Working safely on heavy vehicles suspension systems

Purpose

The purpose of this safety alert is to highlight the risk of crushing or fatal injuries if a vehicle or major components fall due to inadequate support. There is a risk of serious injury or death when workers are under vehicles or parts, such as heavy vehicle axles, and the vehicle or parts fall off the stand. There is also an increased risk when workers are working alone and an incident occurs that limits their ability to get assistance, such as being trapped and not being able to reach their phone.

Background

In a recent incident a worker suffered fatal injuries when struck by an axle that fell while repairs were being undertaken on the suspension arms and bushes of a heavy vehicle tri-axle trailer. At the time of the incident, the trailer was supported on jack stands and all the axles had been disconnected from the main suspension attachment points. The wheels had been removed and the axles were each supported by a pair of jack stands.

_{Photograph 1 - Shows a tri-axle trailer like the one involved in the incident.}

Due to the position of the axle, the axle may not have been stable on the stands and began to rotate causing it to topple off the stands onto the worker. When setting up equipment to support vehicles or vehicle components, it is necessary to check that the position of the stands or the orientation of the components is balanced to minimise the risk of unexpected movement.

_{Photograph 2 - Axles may tend to roll when disconnected due to the location of suspension and braking components fitted}

Action required

A person conducting a business or undertaking (PCBU) must ensure the health and safety of workers while they are engaged for work and other persons who may be affected by the business or undertaking. A PCBU must manage risks to health and safety. To do this, risks must be eliminated, or minimised so far as is reasonably practicable.

In conducting a risk assessment, a PCBU must identify hazards, select and implement control measures using the hierarchy of control. As part of the overall risk management for a PCBU there is a need to maintain and review controls to ensure the controls remain effective. Further details on the risk management process can be found in the How to manage work health and safety risks code of practice.

When planning for work that requires the support of vehicles, or major components of vehicles, consider how to safely support the vehicle or major components by selecting suitable support stands. If the tasks are common, a procedure should be developed on the selection of the stands and the process to set up for the work. Where the job is not regularly done it will be necessary to outline the key steps to identify how to safely support the vehicle and any major components that need to be removed.

Issues that should be included are:

• Selection of suitable jacks and stands with an appropriate rating and fitted with any manufacturer accessories recommended.
• Ensuring the vehicle is immobile (e.g. using chocks) prior to any jacking commencing and that the vehicle is safely supported before any work is done under a raised vehicle.
• Identification of suitable jacking points and positioning of stands.
• Changes to the balance of the vehicle if major components are removed.
• Positioning of stands to support major components that maintains balance and stability.
• If it isn’t possible to ensure major components are supported in a way that ensures they remain stable for the entire duration of the work task, the use of chains, straps or slings should be considered to secure the components against unexpected movement. The components should be lashed to the chassis to ensure they are secured against unexpected movement.
• Checks of the work area to ensure that the slab or ground is level, and the ground condition is hard enough to support the jack and stands. In some cases, it may be possible to use soleboards under the stands if the ground condition looks to be too soft to prevent them becoming unstable. If risks due to poor ground conditions are identified, it may be necessary to get further advice on soleboard size requirements. Jack stands may become unstable due to uneven or soft ground, or due to any excessive side loads being applied.
• Training should be included which covers the elements listed above. Particular attention should be given to identify unbalanced loads of major vehicle components.
• Checking for the available manufacturer’s recommendations included in the maintenance manual. Particularly information on the sequence for disassembly and key instructions related to the steps involved.

Alternatively, it may be possible to lower major components to the ground, or if it is an axle, refit wheels and tyres to allow the tyres to be lowered to the ground and chocked. A PCBU must also manage risks due to remote or isolated work by providing a system of work that includes effective communication with workers. Remote or isolated work is defined as: work that is isolated from the assistance of other persons because of location, time or the nature of the work. If your workers are required to do remote or isolated work, you will need to add suitable information to your procedures on how to control the associated risks with remote work.

_{Photograph 3 - Photo showing safe support of a chassis and axle using stands with wheels and tyres fitted.}