Course-Keeping Performance of a Container Ship with Various Draft and Trim Conditions under Wind Disturbance

Abstract

IMO presented the standard for ship’s manoeuvrability which every ship is recommended to satisfy. Although it specifies a full load and even keel condition as the condition at which the standard applies, practically, ships are operated under various loading conditions of cargo. From this viewpoint, the authors have conducted manoeuvring tests of a container ship under five loading conditions with different combinations of the draft and trim, and one of the authors established the manoeuvring mathematical model of the ship for each condition so far. This study focuses on the course-keeping performance of the same ship under these loading conditions under wind disturbance. It is the aim of this study to discuss both the influences of loading condition and wind condition simultaneously on the check helm and attitude of the ship while maintaining the target course. For this purpose, the arrangement of containers and their weight distribution were designed as exact as possible. For example, the ship with a trim by bow, which is commonly preferred for fuel efficiency, needs to have a larger check helm for course keeping, especially under the condition of wind disturbance diagonally from behind. This kind of knowledge would be useful for safe navigation.