portfolio johan conradie

PORTFOLIO - JOHAN CONRADIE

MECHANICAL DESIGN ENGINEER

SPECIALIZED CONVERTED MINE

TRUCKS AND MODIFICATIONS

During the time I worked at Resonant I was

responsible for the design and checking of designs of

several modifications/alterations of mine trucks. Three

of these trucks were modified by mounting generator

sets on top of the trucks in the place of its haul bucket

(Motivator truck). The fourth modified truck design that

I was responsible for evaluating was one on which a

towing arm was mounted for the purpose of towing a

lowbed trailer.

• Finite element analyses were performed for a

number of load cases for each truck design.

• Modal analyses was performed and design

modifications were suggested for the frameworks

mounted onto the trucks.

• Finite element software were used to design lifting

beams to lift the truck at the rear of the frame and to

analyse the effect the lifting would have on the

framework of one of the trucks.

• A frame was designed for equipment to be mounted

to the front of the chassis. Finite element analysis

was performed on the chassis and the chassis was

modified accordingly.

• A new staircase was designed to provide access to

the driver’s cabin for the Motivator truck.

Clients: Anglo Technical Services, VR Engineering &

Isithelo



HAZARDOUS PETROCHEMICAL

PLANT DESIGN

I was part of a multidisciplinary team that was given

the responsibility to design a highly dangerous

petrochemical plant for an international client.

My main responsibility for this project was to develop

the 3D models of equipment, piping, etc. and

incorporate it into the layout of the plant. This involved

the layout of services, plant building layout and the

general layout of the site.

Further responsibilities and accomplishments:

• Appointed acting lead mechanical engineer in a

large multidisciplinary petrochemical project

• Developed specifications for the production

facility.

• Routing of pipelines and development of isometric

drawings of the pipelines.

• Developed a new numbering system for large

multidisciplinary petrochemical projects.

• Design calculations for pressure vessels (ASME

BPVC) and tanks (API 620 & API 650).

• I facilitated 3D model review sessions in

collaboration with other senior personnel.

• Checking of designs

• Skid frame desings

Client: Confidential



PIPELINE DESIGN AND ANALYSIS

Some of the tasks I performed at Resonant are listed

here:

• Detailed pipe stress analysis using CAESAR II.

o Steel pipes accoring to ASME B31.3 / EN 13480

o GRP pipes according to BS 7159

• Structural design of large piping supports.

• Vibration & modal analysis on pipe structures.

• Flow analysis using AFT Fathom.

• Water hammering analyses.

I did pipe stress analyses and calculations for:

• Dedusting filter pulse tank assembly (consisting

entirely of piping components).

• A SO2 air cooler at Eskom Matimba Power Station.

• Turbine drain lines at Camden Power Station.

• Steam supply and extraction lines on turbines at the

Eskom Komati Power Station.

• Large GRP lines for a water circulating system at

the Bokpoort CSP in the Western Cape.

• Underground fire main lines at Sasol plant in

Temane, Mozambique.

• Wet sulpheric acid pipeline at Sasol, Secunda.

• Glycol supply main lines at Oyu Tolgoi mine.

• Wash bay for buses & LDV’s at Zibulo

(underground mine).

Clients: SPX, IWC, Fibre-Wound, Thermal Energy

Systems



STACK DESIGNS

Fired heater stack Client: SPX

A fired heater stack was due to be replaced by a new

one at a Sasol plant in Secunda. For the detailed

design of stacks, the API 560 method was used. Both

wind loading and the self-weight of the stack was

considered in the calculations.

It was my responsibility to perform all the calculations

necessary for the desing. I also did a Finite Element

Analysis (FEA) to check the stresses in the structure

due to a platform that is attached to the bottom part of

the stack.

Large GRP fan stacks Client: IWC

IWC has designed a 30’ fan stack consisting of 24

GRP sections that are bolted together to form the

stack. Analyses had to be performed to determine

whether the fan stack’s design is adequate for its

design purpose:

• Static stress analyses to determine whether the

structure complies with the relevant BS and SABS

specifications.

• Modal analysis to determine whether the natural

frequencies are not too close to the blade pass

frequency.

• Buckling analysis to determine if the structure will

buckle under internal pressure.



GENERAL STRUCTURAL DESIGN

I was responsible for several general mechanical

design projects. For most projects my approach would

be to start with concept development using 3D

modelling software. This involves design for

accessibility as well as for constructibility. After the

client approves the concept design, the detail design

follows. Design calculations are then performed and

finite element analysis are used to investigate stresses

in components that are hard to qualify through

calculations. A technical report is then written and

manufacturing drawings are produced if required.

Some of the projects I worked on are listed here:

• Design check on the alteration of the supports of a

silo structure

• Filament winder shafts for large GRP piping

• Safety bumpers for large mine trucks:

o Flexible bumper

o Dove type bumper

• Design of more compact ballast weights for the

front of a tractor used in an underground mine

• Design check of a roller support structure

• Rollover (ROPS) frame designs:

o ROPS rame for Land Cruiser bakkies used at

mines

o Frame design for a Safari Viewer bakkie

o Frame design for a Safari Viewer truck