SIMULATION OF LARGE AMPLITUDE ROLL MOTIONS BY HYBRID COMPUTING TOOLS

Based on the sea keeping testing of a fishing vessel series developed at UBC, a ship motion response algorithm is developed. This algorithm which is probably the first algorithm for ship motion response for a series, is tested to see if the effects of variations in beam or draft on ship motions could be predicted for similar fishing vessels not necessarily derived from UBC series. The variations in motion response values obtained by the algorithm are compared with the experimental studies done for hull improvements in a lowing tank. The same algorithm is then used for the design of fishing vessels using an Expert System shell. The objective of this study was to reduce the motion effect on the crew or to increase the crew comfort and safety. Two rules are found to reduce the heave and pitch motion RMS levels at various forward speeds and sea state conditions. We conclude that it is possible to reduce the ship motion RMS values by adding specific rules to the design process. The usage of the algorithm to obtain such rules is outlined. The effect of these rules on the principle dimensions of fishing vessels and cost of the vessels are also given for various hold volume requirements. The results suggest that rules could he used for any small craft and the design method could also be done as an optimization procedure.