The NSW resources regulator recently released a safety bulletin for the NSW mining industry, following an increase in the number of reported incidents involving tracked dozers.
The incidents occurred in a range of different circumstances and there have been several incidents in which machines have overturned.
In each case, the operator was placed at risk of suffering serious injuries.
In the first incident, a dozer operator was instructed to relocate a bund wall in a quarry. As the operator began the first push, the dozer slid sideways and rolled onto its side.
In the second incident, a dozer was working on a stockpile and sunk into a void, after two of the three valves had formed open voids.
The operator had identified that coal had been drawn from the stockpile and that the voids were a hazard.
The operator then proceeded to push across the top of the third valve and sunk into the hidden void.
In the third incident, a dozer operator was pushing coal on a stockpile at night.
It had been raining, several lights were out and the coal was identified as sticky.
The operator had finished several pushes to the valve when he climbed on top of the material and started to push. The coal slumped, rolling the dozer.
In the fourth incident, an operator was working to build a ramp during night shift.
The dozer was working at a 45-degree angle to a previously cut slot.
The dozer was tramming back towards the slot and watching the right-hand track.
The left-hand track travelled over the edge and the dozer slid down the 6.5 metre drop into the slot and rolled onto its side.
Subsequent investigations found there were a number of contributing factors across the numerous incidents reviewed:
· Failure by the machine operators to adequately assess the area before starting work
· Machine operators failing to manage the risks identified in the work area
· Poor lighting, reducing operator visibility
· Supervisors failing in their duty to oversee work
· Machine operators not adequately trained for the task or environment in which they are operating
· Incorrect methods used to ascend/descend slope.
The safety bulletin recommended that mine operators should:
1. Confirm that all reasonably foreseeable operating conditions and practices have been assessed in the operational risk assessment for dozer operations; that the controls identified have been implemented, and they are monitored for effectiveness on an ongoing basis.
2. Review training and assessment material to determine it adequately covers hazards and controls identified in operational risk assessments
3. Conduct pre-task inspections of work areas to identify and manage the hazards present. This practice must be monitored and confirmed by supervisors.
4. Require that ground implements (blades and rippers) are kept as low to the ground as possible during operation, particularly when operating on uneven surfaces.
5. Provide adequate lighting for operation at night
6. Schedule supervisors to conduct routine inspections and task interactions with equipment operators
7. Review stockpiles to confirm that valve locations are easily and readily identifiable for operators
8. Review MDG 28 safety for stockpiles and reclaim tunnels when reviewing the controls necessary to operate dozers on stockpiles.