Underground railway environment in the UK Part 2: Investigation of heat load

Underground railway systems can generate enough heat from their operations to raise tunnel and station temperatures substantially. This may result in passenger discomfort in warm weather conditions if the underground railway environment is not cooled. This part of the paper investigates the heat load in a generic underground railway network using a purposely-developed mathematical model. A theoretical analysis has shown that the major contributor of heat to the tunnel is from the braking mechanism and that for the train carriage is from the passengers. The model has shown that additional cooling to the existing rolling stock may be provided by cooling the tunnels within which they operate.