Coast Guard Exams
Question 4780Deck General70% to pass

The DEEP DRILLER, at a draft of 60 feet and a total vertical moment of 1,012,598 foot-tons, pumps 2,068.7 long tons of ballast overboard. The VCG of the discharged ballast is 15.0 feet. What is the new height of the center of gravity?

AI Explanation
The correct answer is D) 61.16 feet. The key to solving this problem is to use the principles of stability and the change in the center of gravity (CG) due to the ballast discharge. When 2,068.7 long tons of ballast is pumped overboard, the total vertical moment decreases by 2,068.7 * 15.0 = 31,030.5 foot-tons. This decreases the total vertical moment from 1,012,598 foot-tons to 981,567.5 foot-tons. Dividing the new total vertical moment by the new displacement (total displacement minus the discharged ballast) gives the new height of the center of gravity, which is 61.16 feet. The other options are incorrect because they do not accurately reflect the change in the center of gravity based on the given information.

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