-lowable height of the centre of gravity (KG) as a function ofthe draught of the parcel tanker tions should be calculated by the constant displacement (lost

buoyancy) method.2.1 A systematic investigation of damage survival characteristicsshould be undertaken by making calculations to obtain the mini- 3.3 The calculations should be done for the ship freely trimming.

3.4 Only computer calculations acceptable to the Administrationmum required GM or maximum allowable KG at a sufficientnumber of draughts within the operating range to permit the should be used.

3.5 Where the assumed damage causes the ship to trim by theconstruction of a series of curves of ‘‘required GM’’ or ‘‘allowableKG’’ in relation to draught and cargo tank content in way of the stern, the ship in the intact condition should be assumed to have

the largest allowable trim by the stern, consistent with operationaldamage. The curves must be sufficiently comprehensive to coveroperational trim requirements. requirements.

3.6 Where the assumed damage causes the ship to trim by the2.2 Each of the curves thus constructed relates to one positionof assumed damage only and the calculations should be repeated bow the ship in the intact condition should be assumed to have

the largest allowable trim by the bow, consistent with operationalfor each damage and lesser extent of damage to be assumed atany part of the ship. requirements.

3.7 Lesser extent of damage should be taken into account only2.3 Where it can be determined by inspection that the effect ofcertain assumed damage will be less onerous than other assumed where indicated by the presence of subdivision extending into

the maximum extent of damage, e.g. double-bottom tanks, sidedamage, for which calculations are provided and curves prepared,then the investigation of such damage cases may be dispensed ballast tanks, side cargo tanks, fuel tanks and void spaces. How-

ever, the following should be given attention:with.

SECTION 5/4 ANNEX A | 1

.1 ‘‘Lesser extent’’ means the reduction of any one of the three should be used when damage is assumed to occur in the vicinityof the 0.3 L position from the forward perpendicular:maximum dimensions of damage singly or in combination

and also the assessment of the effect of damage affecting any.1 When applying the longitudinal extent of damage applicablecombination of compartments within the maximum extent of

to the foremost part of the ship, no part of the damagedamage.should be assumed to extend abaft the 0.3 L position from.2 Where any damage involves the release of very heavy cargothe forward perpendicular.liquid, then heel to the intact side of the ship may take

.2 When applying the longitudinal extent of bottom damageplace. In such cases the effect of lesser vertical extent ofapplicable to the rest of the ship’s length the damage shoulddamage above the level of the tank top may result in thebe assumed to extend to a foremost limit including a pointlarger angle of heel, since otherwise the effect of cargo lossat 0.3 L minus 5 m abaft the forward perpendicular.may be compensated by flood water entering the double-

bottom tanks on the damaged side. 3.14 In ships carrying liquefied gases, large cargo tanks may besubdivided into sections by centreline and transverse bulkheads3.8 The number of calculations required to show compliance

with survival requirements should be that necessary to obtain which are liquid-tight but which have openings near the top ofthe tank. These openings would permit spillage of cargo fromsufficient data for the loading manual and should be such that all

loading conditions indicated in 1 can be covered, i.e. no additional one section of the cargo tank to another when the ship is heeledwhere the tank is undamaged, or loss of cargo due to spillagecalculations should be necessary once the series of calculations

has been executed. from sections of a damaged cargo tank. The effect of this spillageshould be taken into account in calculations and also in any3.9 Calculations to determine the displacement, trim and the

vertical position of the centre of gravity should be performed for calculation of GM or KG for loading conditions where a ‘‘requiredGM’’ or ‘‘allowable KG’’ curve is to be used.each operational loading condition. The vertical position of the

centre of gravity should be corrected for free surface effects. One 3.15 In ships carrying liquefied gases, the ability of longitudinalbulkheads fitted within cargo tanks to withstand the unequalmethod would be to construct graphs showing the free surface

moments of the criterion angle, for all filling levels at a specific pressures due to flooding of one section of cargo tank shouldonly be considered in the final stage of flooding.gravity of one. The free surface moments for all tanks can then

be taken from the graphs and be multiplied by the cargo specific 3.16 Where lubricating oil drain tanks fitted below the mainengine would be affected by the vertical extent of bottom damagegravity.

3.10 In calculating the effect of free surface of consumable liquids then flooding of the engine-room by way of the drain tank andengine should be assumed to take place.it is to be assumed that, for each type of liquid, at least one

transverse pair or a single centreline tank has maximum free 3.17 In ships with machinery spaces aft, the machinery spaceand steering gear compartment should be regarded as beingsurface, and the tank or combination of tanks to be taken into

account are to be those where the effect of free surfaces is the common for damage purposes when any access is fitted in the aftermachinery space bulkhead, unless a remotely operated slidinggreatest; in each tank the centre of gravity of the contents is to

be taken at the centre of volume of the tank. The remaining tanks watertight door is fitted, or the sill of the access openings fittedwith hinged watertight doors which are to be kept closed at seaare to be assumed either completely empty or completely filled,

and the distribution of consumable liquids among these tanks is is at least 0.3 m above the damage water line and will not besubmerged within the minimum range of residual stability.to be such as to obtain the greatest possible height above the

keel for the centre of gravity. 3.18 Where dry cargoes are carried at the same time as bulkliquid cargoes which require compliance with the requirements3.11 To take account of the presence of structure within cargo

compartments, a permeability of 0.95 should be assumed as stated of the Codes then the permeability of the space carrying the drycargo is to be ascertained.in the Codes. Where, in particular cases such as the cargo tanks

of gas carriers, this assumption would lead to a significant discrep- 3.19 The harmonized regulations specify that no account shouldbe taken of cross-flooding arrangements to attain stipulated limitsancy in cargo tank volume, it is preferable to calculate the perme-

ability taking into account actual tank structure, the volume of of heel in the final state of equilibrium after damage. However,compartments on the opposite sides of a ship could be regardedtank insulation should then be calculated separately and an appro-

priate permeability applied. as single compartments from the aspect of flooding if they wereto be linked by openings or ducts of sufficiently large area. In3.12 Attention should be paid to the possibility of progressive

flooding through deck cargo pipes and common cargo tank venti- such cases consideration should be given to the adequacy of tankair flow and to the effect of free surface.lation pipes, if these are immersed at large angles of heel after

damage. The possibility of progressive flooding through ballast 4 Stability information and Certificate of Fitness4.1 With regard to loading conditions to be submitted to thepiping passing through the assumed extent of damage, where

positive action valves are not fitted to the ballast system at the Administration (exclusive of the loading condition contained inloading and stability manual) the principal objective, at the stageopen ends of the pipes in the tanks served, should be considered.

