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Stability and Subdivision


Intact stability

Intact Stability Code
IMO has long developed intact stability criteria for various types of ships, culminating in the completion of the Code on Intact Stability for All Types of Ships Covered by IMO Instruments (IS Code) in 1993 (resolution A.749(18)) and later amendments thereto (resolution MSC.75(69)).  The IS Code included fundamental principles such as general precautions against capsizing (criteria regarding metacentric height (GM) and righting lever (GZ)); weather criterion (severe wind and rolling criterion); effect of free surfaces and icing; and watertight integrity.  The IS Code also addressed related operational aspects like information for the master, including stability and operating booklets and operational procedures in heavy weather.

In 2008, the Maritime Safety Committee, at its eighty-fifth session, adopted the International Code on Intact Stability, 2008 (2008 IS Code), following extensive considerations by the SLF Sub-Committee and taking into account technical developments, to update the 1993 Intact Stability Code.  MSC 85 also adopted amendments to the SOLAS Convention and to the 1988 Load Lines Protocol to make the 2008 IS Code mandatory, which entered into force on 1 July 2010.  The 2008 IS Code provides, in a single document, both mandatory requirements and recommended provisions relating to intact stability that will significantly influence the design and the overall safety of ships.