Hatch cover loads experienced by M.V. Derbyshire during typhoon 'Orchid'

Tests with a scale model played a crucial role in the understanding of the behaviour of M.V. Derbyshire and also of the hatch cover loads experienced during typhoon “Orchid”. First of all, the results shaped ideas regarding the nature of the behaviour and green seas loading in a qualitative sense. Secondly, the quantitative results provided the basis for a careful risk analysis. The basic assumption underlying all the work is that the results of “accurate and complete” tests with a scale model, after scaling according to Froude’s Law of Similtude, give a realistic impression of the behaviour, wave loads and ingress of water. The present paper reviews aspects of the applied test techniques from this perspective. In addition it describes the MARIN proposal for the step from the model test results to a risk analysis.