Where remote control systems are fitted to ballast valves and of design evaluation, is that the Administration can satisfy itselfthat the calculations presented will cover all conditions of fullthese controls pass through the assumed extent of damage then

the effect of damage to the system should be considered to ensure and partial loading, including variations of draught and trim. Toachieve this objective the Administration may either:that the valves would remain closed in that event.

3.13 Where the ship is required to be capable of sustaining .1 require a complete analysis of survival requirements overthe full range of probable loading conditions; orbottom damage anywhere in its length (L), the following method


.2 undertake approval on the basis of service conditions pro- .3 a damage control drawing showing the position of importantfittings and listing instructions for their control;posed by the builder or owner, in which case the Certificate

of Fitness should be endorsed for the conditions accepted. .4 data relating to the effect of free surface or liquid heeling4.2 Particular attention should be paid to the provision of ade- moments of cargo tanks at all stages of filling;quate stability data to enable the master to take into account .5 example calculations and standard blank forms to facilitateaccurately the effect of liquid heeling moments of the contents of calculations.undamaged tanks. These heeling moments vary with the specific 4.4 The following should be stated on the Certificate of Fitness:gravity of the liquid and the percentage filling of the tanks and may .1 the deepest draught or least freeboard permitted for thosechange significantly in magnitude from condition to condition. loading conditions which require greater freeboard than theAdequate information would include curves showing the variation International Load Line Certificate (1966);of liquid heeling moment with the contents of each individual

.2 the range of specific gravities of cargoes which may betank.carried, this relates to all cargoes;4.3 In addition to the usual loading information required under

.3 the particular cargo tanks in which certain ranges of specificintact stability requirements the master should be supplied withgravities of cargoes may be carried, if relevant;the following information pertaining to damage stability:

.4 details of fittings, valves etc., the control of which is essential.1 data relative to loading and distribution of cargo and ballastfor survival, together with instructions for control, operationnecessary to ensure compliance with damage survival re-and logging; andquirements;

.2 data relative to the ship’s survival capabilities; .5 identification of required loading and stability manual.


SECTION 5/4 ANNEX B

United States Coast Guard additional design andstructural requirements for non-US flag vesselsoperating on the navigable waters of the UnitedStates.

B.1 Certificate of Fitness B.4 Allowable Stresses

B.4.1 The independent tanks, type B, primarily con-The vessel must have a Certificate of Fitness issued by structed of bodies of revolution are to have allowablethe flag administration that is endorsed with the name of stresses from the formula given in 5/4A.4.5.1 the factorsthe cargo that it is allowed to carry, indicating that the for A, B, C and D from the following table.vessel is in compliance with the ‘‘International Code forthe Construction and Equipment of Ships Carrying Nickel steelLiquefied Gases in Bulk’’. and carbon

manganese Austenitic Aluminumsteel values steel values alloy valuesB.2 Shell and Deck Plating

A......... 4.0 4.0 4.0B......... 2.0 1.6 1.5B.2.1 The deck stringer and sheer strake is to be GradeC......... 3.0 3.0 3.0E material or equivalent.D......... 1.5 1.5 1.5B.2.2 The strake of plating at the turn of the bilge is to

be Grade D, Grade E, or equivalent. B.4.2 The independent tanks, type C, and process pressureB.2.3 The remainder of the outer hull steel is to be in vessels are to be in accordance with 5/4A.4.5.1.6 exceptaccordance with 5/4A.4.9.1 and table 5/4A.6.5. the factors of A and B are to be obtained from B.4.1.B.2.4 The above grades of material are to be providedthroughout the cargo area. B.5 Insulation

The insulation is to be determined in accordance with 5/B.3 Contiguous Hull Material 4A.4.8 using an ambient temperature indicated in B.3.B.6 Cargo temperature/Pressure Control

The contiguous hull material is to comply with 5/4A.4.9Where the entire cargo system is designed to withstandand table 5/4A.6. The temperature studies required bythe full vapor pressure of the cargo under conditions of5/4A.4.8 are to assume the following ambientupper ambient design temperatures of 45C (113F) stilltemperature.air and 32C (90F) still water, the cargo system is to beB.3.1 All waters except Alaskan watersdesigned to indefinitely maintain the cargo withouta) Five knots air at −18C (0F).venting to the atmosphere on all products exceptb) Still sea water at 0C (32F).methane. For methane the cargo system is to bedesigned to maintain the cargo without venting to theatmosphere for a minimum period of 21 days while theB.3.2 Alaskan waters

a) Five knots air at −29C (−20F) vessel is in port and assuming the upper ambient designtemperatures mentioned above.b) Still sea water at −2C (28F)

SECTION 5/4 ANNEX B | 1

SECTION 5/4 ANNEX C

Calculation of the Capacity of Foam Systems forChemical Tankers

3.14.5(c) — the foam supply rate based upon the areaprotected by the largest monitor1 In section 3.14 of the Bulk Chemical Code (5/4B.11.310 ø/m2/min × 130.5 m2 = *1,305 ø/minIBC Code) concerning fire-extinguishing arrangements for(* Shall not be less than 1,250 ø/min)cargo tank areas the foam supply has to be determined in

The foam supply rate is therefore 2,610 ø/min which isaccordance with paragraphs 3.14.5 to 3.14.7. In order tothe largest of the three above calculated rates.provide for a correct interpretation of the requirements the2 Determination of the required quantity of foam concen-Sub-Committee on Fire Protection agreed on the followingtrate:example for a calculation of foam system for a chemical3.14.6 — 2,610 ø/min is the foam supply rate fromtanker of 10,000 tonnes deadweight.

