Pure Loss of Stability of Ships in a Quartering Sea and Its Theoretical Prediction

Abstract

The intact stability of a ship travelling in following or quartering seas differs significantly from that in still water, In general, the stability of a ship is reduced when the ship is located at the wave crest, but it is increased when the ship is situated at the wave trough. In this paper, theoretical and experimental analyses have been carried out for the change of stability of a ship in quartering seas. The theoretical explanation of the change of intact stability is described based on the Froude-krylov hypothesis and the predicted righting arm in a quartering sea is compared with the experiments. Agreement between them is satisfactory.