Manoeuvring aspects of fast ships with pods

Currently an increasing number of modern ships is equipped with podded propulsors. Advantages are the possibility to use a diesel-electric propulsion plant and to increase the propulsive efficiency and the manoeuvrability of the ship. Besides application to cruise ships the pod concept is nowadays also applied to other ship types and to vessels of a higher speed range. Major benefits are normally obtained, but still areas of special attention exist. Due to the possibly large steering forces, large steering-induced heeling angles can occur. Additionally, the directional stability of ships with pods tends to be less than comparable ships with conventional propulsion. This paper describes the aspects of application of pods from a manoeuvring viewpoint, compares the manoeuvrability between ship designs with conventional propulsion and pod propulsion and highlights the benefits and points of attention. Design guidelines to improve the manoeuvring performance are given and operational issues are discussed.