Question 5042 Deck General

The correct answer is D) ice accumulates above deck. The natural rolling period of a vessel is determined by its metacentric height (GM). The natural rolling period increases when GM decreases. Ice accumulation above the deck increases the vessel's vertical center of gravity, which in turn reduces the GM and causes the natural rolling period to increase. The other answer choices are incorrect because: A) Placing the setback in the pipe racks does not affect the vessel's GM or natural rolling period. B) An increase in GM would actually decrease the natural rolling period, not increase it. C) Reducing free surfaces, which can increase GM, would decrease the natural rolling period.