Author(s): Junji Sawamura; Hidetaka Senga; Kensuke Imaki; Keisuke Suga; Hyoil Kim
Keywords: No Keywords
Abstract: Ice resistance tests using synthetic ice in a towing tank were conducted to elucidate ice forces that occur when an icebreaker is advancing into ice floes or when ice floes are drifting into a ship. Synthetic ice made from a polypropylene plate with similar density to that of refrigerated ice was used for these tests. The water surface in a towing tank was covered with numerous disk-shaped synthetic ice floes. A ship is rigidly fixed and towed by a carriage at constant speed. A ship advances straight and obliquely into the ice-covered water. The ice forces in surge, sway, and yaw are measured using a load cell. The ice floe removal behavior is recorded by video cameras. The measured ice resistance is compared with ice resistance formulas. The ice resistance of the model test shows good agreement with those of ice resistance formulas. Collision tests were conducted in ice-covered water with large ice floes. The instantaneous ice forces that are exerted when a ship collides with the large ice floe can be measured. Peak force that occurs during a collision with a large ice floe has a small effect on ice resistance in ice-covered water. The relation between the ice force and ship advancing conditions (speed, drift angle, and bow shape) are investigated experimentally to identify the important parameters of ice force.