TUNNEL DISASTER PREVENTING SYSTEM

PROBLEM TO BE SOLVED: To provide a tunnel disaster preventing system by which the number of power lines to be connected to automatic water spraying valves is reduced and also the number of disconnection and short-circuit monitoring circuits is reduced. SOLUTION: One of the two power lines to be respectively connected to a plurality of automatic water spraying valves 41 -4n is mutually and commonly connected with the other so as to be adopted as one common power line 21c, the whole other power lines 221 -22n are made to be optionally selected and a driving power source for driving the automatic water spraying valves is supplied to the common power line 21c and the optionally selected power line with open/close relay 12 and a starting relay 11. The common power line 21c and the optionally selected power line are connected to one disconnection and short-circuit monitoring circuit 10 so as to monitor the disconnection and the short-circuit of the selected power line.