ESTIMATING WAVE DRIFT FORCES BY RECALCULATION FROM A PROTOTYPE

The development of positioning systems requires knowledge of the hydrodynamic forces that cause floating vessels to drift and turn about in waves. There are difficulties inherent in trying to determine these wave drift forces theoretically, through calculations, and there is a significant amount of labor involved in determining them by measurement in an experiment. It is therefore worthwhile, at the early stages of design, to approximate these forces on the basis of a prototype differing in dimensions but similar in hull shape and main dimensions ratio to the vessel in question. This proposed method simplifies estimating the constituents of average drift force and turning moment in irregular seas and takes into account any unique features of the sea spectrum.