This paper describes the results of model tests carried out in ice and open water conditions to evaluate performance of the United States Coast Guard (USCG) Heavy Polar Icebreaker (HPIB) indicative design. The resistance, propulsion and manoeuvring performance in ice conditions was evaluated at three different ice thicknesses (4, 6 and 8 ft.) with flexural strength 100 psi using two power setups, 36500 HP and 65000 HP. Calm water resistance and propulsion tests were also performed to evaluate open water performance. Models were constructed and tested corresponding to two indicative designs, one with triple shaft propulsion system and the other with one centre shaft and two wing podded propulsors. The present paper describes only the results for the model with triple shaft propulsion system.