System and risk approach to ship safety, with special emphasis of stability

Present stability regulations developed over the years by IMO reached definite conclusion with the adoption of the Revised draft of the Intact Stability Code. The criteria included there are working comparatively well with regard to the majority of conventional ships. Advent of very large and sophisticated ships of non-conventional features caused that those criteria may be inadequate, and because of that currently IMO is considering development of criteria based on ship performance. However, with the application of the existing criteria risk level is not known, and there was still a number of ships satisfying criteria that did capsize due to different causes. The present criteria are design criteria of the prescriptive nature. As opposed to prescriptive criteria requirements based on risk analysis offer many advantages.The author proposes that as alternative to existing criteria safety assessment based on risk analysis should be used. This would require holistic and system approach to stability. Safety against capsizing (or LOSA accident) is a complex system where design, operational, environmental and human factors have to be taken into account. The crucial point in safety assessment would be identification of all hazards the ship may be subjected. Although performing risk analysis to stability problems seems to be a very complex task, in the opinion of the author it may be manageable and could be applied for safety assessment of highly sophisticated and costly ships.