A comparative analysis of the seakeeping of a Viking Ship with modern displacement, high-speed displacement and planing hull form types, using Strip Theory and Panels Method

Viking Ships were great instruments of exploration, becoming conquest symbols of the Viking people, reaching farther regions of the world due to their excellent seakeeping. However, how would its seakeeping be compared to other modern boats designs? The present work aims to compare the seakeeping performances of a Viking Ship with three other modern hull types: a displacement hull, a high-speed displacement hull (former semi-displacement) and a planing hull. The calculations of the hydrodynamic coefficients and forces were performed using both the Strip Theory and the Panel Method. For such, two software were employed: MaxSurf Motions and ANSYS AQWA. The parameters used for the comparison of the hulls’ hydrodynamic performances were the vertical acceleration and the Motions Sickness Incidence Index at three different locations onboard. The loading conditions and the main dimensions of the four hull types were adapted to maintain the similarity among them. For the Panel Method, the zero-speed forward and an adaptation for speed conditions were investigated, while for the strip theory a Froude number of 0.35 was used for all hulls, and of 0.6 for the high-speed displacement and planing hulls. The NORDFORSK criteria were used to assess the vertical accelerations. The results demonstrated that the displacement hull presents a better behavior in waves among the four, because of its lower vertical accelerations. In terms of the Motion Sickness Incidence Index, the Viking Ship has shown the best performance, despite being a ship of ancient lines and design.