The broaching of a fast rescue craft in following seas

This paper focuses on investigating the tendency of a fast rescue craft of the Royal Netherlands Sea Rescue Institution (KNRM) to broach in stern and stern-quartering seas by means of quantitative numerical simulation. The aim is to investigate the suitability of a numerical simulation tool, a semi-nonlinear time-domain potential flow boundary element method complemented with additional force components for steering and viscous forces, for this class of problems. The results show that the method can be used to simulate the surf-riding behaviour of this type of vessel, a commonly accepted pre-cursor to broaching behaviour. After inclusion of a limited number of additional manoeuvring coefficients into the method, it was applied to broaching simulations. The results indicate that the method indeed can be applied for predicting the tendency to broach.