Proposal of Optimal Operation in Ship Rolling Motion Considering Sea State Conditions

Most of the research on ship rolling motion concerns a specific type of ship, such as containerships, or analyzes sailing during certain wave characteristics, rather than the full spectrum of waves that can be encountered during the entire sea route. To date, the most frequent merchant ships in the world are general cargo ships, where the ship's behaviour at any sea condition has a great influence on overall safety, as well as the lashing design of non-standardized cargo. For this reason, the present paper aimed to study ship-performance models, starting with concepts of the basic physics of ships and waves. Firstly, the ship's behaviour was analyzed from a theoretical point of view, both in calm waters and when sailing in waves, but independently. Afterwards, the ship-waves system was analyzed during rolling with all variables accounted for at the same moment, with the objective of obtaining roughly realistic models. Relevant results are shown in each of the models, which may be of great interest for ship operators and, in general, for the shipping industry, so as to improve the safety of maritime transport. Finally, these results were validated with a case study.