| 摘要 |
PURPOSE:To reduce a force exerted to a crane with the use of a buoyancy by feeding a regulated amount of compressed air into a reservoir tank while ensuring a weight necessary for submerging the reservoir tank with the use of a ballast tank. CONSTITUTION:An emptied ballast tank 1 and reservoir tank 2 are towed in a lightweight condition on the water surface to a position where they are submerged, with a shut-off valve 11 and an opening 22 being closed so as to prevent water from entering into the tank 2 from the outside. Then, the device is suspended by means of a chain 5, and the shut-off valve 11 for the ballast tank 1 and the opening 22 for the reservoir tank 2 are opened to feed compressed air into the reservoir tank 2 through an air feed pipe 21. Then, water flows into the ballast tank 1 so as to increase the weight, and accordingly, submerging is started. Since water is discharged from the opening 22 of the reservoir tank 2 into which compressed air is charged, the reservoir tank 2 serves as a floating body. |
