Full-Scale Burn Test of a 1992 Compact Pick-up Truck 2013-01-0209

A full-scale burn test of a 1992 compact pick-up truck was conducted to evaluate how temperature distributions changed over time, the manner in which the fire spread, and how burn patterns produced during the fire correlated with important characteristics of the fire such as the area of origin. After the fire was initiated on the lower portion of the dashboard of the test vehicle, it spread locally to nearby dashboard material and, at the same time, developed a strong temperature gradient from the ceiling to the floor. Once the ceiling temperature reached about 600°C, the rate of fire spread increased and, within 1 minute, the passenger compartment was fully involved. Initiation of the engine compartment fire, which occurred about 4 minutes after the passenger compartment was fully involved, was consistent with fire spread through the heating, ventilation, and air conditioning (HVAC) duct that passed through the passenger's side of the bulkhead. Instead of spreading to nearby combustibles on the passenger's side of the engine compartment, the fire spread to the driver's side of the engine compartment, along the bulkhead. This fire movement was likely associated with the wind from the passenger's side towards the driver's side of the vehicle. The fire then spread upwind to the passenger's side of the engine compartment, where the peak temperature occurred in an area of relatively high fuel load. The burn damage to combustible material that remained after the fire was extinguished was consistent with the area of origin being within the passenger compartment. However, melt damage to aluminum components and oxidation patterns on steel surfaces did not correlate with the area of origin.