regulation 3.14.5. This flow rate for thirty2 The Maritime Safety Committee at its forty-fourth ses-minutes will require 30 min × 2,610 ø/sion agreed that this example be followed when calculatingmin = 78,300 litres of foam-water solution.the capacity of foam systems for chemical tankers.If a 5% foam concentrate is used, then 5%

Example of foam system calculation for chemical tanker of the 78,300 litres must be foamof 10,000 dwt concentrate, or 0.05 × 78,300 = 3915 litresShip particulars 3 Determination of the minimum monitor capacity:

3.14.7 — Each monitor must supply at least:— Beam = 14.5 m(a) 50% of the required foam rate; or— Length of cargo area = 56 m(b) 10 ø/m2/min for the area it protects; or— Length of largest cargo = 9 m(c) 1,250 ø/min, whichever is greatertank

50% of the foam supply rate = 2,610 ø/min × 0.5 = 1,305— Cargo deck area = 14.5 m × 56 m = 812 m2

ø/min— Horizontal sectional = 14.5 m × 9 m = 130.5 m2

10 ø/m2/min times the area the monitor protectsarea of single largest= 130.5 m2 × 10 ø/m2/mintank= 1,305 ø/min(Note: For the purpose of this illustration, a single

The minimum monitor capacity is therefore 1,305 ø/min.tank encompasses the entire beam of the ship)Designer wishes to increase monitor spacing to 15 metres— Proposed monitor = 9 mbetween monitors.spacing1 Recalculate required foam supply:— Area protected by = 9 m × 14.5 m = 130.5 m2

3.14.5(a) — same as before—1,624 ø/minlargest monitor3.14.5(b) — same as before—2,610 ø/min3.14.5(c) — larger area covered by monitor is 15 m ×

14.5 = 217.5 m2 10 ø/m2/min × 217.5m2 = 2,175 ø/min

The required foam rate therefore remains 2,610 litres perminute.2 Recalculate required foam concentrate supply:3.14.6 The minimum foam supply rate has not

Calculations changed therefore 3915 litres of foam1 Determination of foam supply rate: concentrate are still required.

3 Recalculate minimum monitor capacity:3.14.5 The largest of:3.14.7 — 50% of foam supply rate 2,610 ø/min ×3.14.5(a) — the foam supply rate based upon the entire

0.5 = 1,305 ø/mincargo deck area. 2 ø/m2/min × 812 m2 =10 ø/m2/min of area protected by monitor1,624 ø/min

= 10 ø/m2/min × 217.5 m23.14.5(b) — the foam supply rate based upon the

= 2,175 ø/minhorizontal sectional area of the singleThe new minimum monitor capacity is therefore 2,175largest tankø/ min.20 ø/m2/min × 130.5 m2 = 2,610 ø/min

SECTION 5/4 ANNEX C | 1

SECTION 5/4 ANNEX D

Resolution A.473(XII)

Adopted on 19 November 1981 equivalent protection against fire or explosion or both to thatrequired by Regulation 60 of Chapter II-2 of the 1978 Proto-Agenda item 10(b)

col relating to the 1974 SOLAS Convention of ships carryingflammable cargoes, and as a result of these investigations, toINTERIM REGULATION FOR INERT GAS SYSTEMS ONdevelop final requirements for chemical tankers and gas car-CHEMICAL TANKERS CARRYINGriers;PETROLEUM PRODUCTS2. AGREES that compliance with additional provisions which

A will be contained in the final requirements should not be re-THE ASSEMBLY, quired to be applied to ships the keel of which is laid before

RECALLING Article 16 of the Convention on the Inter- the date of coming into force of the final requirements.Governmental Maritime Consultative Organization,

RECOGNIZING that Regulation 60 of Chapter 11-2 of the ANNEX1978 Protocol relating to the International Convention for the INTERIM REGULATION FOR INERT GAS SYSTEMSSafety of Life at Sea, 1974, requires new and existing chemical ONtankers of a certain size, when carrying petroleum products, to CHEMICAL TANKERS CARRYING PETROLEUM PROD-be fitted with a fixed inert gas system at specific dates, UCTS

RECOGNIZING ALSO that such ships by the same Regula-PREAMBLEtion are required to have a fixed inert gas system when car-

Administrations are invited to accept the inert gas systemsrying other liquid products having a similar fire hazard,referred to in this Regulation for chemical tankers for whichRECOGNIZING FURTHER the unique feature of parcelcertificates of fitness are issued under the Code for the Con-chemical tankers requiring separation of cargo piping and ofstruction and Equipment of Ships Carrying Dangerous Chemi-vent piping due to the wide spectrum of chemicals carried,cals in Bulk (resolution A.212(VII)). Inert gas systems suppliedRECOGNIZING FURTHER the stringent purity levels re-by one or more oil-fired inert gas generators may be accepted.quired by certain chemicals and compatibility and reactivityAn Administration may accept systems using inert gases fromproblems related to a wide range of chemicals,other sources provided that an equivalent standard of safety isHAVING CONSIDERED the recommendation made byachieved.the Maritime Safety Committee at its forty-fourth session,

This Regulation relates to the carriage in chemical tankers1. ADOPTS the Interim Regulation for Inert Gas Systems onof petroleum products which include crude oil, fuel oil, sludge,Chemical Tankers Carrying Petroleum Products, set out in theoil refuse and refined products (other than petrochemicalsAnnex to this resolution;which are subject to the provisions of Annex II of the 19732. URGES Governments concerned, under the provisions ofMARPOL Convention) and, without limiting the generality ofRegulation 5 of Chapter I of the International Convention forthe foregoing, include the substances listed in Appendix I tothe Safety of Life at Sea, 1974, to apply to chemical tankers asAnnex I of the 1973 MARPOL Convention having a flashpointappropriate the Interim Regulation as equivalent to Regulationnot exceeding 60°C as determined by an approved flashpoint62 of Chapter II-2 of the 1974 SOLAS Convention under Reg-apparatus and whose Reid vapour pressure is below atmo-ulation 60 of the 1978 Protocol with respect to inert gasspheric pressure except when such tanks are cleaned, gassystems;freed and maintained in the gas free condition.3. REQUESTS Governments to inform IMCO as soon as pos-

