Coal Inspectorate | Alert | No.438 V 1 | 02 November 2023

Excavator and water truck collision

What happened?

At 1.30pm on 24 October 2023, while conducting civil works at a coal mine near Toowoomba, a 30-tonne excavator loading topsoil onto an articulated dump truck, slewed to the right and collided with a medium vehicle water truck cabin (refer Figure 1).

How did it happen?

The water truck was watering on the offside of the excavator and had not used positive two-way radio communications with the excavator operator. As a result, the excavator operator, unaware of the hazard, has collided with the nearby water truck, causing moderate damage to the cabin (refer Figure 2). No coal mine workers were injured.

The high potential incident scene was isolated overnight for an inspector to respond to the site.

Key issues

Collisions with another vehicle are one of the top three high potential incidents reported by the coal mining industry. Positive communication is a critical, but administrative control.

Recommendations

Site Senior Executives (SSEs) should review their Principal Hazard Management Plans and site procedures for the hazard of mobile equipment interaction to ensure the risk is being managed effectively.

The review should have a specific focus on persons on foot as well as light and medium vehicles which have an elevated risk when entering heavy-vehicle operational areas.

SSEs should consider implementing industry leading practice in operational areas to ensure the risk remains at acceptable levels and as low as reasonably achievable.

Industry leading best-practice requires workers to make positive communication and for heavy equipment to stop operating when persons on foot, or light and medium vehicles enter the operational area (typically a 50m exclusion zone). Light and medium vehicle operators should have positive communication and observe the stopping of equipment prior to entering the heavy vehicle operational area. Some operators have installed proximity detection to warn heavy vehicle operators of other vehicles entering the exclusion zone. Industry-leading best practice is for the proximity detection to stop the heavy equipment when persons on foot, or light and medium vehicles enter the exclusion zone.

References and further information

The Queensland Mines Inspectorate has published numerous safety notices concerning vehicle collisions or failures including the two below recently.

• Safety Alert 436: Rollover of large excavator while ascending ramp, published 20 October 2023.
• Safety Alert 434: Rear dump truck rollover, published 14 September 2023.

Safety Bulletin 162: Mobile equipment collisions, published on 21 June 2017, highlights mobile equipment interaction as a principal hazard in open cut coal mines. The recommendations in this bulletin remain relevant six years later. Sites must reduce the risk to be as low as reasonably achievable. Eliminate the hazard wherever possible.

Further alerts and bulletins on vehicle interactions can be found on the RSHQ website and in the Mining Hazards Database.