THE ENCOUNTERED EXTREME EVENTS AND PREDICTED MAXIMUM ICE-INDUCED LOADS ON THE SHIP HULL IN THE SOUTHERN OCEAN

This paper studies the causes (ship operations and ice conditions) for the maximum ice-induced loads on the ship hull. Furthermore, the extreme loads are predicted with the Gumbel I asymptotic distribution. The study utilizes the full-scale measurement data collected in the Antarctic waters onboard S.A. Agulhas II between Dec 2013 and Feb 2014. The iceinduced loads were measured at the bow, bow shoulder and stern shoulder. The ice conditions were observed visually and the machinery control and navigational data were recorded continuously.The study showed that the turning of the ship has a major effect on the loading at the stern shoulder. The maximum loads also showed an increasing trend as a function of the observed ice concentration and maximum ice thickness in all three areas of the hull. In addition, the maximum loads at the bow showed a decreasing trend as a function of an increasing ice floe diameter. Furthermore, the study with the return period of the ice-induced loads showed that the return period of the loads was at the same level at the bow and stern shoulder. However, the extreme values exceeded with a probability of 1 % or 0.1 % are clearly higher for the bow.Copyright © 2015 by ASME