On the time dependence of survivability of ROPAX ships

The time dependence of survivability of ROPAX vessels, when sustaining side collision damage in waves, is investigated herein by use of numerical simulations of ship motion and flooding. Conducted research confirms that ROPAX ships characteristically capsize fast, when sustaining damage leading to capsizing. A probabilistic analysis of the survive time after collision damage reveals that even for the most generic damage conditions assumed, the survival time in the case of capsizing remains short, which is characteristic of this type of ship design, disposing the typically large undivided deck to be subject to flooding in higher waves. In a case study, the unconditional survivability in waves, corresponding to survival s-factor of SOLAS regulations, is alternatively assessed with numerical simulations. The estimated survivability proves to be time independent in terms of practical implications. Observed deviations between current SOLAS formulation and simulations, suggest the employment of comprehensive simulation methods when more reliable estimations and assessments of survivability are required.