| 摘要 |
A semi-submersible offshore structure such as an oil ring has a pair of submerged floats 1, 2 arranged side-by-side at the port and starboard sides, a plurality of supporting columns 3A, 3B extending upright from respective submerged floats 1, 2, the submerged portion of each supporting column 3A, 3B producing a certain level of buoyancy, and an upper structure 5 carried by the supporting columns 3A, 3B. The semi-submersible offshore structure further has a plurality of columnar floats 7 disposed between the supporting columns 3A, 3B on both submerged floats 1, 2 at the fore side of the upper structure 5 and between the supporting columns 3A, 3B on both submerged floats 1, 2 at the aft side of the upper structure 5. The columnar floats 7 are suspended from substantially breadthwise mid portions of the upper structure 5 at the fore and aft sides of the upper structure 5. The lower ends of the columnar floats 7 are positioned at a level which is below the water level but above the level of the lower ends of the submerged floats 1, 2. <IMAGE> |
