Design Methodology and Development of an Independently Rotating Multi-Hull Vessel

Abstract

Aquaculture farms play a vital role for food security in Japan. The cultivation potential is directly related to the quality of the marine environment. Water quality parameters such as dissolved oxygen and temperature need to be measured and monitored regularly throughout the cultivation period. Energy efficiency and ease of navigation are the prime requirements for environmental survey vessels. In this paper, a new and novel automated vessel is introduced and design methodology is explained. Multi-hull innovative vessel is named as ‘Quadmaran’ and developed particularly for carrying out environmental surveys. The vessel consists of four hulls each capable of rotating independently thereby leading to better sailing performance and excellent stability. It is equipped with devices to measure quality parameters at various water depths and includes a dynamic positioning system aiding for the environment data collection. The basic design criteria of the Quadmaran is derived and understood in this study. Scaled model (1/3 scale) is fabricated for tank tests and resistance tests are carried out in a circulating water tank at Osaka Prefecture University, Osaka, Japan. With the knowledge gained from tank tests, multi-hull phenomenon of the Quadmaran is studied and interaction between the hulls is investigated. It is found that wave interference due to hull orientation becomes significant for Froude number greater than 0.5 and resistance of Quadmaran is found to be less than two times the twin hull resistance for same water draft. Further, an attempt is made to understand how the configuration arrangement affects the resistance of the vessel.