The NSW Resources Regulator is investigating an unplanned explosion that occurred on an open cut coal mine in the state.
An excavator was excavating blasted waste material during a night shift when it struck an unexploded device. The operator unintentionally triggered the unidentified explosive, showering the area in flyrock.
Multiple pieces of flyrock struck the windscreen and body of the excavator, damaging the windscreen. Fortunately, the screen held and the operator’s cabin was not breached.
Rock from the explosion was scattered up to 63m from the dig face, damaging the side mirror of a nearby haul truck that was actively being loaded, and striking a dozer that was also operating in the area.
“The operator was not injured but this incident had the potential to cause serious injuries to the excavator operator and highlights that large amounts of energy are released when explosives are initiated,” the Regulator said.
“Every effort should be taken to identify and treat misfires, however it is still possible for misfires to go undetected until excavation activities are conducted.
“It is necessary to ensure that equipment used in excavating previously blasted areas is adequately designed and maintained to provide a high level of protection for the operators.”
Following the incident, the NSW Resource Regulator recommended that mine operators should:
- minimise the incidences of personnel on the ground or in unprotected cabins in proximity of mining activities in blasted ground
- review blast design processes to ensure that blast designs take into consideration any geological features, potential blast damage, priming and loading of explosives or other considerations that might contribute to misfires
- review explosives control plans to ensure that post-blast inspections are properly conducted to identify areas of potential misfires
- review explosives control plans to ensure any misfires that are identified are marked on dig/drill plans and are monitored until they have been completely excavated and cleared
- ensure equipment used for excavating blasted ground is suitable and able to withstand flyrock, over-pressure or other potential consequences of inadvertently initiated explosives, for example the use of hardened/laminated glass for operator cabins
- all shotfirers refamiliarise themselves with the requirement to take all reasonable steps to prevent misfires
- training excavator/dozer operators in identifying explosives and the risks associated with misfired explosives.