A jack-up is trimmed six inches by the bow. The moment required to change trim one inch is 1200 foot-kips. Transferring 200 kips of drill water from a tank with an LCG of 20 feet to a tank with an LCG of 140 feet results in a final trim of __________.
• Trimming moment and the formula relating weight movement, distance moved, and change in trim • How to use Moment to Change Trim 1 inch (MCT 1") to find total change in trim • Effect of an existing trim (by the bow) when you create a new trimming moment (toward the stern)
• First, calculate the trimming moment created by moving 200 kips of drill water from LCG 20 feet to LCG 140 feet. What formula links weight, distance moved, and trimming moment? • Then, use the given MCT 1" to figure out how many inches of trim this new moment will cause. Will that be by the bow or by the stern? • Finally, combine the original trim (6 inches by the bow) with the new trim you just calculated. Does the new trim fully cancel the original bow trim, or does it overcorrect to stern trim?
• Be sure you convert the change in trim from inches to feet and inches before matching the choices. • Confirm the direction of trim after the transfer (bow down or stern down) before selecting your answer. • Double-check that you used the distance moved as the difference in LCGs (140 ft – 20 ft), not just one of the LCG values alone.
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