The passive fire protection of mining vehicles in underground mines
It is highly important to mitigate vehicle fires in underground mines to prevent or mitigate the fires from happening in the first place, since the environment is so hostile and difficult to work in when the fire has already developed.
By: Rickard Hansen, CTIF Scientific Advisory Group
Vehicle fires in underground mines pose a certain risk for which measures to prevent or mitigate the fires are highly important.
Fire protection measures can be divided into active and passive measures, where the former require an external power to work in the event of a fire and passive fire protection measures could include an existing partition preventing fire spread.
As passive fire protection does not rely on activation, it is expected to provide high reliability, a robust solution, and should be considered during the design process. This article investigates passive fire protection measures that could be implemented with respect to the design of mining vehicles (a generally overlooked field). Different vehicle sections and fuel items are analysed, applying data from full-scale fire experiments, cone calorimeter tests as well as statistical data.
Earlier work on fire protection of mining vehicles and heavy-duty vehicles in general was limited, focusing mainly on active fire protection systems. In the few publications found where passive fire protection on vehicles was investigated, this is mainly aimed at the post-collision scenario with an ensuing fire. Fire protection measures on a passenger car or a bus above ground will be aimed at ensuring the safe evacuation of passengers. Fire protection measures on a mining vehicle may also be aimed at mitigating the effects on the surroundings, allowing for a safe evacuation of the affected part of the mine or enabling a firefighting operation.
The presented passive fire protection measures of the article include for example the application of threshold distances (hydraulic hoses and electrical cables), insulation and shielding of fuel items (engine bay, hydraulic hoses, etc.), the steering of flames and fire gases (tyres), fire-resistant sealings (engine bay, wheelhouse, etc.), fire-resistant materials (engine bay, tanks, etc.) and reposition or mechanical protection (engine bay, tanks, etc.).
Furthermore, it was found that passive fire protection should include the use of several measures simultaneously to ensure fire protection throughout the different phases of a fire.
Several risks are addressed in this article, yet there are additional risks which should be investigated in any future work. These include, for example, the alternative types of fuel seen on mining vehicles or the risk when refuelling a vehicle.
By: Rickard Hansen
For the Sustainable Minerals Institute, University of Queensland
Brisbane QLD 4072, Australia
Photo & Video Credit: Björn Ulfsson / MSB.se. Full scale fire test with a mining vehicle in a mine, performed by Rickard Hansen.