In August 2016, two shotfirers were attempting to initiate an open pit blast with a remote firing device (RFD). After two failed a tempts, it was decided to manually fire the shot using a stomper (manual initiation device).
The shotfirers rolled out detonating cord from the blast site to the firing position on the waste dump, located outside the blast excl sion zone. A long-period delay detonator (LP detonator; 3.6 m lead, 9.6 sec) was connected to the stomper.
On the first attempt the stomper’s shot-shell failed. On the second attempt the shot-shell fired, but when the detonator did not fire i stantly one of the shotfirers thought the detonator had failed. The shotfirer cut the detonating cord below the detonator and picked up the detonator (and attached cord) to discard it. At this point the shotfirer realised it was a LP detonator and dropped it – a few seconds before it fired, initiating the attached detonating cord.
Without reporting the incident to the quarry manager, the blast crew proceeded to fire the shot manually after sunset, with a new LP detonator. Fortunately, there were no serious injuries or fatalities.