Rock burst led to investigation that revealed lacking communication plan
Mining company Vale Canada Limited has been fined $175,000 after pleading guilty to health and safety violations that were discovered after two workers were injured on the job.
The incident happened in August 2020 while two Vale employees were working on a construction ramp in the underground section of the mine in the Town of Garson, which is part of the City of Greater Sudbury.
The Ministry of Labour, Immigration, Training and Skills Development says the workers were bolting a large steel screen to a section of rock face and were in the process of unloading addition screening to finish the task when they experienced a rock burst, “a seismic event occurred in the rock pillar behind the rock face.”
Rock was ejected, hitting and injuring the workers. One of them was critically hurt. The ministry investigation discovered the cause of the rock burst was caused by “the existence of an undiscoverable angular plane in the rock that could not have been detected by Vale or its ground control engineers.”
Even though the cause of the rock burst wasn’t preventable, the investigation revealed more rock was being removed with each round of ramp construction than what had been modeled on survey prints. The changing conditions were not being communicated to Vale’s ground control engineers.
“Although these factors did not contribute to, and could not have prevented the rock burst, the Ministry determined the Company program lacked specifics as to the kind of information that workers should be communicating to their supervisors, and in turn, Vale’s ground control engineers.”
The Mines and Mining Plants Regulation requires a written program to provide “timely communication of information between workers and supervisors in the mine respecting ground stability, ground movement, falls of ground.”
Vale failed to ensure this regulation was implemented.