The application dates stipulated in Chapter II-2 of the 1978sible on measures taken to implement this Interim Regulation.SOLAS Protocol apply to chemical tankers covered by this

B Regulation.THE ASSEMBLY, INTERIM REGULATION

HAVING ADOPTED the Interim Regulation for Inert Gas 1 Inert gas generator systems* shall be designed, constructedSystems on Chemical Tankers Carrying Petroleum Products, and tested to the satisfaction of the Administration. They shall

RECOGNIZING that the Interim Regulation has been de- be designed and operated so as to render and maintain the at-veloped for the inerting of cargo tanks on chemical tankers con-taining petroleum products,

* ‘‘Inert gas generator system’’ means the machinery dedicated to the1. URGES the Maritime Safety Committee as a long-termproduction and supply of inert gas and includes the air blowers, com-goal to investigate a possible extension of the Interim Regula- bustion chambers, oil fuel pumps and burners, gas coolers/ scrubbers

tion to the inerting of cargo tanks containing other flammable and automatic combustion control and supervisory equipment, e.g.flame failure devices.liquids, and to investigate other alternatives for achieving

SECTION 5/4 ANNEX D | 1

mosphere of cargo tanks** non-flammable at all times when phur combustion products. The cooling water arrangementsshall be such that an adequate supply of water will always besuch tanks are used for the carriage of petroleum products as

defined above. available without interfering with any essential services on theship. Provision shall also be made for an alternative supply of2 The systems shall be capable of:

.1 inerting empty cargo tanks by reducing the oxygen con- cooling water.tent of the atmosphere in each tank to a level at which 5.2 Filters or equivalent devices shall be fitted to minimizecombustion cannot be supported; the amount of water carried over to the inert gas main.

.2 maintaining the atmosphere in all parts of each cargo 6.1 Two air blowers shall be fitted to each inert gas generator,tank designated to carry flammable products requiring which together shall be capable of delivering to the cargoprotection by an inert gas system with an oxygen content tanks, required to be protected by the system, at least the vol-not exceeding 8 per cent by volume and at a positive ume of gas required by paragraph 3. An Administration maypressure at all times in port and at sea except when it is permit only one blower if it is capable of delivering to the pro-necessary for such a tank to be gas free; tected cargo tanks the total volume of gas required by para-

.3 eliminating the need for air to enter a tank during normal graph 3, provided that sufficient spares for the air blower andoperations except when it is necessary for such a tank to its prime mover are carried on board to enable any failure ofbe gas free; the air blower and its prime mover to be rectified.

.4 purging empty cargo tanks of flammable vapour, so that 6.2 The inert gas systems shall be so designed that the maxi-subsequent gas freeing operations will at no time create a mum pressure which they can exert on any cargo tank will notflammable atmosphere within the tank. exceed the test pressure of any cargo tank.

3.1 The systems shall be capable of delivering inert gas to the 6.3 Where more than one inert gas generator is provided suit-cargo tanks at a rate of at least 125 per cent of the maximum able shut-off arrangements shall be provided on the dischargerate of discharge capacity of the ship expressed as a volume. outlet of each generator plant.An Administration may accept inert gas systems having a 6.4 Arrangements shall be made to vent the inert gas to the at-lower delivery capacity provided that the maximum rate of dis- mosphere in case the inert gas produced is off-specification,charge of cargoes from cargo tanks being protected by the sys- e.g. during starting-up or in case of equipment failure.tem is restricted to 80 per cent of the inert gas capacity.

6.5 Where inert gas generators are served by positive displace-3.2 The systems shall be capable of delivering inert gas withment blowers a pressure relief device shall be provided to pre-an oxygen content of not more than 5 per cent by volume invent excess pressure being developed on the discharge side ofthe inert gas supply main to the cargo tanks at any requiredthe blower.rate of flow.7 Two fuel oil pumps shall be fitted to each inert gas genera-4.1 Suitable fuel in sufficient quantity shall be provided fortor. An Administration may permit only one fuel oil pump onthe inert gas generators.condition that sufficient spares for the fuel oil pump and its4.2 The inert gas generators shall be located outside the cargoprime mover are carried on board to enable any failure of thetank area as defined in the Bulk Chemical Code. Spaces con-fuel oil pump and its prime mover to be rectified by the ship’staining inert gas generators should have no direct access to ac-crew.commodation, service or control station spaces, but may be lo-8 A gas regulating valve shall be fitted in the inert gas supplycated in machinery spaces. If they are not located inmain. This valve shall be automatically controlled to close asmachinery spaces they shall be located in a compartment re-required in paragraphs 17.2 and 17.3. It shall also be capableserved solely for their uses. Such a compartment shall be sepa-of automatically regulating the flow of inert gas to the cargorated by a gastight steel bulkhead and/or deck from accommo-tanks unless other means are provided to automatically controldation, service and control station spaces as defined in thethe inert gas flow rate.Bulk Chemical Code. Adequate positive pressure type mechan-9.1 At least two non-return devices, one of which shall be aical ventilation shall be provided for such a compartment. Ac-water seal, shall be fitted in the inert gas supply main in ordercess to such compartments located aft shall be only from anto prevent the return of flammable vapour to the inert gas gen-open deck outside the cargo tank area. Access shall be locatederator and to any gas-safe space under all normal conditions ofon the end bulkhead not facing the cargo area and/or on thetrim, list and motion of the ship. They shall be located be-outboard side of the superstructure or deckhouse at a distancetween the automatic valve required by paragraph 8 and theof at least 25 per cent of the length of the ship but not lessfirst connexion to any cargo tank or cargo pipeline. An Admin-than 5 m from the end of the superstructure or deckhouse fac-istration may permit an alternative arrangement or device pro-ing the cargo area. In the case of such a compartment being lo-viding a measure of safety equivalent to that of a water seal.cated in the forecastle, access shall be through the deckhead9.2 The devices referred to in paragraph 9.1 shall be locatedforward of the cargo area.in the cargo tank area on deck.4.3 Inert gas piping systems shall not pass through accommo-

dation, service and control station spaces. 9.3 The water seal referred to in paragraph 9.1 shall be capa-ble of being supplied by two separate pumps, each of which5.1 Means shall be provided which will effectively cool the vol-

ume of gas specified in paragraph 3 and remove solids and sul- shall be capable of maintaining an adequate supply at alltimes.9.4 The arrangement of the water seal and its associated provi-** Throughout this Regulation the term ‘‘cargo tank’’ includes also

‘‘slop tanks containing oil residues’’. sions shall be such that it will prevent backflow of flammable


vapours and will ensure the proper functioning of the water ply with the requirements of the Bulk Chemical Code for con-trolled venting, such arrangements shall comply withseal under operating conditions.

