Impact assessment of the new North Atlantic wave data on long-term hull girder wave loads

Abstract

In December 2022, a new revision of International Association of Classification Societies Recommendation 34 came into force. The Recommendation includes completely updated data on wave statistics in the North Atlantic. The new revision of the document, on the one hand, made it possible to take into account modern methods of forecasting sea waves and the peculiarities of ship traffic on the North Atlantic routes; and on the other hand, it raised concerns among a number of international professional associations. A number of publications show that the calculated long-term wave parameters in the new revision have decreased compared to the previous revision of the Recommendation. In this article, independent comparative calculations of the long-term distribution of wave bending moment and wave shear force for four ships of different sizes and architectural and structural types are performed. The comparison between the values of wave loads using wave data in the previous revision of the Recommendation and the new revision are obtained. It is shown that the decrease in wave load values can reach up to 20 %. Additionally, the calculations of wave loads for the considered vessels were carried out in accordance with the requirements of regulatory documents. It was shown that despite the reduction in the wave loads obtained using direct calculation methods, good agreement of wave loads with the requirements of regulatory documents is ensured when using the new revision of the Recommendation.