| 摘要 |
PURPOSE:To restrain oscillation of an off-shore structure to the least minimum under various sea conditions, by enabling an under-water hull to ascend and descend with respect to a hull above the water so that the under-water hull is held at a suitable depth, depending upon sea condition. CONSTITUTION:Upper hull struts 3 each formed with a vertical hollow portion are planted to an upper hull which is above the water, at predetermined positions of the upper hull. Struts 4 of a lower hull 5 which is under the water, are slidably fitted into the hollow portions of the upper hull struts 3 so that the lower hull 5 may be ascend and descend with respect to the upper hull 1. Accordingly, the lower hull 5 is elevated as shown in Fig. (a) when the sea is calm, while the lower hull 5 is held at a predetermined depth, as shown in Fig. (b), by charging ballast into the upper hull struts 3, the lower hull struts 4 and the lower hull 5, when the sea is restless. |
