Simulating mustering and evacuation processes onboard passenger vessels: model and applications

The analysis of evacuation processes onboard passenger ships has attracted increasing interest over the last years. Especially the introduction of so called performance based requirements as stated in SOLAS II-2/28-1.3 leads towards a more comprehensive assessment. However, for a thorough investigation of the evacuation performance it is not sufficient to look only at the geometry, like hydraulic or flow models do. Behavioural and procedural aspects have also to be taken into account, although one will never be able to predict exactly what will happen. Since knowledge of the initial conditions, influencing factors, and laws of human behaviour is limited, it does not make sense to include factors that cannot be quantified. Therefore, a compromise has to be found: to get as close to reality as necessary and to provide a method as flexible, straightforward, and comprehensible as possible. This, of course, is a crucial question in evacuation assessment and modelling of real world processes in general. We present a microscopic simulation model that is capable of representing every individual person and his/her characteristic abilities as well as all necessary details of the floor plan and at the same time allows for a fast and efficient simulation. The behavioural and procedural aspects of mustering and evacuation are also included: waypoints, mustering stations, and embarkation stations define the sequence of events for different groups of persons. This accounts for social influences like group formation. The general philosophy with respect to the individual motion is to focus on the measurable quantities like walking speed and orientation frequency and to represent the remaining psychological factors via stochastic parameters. The implementation of the model is outlined and simulation results for passenger ships and High Speed Passenger Craft (HSC) are shown. However, the validity of the assumptions and the scope of the applications will have to be further scrutinized by comparison with detailed empirical data from actual drills or evacuations, as far as available.