Evaluation and Preliminary Design of a Specialized Wellboat for Efficient and Gentle Transport of Live Fish

Abstract

One of the greatest challenges the world faces today is to produce and supply sufficient healthy and nutritious food to sustain the needs of a rapidly growing population. Aquaculture is predicted to be an important future resource for food supply, as fish farming may be performed in a sustainable way with a low carbon footprint.

Wellboats are used to transport fish between seawater cages and processing plants. Modern wellboats are multi-functional and can perform several operations such as parasite treatment and sorting of fish. These vessels have a high level of complexity and a expensive. The use of multi-vessels is often limited to different operations which result in a limited use of the technology.

The first objective of this thesis has been to evaluate if a specialized vessel, for pure transportation of harvestable fish, is an efficient alternative for future market needs. The second objective was to suggest modifications and improvements to an existing wellboat design to achieve a specialized design for pure transportation of fish. Correct dimensions and general arrangement, improving fish welfare and analyzing costs and economical aspects were all important issues which were addressed. The most important information for this thesis was obtained during an excursion with Gåsø Viking where the vessel and crew were observed during normal operation. The preliminary design of a specialized vessel is based on M/S Gåsø Viking as a reference vessel.

The resulting requirements for the new design was to increase the hold capacity to approximately 3500 m$^3$ in order to increase the efficiency of the vessel. An analysis of main dimensions was conducted, which recommends to increase the length of the vessel and keep the breadth and depth constant. The total length of the vessel was therefore increased with approximately 5 m and a general arrangement drawing was developed.

One of the main drivers in the development of wellboat technology is the well-being of the fish and fish welfare is expected to become even more important in the future. The specialized vessel will have improved fish welfare as systems, which may have been experienced as stressful for the fish, are removed. Furthermore, the increased ship length gives room for straighter transport lines within the vessel.

Modifications were made in the accommodation area on board, by request from the crew who believed this would increase the overall comfort on board.

A capital expense estimation was developed for the specialized vessel which resulted in a decrease of 20 MNOK (1\%) of the investment cost compared to the reference vessel.

This design is believed to improve fish welfare, give greater comfort and optimal solutions for the crew on board and reduce the capital expenses for the vessel. The solutions presented in this thesis depict an industry which is still novel with several areas of improvement to reduce costs and improve product quality for both producers and end comsumers.