According to the NSW EPA, more than 200 trucks catch fire every year in NSW with many being avoidable. A truck fire can cause a significant disruption to a transport business, local government and road users. The cargo may be destroyed and the fire often results in the loss of the truck which is hard to replace quickly in 2022.
Many truck fires are preventable. Factors that may cause fires can be identified and eliminated before the vehicle takes to the road and/or can be identified by the driver before or during a trip. So the NSW EPA has released checklist to help everyone in the supply chain takes steps to identify potential fire hazards.
The EPA NSW checklists come from experience of heavy vehicle fires in Australia. They represent
the accumulated knowledge of vehicle-fire investigators.
The sources of heat that can occur on a heavy vehicle and which need to be mitigated are:
- Electrical
- Exhaust
- Brake
- Friction
- Chemical.
Combustible materials can react with oxygen when heated without catching fire. The materials often darken, which indicates that chemical changes are occurring without sufficient release of energy for the material to reach the unpiloted ignition temperature. Oxidation of fuel without flame is called pyrolysis.
Pyrolysis will occur at the fringes of a fire where the temperature is not yet extreme but where the material properties of combustible matter are changing.
Signs of pyrolysis should never be ignored. Inspection for fire risk is intended to identify signs of pyrolysis. Such signs should never be ignored and must be resolved. The vulnerable locations are close to heat sources (such as the exhaust pipe or electrical terminals).
Pyrolysis introduces carbon into the situation. Carbon can conduct electricity so pyrolysis can be the first stage in the breakdown of electrical insulation.
The smell or sight of smoke should never be ignored. It is a sure sign that pyrolysis and maybe flame exists. If smoke is smelt, seen or anticipated, the situation must be resolved.
Note: The engine block does not reach the auto- ignition temperature of hydrocarbon fuels (diesel and oil) likely to be found in the engine compartment. The exhaust pipe does.