9.5 Provision shall be made to ensure that any water seal is Regulation 58(a) of Chapter II-2 of SOLAS 1974 and shall con-sist either of one or more mast risers or a number of high ve-protected against freezing, in such a way that the integrity of

water seal is not impaired by overheating. locity vents. The inert gas supply mains shall not be used forsuch venting.9.6 A water loop or other approved arrangement shall also be

fitted to all associated water supply and drain piping and to all 12.1 The arrangements for inerting, purging or gas freeing ofventing or pressure sensing piping leading to gas-safe spaces.* empty tanks as required in paragraph 2 shall be to the satisfac-Means shall be provided to prevent such loops from being tion of the Administration and shall be such that the accumula-emptied by vacuum. tion of flammable vapours in pockets formed by the internal9.7 Any water seal or equivalent device and all loop arrange- structural members in a tank is minimized.ments shall be capable of preventing the return of flammable 12.2 When in accordance with paragraph 3 and Administrationvapours to an inert gas generator at a pressure equal to the permits a system designed to supply only one or two tanks si-test pressure of the cargo tanks. multaneously, the outlet pipes should be sized such that an9.8 The second device shall be a non-return valve or equiva- exit velocity in the outlet pipes of 20 m/s can be maintained.lent capable of preventing the return of vapours or liquids or 13 Means shall be provided for continuously indicating theboth and fitted between the water seal (or the equivalent de- temperature and pressure of the inert gas at the discharge sidevice) required in paragraph 9.1 and the first connexion from of the system, whenever it is operating.the inert gas main to a cargo tank. It shall be provided with

14.1 Instrumentation shall be fitted for continuously indicatingpositive means of closure. As an alternative to positive meansand permanently recording, when the inert gas is being sup-of closure, an additional valve having such means of closureplied:may be provided between the non-return valve and the first

.1 the pressure of the inert gas supply mains between theconnexion to the cargo tanks to isolate the water seal (or equiv-non-return devices required by paragraph 9.1 and thealent device).cargo tanks; and9.9 As an additional safeguard against the possible leakage of

.2 the oxygen content of the inert gas in the inert gas sup-flammable liquids or vapours back from the deck main, meansply main.shall be provided to permit this section of the line between

the valve having positive means of closure referred to in para- 14.2 The devices referred to in paragraph 14.1 shall be placedgraph 9.8 and the valve referred to in paragraph 8 to be in the cargo control room where provided. Where no cargovented in a safe manner when the first of these valves is control room is provided, they shall be placed in a position eas-closed. ily accessible to the officer in charge of cargo operations.10.1 The inert gas main may be divided into two or more 14.3 in addition, meters shall be fitted:branches between the non-return devices required by para- .1 in the navigating bridge to indicate at all times the pres-graph 9 and the cargo tanks. sure referred to in paragraph 14.1.1; and10.2 Inert gas supply mains shall be fitted with branch piping

.2 in the machinery control room or in the machinery spaceleading to each cargo tank designated for the carriage of flam-to indicate the oxygen content referred to in paragraphmable products required to be inerted by this Regulation.14.1.2.Each cargo tank containing or loading products not required

15 Portable instruments for measuring oxygen and flammableto be inerted shall be separated from the inert gas main by:vapour concentration shall be provided. In addition, suitable ar-.1 removing spool pieces, valves or other pipe sections, andrangement shall be made on each cargo tank such that the con-blanking the pipe ends; ordition of the tank atmosphere can be determined using these.2 arrangement of two spectacle flanges in series with provi-portable instruments.sions for detecting leakage into the pipe between the two16 Suitable means shall be provided for the zero and span cali-spectacle flanges.bration of both fixed and portable gas concentration measure-10.3 Means shall be provided to protect cargo tanks againstment instruments, referred to in paragraphs 14 and 15.the effect of overpressure or vacuum caused by thermal varia-

tions when the cargo tanks are isolated from the inert gas 17.1 Audible and visual alarms shall be provided to indicate:mains. .1 low water pressure or low water flow rate to the cooling10.4 Piping systems shall be so designed as to prevent the ac- and scrubbing arrangement referred to in paragraph 5.1;cumulation of cargo or water in the pipelines under all normal .2 low fuel supply;conditions.

.3 high gas temperature as referred to in paragraph 13;10.5 Suitable arrangements shall be provided to enable the in-

.4 failure of the power supply to the inert gas generators;ert gas main to be connected to an external supply of inert

.5 oxygen content in excess of 8 per cent by volume as re-gas.ferred to in paragraph 14.1.2;11 Unless the arrangements for venting of all vapours dis-

placed from the cargo tanks during loading and ballasting com- .6 failure of the power supply to the indicating devices as re-ferred to in paragraph 14.1 and to the automatic controlsystems for the gas regulating valve referred to in para-* Gas-safe space is a space in which the entry of hydrocarbon gases

would produce hazards with regard to flammability or toxicity. graph 8 and the inert gas generator;


