Structural Analysis of a stabilized Mono-Hull Cargo Vessel Designed for High Speed Sea Transport

In this paper the structural design work of an innovative trimaran ship for the transport of ro-ro cargo is presented. The project was carried out in cooperation with a private Company, the Department of Naval Architecture of the University of Genova and MARIN Institute. The vessel consists of a central displacement hull with a wave-piercing bow, and two outriggers connected to the main hull by wing arms. The particular shape of the main hull with its wavepiercing bow, aims to give lower hydrodynamic resistance and minimal pitching motion. In waves this results in low occurrence of hull slamming and whipping shock. The two symmetric outriggers produce a positive hydrodynamic interaction with the main hull leading to a reduction in resistance, and guarantee transverse stability avoiding rhythmic rolling settling. For the structural design of the trimaran a longitudinally and transversally framed hull structure in high tensile steel was chosen for main hull, outriggers, wing arms and superstructures. This allowed to obtain very high strength together with minimum weight. In this paper a first general description of the structural design is presented highlighting the most important structural characteristics of the vessel; then the complete FEM model analysis of the vessel performed with MAESTRO software is presented, with the description of the global dynamic loads used for the FEM analysis. A detailed explanation of the used methodology is presented along with a discussion of the obtained results, giving demonstration of the real potential of this innovative design.