Recent developments of theoretical prediction on capsizes of intact ships in waves

This paper overviews latest developments at Osaka University on theoretical prediction techniques for capsizes of intact ships in waves. First, analytical prediction formulae for predicting the amplitude of parametric rolling in head and following waves are examined for both conventional and modern container ships. Second, an analytical calculation method for capsizing probability is extended to the case of beam-sea capsize with trapped water on deck and the effect of water on deck is remarked with this method. Third, a new prediction technique for threshold of surf-riding in quartering waves as a heteroclinic bifurcation is presented with a successful example. Then the relationship between the threshold and broaching is discussed. These outcomes could directly contribute to development of performance-based or risk-based intact stability criteria, which are under discussion at IMO as its long term task.