The sub-contractor was on-site at the quarry to undertake drilling operations, but hadn?t been signed onto the pre-blast checklist.
The explosives company that had been employed to conduct the blasting had loaded the drill holes, with the shotfirer unwinding the bellwire to a point 150m from the blast site.
Workers then worked through the checklist, gave the all clear and sounded the blast siren. After a final visual check and a last radio communication, the shotfirer detonated the blast. Unknown to him, however, the drilling sub-contractor had returned to the drill rig, only 20-30m from the blast site. Incredibly, he was unharmed.
According to the Workplace Standards Tasmania, the incident occurred because of a number of oversights. Primarily, the driller had not been signed into the quarry entry point, partly because traffic management plans and exclusion zones were inadequate. Likewise, the shotfirer commenced the blast preparation procedure before ensuring all personnel were outside the exclusion zone. Problematically, it was the explosives company that communicated the ?all clear? and ?OK to proceed?, not the quarry as required.
While the sub-contractor was lucky to survive the incident this time, had things gone differently, the company could have been liable for three years? imprisonment and a $780,000 fine, along with the tragic consequences of a loss of life.
? Source: Workplace Standards Tasmania