Coal Inspectorate | Bulletin | No.213 V 1 | 15 August 2023

Dozer rollovers

What happened?

Resources Safety and Health Queensland is cracking down on Queensland coal mines that are failing to protect workers from dozer rollover incidents. The industry’s independent safety regulator will be targeting mines and suspending operations when the risk is not at an acceptable level, after noticing an increase in bulldozer rollovers, including two in the past week. There have been 19 dozer rollover incidents from January 2022 to August 2023.

August 2023 incidents

Incident 1

On 7 August 2023 a Coal Mine Worker (CMW) in Blackwater was required to push high waste material down using a CAT D11T Dozer to allow for the safe excavation of material using a large hydraulic excavator. Prior to executing the task, the work area inspections had not identified the hazards present which included an over-steepened excavated face on the high wall, the substandard berms in place, and the steps required to safely complete the task (refer to Figure 1).

Incident 2

On 8 August 2023, a CMW in Isaac Plains was in the process of marking out the dig limits for an excavator double benching in the area with a CAT D10T dozer. The coal mine worker identified the area had no edge protection berms in place and did not manage the risk associated with this hazard. While reversing towards the edge, without the edge protection berm, the dozer has breached the open edge and rolled approximately 110 degrees to the bottom of the slope (refer to Figure 2).

Dozer rollovers from 2022-2023

• On 5 January 2022 at the Curragh open cut mine, a bulldozer came to rest at a lean when the bench it had been working on failed. The operator of the vehicle did not sustain injuries.
• On 16 January 2022 at Lake Vermont open cut mine, whilst being operated in remote control mode, a bulldozer reversed over a bund. The vehicle rolled onto its roof. The operator of the vehicle did not sustain injuries.
• On 28 January 2022 at the Saraji open cut mine, a bulldozer tracked beside a heaped pile of dirt. The operator failed to identify a large rock on the right-hand side of the bulldozer’s blade. The vehicle travelled up the rock and slowly tipped, landing on its side. The operator of the vehicle did not sustain injuries.
• On 7 May 2022 at the Lake Vermont open cut mine, the operator of a bulldozer was loading a train from the stockpile at the CHPP. Whilst reversing down a ramp that had been pushed, the left-hand side of the ramp gave way causing the vehicle to slide down, coming to rest on its side. The operator of the vehicle did not sustain injuries.
• On 6 June 2022 at the Byerwen open cut mine, a bulldozer was slot pushing. While reversing back up the slot, the vehicle slid and rolled into the adjacent slot coming to rest on its side. The operator of the vehicle did not sustain injuries.
• On 24 June 2022 at the Foxleigh open cut mine a bulldozer was being used to prepare an excavator bench. It reversed over a safety rill resulting in it rolling over. The operator of the vehicle did not sustain any injuries.
• On 30 June 2022 at the Middlemount open cut mine, a bulldozer was working on a rehabilitating contour drain. The vehicle trammed onto a rock while compacting the batter. The operator exited the cab to discuss recovery options with his supervisor. Approximately 10 minutes later the vehicle tipped onto its side before it could be recovered. No injuries were sustained as a result of the incident.
• On 31 July 2022 at the Capcoal Surface coal mine (ex German Creek), a clean-up bulldozer was relocating at excavator face. The operator decided to walk through the roadway bund. The vehicle track climbed onto a large rock when exiting the bund causing the vehicle to topple. No injuries were sustained as a result of the incident.
• On 6 August 2022 at the Dawson open cut mine, a bulldozer was being used to undertake slotting work. As it reversed the left-hand track slipped into an adjacent slot resulting in the vehicle coming to rest on a precarious angle. The operator of the vehicle did not sustain injuries as a result of the incident.
• On 2 October 2022 at the Coppabella open cut mine, a bulldozer cleaning up an excavator bench reversed over the edge of the bench resulting in the vehicle rolling onto its side. The operator did not sustain any injuries.
• On 9 November 2022 at the Curragh open cut mine, a bulldozer reversed out of the bulk push area on uneven ground. The vehicle slowly rolled onto its side. The operator did not sustain any injuries.
• On 24 January 2023 at the Saraji mine a D11R Dozer spreading material across the drill pattern floor when the Dozer had reversed up the bund pivoting almost parallel to the edge before rolling down the batter coming to rest on its tracks the initial estimate of drop was 6-8m further investigation has raised this to 8-10m drop. Operator taken to hospital with suspected hip and rib injuries. Directive s170 given to hold scene.
• On 25 January 2023 at Commodore mine during dozer push operations in Creek Pit, 475 Dozer has moved in an uncontrolled way and slipped down the low wall batter.
• On 6 March 2023 at the Central Highlands mine, the operator was conducting rehabilitation as per site exit procedure on the D9 dozer pushing parallel to a 2-metre drop, the edge gave way and dozer rolled onto its side.
• On 25 April 2023 at the Newlands mine, an operator was working in the bulk push at ramp 15 trimming up rills before moving to another area. When reversing back to the top of the push the operator was looking over his right shoulder when the left-hand track has gone over the edge of a drop off and rolled onto its left-hand side.
• On 10 May 2023 at the South Walker creek mine, The Dozer operator had started reversing back for their next push on free dig material (dozer was on an angle in the push) they stopped the dozer due to excessive dust and lack of vision while parked the dozer has rolled onto its side. Position of lighting plant identified as possibly contributing to incident. No injuries reported by operator.
• On 27 May 2023 at the Peak Downs mine, a CMW was operating a dozer near the edge of the stockpile working on a bench approx. 8 to 10 metres above ground level when the bench has slumped, and the dozer has ridden the slumped coal to ground level then rolled onto its side.
• On 7 August 2023, a coal mine worker in Blackwater was required to push high waste material down using a CAT D11T Dozer to allow for the safe excavation of the material using a large hydraulic excavator. Prior to executing the task, the work area inspections had not identified the hazards present which included an over-steepened excavated face on the high wall, the substandard berms in place, and the steps required to safely compete the task.
• On 8 August 2023, a coal mine worker in Isaac Plains was in the process of marking out the dig limits for an excavator double benching in the area with a CAT D10T dozer.  The coal mine worker identified the area had no edge protection berms in place and did not manage the risk associated with this hazard. While reversing towards the edge, without the edge protection berm, the dozer has breached the open edge and rolled approximately 110 degrees to the bottom of the slope.

Key issues

• Edge protection substandard or absent.
• Failure by the supervisor and machine operator to adequately assess the area for hazards before starting work.
• Failure to prepare the work area to ensure an acceptable level of risk.
• Supervisor and machine operator's hazard identification was absent or ineffective.
• Supervisors did not consider if the operator's training was adequate for the task.

Recommendations

All Site Senior executives should regularly audit:

• the Safety and Health Management System (SHMS) and ensure adequate edge protection is applied in all areas of dozer operation.
• the height and width of the edge protection berms that will prevent or reduce the likelihood of these incidents reoccurring.
• the effectiveness of supervisor's hazard identification and risk control skills and take corrective action when deficiencies are detected.