Ship capsizing analysis using advanced hydrodynamic modelling

A ship's stability is fundamental to the safety of its crew, its cargo, and the environment. Several ocean-going vessels are lost due to instability e ach year, particularly in high seas. To prevent such losses, a better under standing of ship stability is necessary. In this paper we analyse the stabi lity of ships using advanced mathematical models and methods. All the rigid -body motions of a ship, as well as memory effects in the fluid, are accoun ted for. The analysis shows that a ship's dynamics depend strongly on the n onlinearities of the ship-fluid system. In our analysis of a particular shi p, we notice a sequence of bifurcations when wave heights increase, and rye believe that this is an explanation for capsizing. Critical wave heights f or capsize were identified. In quartering seas, the required wave height wa s much lower compared with following seas. A path-following method to deter mine the stability limits in a systematic manner is being developed.