The NSW Resources Regulator recently issued a safety alert for the mining industry after an unattended CAT793D haul truck rolled 65-metres from a workshop designated parking line and collided with a pump and infrastructure at a wash bay.
The incident, which occurred on 10 January 2021, involved an operator who parked the haul truck on the workshop deadline for a defect repair.
The truck was parked across a parking hump and the engine was switched off. Soon after the operator disembarked from the vehicle, it started rolling backward.
The operator unsuccessfully attempted to stop the runaway vehicle. After rolling 65 metres, the truck collided with a pump and associated infrastructure at a heavy vehicle wash bay.
An initial investigation at the site identified the following:
The park-up hump at the workshop deadline was not constructed to the site standard.
The post-incident inspection of the truck cab found that the park brake had not been selected.
The fail-safe park brake mechanism did not activate when the truck’s ignition was switched off.
Further investigation on the vehicle found that a solenoid on one of the park brake valves failed and the air pressure did not bleed from the park brake circuit.
This resulted in the park brake not being engaged automatically. The remainder of the fleet onsite was inspected and the same fault was also identified on another vehicle.
The alert subsequently recommended mine operators ensure:
All mobile plant park-up areas are designed, constructed and maintained to enable safe and stable parking.
Work area inspections verify that mobile plant park-up areas are constructed and maintained to the standard.
Brake testing regimes on mobile plant includes testing fail-safe mechanisms and interlocks.