Ship Capsize Risk in a Seaway Using Fitted Distributions to Roll Maxima

Abstract

This paper presents an efficient method for determining capsize risk for a given seaway and ship operational condition using time domain simulations. The risk of capsize during 1 h exposure to a given seaway is dependent on the wave process realization, which is determined by a seed number and resulting random wave phases. The dependence of maximum roll angle on wave process can be modeled by fitting a suitable distribution to maximum roll angles from a moderate number of simulations. Sample computations for a naval frigate demonstrate that a Gumbel distribution provides a very good fit to maximum roll angles from different wave realizations. [S0892-7219(00)00402-7]