| 摘要 |
PURPOSE:To ensure safe navigation by a method wherein a leg is divided about at its central part into 2 parts of an upper and a lower leg, and the lower leg is threadedly joined with the upper leg, so that the leg is expandable. CONSTITUTION:With a motor 10 driven, a lower leg 1a is rotated through a rotary shaft 9, and the lower leg 1a is engagedly inserted into an upper leg 1 through the operation of square screws 7 and 7a for transportation. When a rig arrives at a working sea surface, with the motor 10 driven, the lower leg 1a is lowered through reversing of a rotary shaft 9 to bring the leg into an expanded state. and with this, a jack-up rig is installed. |
