addendum no.5.1 - attachment method statement

Revision 1 August 2013 Page i

METHOD STATEMENT

Erection of 529 Series Tower Using Two Cranes

Signatures of design team of Eskom Lines Engineering Services (LES)

Name Functional Responsibility Date Signature

Neels Henderson Author

Bertie Jacobs Author

Viven Naidoo Peer Review - General

Approval by LES Manager

Riaz Vajeth ……………………………...

Name ……………………………...

Signature

Engineering manager ……………………………...

Designation ……………………………...

Date

Revision Control

Lines Engineering document no. Revision no. Date

0 January 2014

Copyright Warning

COPYRIGHT © ESKOM HOLDINGS LIMITED

NO PUBLICATION OR DISSEMINATION OF ITS CONTENTS IS ALLOWED WITHOUT WRITTEN PERMISSION

METHOD STATEMENT

ERECTION OF 529 SERIES OF TOWERS USING

TWO CRANES

Revision 0 August 2013 Page ii

REVISION CONTROL

Revision Change Log Date

0 January 2014

METHOD STATEMENT


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TABLE OF CONTENTS

PAGE

REVISION CONTROL ................................................................................................................. 2

TABLE OF CONTENTS .............................................................................................................. 3

METHOD STATEMENTS ............................................................................................................ 4

GENERAL ..................................................................................................................... 4 1.

TERMS, DEFINITIONS AND ABBREVIATIONS ............................................................................. 4 1.1.

INTRODUCTION ............................................................................................................................. 6 1.2.

PURPOSE ....................................................................................................................................... 6 1.3.

EQUIPMENT LIST ........................................................................................................................... 6 1.4.

INSPECTIONS ................................................................................................................................ 6 1.5.

TOWER ERECTION METHOD STATEMENT ................................................................ 8 2.

QUALITY ASSURANCE/QUALITY CONTROL MONITORING ................................... 12 3.

HAZARDS ........................................................................................................................................ 12 3.1.

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Revision 0

METHOD STATEMENTS

GENERAL 1.

TERMS, DEFINITIONS AND ABBREVIATIONS 1.1.

e.g.: Definitions:

Term Definition

Toolbox talk A daily short discussion of a supervisor to convey safety issues, work methods etc.

surrounding a specific procedure or task to be done.

Competent person Any person having the knowledge, training and experience specific to the work or task

being performed: Provided that where appropriate qualifications and training are

registered in terms of the provisions of the South African Qualifications Authority Act,

1995 (Act No. 58 of 1995), these qualifications and training shall be deemed to be the

required qualifications and training;

Construction work The erection, maintenance, alteration, renovation, repair, demolition or dismantling of

or addition to a building or any similar structure

The installation, erection, dismantling or maintenance of a fixed plant where such work

includes the risk of a person falling

The construction, maintenance, demolition or dismantling of any bridge, dam, canal,

road, railway, runway, sewer or water reticulation system or any similar civil

engineering structure

Construction

vehicle

Means a vehicle used for means of conveyance for transporting persons or material

or both such persons and material, as the case may be, both on and off the

construction site for the purposes of performing construction work

Contractor An employer who performs construction work and includes principal contractors

Design In relation to any structure includes drawings, calculations, design details and

specifications;

Designer – any

person who-

Prepares a design

Checks and approves a design

Arranges for any person at work under his control (including an employee of his,

where he is the employer) to prepare a design

Architects and engineers contributing to, or having overall responsibility for the design

Build services engineers designing details for fixed plant

Contractors carrying out design work as part of a design and build project

Fall prevention

equipment

Means equipment used to prevent persons from falling from an elevated position,

including personal equipment, body harness, body belts, lanyards, lifelines or physical

equipment, guardrails, screens, barricades, anchorages or similar equipment

Health and safety

plan

Means a documented plan which addresses hazards identified and includes safe work

procedures to mitigate, reduce or control the hazards identified

Material hoist Means a hoist used to lower or raise material and equipment, and includes

cantilevered platform hoists, mobile hoists, friction drive hoists, scaffold hoists, rack

and pinion hoists and combination hoists

Method statement Means a written document detailing the key activities to be performed in order to

reduce as reasonably as practicable the hazards identified in any risk assessment

Mobile Plant Means machinery, appliances or other similar devices that is able to move

independently, for the purpose of performing construction work on the construction site

Principal contractor Means an employer, as defined in section 1 of the Act who performs construction

work and is appointed by the client to be in overall control and management of a part

of or the whole of a construction site

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Revision 0 August 2013

Professional

engineer or

Professional

certificated

engineer

Means any person holding registration as either a Professional Engineer or

Professional Certificated Engineer under the Engineering Profession Act, 2000 (Act

