The Passive Fire Protection of Mining Vehicles in Underground Hard Rock Mines

Vehicle fires in underground mines pose a certain risk for which measures to prevent or mitigate the fires are highly important. This paper presents a study on passive fire protection measures to counter this risk, where data from full-scale fire experiments, cone calorimeter tests and statistical studies were applied. It addressed an overall question: what passive fire protection measures could be implemented with respect to the design of mining vehicles? Relying entirely on one type of passive measure may only be adequate for a specific stage of a fire and additional measures may be warranted for the other stages. Threshold distances for fuel components were calculated, and it was found that the combination of hydraulic hoses and electrical cables resulted in larger threshold distances, contributed to by the higher flame heights of the hydraulic hoses and the lower critical heat flux of the non-fire-resistant electrical cables. A pool fire along the underside of the vehicle will pose a certain risk, and passive fire protection measures should be focused at ignition prevention, making high demands on the insulation/shielding along the underside. Tyre fires could be prevented by steering the flow of flames and fire gases away from the tyres. An increased knowledge of such possible passive fire protection measures would improve the fire safety in underground mines.