PRELOADING OF LEGS OF SELF-ELEVATING TYPE OFFSHORE WORKING PLATFORM AND WORKING PLATFORM THEREOF

摘要

PURPOSE:To apply preloading to the legs of an offshore working platform without the need to make an elevator device larger by a method in which legs to be preloaded are held by an elevator device, other legs close to the legs are raised, and loads to the other legs are zeroed. CONSTITUTION:When applying preloading to the legs 2A and 2C of an offshore working platform 1, all of the legs 2A-2D are first lowered in such a way as to cause the tips of the legs to reach the seabed. The legs 2A and 2C are then held by an elevator device 10 and the elevator device 10 is operated in the direction of lowering the platform 1 to reduce loads to be applied to the legs 2B and 2D. When the load is zeroed, the elevator 10 is stopped and held for serveral minutes and preloading is applied to the legs 2B and 2D. The load is measured by using a limit switch 13 provided to the side end of the elevator 10 for a buffer part 8 attached to the supporter 7. Afterwards, the legs 2B and 2D are restored to their original positons, and preloading is likewise applied even to the legs 2A and 2C.