Field Measurements of Local Ice Load on a Ship Hull in Pack Ice of the Southern Sea of Okhotsk

Field tests have been performed on board Soya, an icebreaking patrol ship of Japan Coast Guard (JCG), in three winters of 2005, 2006 and 2007 when she sailed ice-covered waters in the southern part of the Sea of Okhotsk. In the test, local ice loads acting on the ship hull were measured. On board measurements of ice conditions including ice thickness and ice concentration were also performed. Measured data were divided into segments of 2 km in length. The maximum ice load, average ice concentration and ice thickness were calculated as representative values for each segment. This paper describes the method of the field test. Ice load data measured in the three winters are presented. Effects of ice thickness and concentration on the ice loads are discussed.