To surely bind and fix a fire extinguishing hose car having a low axle shaft and also to surely bind and release even if a locking member is damaged by moving back and forth of the hose car.

A receiving member 12 having a receiver 13 for receiving an axle shaft 11 of a hose car from back side is installed on a loading plate 7 and a locking member 15 capable of closing an opening 14 at a lower revolving position and opening at an upper revolving position is mounted as freely rotatable on the receiving member 12. The locking member 15 is fixed towards a close direction always by an elastic member and an automatically releasing mechanism 21 is mounted on the locking member 15, the opening 14 is released by automatically revolving upper the locking member when the load plate 7 is lowered.