.7 low water level in the water seal as referred to in para- room, where provided, but in each case in such a position thatthey are immediately received by responsible members of thegraph 9.1;crew. All other alarms required by this paragraph shall be audi-.8 gas pressure less than 100 mm water gauge as referred toble to responsible members of the crew either as individualin paragraph 14.1;alarms or as a group alarm..9 high gas pressure as referred to in paragraph 14.1.117.6 In respect of paragraph 17.1.7 the Administration shall be17.2 Automatic shut-down of the gas regulating valve and ofsatisfied as to the maintenance of an adequate reserve of waterthe fuel oil supply to the inert gas generator shall be arrangedat all times and the integrity of the arrangements to permit theon predetermined limits being reached in respect of para-automatic formation of the water seal when the gas flowgraphs 17.1.1 and 17.1.3.ceases. The audible and visual alarm on the low level of water

17.3 Automatic shut-down of the gas regulating valve shall be in the water seal shall operate when the inert gas is not beingarranged in respect of paragraph 17.1.4. supplied.17.4 In respect of paragraph 17.1.5, when the oxygen content 17.7 An audible alarm system independent of that required inof the inert gas exceeds 8 per cent by volume, immediate ac- paragraph 17.1.8 or automatic shut-down of cargo pumps shalltion shall be taken to improve the gas quality. Unless the qual- be provided to operate on predetermined limits of low pres-ity of the inert gas improves, all operations in those tanks to sure in the inert gas mains being reached.which inert gas is being supplied shall be suspended so as to 18 Detailed instruction manuals shall be provided on board,avoid air being drawn into the tanks. The deck isolation valve covering the operations, safety and maintenance requirementsreferred to in paragraph 9.8 shall be closed and the off-specifi- and occupational health hazards relevant to the inert gas sys-cation gas shall be vented to atmosphere. tem and its application to the cargo tank system. The manuals17.5 The alarms required in paragraphs 17.1.5, 17.1.6 and shall include guidance on procedures to be followed in the

event of a fault or failure of the inert gas system.17.1.8 shall be fitted in the machinery space and cargo control


SECTION 5/4 ANNEX E

Resolution A.567(14)

Adopted on 20 November 1985 Bulk (resolution A.212(VII)) and under the International Codefor the Construction and Equipment of Ships Carrying DangerousAgenda item 10(b)

Chemicals in Bulk (resolution MSC.4(48)).This regulation shall be applied to chemical tankers as requiredREGULATION FOR INERT GAS SYSTEMS ON CHEMI-

by the draft amendment to regulation II-2/55.5 of the 1974 SO-CAL TANKERSLAS Convention as amended (resolution A.566(14)).

THE ASSEMBLY,REGULATIONRECALLING Article 15(j) of the Convention on the Interna-1 Inert gas generator systems* shall be designed, constructedtional Maritime Organization concerning the functions of theand tested to the satisfaction of the Administration. They shallAssembly in relation to regulations and guidelines concerningbe designed and operated so as to render and maintain the atmo-maritime safety,sphere of cargo tanks** non-flammable at all times except whenRECALLING ALSO resolution A.473(XII) which was adoptedsuch tanks are required to be maintained empty and gas-free.to provide an interim solution for the requirements of inert gasInert gas systems supplied by one or more oil-fired inert gassystems applicable to chemical tankers carrying petroleum prod-generators may be accepted. An Administration may accept sys-ucts, pending the possible development of final requirementstems using inert gas from other sources provided that an equiva-applicable to chemical tankers carrying all flammable cargoes,lent standard of safety is achieved.RECOGNIZING that the development of such requirements2 The systems shall be capable of:is not needed on the basis of results of scientific studies under-

.1 inerting empty cargo tanks by reducing the oxygen contenttaken by industry, but that the extension of the regulation inof the atmosphere in each tank to a level at which combus-resolution A.473(XII) to cover the carriage of petroleum and othertion cannot be supported;liquid products would meet the purpose,

.2 maintaining the atmosphere, in all parts of each cargo tankNOTING that regulation II-2/60 of the International Conven-designated to carry flammable products requiring protectiontion for the Safety of Life at Sea, 1974 (1974 SOLAS Convention)by an inert gas system, with an oxygen content not exceedingas amended requires inter alia new and existing tankers of a8% by volume and at a positive pressure at all times in portcertain size, including chemical tankers, when carrying petroleumand at sea except when it is necessary for such a tank toproducts, to be fitted with a fixed inert gas system by specificbe gas-free;dates,

.3 eliminating the need for air to enter a tank during normalNOTING FURTHER that the draft amendment to regulationoperations except when it is necessary for such a tank toII-2/55.5 of the 1974 SOLAS Convention as amended (resolutionbe gas-free;A.566(14)) exempts certain chemical tankers and gas carriers car-

.4 purging empty cargo tanks of flammable vapour, so thatrying flammable products from the requirements for inert gassubsequent gas-freeing operations will at no time create asystems of regulation II-2/ 60 of that Convention under certainflammable atmosphere within the tank.conditions,

3.1 The systems shall be capable of delivering inert gas to theHAVING CONSIDERED the recommendation made by thecargo tanks at a rate of at least 125% of the maximum rate ofMaritime Safety Committee at its fifty-first session,discharge capacity of the ship expressed as a volume. An Adminis-1. ADOPTS the Regulation for Inert Gas Systems on Chemicaltration may accept inert gas systems having a lower deliveryTankers set out in the Annex to the present resolution, whichcapacity provided that the maximum rate of discharge of cargoessupersedes resolution A.473(XII);from cargo tanks being protected by the system is restricted to2. INVITES Governments to apply the above Regulation to80% of the inert gas capacity.chemical tankers for the purpose of the implementation of the3.2 The systems shall be capable of delivering inert gas with andraft amendment to regulation II-2/ 55.5.oxygen content of not more than 5% by volume in the inert gas

ANNEX supply main to the cargo tanks at any required rate of flow.REGULATION FOR INERT GAS SYSTEMS ON CHEMI-

CAL TANKERS* ‘‘Inert gas generator system’’ means the machinery dedicated to the

production and supply of inert gas and includes the air blowers, combus-PREAMBLEtion chambers, oil fuel pumps and burners, gas coolers/ scrubbers andAdministrations are invited to accept the inert gas systemsautomatic combustion control and supervisory equipment, e.g. flame fail-referred to in this Regulation for chemical tankers for which ure devices.

certificates of fitness are issued under the Code for the Construc- ** Throughout this Regulation the term ‘‘cargo tank’’ includes also‘‘slop tanks containing oil residues’’.tion and Equipment of Ships Carrying Dangerous Chemicals in

SECTION 5/4 ANNEX E | 1

4.1 Suitable fuel in sufficient quantity shall be provided for the 8 A gas regulating valve shall be fitted in the inert gas supplymain. This valve shall be automatically controlled to close asinert gas generators.

