Evaluation of a small and fast planing boat's seakeeping performance at the design stage

Abstract

Seakeeping performance of a planing boat should be sufficiently considered and evaluated at the design stage for its safe running in rough seas. Model tests in seakeeping model basins are often performed to predict the performance of full-scale planing boats. But, there are many restrictions in carrying out model tests due to tank size and wave maker capacity, in particular, for fast small planing boats. In this research, model tests are carried out, and results are summarized and analyzed to predict a 3 ton-class high speed planing boats. In a towing tank, towing tests for a bare hull model are performed in regular head waves and long crested irregular head waves. Motion RAOs are derived from irregular wave tests, and they are in good agreements with RAOs in regular waves. Next, model ships with one water-jet propulsion system are built, and free running model tests are performed in ocean basins. Wave conditions such as significant heights, modal periods, and directions are varied for the free running tests. RMS values of motions accelerations are obtained and they are compared with the operability criteria, and are used to predict the full-scale boat performances. ？ SNAME 13th International Conference on Fast Sea Transportation, FAST 2015. All rights reserved.