PURPOSE: To allow an explosion-proof travelling car to travel for a long time without time limit by supplying oil pressure, namely, energy beyond the scope of explosion-proof through an oil/light-composite cable to the explosion-proof travelling car body travelling in a dangerous area.

CONSTITUTION: A hydraulic electric generator 2a is loaded in an explosion-proof travelling car 1, while a controller 3 and an oil pressure generating device 4a are arranged on the outside of a dangerous area, and connected to the explosion-proof travelling car body by an oil/light-composite cable 5a. The oil pressure generating device 4a generates oil pressure as energy beyond the scope of explosion-proof to send the oil pressure through the oil/light-composite cable 5a to the hydraulic electric generator 2a, and the hydraulic electric generator 2a converts the oil pressure into electricity as power energy. The explosion- proof travelling car body 1 is remotely controlled by the controller 3 through an optical fiber in the oil/light-composite cable.