PROBLEM TO BE SOLVED: To improve the transportation efficiency of materials and tools to a power transmission tower, and to shorten the period for the replacement and maintenance. SOLUTION: The required materials and tools are put into a transit vessel 1 and transported directly to the top of the power transmission tower 4 by hanging them on a rope 3 of a helicopter 2. The rope 3 is supported at its upper end to a main hook 5, arranged at the bottom of a fuselage of the helicopter 2 so as to be balanced with the hook, and attached at its lower end with a cargo hook 7 that operates integrally with a rotary actuator 6. The cargo hook is hung over to a shackle (connecting metal fittings) 8, to hang down the transit vessel 1. The shackle 8 gathers upper ends of four wires 9 into a single piece, and lower ends of the wires 9 are connected to four corners of the upper surface of the transit vessel 1. An insulating tube 10 that feeds air to the rotary actuator 6 is arranged along the circumference of the rope 3, and the rope 3 and the tube 10 are coupled at their middle points by a swivel (rotating joint) 11, to prevent distortions of the rope and the tube. A guide rope 12 is hung downward in the lower part of the transit vessel 1, and the transit vessel 1 hung down from the helicopter 2 can be pulled in, by grasping the guide rope 12. COPYRIGHT: (C)2005,JPO&NCIPI