Probabilistic assessment of damaged ship survivability in case of grounding: development and testing of a direct non-zonal approach

• A probabilistic approach for damaged ship survivability assessment is presented.
• Bottom grounding is addressed, with specific attention to passenger ships.
• The geometrical and probabilistic model for the considered damage type is described.
• Damage cases and p-factors are determined by means of a direct non-zonal approach.
• Testing example results, obtained for a simplified box-shaped ship, are reported.

This paper presents the results of ongoing research efforts aimed at the theoretical development and practical implementation of a probabilistic framework for regulatory assessment of ship survivability following grounding accidents, with particular attention to passenger vessels. In the envisioned framework, the probabilities of flooding of a compartment, or a group of compartments, i.e. the so-called “p-factors”, are determined using a flexible and easily updatable direct non-zonal approach. The assessment of the conditional ship survivability, on the other hand, is based on the SOLAS “s-factor”. The general framework is described, together with implementation details in the specific case of bottom grounding. Testing results, carried out using a specifically developed software tool, are also reported.