Intact stability of historic passenger ships in light of the second generation intact stability criteria

The paper examines the intact stability of historic passenger ships from the point of view of the contemporary notion of the intact stability, i.e. the Second Generation Intact Stability Criteria (SGISC) framework. An intact stability assessment using the Vulnerability Level 2 calculation procedures of SGISC for the dead ship condition was performed on four ocean liners: RMS Titanic, RMS Queen Mary, SS United States and SS Michelangelo, and two cruise ships: MS Song of America and MS Costa Concordia. In addition, the intact stability of the selected ships was appraised using the presentday mandatory intact stability requirements contained in the 2008 Intact Stability Code. The selected ships are believed to be good representatives of the main trends in passenger ship design over a one-hundred-year span bounded by two well-known maritime catastrophes: the sinking of the Titanic in 1912 and the Costa Concordia disaster in 2012. The paper offers an insight into how major design changes have affected the intact stability properties of passenger ships over this period. It was found that the examined ocean liners would perform well in terms of intact stability in the dead ship condition even from the point of view of the SGISC. The analysis also confirmed the advantages of the approach using the SGISC framework over simplified, (semi)empirical stability assessment methods. By looking into the evolution of the intact stability of ocean liners and cruise ships from the contemporary perspective, the paper draws the conclusions which are considered useful for the design of future passenger ships. ©2021: The Royal Institution of Naval Architects.