Question 2100 Deck Safety

The correct answer is D) KG. Topside icing increases the vertical center of gravity (KG) of the vessel, which decreases the vessel's stability. As ice accumulates on the superstructure and deck of a vessel, the center of gravity is raised, making the vessel more prone to heeling and capsizing. This is because the increase in KG reduces the vessel's righting moment, which is the force that counteracts the heeling moment caused by external forces. The other answer choices are incorrect because they do not directly explain how topside icing affects vessel stability. Displacement and draft may change due to the added weight of the ice, but these factors do not directly impact stability in the same way as the increase in KG. Free surface effect is a different phenomenon that can also decrease stability, but it is not the primary reason for the instability caused by topside icing.