4.2 The inert gas generators shall be located outside the cargo required in paragraphs 17.2 and 17.3. It shall also be capable ofautomatically regulating the flow of inert gas to the cargo tankstank area as defined in the Bulk Chemical Code and the Interna-

tional Bulk Chemical Code. Spaces containing inert gas genera- unless other means are provided to automatically control the inertgas flow rate.tors should have no direct access to accommodation, service or

control station spaces, but may be located in machinery spaces. 9.1 At least two nonreturn devices, one of which shall be a waterseal, shall be fitted in the inert gas supply main in order to preventIf they are not located in machinery spaces they shall be located

in a compartment reserved solely for their use. Such a compart- the return of flammable vapour to the inert gas generator and toany gas-safe space under all normal conditions of trim, list andment shall be separated by a gastight steel bulkhead and/or deck

from accommodation, service and control station spaces as de- motion of the ship. They shall be located between the automaticvalve required by paragraph 8 and the first connection to anyfined in the Bulk Chemical Code and the International Bulk

Chemical Code. Adequate positive-pressure-type mechanical cargo tank or cargo pipeline. An Administration may permit analternative arrangement or device providing a measure of safetyventilation shall be provided for such a compartment. Access to

such compartments located aft shall be only from an open deck equivalent to that of a water seal.9.2 The devices referred to in paragraph 9.1 shall be located inoutside the cargo tank area. Access shall be located on the end

bulkhead not facing the cargo area and/or on the outboard side the cargo tank area on deck.9.3 The water seal referred to in paragraph 9.1 shall be capableof the superstructure or deckhouse at a distance of at least 25%

of the length of the ship but not less than 5 m from the end of of being supplied by two separate pumps, each of which shallbe capable of maintaining an adequate supply at all times.the superstructure or deckhouse facing the cargo area. In the

case of such a compartment being located in the forecastle, access 9.4 The arrangement of the water seal and its associated provi-sions shall be such that it will prevent backflow of flammableshall be through the deckhead forward of the cargo area.

4.3 Inert gas piping systems shall not pass through accommoda- vapours and will ensure the proper functioning of the water sealunder operating conditions.tion, service and control station spaces.

5.1 Means shall be provided which will effectively cool the vol- 9.5 Provisions shall be made to ensure that any water seal isprotected against freezing, in such a way that the integrity ofume of gas specified in paragraph 3 and remove solids and sulphur

combustion products. The cooling water arrangements shall be water seal is not impaired by overheating.9.6 A water loop or other approved arrangement shall also besuch that an adequate supply of water will always be available

without interfering with any essential services on the ship. Provi- fitted to all associated water supply and drain piping and to allventing or pressure sensing piping leading to gas-safe spaces.*sion shall also be made for an alternative supply of cooling water.

5.2 Filters or equivalent devices shall be fitted to minimize the Means shall be provided to prevent such loops from being emp-tied by vacuum.amount of water carried over to the inert gas main.

6.1 Two air blowers shall be fitted to each inert gas generator, 9.7 Any water seal or equivalent device and all loop arrangementsshall be capable of preventing the return of flammable vapourswhich together shall be capable of delivering to the cargo tanks,

required to be protected by the system, at least the volume of to an inert gas generator at a pressure equal to the test pressureof the cargo tanks.gas required by paragraph 3. An Administration may permit only

one blower if it is capable of delivering to the protected cargo 9.8 The second device shall be a nonreturn valve or equivalentcapable of preventing the return of vapours or liquids or bothtanks the total volume of gas required by paragraph 3, provided

that sufficient spares for the air blower and its prime mover are and fitted between the water seal (or the equivalent device)required in paragraph 9.1 and the first connection from the inertcarried on board to enable any failure of the air blower and its

prime mover to be rectified. gas main to a cargo tank. It shall be provided with positive meansof closure. As an alternative to positive means of closure, an6.2 The inert gas systems shall be so designed that the maximum

pressure which they can exert on any cargo tank will not exceed additional valve having such means of closure may be providedbetween the nonreturn valve and the first connection to the cargothe test pressure of any cargo tank.

6.3 Where more than one inert gas generator is provided, suitable tanks to isolate the water seal (or equivalent device).9.9 As an additional safeguard against the possible leakage ofshutoff arrangements shall be provided on the discharge outlet

of each generator plant. flammable liquids or vapours back from the deck main, meansshall be provided to permit this section of the line between the6.4 Arrangements shall be made to vent the inert gas to the

atmosphere in case the inert gas produced is off-specification, valve having positive means of closure referred to in paragraph9.8 and the valve referred to in paragraph 8 to be vented in ae.g. during starting-up or in case of equipment failure.

6.5 Where inert gas generators are served by positive displace- safe manner when the first of these valves is closed.10.1 The inert gas main may be divided into two or morement blowers, a pressure relief device shall be provided to prevent

excess pressure being developed on the discharge side of the branches between the nonreturn devices required by paragraph9 and the cargo tanks.blower.

