A Multi-Level Approach for Flooding Risk Estimation and Assessment of Passenger Ships

Abstract

Against the background of using the Index of Subdivision as a reference to address the safety level of ships when damaged, following primarily collision accidents, the EC-funded FLARE project is making inroads towards a direct assessment of the flooding risk, which is ship specific and considers the operating conditions and all accident-types leading to hull breach and flooding, namely collisions, bottom and side groundings. This is enabled by using a newly developed two-level approach Potential Loss of Life (PLL) of People On Board (POB); level 1 is a semi-empirical approach with the risk models formulated by use of data from a newly composed accident database, while level 2 is determining the flooding risk by a first principles approach, using time-domain flooding and evacuation analyses simulation tools in pertinent emergencies. Level 2 is considered in two sub-levels (Level 2.1 and Level 2.2), the former involving some simplifying assumptions in the risk calculation. In addition to addressing all accident types and modes of loss of ship and of POB, the FLARE framework and methodology considers active and passive measures of risk prevention and control, hence with application potential to both newbuildings and existing ships. It also facilitates real-time flooding risk evaluation for risk monitoring and effective control in emergencies. Key objectives of the FLARE project are to provide the technical basis for the rational determination and assessment of flooding risk and to prepare a proposal for the revision of relevant IMO SOLAS regulations towards a risk-based approach to contain and control flooding emergencies. The paper briefly describes the FLARE flooding risk assessment framework and provides risk estimation results at all three levels for one cruise ship and one RoPax, including comparisons with available IMO societal criteria, as well as a summary of results for a further 7 ships at levels 2.1 and 2.2. In the light of the results presented, the paper draws conclusions on the progress made and offers recommendations for the way forward.