Damage Stability Requirements for Passenger Ships - Collision Risk based Cost Benefit Assessment

Currently built passenger ships have to comply with SOLAS 2009 probabilistic damage stability requirements. There are, however, serious concerns regarding the sufficiency of these requirements with respect to the Required Subdivision Index R, which should properly account for the risk of People On Board (POB) and ship's inherent survivability in case of loss of her watertight integrity. In recent years extensive research on determining the appropriate level of R using risk-based methods has been carried out. The urgency of the matter was reinforced by the quite recent Costa Concordia (2012) accident, even though this accident was not related to a collision event. This paper outlines the objectives, the methodology of work and first results of the ongoing studies funded by EMSA (EMSA HI project) focusing on risk-based damage stability requirements for passenger ships. In compliance with IMO Formal Safety Assessment process a collision risk model is further developed based on the results of EU GOALDS project and a new required index shall be suggested by means of cost-benefit assessment. The updated collision risk model uses information from the most recent analysis of casualty reports of databases considering the period 1990 to 2012.