Measurement and prediction of wave loads on a high-speed catamaran fitted with active stern tabs

Measurements of unsteady loads within the structure of an 86 m high-speed catamaran ferry have been made for a variety of speeds and encountered sea direction and the increase in unsteady bending moment with wave height determined. The measurements are compared with the predictions of a time domain strip theory which predicts unsteady loads and motions. There is a significant non-linear dependence on wave height for both motions and loads. Good agreement is found between computed and measured unsteady bending moments at speeds from 12.5 to 37.5 kt in bow quartering seas. Rather larger computed values were found in head seas and much smaller computed values in beam seas. This is because the direction of encountered seas was not always exactly in the centre of each directional sector, where the computed values are determined. © 2005 Elsevier Ltd. All rights reserved.