On the High-Performance Hydrodynamics Design of a Trimaran Fishing Vessel

Trimaran hull form as multihull ship becomes more attractive these days in various ship types. It offers more advantages in terms of seakeeping performances, particularly on the application of a fishing vessel. However, thus far, the conventional design of fishing vessels is not favorable to ensure the safety of a vessel sailing in a rough sea. In conjunction with such issues, we discuss a trimaran fishing vessel design based on the seakeeping criterion to evaluate the dynamic stability, ship motion RAOs, and ship resistances at the initial design stages using linear strip theory. The intact stabilities are calculated to complement the seakeeping results. The analytical method based on the slender body method is used to evaluate the steady wave resistances. The results of heave, pitch, roll motions, and the ship resistances are discussed. At the zero speed and forward speed, the trimaran shows a favorable motion amplitude, although in forward speeds at the case of head seas there is no significant difference. The trimaran presents a favorable steady-resistance up to the ship speed of Fn=0.27, and it becomes deteriorating than the monohull at higher ship speeds. However, the added wave resistances of the wavelength range 1.0 – 3.0 shows significant added resistances at Fn=0.25 and Fn=0.35, respectively. The results of this study present promising seakeeping and resistance characteristics of the trimaran hull form. The trimaran hull form ensures the safety, reliability, and operation efficiency of ships sailing in broader ranges of violent-sea environment.

Strength Analysis of a RO-RO SWATH Ship Deck Layout

The purpose of the paper is to obtain the loads that occur in the connecting deck of a multihull ship, considered on a beam wave. Therefore, is written and used a macro command for obtaining the displacement distribution in order to simulate the bending generated by the beam waves loading. A strength analysis of the loaded connecting deck layout is also performed, to obtain the loads that act upon the structure. In order to determine the stress hot spots and to compare the stresses to the yield point, a linear static analysis is considered.