No.9 2022/2023 - MARIN - Roll Risk Estimator
IG Circular August 2022
The International Group is a member of the Maritime Research Institute of the Netherlands (MARIN) Top Tier project. The project has been established to examine and assess the causes of container losses arising from at-sea incidents onboard various sizes of container ships, with a particular focus on ultra-large ships.
The project has been approved by a cross-section of industry, academic and government interests, and MARIN will produce a report of its findings, including recommendations, in due course. It is envisaged that the recommendations will eventually lead to operational and technical improvements that should mitigate the risk and underlying causes of container losses at sea.
The International Group has received the annexed roll risk estimator [use the MARIN link for the updated excel sheet to be used as an annexe to this circular]. It indicates combinations of speed, heading and wave period that result in the unfavourable tuning of roll motions that should be avoided. It does not give an indication of the maximum roll motion, and at which wave height the vessel is vulnerable to adverse rolling must be judged by the master’s experience. In addition, it does not address other dangerous ship behaviour like, e.g., large vertical accelerations, shipping green water and slamming.
All clubs in the International Group have issued a similarly worded circular.
For: West of England Insurance Services (Luxembourg) S.A.
Loss Prevention Manager