Analysis of the direct strength of container ships according to UR-S11A

The UR-S11A standard regarding the longitudinal strength for container ships was put forward in the latest unified requirements published by International Association of Classification Societies (IACS). Traditionally, the longitudinal strength of container ships is to be verified according to UR-S11, but now the new standard is stricter in this issue. In this paper, a comparison is made between the loads of UR-S11 and UR-S11A, and in order to find out the influence of the new standard on the longitudinal strength of container ships, a structural strength analysis is executed and compared toward a 4 250 TEU container ship according to both UR-S11 and UR-S11A. It is noted that the wave loads under UR-S11A are much larger than that for UR-S11. In brief, the new standard puts higher requirements on the structural strength of container ships based on the calculation results. It provides valuable references for research and technical personnel in terms of the cargo hold FEM analysis of container ships. Meanwhile, it also gives valid suggestions for the future container ship design.