Correct as at 19th April 2024. It may be superseded at any time.
Extract taken: from Vehicle Inspection Portal > VIRMs > In-service certification (WoF and CoF) > Heavy trailers > Steering and suspension > Steering and suspension systems
6-1 Steering and suspension systems
Reasons for rejection
Condition
1. Refer to general trailer pages.
2. An axle-stop has been removed, or its condition is such that it may not be effective.
Performance
3. Refer to general trailer pages.
Modification and repair
4. A modification or repair affects the steering and suspension system and:
a) is not excluded from the requirements for HVS certification (Table 6-1-1), or
b) the modification is not for the purpose of law enforcement or the provision of emergency services, or
c) is missing proof of HVS certification, that is the vehicle has been modified or repaired, and:
i.no LANDATA record has been entered, or
ii. no valid LT400 form from an HVS certifier of category HVEC or HMCD has been presented.
Note 1
Axle-stop device means a device to control the movement of the axle in the event of suspension failures (eg a shacke stop, security strap [SAF] or catch strap [BPW]).
Note 2
Ballrace turntable means a device incorporating a low-friction ball bearing fitted between two substantial structural components of a vehicle to enable rotational motion between those components about a vertical axis.
Note 3
Steering system means those components, parts and systems that connect the driver’s controls to a vehicle’s wheels or tracks by means of which the direction of motion of a vehicle is controlled.
Note 4
Suspension system means a system that allows controlled and limited movement of an axle relative to the chassis or body of a vehicle; and includes a spring and damping system and any associated controls.
Table 6-1-1. Requirements for HVS certification
HVS certification is required | HVS certification is not required |
|---|---|
1. A steering or suspension system that is modified, including a replacement system that is not identical to the system fitted by the vehicle manufacturer. 2. The steering system of a vehicle to which a second steering axle is fitted to form a twin-steer axle set. 3. Any components showing successive repairs. | 1. Any modification or repair likely to have been carried out before 1 January 1997. (Modifications and repairs before this date generally required certification but for inspection purposes no evidence of this is required.) 2. Any repair or modification not listed in the left-hand column unless the vehicle inspector considers that certification is required because the modification or repair has affected the vehicle’s safety performance (a second opinion from an expert may be needed, eg the manufacturer’s representative, or a reputable workshop). |
Summary of legislation
Applicable legislation
Permitted equipment
1. A trailer may be fitted with with an axle-stop device.
2. A trailer may be fitted with a ballrace turntable.
Condition
3. Refer to general trailer pages.
4. The suspension system must have adequate strength for all conditions of loading and operation for which the vehicle was constructed.
5. A ballrace turntable must be securely fastened and within safe tolerance of its original condition.
6. An axle-stop device fitted to a vehicle must be within safe tolerance of its original condition.
Performance
6. Refer to general trailer pages.
7. The suspension system must have performance characteristics for all conditions of loading and operation for which the vehicle was constructed.
Modification and repair
8. A modification or repair that affects the steering or suspension system must be inspected and certified by an HVS certifier of category HVEC or HMCD unless the vehicle:
a) is excluded from the requirement for HVS certification (Table 6-1-1), and
b) has been inspected in accordance with the requirements in this manual, including those for equipment, condition and performance.
Page amended 1 April 2023 (see amendment details).