In conducting a hot-seat changeover on a rear dump truck at the ROM pad, the oncoming operator drove his light vehicle up to the truck and parked out of its line of sight, in violation of the no-go zone for light vehicles.

The hot-seat change was completed and the truck then drove over the light vehicle. Fortunately, the offgoing operator exited the light vehicle before impact.

A constant alarm from a defective proximity device on nearby plant contributed to the incident because the noise interfered with the truck’s proximity warning device.

In a related incident, during a hot-seat changeover on a rear dump truck at the go-line, the oncoming operator, unaware that the vehicle was also being refuelled, drove off with the fuelling line still attached. Fortunately, the service truck operator was not injured.

“The investigation into these incidents found that the safety and health management systems at each mine had not adequately considered hot-seat changeovers and consequently risk was not being managed to ‘as low as reasonably achievable’,” the inspectorate said.

The first incident highlights the risk in conducting hot-seat changeovers at an active work area rather than in the less complicated, more easily managed confines of an organised go-line or hard-stand area, it said.

Refuelling at the same time as conducting a hot-seat changeover might appear convenient but should be recognised as a hazard.

“The second incident illustrates poor risk management and lack of understanding of the purpose and scope of a no-go zone. This lack of understanding permitted an inappropriate activity and put a person at risk, defeating the purpose of the go-line,” the inspectorate said.

It recommended that the use of go-lines be optimised and that the conduct of other activities nearby during a hot-seat changeover, particularly activities involving pedestrians, be recognised as having an unacceptable level of risk.

Also, supervisors should be trained, competent and accountable, the inspectorate said.