Cruise Ship Survivability in Waves

Abstract

Recent developments in damage stability legislation have drawn from ships with simple internal architecture such as RoPax and cargo ships. However, ships with complex internal architecture, such as cruise ships, have been rather neglected. In a regulatory context, cruise ships are currently grouped with RoPax and other passenger ships and this can be misleading. Moreover, it is well known that cruise ships vary significantly in their behaviour post-flooding incidents in comparison to RoPax ships. This problem has been acknowledged by the Cruise Ship Safety Forum Steering Committee who consequently funded the Joint Industry Project eSAFE to undertake cruise ship-focused research on damage stability. This entails analysis of pertinent simplifications embedded in SOLAS, the development of a methodology to combine consequences from collision and grounding accidents, the establishment of new survival criteria for cruise ships and finally the development of guidelines to use numerical flooding simulation in seaways as an alternative approach to assessing ship damage survivability. The findings of this research are presented in this paper, based on a full set of time-domain numerical simulations along with static calculations for a number of cruise ships. A new s-factor is derived catering specifically for cruise ships that accounts more accurately for survivability in a wave environment. A number of simulations are undertaken on varying size cruise ships with the view to deriving a relationship between the critical significant wave height and the residual stability properties of such vessels. The results provide the requisite evidence for comparison between SOLAS 2009 A-Index and the ensuing Damage Survivability Index.