Resistance tests in ice with the USCGC Healy

Model tests to measure the resistance of a 1:23.7 scale model of the USCGC Healy in ice were conducted at IMD. Results showed that the total ice resistance, which was equal to the total resistance minus the open water resistance, was linearly dependent on velocity, and proportional to ice thickness squared, for constant ice strength and velocity. The model was tested at two hull-ice friction coefficients and the results showed that the hull-ice friction coefficient had a greater effect in thicker ice, but was independent of velocity. Results from varying the ice strength showed an effect, which increased considerably with ice thickness. At 27 mm ice thickness, doubling the ice strength caused RIT to increase by about 25 %; at 76 mm ice thickness, doubling the ice strength caused a 40 % increase in RIT.NRC publication: Ye