To float a power cable and a control cable and a discharge hose, in which one end each is connected to a water-bottom self-propelled car and the other end is led out to the ground, in water, and adjust buoyancy thereof.
About the overall length of a power cable 26 and a control cable 28 is covered with a buoyancy hose 30. A check valve 48 is installed at one end section on the side coupled with a water-bottom self-propelled car 10 of the buoyancy hose 30. A discharge hose 22 is bound with the buoyancy hose 30 by bands 42, 42... in a culvert 40. The buoyancy hose 30 loses buoyancy and sinks when water is flowed into the buoyancy hose 30 from the other end of the buoyancy hose 30 and the inside of the hose 30 is filled with water, and water on the inside is flowed out from the check valve 48, the inside of the buoyancy hose 30 is filled with air and buoyancy is increased and the buoyancy hose 30 is floated in water when air is pressed in at fixed pressure or more.
JINNO KOICHI
HAGIWARA TATSUTO
KAMINO KAIJI KOGYO KK
DENGYOSHA MACH WORKS