International Shipbuilding Progress

Laboratory methods of measuring the wall-friction and micro-geometry of an irregularly rough surface are described. These methods have been used, for the case of a simulated ship-hull roughness, in an attempt to quantify the total flat-plate wall-friction coefficient at full-scale Reynolds numbers and to investigate the consequences of painting the surface in terms of both the wall-friction and surface micro-geometry.

In this paper the ship dynamics equations and random function methods have been applied to determine the probability of capsizing. It examines a particularly dangerous situation – the parametric roll resonance, which is dependent on ship loading and on the sea state. The presented method is based on Y. Goda’s wave group model. Also presented are some results of experiments on the capsizing of a cylindrical model by the parametric resonance on a regular wave.