Stability of ships: risk assessment due hazards created by forces of the sea

The crucial point in safety assessment is identification of all hazards the ship may be subjected. The most important hazards are those that are created by the forces of the sea. Simple criterion that takes into consideration forces of the sea is weather criterion included in the IMO Intact Stability Code. The author suggests to take account of all hazards posed by forces of the sea when performing risk analysis. For this purpose those hazards should be decomposed into hazardous situations and further in a number of possible capsizing scenarios. As an example fault tree and event tree for parametric resonance in following waves are shown. The trees could be used for evaluation of probabilities of capsizing.