(www.MaritimeCyprus.com) In recent years, cargo collapse accidents that are thought to have been caused by parametric rolling have occurred successively in large containerships and car carriers, including an accident in which more than 2,000 containers were lost or damaged. In response to this situation, various organizations, institutions and groups have issued alerts and proposed numerous measures related to parametric rolling.
The International Maritime Organization (IMO) issued “Interim Guidelines on the Second Generation Intact Stability Criteria” – MSC.1/Circ.1627 (hereinafter, SGISc), which specifies criteria for assessing vulnerability to parametric rolling. A variety of measures for avoiding parametric rolling have also been developed and recommended, including the preparation of tables and polar charts of predicted parametric roll response, installation of rolling reduction devices, such as anti-roll tanks, and introduction of parametric rolling alert systems.
With this background, Nippon Kaiji Kyokai decided to publish these Guidelines, which summarize the requirements to affix the related notations to classification characters of ships that take effective measures against parametric rolling, together with the related requirements. The Appendices of the Guidelines also provide fundamental knowledge of the mechanism, features and points to note in connection with parametric rolling, an outline of the parametric roll response calculation, an introduction to devices and techniques for preventive measures against parametric rolling and the method for preparing polar charts.
You can click below to download the ClassNK "Guidance on Preventive Measures against Parametric Rolling":