No. 46 of 2000);

Risk assessment Means a programme to determine any risk associated with any hazard at a

construction site , in order to identify the steps needed to be taken to remove, reduce

or control such hazard;

Structure means- any building, steel or reinforced concrete structure (not being a building), railway line

or siding, bridge, waterworks, reservoir, pipe or pipeline, cable, sewer, sewage works,

fixed vessels , road, drainage works, earthworks, dam, wall, mast, tower, tower crane,

batching plants, pylon, surface and underground tanks, earth retaining structure or

any structure designed to preserve or alter any natural feature, and any other similar

structure

any formwork, false work, scaffold or other structure designed or used to provide

support or means of access during construction work

any fixed plant in respect of work which includes the installation, commissioning,

decommissioning or dismantling and where any such work involves a risk of a person

falling two meters or more

e.g.: Abbreviations in alphabetical order:

Abbreviation Description

EMP Environmental management plan

HIRA Hazard identification and Risk analysis

PPE Personal protective equipment

RoD Record of decision

UTS Ultimate tensile strength

ITP Inspection and test plan

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INTRODUCTION 1.2.

The method statement provided below are to be used for the construction of transmission lines using the 529

series of cross rope structures (529A and 529C), in order to meet the requirements, as set out in the

construction regulations. It is however still the responsibility of the contractor to provide and demonstrate to the

client a suitable and sufficiently documented health and safety plan which includes safe work

procedures/method statements to mitigate, reduce or control the hazards identified.

PURPOSE 1.3.

To provide guidelines for the procedure of erecting the 529 series of structures using two cranes in a tandem lift

operation without any spreader bars. This method statement will only highlight additional requirements and/or

deviations from the already approved method statement dealing with erection of guyed structures. All

equipment, tools and safety procedures need to be used and adhered to as per the already approved method

statement(s) dealing with cross rope type structures.

EQUIPMENT LIST 1.4.

Notwithstanding any existing equipment already used on site to lift the cross rope type structures the following is

the minimum requirements for the tandem lift.

Two cranes with capability of reaching 50 m and capacity to lift 3 tons at a radius of 12 m. The

minimum size of crane is to be not less than 70 tons.

Rigging slings and shackles of capacity not less than 6 tons and of connecting length 0.5 m should be

used.

INSPECTIONS 1.5.

Ensure that the following inspections have been carried out prior to start lifting the structures:

Tower masts assembled correctly with all members in place, bolts tightened, punched and painted.

The orientation of the masts after assembly on the ground should be as the normal with lifting lugs

pointing to the top and can be seen in Photo 1.

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Photo 1: Orientation of masts after assembly prior to lifting.

The position of the towers and cranes should be correct in relation to the foundation(s) according to

Figure 1.

All four guy ropes are of the correct length, size, strength and attachments suitable for attachment to

masts and foundation links.

Cross rope and spacer rope correctly installed and positioned in correct attachment holes to the

structure.

All hardware present on site for phase conductors correctly assembled complete with insulators of

correct strength, type and number of discs in the case of glass insulators. The hardware, insulators

and running blocks should be laid out in the direction as per Figure 1. It is important that the cross-

rope is laid out on the ground, simulating the bow shape in the final erected position. Using this

position of the cross-rope the hardware is now positioned on the ground as indicated in Figure 1.

Running blocks correctly attached to the hardware with pilot wires or guide wires in place. The plates

and running blocks to attach the earth wire should also be assembled in place before lifting complete

with pilot wires.

All rigging material, shackles, rope blocks, chain blocks, load cells and slings of correct lengths and

capacity complete with inspection certificates available to perform the lift.

The lifting sling lengths need to be calculated by taking into account the mast length to be lifted as well

as the crane reach at the particular position radius considering the available distance available

between crane hook and top lifting hole on the 529 top rigging hole. This sling should be as short as

possible.

The following additional inspection sheets should be completed to ensure that all inspections have been done

prior to lifting.

PDPNEG-IRP-10 Pre erection inspection – Guyed tower

PDPNEG-IRP-06 Guyed tower inspection

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TOWER ERECTION METHOD STATEMENT 2.

After all the inspections have been conducted and confirmed that everything is in order, can the lifting operation

begin.

2.1 Ensure the cranes are positioned as per Figure 1 with the crane(s) a distance of approximately 12 m

from mast foundation and orientated such that no interference between the crane and final guy rope

positions will exist. Check that wind speed is below 10 m/s.

Figure 1: Plan view of mast and crane positions relative to tower foundations.

2.2 Check that mast bottom protection to prevent damage to galvanizing and steelwork is in place. See

also photo 2 for example of such protection.

