Evacuability of Passenger Ships at Sea

The term Evacuability (passenger evacuation performance capability) entails a wide range of capabilities encompassing evaluation of evacuation time, identification of potential bottlenecks, assessment of accommodation module layout, life saving appliances, passenger familiarisation with a ship’s environment, crew training, effective evacuation procedures/strategies, intelligent decision support systems for crisis management and design/modification for ease of evacuation. From a technical point of view, the mass evacuation of thousands of people from an extremely complex environment with unknown inaccessibility problems exacerbated by (potentially co-existing) incidents such as progressive flooding, cargo shift, foundering, fire/smoke and the inherent uncertainty deriving from unpredictability of human behaviour, is a problem with severe modelling difficulties at system, procedural and behavioural levels. In this respect, Evacuability represents a risk measure of passenger evacuation at sea, expressed as an index. Addressing the above, this paper focuses on the development of a passenger evacuation simulation model developed by SSRC in collaboration with Deltamarin, RCI and Color Line. Code-named Evi (Evacuability index), it represents the state-of-the-art computer simulation-based capability for the prediction of passenger mustering and evacuation whilst accounting realistically for human and ship behaviour in a sea environment. Unlike earlier models, Evi has been developed from the outset for application to passenger ships in a sea environment, including the largest cruise liners and Ropax. Purposely conducted shipboard experiments coupled with valuable input and feedback from owners/operators helped refine and render the model a practical tool for ship designers, operators and regulators. Modelling uncertainty in all the parameters that may affect evacuation times and ability for real time interaction/interrogation/visualisation and play back of any given (or online devised) scenario as video, provide for wide-ranging capability in dealing with the most complex of evacuation scenarios. As a result, Evi is currently used routinely for evacuation analysis of existing and new designs and is being systematically assessed by shipyards and classification societies for use in ship design and certification. Following definition of the shipboard evacuation problem and an outline of the modelling involved in Evi, sample results from recently conducted benchmarking tests, devised by the IMO Working Group on Evacuation Analysis, are presented and discussed and recommendations given on the way forward concerning development and implementation of advanced tools to ship design, training and operation.