METHOD AND APPARATUS FOR PREVENTING DAMAGE ON RACK OF LANDING AND ELEVATION TYPE OFFSHORE WORKING PLATFORM

摘要

PURPOSE:To prevent the breakage of the rack of a landing and elevation type offshore working platform by a method in which the platform is lowered by as much a distance as the back rush of the rack and pinion vertically moving on the platform, the turning of all pinions is confirmed, and operation is stopped when even one pinion is not working. CONSTITUTION:Legs 6 are landed on the sea bed 8, and a working platform 1 is held by vertically moving it by means of an elevating device 2 with pinions 3-5 to be coupled with the racks 6a of the legs 6 on the offshore working platfrom 1. the revolving number of motors 9 driving the elevating device 2 is confirmed by a sensor, and when a disorder occurs in any one of the motor brakes, the difference in revolving numbers between normal motors and the disordered motor is detected. When the difference exceeds a specified value, the operation is soon stopped. Also, when the platform 1 goes down, it it moved by as much a distance as the back rush between the rack and the pinions in the early period, and whether all the pinions can turn is tested.