Worldwide, the mining industry continues to work long hours to fulfil intense operating schedules. As a result, much of today’s heavy duty mining equipment is in use almost 24/7.

Operating in an extremely challenging environment; with extensive vibration, prolonged vehicle use and excessive dirt and dust all increasing overheating risk, heavy duty mining vehicles are inevitably prone to elevated fire risks.

Holger Pfriem, managing director, Dafo Asia, and business manager, Dafo Vehicle Fire Protection, discusses the different fire risks associated with heavy vehicles at mines, particularly as technology continues to evolve. He also explores how mine operators can maximise safety and minimise downtime.

What’s influencing fire risk?

Although a mine’s specific risks will be highlighted in its individual risk assessment, there are some common risks that need to be addressed to ensure the safe operation of heavy equipment at mines.

  1. Overheating

On busy mining sites, it can be more complicated to maintain clean engine compartments for vehicles and machinery at all times, as operations naturally generate excessive dust and dirt, which builds up over time. However, it’s important that this is monitored and controlled effectively to reduce risk of overheating.

Although overheating on its own doesn’t necessarily constitute fire risk, when combined with other factors, which may be caused by equipment wear and tear over time – such as loose cables and sparks, or damage to a diesel-engine vehicle’s injection pipe – that overheating can significantly accelerate fire risk.

Overheating is inevitable for mining equipment, but controlling it is critical to prevent larger problems that increase fire risks.

  1. Electrification

The adoption of electric vehicles and machinery on mining sites is increasing significantly in line with global sustainability targets.

Although arguably less prone to overheating, electric vehicles (EVs) bring about a different kind of fire risk, which stems from the lithium-ion (li-ion) batteries that are often used to power them.

Li-ion battery fire risks occur for four main reasons:

  • Over/under charging
  • Mechanical influences or failures
  • Exposure to heat
  • Production issues.

Each of these issues can cause an internal short-circuit within the battery, which will often lead to a process called thermal runaway. In thermal runaway, a battery will experience rapid temperature rises, which can quickly result in fire, hazardous gas emissions (eg carbon monoxide), as well as large explosions.

Before temperatures begin to rise, a short-circuiting battery will vent toxic gases, as a precursor to thermal runaway. Detecting thermal runaway at this point is critical to controlling risk, and that requires a unique protection solution – as traditional detection systems will often only identify thermal runaway once temperatures have started to climb.

  1. Automation

Accelerated by the pandemic, automation of mining vehicles and machinery is at an all-time high, enabling continuous operations, reducing health risks associated with mine working conditions and also improving operational efficiency.

Although a significant technological leap forward for mines, vehicle automation does adjust fire risks. For example, with vehicles operating independently, further from mine personnel, it can be more challenging to detect fire risk quickly and implement the necessary preventative actions.

This is seeing a growing requirement for automatic detection and suppression solutions, which can detect and respond almost immediately to suppress risk, decreasing downtime risk, as well as limiting damage to the vehicle and surrounding valuable assets.

How can operators reduce risks?

There are several key steps operators can take to reduce the different fire risks associated with heavy vehicles and machinery, including:

  1. Understanding the risks – through a comprehensive risk assessment.
  2. Reconsidering the risk assessment map as processes, equipment and technology changes.
  3. Selecting the right detection system that addresses the site’s individual risks.
  4. Understanding li-ion battery chemistry to select the best protection solution.
  5. Choosing the right suppression agent for the given application.
  6. Minimising false activations by ensuring systems are compatible with vehicle technology.
  7. Protecting all equipment – eg both combustion-engine vehicles and EVs.
  8. Ensuring regular maintenance to keep systems operating effectively.
  9. Training key personnel, so they know how to respond in the event of a vehicle fire.
  10. Considering the site as a whole, including how new vehicles and machinery will operate in context.

Effectively suppressing a mining site’s fire risks is about developing tailored solutions to address individual risks. In turn, this will maximise safety and minimise operational downtime.