The death of an experienced load operator who plunged down an underground stope at a Goldfields mine has prompted a WA coroner to recommend the use of physical barriers in all underground mines to manage the hazards of open holes.
Wayne Lance Ross, 45, died from multiple injuries when the underground loader he was driving fell 25m down an underground stope at BHP Billiton Nickel West Perseverance nickel mine near Leinster in April 2010.
Mr Ross was a competent and experienced loader operator. The inquest last month investigated how the loader fell and what could have been done to prevent the accident.
In findings published this month, Coroner Barry King ruled Mr Ross' death an accident.
Mr King said Mr Ross had gone to the top level with instructions from his supervisor to check and prepare it for a survey of the stope - a vertical void between levels. Mr Ross had assessed his task as low risk and not out of his normal scope of work.
He said it appeared Mr Ross may have understood his instructions were to place a "bund of rock material" at the edge of the stope if one was not already in place.
Mr King said given the supervisor knew a bund was not required for the survey, it was unlikely he instructed Mr Ross to construct one at the edge of the stope.
"He (Mr Ross) may have considered that his instructions, as he understood them, authorised him to operate his loader past the position of the bollards, but any conclusion would be speculatory at best," Mr King said.
Mr King said poor visibility and "possibly due to the bend in the drive and an illusion caused by the appearance of the far edge of the stope", Mr Ross failed to stop in time to prevent his loader dropping into the stope.
Nickel West filled in the stope and stopped mining at the orebody after Mr Ross' death.
Open-stope mining is common in WA, with about 35 operational mines using some form of the method, Mr King said.
Mr King said a procedure had been implemented at Nickel West's Cliffs Mine where bunds or hard barricades were always put in place before voids were created.
He recommended that mine operators, where possible, manage the hazards by using physical barriers to prevent equipment from getting near the edge of open holes.
A spokeswoman said BHP Billiton would reflect on the findings and would continue its focus on operating safely. "We remain deeply saddened by the loss of Wayne Ross, a father, friend and workmate," she said.