A mine worker learnt the hard way to check depth before entering water bodies.
Authorities recently examined how a dozer became partially submerged at a coal operation in Central Queensland’s Isaac region.
Investigators found night-shift employees had failed to inform day colleagues three metres was excavated from the pit floor in front of the coal rib. The slope was raised as the water level increased with a bund installed. This was intended to manage a water ingress into the work area that was contained by a solid coal rib.
“Before the day shift started the edge created by the change in cut height was completely concealed by water,” Resources Safety and Health Queensland’s coal inspectorate said in a safety notice.
“The day shift dozer operator walked the bulldozer through the bund and entered the body of water. As the machine walked further towards the back of the pit it fell off the water covered edge that had been created by the night-shift mining activities.”
The following recommendations were made:
- conduct local area hazard management (SLAM/TAKE 5)
- handovers insufficiently covered the changes in conditions and new hazards
- geofencing was not a control practiced at the mine for tasks of this risk profile
- suspending mining and installing water pumps could have mitigated the water hazard
- better train staff in standard operating procedures for edges and working near water bodies
- GPS units were not regularly programmed with locations of trenches, sumps and other hazards
- stay aware of changing environmental conditions including water and hazards then stop to reassess risks
- edges created by floors cut at different levels were a hazard that had to be appropriately reported, controlled and managed
- safety and health management system (SHMS) procedure knowledge was too limited for working around bodies of water even though after workers were trained
- photos and other shift task documents used at the pre-shift meeting inaccurately reflected water levels, changes in the coal floor level and other pit conditions.
Site senior executives were urged to:
- implement engineering systems that help identify trenches, sumps and edges such as GPS-enabled mobile plant
- implement geofencing capabilities on operational mobile plant and ensure it is used and updated appropriately
- edges of all heights present more risk when concealed by water and/or the angle, colour and presentation of the ground
- ensure operators are sufficiently trained in and comply with all SHMS requirements for edges and working near bodies of water
- identify all operational areas containing edges with a vertical drop of one metre or more
- and adopt appropriate control measures
- review systems for dealing with different level surface cuts (including trenches and sumps) that may seem to be level and flat
- review systems for dealing with bodies of water or other liquids at the mine including storage and water ingress to pits and working areas.
