The Study on the Ice Sea Trial in Chukchi Sea Using Korean Icebreaker “Araon”

The ice sea trial measurement in Chukchi Sea using research vessel Araon was performed on July 2010. It was the first voyage to the Arctic Sea. The latitude of the route was between 73 degree north to 80 degree north. Araon is the first Korean Ice breaking research vessel. The principle dimension is 110m length, 19m beam and 7.3m draft. Araon was designed to break 1.0m level ice of 630 kPa flexible ice strength. Four attempts to know the performance of the ship in Arctic region were carried out and the results were summarized in this paper. The basic datum for the sea trial such as ship speed, power of engine, wind speed, location of the ship, air temperature, drafts, heading of the ship etc., were measured during the trail in every second by the video recording. Simultaneously the ice information such as ice thickness, compressive strength, temperature of ice, snow depth, free board of ice floe were measured in each field by the coring tool, auger and compression test equipment. The ice sea trial was performed in large ice floes rather than level ice because the sea ice condition on July and August in Chukchi Sea has no uniform level ice and starts to melt. The size of four ice floes is about 100m to 300m length and 100m to 200m wide beam. It was some second year ice and most of first year ice floes. The mean flexible strength of ice was less than 250 kPa. The analysis result of the ice sea trial shows the relation between the ice thickness, ice strength, ship speed and power of engine. Araon is possible to operate at 1.5 knots in 2.5m ice thickness with 5 MW engine power when the strength of ice floe is 250 kPa. The speed reaches 3.1 knots at same ice condition if the power is increasing up to 6.6 MW. She has good performance compare to the design target (3 knots in 1.0m level ice and 630 kPa of flexible strength) but it’s come from the different ice types and low flexible ice strength. The more detail analysis result was discussed in this paper.