Development of a Mesoscopic Egress Model to Estimate the Evacuation on Board Ro–Ro Ships

This paper presents a new evacuation model for fast and affordable simulations of evacuation based on Togawa’s theory for multi-compartment configurations. The aim is to track the evacuee’s path and to estimate the congestion (or the queues) behind each doorway at each time step to model the evacuation process. In this approach, only two parameters drive the formation of congestion, namely the maximum out-coming people flux and the width of the doorway. For a real application, such as evacuation in a building or a boat, a geometrical configuration is considered by a “tree structure” where each doorway is connected to the others up to the main exit. The originality of this paper is in proposing a theoretical expression for the people flux feeding the congestion for people which are located just behind a given doorway. Moreover, this contribution proposes various new experimental tests to qualify and to validate the proposed model. All experimental data (146 evacuation exercises) are available in an open access database for further uses. In this communication, a sensitivity analysis is proposed on a single deck evacuation of the RMS Titanic (the best documented ship for its geometry) with 1126 people. This analysis demonstrates that, between the free walk speed and the maximum out-coming people flux per length of doorway, this latter variable is the most influential parameter of the present model, accounting for 22% of variations in evacuation time. The model has been applied to estimate evacuation times for generic Ro–Ro ships, to test some existing alternatives to abandon a ship and to propose some new perspectives to optimize the evacuation.