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Publisher's Foreword
Introduction
Generic Diagrams

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Barloworld 
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Brasa Marcopolo
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Freightliner
FUSO / Canter
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MAN Truck & Bus
Mercedes Benz Commercial Vehicles
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Scania
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Toyota SA
Tyco / Navistar
Volvo
Western Star

Trailers

DUNCANMEC
Fruehauf Components
GRW Engineering
Henred / SA Truck Bodies
IMS
TEE

Transport Information

Turning Ability
Semi-Trailers Regulation 219
Vehicle Data Plates
Bridge Formula & Conversion
Live Vehicle Population
Conversion Table

Copyright © 1999 FleetWatch magazine and FleetWatch On-Line.

No part of this publication may be reproduced without the prior written permission from the publishers. Views published are not necessarily those of the publishers.

 

TRUCKS - GENERIC DIAGRAM FOR DIMENSIONS
Please refer to these explanatory generic diagrams as a reference to the dimensions of vehicles as detailed in the specifications contained in this guide.

REFERENCE

OL Overall Length FOH Front Overhang
OW Overall Width ROH Rear Overhang
OH Overall Height BBC Bumper to Back of Cab
WB Wheel Base CA Cab to Rear Axle

GENERIC DIAGRAM FOR REAR OVERHANG
Please refer to these explanatory generic diagrams as a reference to the dimensions as detailed in the specifications contained in this guide.

Rear Overhang Legislation

Regulation 356(2)(c) pertaining to the maximum rear overhang of a motor vehicle was amended on December 4th 1998.

The amendment increases the maximum rear overhang of a goods vehicle from 50% to 60% of the wheelbase. The amendment provides for an increase in the maximum legal structural body length of conventional goods vehicle by 10% of the wheelbase. For example a truck with a wheelbase of 5000 mm will now be able to achieve a maximum body length of 500 mm longer than was possible before the amendment.

A further benefit that will accrue from the introduction of the increase in the maximum rear overhang is to provide for the fitting of an airlift tag axle to a 4x2 chassis, hitherto not legally possible, as the rear overhang was not legal when the tag axle was raised. The new rule now opens the door to 6x2 base models.

The amendment applies with immediate effect.


REAR OVERHANG

The rear overhang of refuse collector, road making and road construction vehicles and farming vehicles is 70% of the wheelbase.


THE DETERMINATION OF FRONT OVERHANG
REGULATION 226(b)
TRAILERS AND SEMI-TRAILERS
60% OF WHEELBASE OR 5.8 m MINUS HALF OF WHEELBASE


Example
trailer with a 8.5 m wheelbase

60% of 8.5m = 

5.1 m

5.8m-8.5x0.5 =

1.55m

THE MAXIMUM FRONT OVERHANG IS 1.55 M


Example
trailer with a 3.5 m wheelbase

60% of 3.5m = 

2.1 m

5.8m-3.5x0.5 =

4.05m

THE MAXIMUM FRONT OVERHANG IS 2.1 M


THE MAXIMUM FRONT OVERHANG
IS 1.8 M IRRESPECTIVE 
OF WHEELBASE

ALL SEMI-TRAILERS

REFERENCE

OL Overall Length
WB Wheel Base
FOH Front Overhang
ROH Rear Overhang
DBL Drawbar Length

THE DETERMINATION OF FRONT OVERHANG
REGULATION 226(b)
TRUCK AND BUSSES
DETERMINATION OF FRONT OVERHANG ACCORDING TO POSITION OF DRIVER'S SEAT


UNDERSTANDING WHEELBASE & REAR OVERHANG
THERE SEEMS to be some difficulty in understanding the application of wheelbase related to front and rear overhang where axle units are involved. The following diagrams illustrate the methodology in the determination of the relevant dimensions

REFERENCE

OL Overall Length

FOH+WB+HAU+ROH

FOH Front Overhang Distance from front end to centre of rear axle unit
WB Wheelbase Distance from centre of front axle to centre of rear axle unit
HAU Half Axle Unit Half the distance from centre of first axle to centre of last axle of rear axle unit
ROH Rear Overhang Distance from centre of rearmost axle to rear end

 


REFERENCE

OL Overall Length

FOH+WB+HAU+ROH

FOH Front Overhang Distance from front end to centre of kingpin
WB Wheelbase Distance from centre of kingpin to centre of rear axle unit
HAU Half Axle Unit Half the distance from centre of first axle to centre of last axle of rear axle unit
ROH Rear Overhang Distance from centre of rearmost axle to rear end