Supporting Technical Assessments

Resources Safety 100 Plain Street EAST PERTH WA 6004 Department of Consumer Email: [email protected] Phone: + 61 8 9222 3333 and Employment Protection Website: www.docep.wa.gov.au/ResourcesSafety Fax: + 61 8 9325 2280 Mines Safety Bulletin No. 75 Date: 10 January 2006 Subject: Fire and explosion in a working party magazine This bulletin is issued following extensive investigation, technical review and test-work relating to a fire and subsequent explosion that occurred in a working party explosives magazine underground at a mine with sulphide mineralisation during 2005. Incident At about 5.45 am, a fire behind the locked gates of a working party magazine was observed by underground personnel who were passing the area. Attempts were made to put out the fire using Dry Chemical Powder (DCP) fire extinguishers, but these attempts were unsuccessful. It was estimated that in excess of six tonnes of explosives and between 1,500 and 3,000 detonators were stored in the working party magazine at the time of the fire. Five people were able to escape from the mine through the decline portal entrance while a further 22 personnel, who were unable to use this means of egress, travelled to fresh-air bases and refuge chambers underground where they were all accounted for. Once accounted for, the personnel were moved to the shaft plat in preparation for evacuation from the mine. Delays occurred in evacuating personnel through the shaft, as it was in transition from shaft sinking to equipping the production winding system. This necessitated the completion of a risk analysis so that the sinking kibble could be safely used for the evacuation of personnel. About two hours after the fire was identified an explosion occurred which knocked out the underground communications. The explosion also stopped two surface fans for a brief period until they could be restarted. Injuries Four people in the vicinity of the working party magazine, who attempted to fight the fire, suffered smoke inhalation. No personnel suffered any serious injuries during the emergency evacuation from underground. The potential for serious consequences is, however, obvious. Causes The cause of the ignition in the magazine was not determined with certainty due to the damage sustained. However, the following contributory factors were evident as a result of investigation, technical review and testing:

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