Abstract
A "Resonance-Free SWATH (RFS)" ship is introduced as an example of the oceangoing large fast ship. Because of the extraordinary small water plane area, the restoring moments of the RFS are negative, which leads to resonance-free in the motion responses. The RFS is designed to cross 4,800 nautical miles of Pacific Ocean in 5 days punctually at a high speed of 40 knots, with the good seaworthiness such as no speed reduction or absolutely no slamming even in the rough sea. To verify the seaworthiness of the RFS, experiments in towing tank and theoretical calculations based on the strip theory are carried out to examine hydrodynamic forces and motion responses in waves. The results are compared with those of various hull forms, i.e. mono-hull, ordinary SWATH and trimaran. The predominance of the RFS regarding seaworthiness will be pointed out in the conclusion.
