Your vessel is damaged with no list, but down by the stern. There is progressive flooding and trim by the stern is increasing. What is the effect on transverse stability after the deck edge at the stern is submerged?
β’ Transverse stability components (GM, KB, BM, KG) and how each can change when the hull or deck becomes immersed β’ Effect of immersed deck edges and loss of waterplane area on BM in damaged conditions β’ Difference between weight added high (KG change) and change in geometry of the waterplane (BM change)
β’ When the stern deck edge goes under, what happens to the shape and area of the waterplane at that end of the ship? Does it increase or decrease? β’ How does a reduction in effective waterplane area at one end of the ship affect BM = I/β and thus GM, assuming displacement is already increasing slowly from flooding? β’ Is water that pours over a submerged deck edge always a significant added high weight affecting KG, or is the main effect something else in this scenario?
β’ Write out GM = KB + BM β KG and think: in this situation, which term is most directly affected by the deck edge submerging at the stern? β’ Recall that BM = I/β: Does the second moment of area (I) of the waterplane get larger or smaller when the deck edge at one end goes under? β’ Check whether any option conflicts with the idea that submerging deck edges usually means a loss in effective waterplane width at that end, and what that means for BM and GM.
No comments yet
Be the first to share your thoughts!