Fire Safety Science Digital Archive

Full-scale experiments of automobiles fire were carried out to develop a design fire source for structural fire resistance design of car park buildings. Tested vehicles include five four-doors sedans. Each vehicle was tested one by one. Side windows on drivers and attendant seats were left open at about 10cm width. Driver’s seat was ignited by a cloth dipped with methyl alcohol. An open-air test and four calorimeter tests were carried out. In all of the tests, radiant heat flux was measured at neighboring positions of front, rear and sides. Burning behavior were observed by eye and recorded by videotapes. In calorimeter tests, tested vehicle was put on a loading table to measure mass loss rate. Heat release rate was measured by oxygen calorimetry. After ignition, fire spread rapidly to front part of cabin. Soon after that, fire spread toward engine room. Then fire spread to rear part of cabin and to trunk room. Finally front and rear bumpers burned. Total fire duration was about 40~80 minutes. Peak heat release rate were 3 to 4MW. The result shows that total burning duration is proportional to body weight of vehicle. Burning duration of internal parts and time to fire spread to adjacent parts also have correlation with body weight. Height of flame ejected from windows, from front grill or from trunk depends on body weight as well. On the other hands, height of flame from burning tires and bumpers did not vary significantly with body weight. Total heat release rate could be expressed by the sum of cabin and external combustion. HRR of cabin combustion is correlated by ventilation factor of vehicle window openings (ventilation- controlled burning). Peak HRR of external combustion is almost constant regardless with body weight.