Statistical analysis of ship accidents and review of safety level

Safety may be defined as an acceptable state of risk by society. In this respect, for assessing the current safety level of ships, it is necessary to quantify the risk level of the operating world fleet, thus estimate and assess the basic contributors to risk, namely the frequency of maritime accidents and the extent of their consequences. The present investigation was motivated by earlier published work of Det Norske Veritas (DNV, 2006), in which they were some alarming signals of worsening of the level of maritime safety. A justified question therefore is whether and how the level of ship safety changed thereafter. Recalling that a fundamental step of a Formal Safety Assessment of maritime assets is the investigation of relevant casualty reports and the analysis of historical data, which characterise the maritime safety performance in the studied period, the herein presented work deals with a systematic analysis of ship accidents in the last decade as a way to evaluate the current level of safety for the majority of ship subtypes present in the world merchant fleet and to conclude on the foreseeable future. The presented analysis also includes a deeper investigation about possible relationships between accident rates and ship's age, which proved more complex than initially thought. The outcome of the present study indicates that in the last decade although the frequencies of ship accidents generally increased, the safety level of various ship types did not significantly change, as the consequences of accidents remained in average at about the same level.