SEAKEEPING IN THE NAVIGATION – EXAMPLE IN TRIMARAN SHIPS

Abstract

Seakeeping ability is a measure of how well-suited a floating structure is to conditions when underway. A ship, boat, vessel or any other floating structure which has good seakeeping ability is said to be very seaworthy and is able to operate effectively even in high sea states. This paper presents an investigation of the seakeeping behaviour of a fast ferry multihull, which is a typical trimaran for operations in the Mediterranean sea. Numerical results and the measurements at the trimaran agree quite well in frequency and time domain. The movements in trimaran ships are less than the movements of a conventional boat (monohull) equivalent. Assuming linearity, the trimaran’s raos (Response Amplitude Operator) depend only on the trimaran’s geometry, speed and heading. Although seakeeping theory has been extensively applied for monohulls, such studies have not been accomplished for trimarans. This paper provides important information regarding the seakeeping of trimaran ships and how to be used in numerous scenarios.