A split hydraulic pipe leaking fluid onto the engine of the truck engine has been identified as the cause of the underground fire at Newmont Waihi Gold which left 28 miners trapped in refuge chambers.
The Ministry of Business Innovation and Employment investigation into the underground fire in the Martha Mine in July reports a split in the hydraulic line consequently spraying oil into the exhaust caused the fire.
The entrance to the underground Waihi mine that caught fire.
The 30 tonne Komatsu mining truck caught fire near the entrance to the mine at about 5am on July 17. A total of 28 miners took refuge in underground chambers and were evacuated to the surface uninjured by midday.
The Ministry of Business Innovation and Employment have now completed their investigation and are satisfied with their decision, but Newmont Gold’s own investigation into the incident and their response continues.
Newmont Waihi Gold Communication Advisor Linda Willoughby says the underground truck fire, combined with heavy rain and floods, have impacted Newmont’s activities in the last few weeks.
“We have bounced back to routine though,” says Linda.
“The Ministry of Business Innovation and Employment (formerly the Department of Labour) investigation into the underground truck fire is complete and our own Newmont investigation is almost finished.”
The initial finding is that the fire was caused by a split hydraulic line spraying oil onto the engine exhaust.
The report found the oil spraying into the exhaust ignited causing a flashback to the source of the oil which then also caught fire.
The driver, who noticed smoke coming from under the bonnet, was immediately evacuated to the surface while the miners then took refuge in three separate refuges with eight men located in one, five in another and a further 15 in the third.
The miners, some of which are contractors working in the mine, were just about to finish their night shift, after starting work at 7pm the previous evening when the truck caught fire and they were forced to use the emergency pods.
Newmont Waihi Gold General Manager Glen Grindlay says only one miner needed medical attention for smoke inhalation.
Glen is satisfied that the rescue efforts were timely and undertaken in the proper manner and says at no time was there any danger of any explosion.
Glen says the refuge chambers are of varying sizes and have air, water and first aid supplies, while the miners wait until given the all-clear.
The mine was closed while the investigation was carried out.
Glen says while it is unusual for a truck to catch fire it was not unheard of.
The crew caught in the drama had undergone a safety drill around four days prior to the incident and Glen says some thought this fire was another drill.
Newmont Gold Waihi operates under New Zealand mine safety standards and the more stringent Australian standards, says Glen.
Newmont Waihi Gold is owned by Newmont Mining Corporation which is based in Denver, Colorado.
The company manages the Martha, Favona and Trio mines in Waihi.