A near miss incident involving a mortar used to fire impact sensitive explosive charges has occurred after two operators were asked to set up and arm a 2.2 kg mortar device, according to the Western Australian Department of Consumer and Employment Protection (DOCEPWA).
The mortar device became armed in a draw point for firing at the end of the day shift and had become blocked by large rocks that required an explosive charge to remove them, according to a safety alert from DOCEPWA.
“As a result of a preliminary assessment undertaken by an operator, it was apparent that the explosive booster prematurely detonated inside the mortar barrel upon initiation of the propelling charge,” according to a safety alert from DOCEPWA.
The DOCEPWA alert said the likely cause of this particular incident was found to be a misaligned well in the centre of the plastic tailfin used to mount the impact fuse assembly and hold the booster charge.