Optimizing ships' behaviour when sailing in following seas

Abstract

Ships are built for sailing and transporting cargo on seas and oceans in weather conditions that are not friendly all the time. Even if the weather forecast is transmitted to vessels, the way of acting is a matter of officers' judgement, based on their knowledge and experience. The subject of this paper is to analyse the behaviour of a port container vessel in different weather conditions. The method consists in using a specially developed software which takes into account the main particulars, the actual stability and the dynamic characteristics of the individual ship in the real voyage conditions, in order to obtain the Dangerous Zone Diagram. In order to avoid surf-riding and broaching the master should reduce speed to less than the critical speed. The results of the study are presented in a diagram that allow us to analyse the situation and to determine the ways for avoiding dangerous conditions by changing the course or the speed. The study should be regarded as a supporting tool during the decision making process..