Design and operational aspects of high speed semi-planing and planing craft

Powering, seakeeping and manoeuvring plays an important part in the design of high speed semi-planing and planing craft. This paper describes tools that can be used to evaluate the performance in calm water and in waves. Tools for prediction of resistance and propulsion system efficiency are presented. Practical examples are given with reference to MARINTEK's database for high speed craft and to the theoretical methods derived. Methods for determining the manoeuvring characteristics are also presented. Database results from model and full scale tests are given and correlation to theoretical tools is outlined. Practical examples of steering capacity and simulation of craft behaviour in an actual route are given. The wave induced responses of high speed craft are important in several ways. Motions, accelerations and loads should be reduced to a minimum. Further, the behaviour out from safe operation in waves, i.e. broaching, porpoising, directional stability and dynamic stability should be as good as possible. The craft ability to cope with difficult situations after having accidents is also of great importance. The interaction between craft steering and powering systems and the hull responses must be detected and referred to standard criteria. Methods for such investigations are described, and criteria are discussed. The theoretical tools and the test methods which are applied at MARINTEK are described and examples are given.