The vehicles do not explode, for one thing, and it takes 5 or 10 minutes before the fire or smoke reaches the passenger compartment. So there is normally enough time to take some initial action before the rescue services arrive.
Analyses of real accidents with subsequent fires show that after a crash the fire generally starts in the engine compartment and spreads toward the passenger compartment. Fires are mostly caused by fuel or oil escaping, coming into contact with hot parts of the vehicle and then igniting. Short circuits in wiring looms can also cause fires.
In order to obtain more detailed information about how fires develop, the UDV (German Insurers Accident Research) took part in a series of fire tests carried out by DEKRA Automobil GmbH in November 2008. The aim of these tests was to reconstruct real accident scenarios as far as possible and examine how fires actually develop. In addition, comparisons were to be drawn with the findings about how fires develop in vehicles not involved in accidents.
- How a fire develops after an accident, particularly the speed at which it spreads, depends on many factors (such as the amount of fuel or oil that escapes or the weather conditions at the accident location). Despite that, however, it is possible to make the following general remarks:
- The fire spreads relatively slowly in the first few minutes so that it takes 5 to 10 minutes for the smoke and flames to reach the passenger compartment.
- The fuel tank does not explode because it is designed in such a way as to allow excess pressure to be released in good time.
- There is no essential difference in how a fire develops in a vehicle involved in an accident as opposed to one that has not been in an accident.
After an accident with a subsequent car fire, it generally takes a few minutes for the fire service to arrive after an emergency call is made, assuming the accident has been noticed in good time. In these valuable first few minutes, first aiders can generally take action safely. This includes both rescuing the occupants from the vehicle and extinguishing the fire, provided there is a fire extinguisher to hand.