Full Scale Measurement on Level Ice Resistance of Icebreaker

Abstract

This paper presents results from the investigation of ship resistance on first year level ice in the Barent Sea. The basis for the work is the availability of full scale measurement data obtained on board of KV Svalbard in 2007. Measurements were made of the ice thickness, ship speed over ground in addition to setting power. The ice thickness was measured by means of an electromagnetic device, which enables careful selection of the time sequences for which level ice is present. By utilizing Newton II law and conservation of energy, the total resistance can be determined. The ice resistance in level ice was then obtained by subtracting the open-water resistance from the total resistance. The open-water resistance was measured when the ship was traveling in open water during the expedition. The relationship between the ship resistance and the ship speed over ground in level ice was finally obtained and compared with the Lindqvist formulation of estimation of ice resistance.