A Discussion on Design Fires for an Example High-Speed Railway Train Car

High-speed rail systems are expanding everywhere for carrying thousands of passengers every day. Train cars in underground spaces travel under dense urban areas, tunnels in mountainous places and bridges across rivers. Design fire in burning a train car should be studied carefully for fire hazard assessment in those long underground or enclosed spaces. There are full-scale burning testing results on the main combustibles including seat, curtain and passenger luggage in some train cars. The heat release rate of a high-speed train car model CRH1 will be studied using such data together with a two-layer fire zone model, the Consolidated Model of Fire and Smoke Transport (CFAST). Simulation will be performed on the full-sized train car with the heat release rate of the seat measured by experiment. Two fire scenarios with ignition points located in the front and rear areas of the train compartment are considered. The results of the fire simulations show that the heat release rate can reach 43 MW. The value is similar to the full-scale burning experiments on train cars in Sweden and South Korea. Active fire protection systems have to be seriously considered in those underground or enclosed areas.