A water supply system, including water mains, fire lines or standpipes, is required to provide water for fire fighting within the tunnel through hydrants (Fig 1) or hose valves (Fig 2) and to possibly provide water for a Fixed Fire Suppression System if installed in the tunnel (see Section 6.3.3 "Water supply" of report 05.05.B 1999). The source of water can be from a water distribution system or from a water tank. The required system pressure must match the requirements of the responding fire brigade.
Hose valves are required within the road tunnel to provide a point of connection for the Fire Brigade to attach fire hoses and gain access to the water supply. Hydrants should be installed at regular intervals within the tunnel (see Section 6.3.3 "Water supply" of report 05.05.B 1999). The hydrant connections must be compatible with the responding local fire brigade(s).