Project Mohole Heaving Motion Calculation, Four Column Drilling Platform Ship Motion Study

摘要

The fundamental analysis of heaving motion study of the 4-barrel drilling platform was based on the principle of single-degree-freedom of forced vibration with damping. These barrels, each with a diameter of 35 ft.-0 in., length of 72 ft.-8 in., and braced together by horizontal trunk type members, carry a platform 200 ft. x 200 ft. in size. Two sizes of horizontal bracing members were used in this investigation; one with cross section 16 ft. x 20 ft. (width x height); the other 20 ft. x 20 ft. Different values of damping coefficient and added mass for these two sizes of bracing were calculated. Then heaving amplitudes were calculated. The results show that the practical highest heaving amplitude of the larger size of 20 ft. x 20 ft. bracing is reduced 39% from that of the smaller size (16 ft. x 20 ft.). (Author)