Experimental study on tire fire penetration into a motorcoach passenger compartment

Two full-scale fire experiments were conducted to determine the mode of penetration of a tire fire into the passenger compartment of a motorcoach. A special burner was designed to imitate the frictional heating of hub and wheel metal caused by failed axle bearings, locked brakes, or dragged blown tires. For the first experiment, heating to obtain tire ignition was initiated on the exterior of the passenger side tag axle wheel and for the second, on the exterior of the passenger side drive axle wheel. Measurements of interior and exterior temperatures, interior heat flux, and heat release rate were performed. Standard and infrared videos and still photographs were recorded. Both experiments showed that the tire fires ignited the plastic fender and glass-reinforced plastic exterior side panel (below the windows) upon which the fires spread quickly and penetrated the passenger compartment by breaking the windows. Measurements showed that other potential fire penetration routes (flooring and lavatory) lagged far behind the windows in heating and degradation. Copyright (c) 2012 John Wiley & Sons, Ltd.