As a key parameter, icebreaking capability is often used to judge whether a polar ship could navigate in level ice at a certain speed. This paper presents two methods to calculate icebreaking capability. The first one is a static method based on the estimation of ice resistance under different ice thicknesses and ship speeds. The second is a dynamic method that involves solving the equation of motion. A series of model tests with a double-acting icebreaking tanker were also carried out in the

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... e basin of the Krylov State Research Center to measure ice resistances. The simulated ice resistances were compared with model tests results for both ahead and astern running operations. The calculated icebreaking capability based on static and dynamic methods was validated with the model test result. A good agreement was achieved between measurement and simulation. The discrepancy between the model test result and the result simulated by the static or dynamic method was minor.