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Photo 2: Example of tower bottom protection to prevent damage to galvanizing during lifting.

2.3 Check that the hardware is connected to the cross rope at the correct position(s) on the cross rope,

complete with insulators, running blocks and pilot or guide ropes in the running blocks. The orientation

of the hardware and insulators should be such that minimum bending should be induced on the

insulators during the lifting process. To minimise bending of the insulators, temporarily protective

covering (thick wall plastic tubes used for guy foundations for example) can be utilised for additional

protection during lifting.

2.4 Ensure the spacer rope is securely attached in the correct attachment hole(s) on the structures.

2.5 Connect each crane to its corresponding mast using the rigging hole at the top of the mast as indicated

in Figure 2. This hole is 25.5 mm in diameter, suitable for M24 bolt.

Figure 2: Top rigging hole on mast to be used for lifting.

2.6 Ensure that lifting foreman (or person responsible and in charge of lifting operation) has checked all

connections and slings and that he has contact and/or radio communication with both crane drivers.

Top rigging hole

to be used for

tandem lifting.

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2.7 Clear all people away from the lifting site, to a radius of 50 m from centre of tower foundations to a safe

location.

2.8 Start the lifting process slowly so that both masts are lifted equally at the same rate at all times.

Continue lifting until spacer rope and cross rope is just off the ground and that the hardware is starting

to lift. Check that nothing gets tangled or hooked which can cause a problem during the remainder of

the lifting process.

2.9 Continue lifting, ensuring that the insulators experience no or very little bending. The crane hook

should still be hanging vertically down with very little side force due to the attached cross rope with

hardware.

2.10 Complete the lifting process checking constantly that the side force on the crane hook is small and that

the crane operators are comfortable with the operation. Crane operators to ensure that head of cranes

always line up with the crane lifting hooks. If at any stage the crane hooks are not hanging vertically

down with a 20 degree tolerance, the lifting operation should be stopped and checked with the crane

operators before continuing. All parties should agree that it is safe to continue the lifting operation

before carrying on.

2.11 Once both masts are upright/vertical, suspended completely by the two cranes with bottom of masts

about 0.5 m above ground, workers can approach from a safe position (in-line with the centre phase) to

assist lowering the bottom of the masts onto the mast foundations.

2.12 Lower the masts simultaneously into the locating pins on the foundations and continue the lowering

process so that cross rope have some tension on it. Figure 3 indicates the position of the masts prior

to attaching the guy ropes to the guy anchor links.

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Figure 3: Position of masts prior to attaching guy ropes to guy anchors.

2.13 Connect the guy ropes to its foundation anchors and ensure all guy ropes are properly connected with

correct guy hardware and that masts are more or less plum in the vertical and transverse plane.

2.14 Slacken the cranes (to a load of about 1 ton) and ensure that the masts are safely supported by the

guys only before sending workers up to unhook the cranes. The workers climbing up the masts should

be wearing the appropriate safety clothing and equipment whilst using suitable fall protection

system(s).

2.15 Complete plumbing the towers in the vertical and transverse plane with guys correctly tensioned to

2.35 tons for glass insulators and 2.15 tons for composite insulators.

2.16 Disconnect and remove all rigging equipment, perform final erection inspections and clean up the site.

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QUALITY ASSURANCE/QUALITY CONTROL MONITORING 3.

For all aspects of the construction, the contractor will comply with the design and method statement as set out

by the designer.

All relevant ITP documentation should be signed off, for each aspect of the design, after inspection by the

appointed site representative of both the contractor and the client as set out in the construction regulations on

the relevant ITP forms.

Hazards 3.1.

Environmental:

Sharp objects like tower steel, conductor ends, planks with nails etc.

Nip points on ring views, block and tackles, press etc.

Noise from equipment.

Mud, wet steel, long grass, loose stones, soil and uneven surfaces, excessive wind.

Crane can sink into the ground.

Moving trucks and LDV’s.

Human:

Miscommunication between winch/tensioner/crane operators.

Falling objects like tools, bolts and nuts etc.

Working at heights on towers and conductors.

Climber attaches to a portion of the tower suspended by the crane.

Poor rigging practice – incorrect use of shackles, attachment below center of gravity, overloading of crane etc.

Employees not using PPE / climbing equipment correctly.

Equipment:

Lifting of equipment and materials with slings / cranes – slings can break / crane faulty etc.

Sudden release of tension in slings/conductor/stay-wires.

Winching of the conductor/moving wires.

Overloading of the structure in a temporary state of weakness because of loose bolts etc. during erection / loading during stringing.

addendum no.5.1 - attachment method statement

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