Performance-based damage survivability of passenger ships and design implications

• Main Author: Tsakalakis, Nikolaos
• Published: University of Strathclyde 2012
• Subjects: 623.8
• Online Access: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.576320

The introduction of the probabilistic framework for damage stability, namely SOLAS 2009, introduced in 1st of January 2009 was a step change in regulation history and subsequently in Naval Architecture as a whole industry. The industry, as well as the academia though, was caught unprepared for such a ground breaking change, leading to confusion and retrospectively wrong decisions and misconceptions. It has been proven that survivability is not predicted accurately by the SOLAS s-factor and that harmonisation could not actually work. Furthermore it is believed, and thus still dealt with by deterministic means, that the water on deck problem has not been resolved. To this end, the focus in this study is on passenger vessels. An attempt has been made to highlight not only the shortcomings of the probabilistic framework but also the sheer benefits from utilising such a method. SOLAS 2009 has been benchmarked against conventional methods so as to prove the later. More specifically it has been shown how the survivability of a given damage scenario can be accurately predicted and how time to capsize can actually be related to survivability in waves. In order to achieve this, established concepts like the critical significant wave height have been revised. Moreover, the proposed modifications of the s-factor can link it directly to performance-based standards such as Safe-Return-to-Port. Finally, it has be demonstrated how, when freed of its "childhood" illnesses, the probabilistic framework can provide with an irreplaceable, handy tool with which to make goal-based design and really exploit all the hidden potential leading to safer and more functional ships.