Study on the procedure to obtain attainable speed in pack ice

Abstract

Cost evaluation for voyage route planning in ice covered sea is one of the major topics among ship owners. Information of ice properties, such as ice type, concentration of ice, ice thickness, flexural strength of ice and speed-power relation in given ice properties, are very important to decide optimum route in cost perspective. To find procedure of attainable speed evaluation at any designated pack ice condition model test results of resistance, self-propulsion and overload test in ice and ice free water were used. Also calculation of net thrust and estimation of ice resistance by empirical formula were performed. All model tests were carried out in KRISO ice tank and towing tank. Combination of model test results and careful observation of underwater videos shows physical phenomena of underwater situation and suitable buoyancy and clearing resistance of empirical formula. Detailed description of determination of attainable speed in certain power and pack ice condition will be presented in this paper.