Application of the 2nd Generation Intact Stability Criteria for fast semi displacement ships

The Second Generation Intact Stability Criteria (SGISC) are developing since 2002 after a series of naval ac-cidents, which clearly demonstrated that actual stability criteria are not adequate to account for significant changes in the design and operation characteristics of new commercial ships. The philosophy is a multi-level approach in which successive levels are less conservative and more accurate, arriving, if necessary, to the Di-rect Assessment of stability failures. In this paper, Level 1 and 2 of the three main stability failure modes of the SGISC: The Parametric Roll, Pure Loss of Stability and Surf-riding/Broaching are studied on four naval ships the Systematic Series D two-parent hulls, the ONRT, benchmark ship from research version of the US Navy, and FREMM, a class of mul-ti-purpose French- Italian frigates. For every ship typology, when one was found vulnerable to 2nd level, the corresponding criteria were analyzed by navigation conditions to estimate operational limits.