Design Aspects of Survivability of Surface Naval and Merchant Ships

The paper addresses various design aspects of survivability for surface naval and merchant ships through a common rational probabilistic methodology. It is based on earlier work of Kurt Wendel on a probabilistic approach to the damage stability of surface ships. This method was adopted by SOLAS 1974 through Res. A.265 (VIII) as an alternative to the deterministic SOLAS criteria for passenger ships and finally by SOLAS 1992 for the evaluation of stability of new cargo ships. The method is currently under review by IMO for application to all types of merchant ships in the framework of harmonization of all existing stability rules. Recently the method found access into the design process of modern naval ships. The declining defence budgets world-wide and the reduced manning requirements bound the size and thus the payload of modern naval ships, required in addition to operate in an increased dangerous warfare environment. This stressed the need for the introduction of a new naval ship design philosophy, namely the enhanced survivability. Most designer decisions, associated with survivability, as compartmentation and arrangements, are taken at the preliminary design stage and are very difficult and costly to change, if at all, in latter stages. Therefore, a proper guidance in the preliminary design stage would greatly help the designer to achieve his goals. The paper addresses the fundamental aspects of survivability and introduces this relatively new probabilistic approach for assessing the damage stability and survivability properties of both naval and merchant ships.