An Analysis of the Effects of Ventilation on Burn Patterns Resulting from Passenger Compartment Interior Fires

Vehicle fire investigators often use the existence of burn patterns, along with the amount and location of fire damage, to determine the fire origin and its cause. The purpose of this paper is to study the effects of ventilation location on the interior burn patterns and burn damage of passenger compartment fires. Four similar Ford Fusion vehicles were burned. The fire origin and first material ignited were the same for all four vehicles. In each test, a different door window was down for the duration of the burn test. Each vehicle was allowed to burn until the windshield, back glass, or another window, other than the window used for ventilation, failed, thus changing the ventilation pattern. At that point, the fire was extinguished. Temperatures were measured at various locations in the passenger compartment. Video recordings and still photography were collected at all phases of the study. Although the fire origin and source were known, the vehicle burn patterns were analyzed and conclusions drawn based on the post-fire evidence regarding: ability to determine a window was open during the fire, which window was open, the effect the open window had on burn patterns and burn damage, and the ability to determine the fire origin. Thermocouple readings were plotted and analyzed post-test to study temperature characteristics during the burn tests.