Trimaran Hull Design for Fast Ferry Applications

Research studies about hydrodynamic performance of trimaran hull configurations and their application to real ship design, are relatively recent, having generally appeared in the last two decades of the last century, without relevant follow up in the shipbuilding world. The proposed paper aims to describe the main features of the hydrodynamic design of a trimaran ship as an alternative solution to contemporary mono hull or catamaran fast ferries (36-40 knots of service speed). This work has been developed in the frame of a three year joint research project of the Departments of Naval Architecture of the Universities of Genova, Trieste and Napoli and the University of Ancona. Comparison of the main resistance and seakeeping properties of two different trimaran design (having different hull forms but equivalent in terms of main geometric parameters and total displacement), tested in model scale with different side hulls positions will be addressed in the paper. The design exercise presented in the paper has comprehended also other aspects such as the implications that different hull typologies can have on the general layout of the vessel, problems related to the intact and damaged stability, internal spaces and propulsion arrangements.