The prevalence of fire-related incidents in Australian mines means it is high time we take a more careful look under the bonnet of the heavy machines that keep that sector running.
Fires can occur wherever there is significant heat and flammable materials but no more so than the equipment and vehicles that are vital to a mine’s operation. Heavy vehicles are significant risks due to the long hours they operate and the inevitable wear and tear of machinery and components.
Highlighting the risk of fires in mining equipment and vehicles becomes clear when we consider the potential domino effect of danger that threatens an entire mining site. An example of this occurred in 2018 in the Tritton Copper Mine, where 19 workers were trapped 900m underground after a haul truck caught fire within the mine’s main decline. The workers were forced into the refuge chamber and had to rely on the self-contained air supply with no communications. Fortunately, they were eventually evacuated without suffering any permanent injury. An investigation later determined that the fire was likely caused by the truck’s diesel fuel escaping the fuel system and contacting hot components in the engine compartment.1
Fire originating from heavy machinery can lead to further problems that exacerbate the situation, causing widespread operational damage and potentially loss of life. It is no secret that fire is still a major concern in the mines, making up most of the reported incidents across the country. New South Wales, for example, recorded 55 incidents involving fires on mobile plant in the third quarter of the 2020 financial year. This compared to 45 reported incidents in the 2020 financial year’s second quarter.2 In Queensland, the high potential incident (HPI) frequency rate increased in the 2019–2020 financial year by 3%, with reported incidents increasing in surface coal (up 7%), underground coal (up 16%) and underground mineral mines (up 24%) during the reporting year.
The Queensland Mines and Quarries Safety Performance and Health Report 2019–2020 stated that the most frequently reported HPIs for mines was fire on vehicles or plant.3
Mining conditions with harsh off-road operations can often cause pressurised oil and fuel lines to perish over time, or vibrations that cause components to become loose or leak. Other reported causes for vehicle or machine fires include alternator faults, jammed starter motors, overheated cables or frictional heat from rubbing against moving parts. Due to these ever-present risks, states provide a regulatory framework that requires suitable emergency procedures to handle fires, including the need for effective fire suppression systems. These systems are often required to be of suitable use and placed in the engine compartment of vehicles and machinery, and in other likely combustion compartments.4
With regulations in place and fires still prevalent, there are several important considerations when reviewing fire suppression systems:
- Non-restrictive installation: Fire suppression systems must be close enough to high-risk areas to suitably prevent fire danger. Much like Wormald’s Rotarex FireDETEC Compact Line Suppression (CLS) system, effective systems should comprise flexible sensor tubing, which can be installed directly above and around an engine to ensure maximum fire coverage.
- Early fire detection: Fire suppression systems and detection must suit the hazards present. It is important to review the temperature and direction that your fire suppression system operates.
- Suppression scale: Vehicular-based fires and other fires related to mining activities have a wide spectrum of causes and intensities. That is why suitable fire suppression systems must include the appropriate extinguishing agent delivered at the correct volume and temperature. Larger fires originating from larger machines, for example, are best suppressed by Wormald’s water-based firefighting foam products that cool flammable liquid fires and coat the fuel, preventing its contact with oxygen. Comparatively, Wormald’s Rotarex CLS system is suitable for fire originating on smaller machines, as it contains compact tube depressurisation that actuates the special pressure differential valve and instantly floods the entire engine compartment with FireDETEC TS55 extinguishing agent.
As fires remain a prevalent hazard to Australian mining, it is important to do all you can to mitigate the risk.
This includes taking the flammability of the haul into consideration and ensuring that any toxic, flammable or combustible materials are kept safely away from heat sources like turbo and exhaust systems. However, it is also vital to the safety of miners, equipment and the entire operation that appropriate attention is given to the systems in place to remove the danger if it ever arises.
For more information, go to wormald.com.au
- http://dmp.wa.gov.au/Documents/Safety/MSH_G PurchaseOperationMaintenanceOfUGDieselEquipment.pdf