7 Two fuel oil pumps shall be fitted to each inert gas generator. 10.2 Inert gas supply mains shall be fitted with branch pipingleading to each cargo tank designated for the carriage of flamma-An Administration may permit only one fuel oil pump on condition

that sufficient spares for the fuel oil pump and its prime moverare carried on board to enable any failure of the fuel oil pump * Gas-safe space is a space in which the entry of hydrocarbon gases would

produce hazards with regard to flammability or toxicity.and its prime mover to be rectified by the ship’s crew.


ble products required to be inerted by this Regulation. Each room is provided, they shall be placed in a position easily accessi-ble to the officer in charge of cargo operations.cargo tank containing or loading products not required to be

inerted shall be separated from the inert gas main by: 14.3 In addition, meters shall be fitted:.1 in the navigating bridge to indicate at all times the pressure.1 removing spool-pieces, valves or other pipe sections, and

blanking the pipe ends; or referred to in paragraph 14.1.1; and.2 in the machinery control room or in the machinery space.2 arrangement of two spectacle flanges in series with provi-

sions for detecting leakage into the pipe between the two to indicate the oxygen content referred to in paragraph14.1.2.spectacle flanges.

15 Portable instruments for measuring oxygen and flammable10.3 Means shall be provided to protect cargo tanks against thevapour concentration shall be provided. In addition, suitableeffect of overpressure or vacuum caused by thermal variationsarrangement shall be made on each cargo tank such that thewhen the cargo tanks are isolated from the inert gas mains.condition of the tank atmosphere can be determined using these10.4 Piping systems shall be so designed as to prevent the accu-portable instruments.mulation of cargo or water in the pipelines under all normal16 Suitable means shall be provided for the zero and span calibra-conditions.tion of both fixed and portable gas concentration measurement10.5 Suitable arrangements shall be provided to enable the inertinstruments, referred to in paragraphs 14 and 15.gas main to be connected to an external supply of inert gas.17.1 Audible and visual alarms shall be provided to indicate:11 Unless the arrangements for venting of all vapours displaced

.1 low water pressure or low water flow rate to the coolingfrom the cargo tanks during loading and ballasting comply withand scrubbing arrangement referred to in paragraph 5.1;the requirements of the BCH and IBC Codes for controlled

.2 low fuel supply;venting, such arrangements shall comply with regulation II-2/

.3 high gas temperature as referred to in paragraph 13;59.1 of SOLAS 1974 as amended and shall consist either of one

.4 failure of the power supply to the inert gas generators;or more mast risers or of a number of high velocity vents.

.5 oxygen content in excess of 8 per cent by volumes as referred12 The arrangements for inerting, purging or gas-freeing ofto in paragraph 14.1.2;empty tanks as required in paragraph 2 shall be to the satisfaction

.6 failure of the power supply to the indicating devices asof the Administration and shall be such that the accumulation ofreferred to in paragraph 14.1 and to the automatic controlhydrocarbon vapours in pockets formed by the internal structuralsystems for the gas regulating valve referred to in paragraphmembers in a tank is minimized and that:8 and the inert gas generator;.1 on individual cargo tanks the gas outlet pipe, if fitted, shall

.7 low water level in the water seal as referred to in para-be positioned as far as practicable from the inert gas/airgraph 9.1;inlet and in accordance with regulation II-2/ 59.1.9.3 of the

.8 gas pressure less than 100 mm water gauge as referred to1974 SOLAS Convention as amended, or 8.2.2.3 of the IBCin paragraph 14.1;Code. The inlet of such outlet pipes may be located either

.9 high gas pressure as referred to in paragraph 14.1.1.at deck level or at not more than 1 m above the bottom of17.2 Automatic shutdown of the gas regulating valve and of thethe tank;fuel oil supply to the inert gas generator shall be arranged on.2 the cross-sectional area of such gas outlet pipe referred topredetermined limits being reached in respect of paragraphsin subparagraph 12.1 shall be such that an exit velocity of17.1.1 and 17.1.3.at least 20 m/sec can be maintained when any three tanks17.3 Automatic shutdown of the gas regulating valve shall beare being simultaneously supplied with inert gas. Theirarranged in respect of paragraph 17.1.4.outlets shall extend not less than 2 m above deck level.17.4 In respect of paragraph 17.1.5, when the oxygen content ofWhen in accordance with paragraph 3 an Administrationthe inert gas exceeds 8% by volume, immediate action shall bepermits a system designed to supply only one or two tankstaken to improve the gas quality. Unless the quality of the inertsimultaneously, the outlet pipes should be sized such thatgas improves, all operations in those tanks to which inert gas isan exit velocity in the outlet pipes of 20 m/sec can bebeing supplied shall be suspended so as to avoid air being drawnmaintained;into the tanks. The deck isolation valve referred to in paragraph.3 each gas outlet referred to in subparagraph 12.2 shall be9.8 shall be closed and the off-specification gas shall be ventedfitted with suitable blanking arrangements.to atmosphere.13 Means shall be provided for continuously indicating the tem-17.5 The alarms required in paragraphs 17.1.5, 17.1.6 and 17.1.8perature and pressure of the inert gas at the discharge side ofshall be fitted in the machinery space and cargo control room,the system, whenever it is operating.where provided, but in each case in such a position that they are14.1 Instrumentation shall be fitted for continuously indicatingimmediately received by responsible members of the crew. Alland permanently recording, when the inert gas is being supplied:other alarms required by this paragraph shall be audible to re-.1 the pressure of the inert gas supply mains between thesponsible members of the crew either as individual alarms or asnonreturn devices required by paragraph 9.1 and the cargoa group alarm.tanks; and

.2 the oxygen content of the inert gas in the inert gas sup- 17.6 In respect of paragraph 17.1.7 the Administration shall besatisfied as to the maintenance of an adequate reserve of waterply main.

14.2 The devices referred to in paragraph 14.1 shall be placed at all times and the integrity of the arrangements to permit theautomatic formation of the water seal when the gas flow ceases.in the cargo control room where provided. Where no cargo control


The audible and visual alarm on the low level of water in the 18 Detailed instruction manuals shall be provided on board,covering the operations, safety and maintenance requirementswater seal shall operate when the inert gas is not being supplied.

17.7 An audible alarm system independent of that required in and occupational health hazards relevant to the inert gas systemand its application to the cargo tank system. The manuals shallparagraph 17.1.8 or automatic shutdown of cargo pumps shall be

provided to operate on predetermined limits of low pressure in include guidance on procedures to be followed in the event ofa fault or failure of the inert gas system.the inert gas mains being reached.


ships abs ibc igc rules

Documents