Real-time evaluation of second generation intact stability criteria

Abstract

The performance of a vessel cannot solely be determined as a function of its size, speed and autonomy. The seakeeping behaviour of the vessel in extreme weather conditions is very difficult to predict and the IMO is in the process of introducing new intact stability regulations to deal with failure modes generally associated with extreme weather conditions such as parametric rolling, broaching or pure loss of stability in astern waves. Traditionally, the on-board crew only operates the vessel from one location to another whilst any other repairs, maintenance or decisions will be carried out by a support crew onshore. The rapid increase of computer power and communication technology allows the on-board crew to perform an advanced computation based on the real-time behaviour of the sailing vessel. At the International Maritime Organisation (IMO), the development of second generation intact stability criteria is thoroughly discussed before being implemented and enforced in the maritime industry. The lower level (level 1) criteria are conservative but can be easily implemented in stability codes. In this particular study it is examined how an existing and extensively used commercial computer code, in the present case GHS