Fire Spread

Fire spread is a very important issue during fires in tunnels. The elongated geometry of a tunnel with a relatively low ceiling height can cause the flames and hot gases to extend long distances along the ceiling, increasing the risk of fire spread. The use of ventilation in the tunnel as well as different types of vehicles, commodities and materials influences the fire spread. This chapter contains both a summary of traditional ignition and fire spread theory and experience especially related to situations in tunnels with risk for fire spread. Different aspects of spread and burning of liquids are presented and discussed.