Hull Forms for Icebreaking Tankers

The optimum design for an icebreaking tanker will depend on the trade route and the cargo delivery requirements. For example, the hull shape of a ship that spends almost all of its time operating in heavy ice can be optimized for low speed icebreaking conditions. In contrast, a ship that spends a small portion of its time in light ice that has been previously broken and the rest of its time in open water can be optimized for different requirements. The challenge for the designer is complicated by the observation that many ship design features that enhance powering performance in ice are detrimental to open water performance. This paper presents predictions of ship resistance in pack ice, level ice and open water for four tanker designs, which include a conventional hull with no modification for ice at all and three designs proposed for operation in Arctic ice conditions. The predictions of ship performance are based on model experiments carried out in Canada and Korea. The resistance of the four hulls in open water, two concentrations of pack ice and two level ice thicknesses are compared and discussed. Information of this sort is essential for developing the optimum ship design for a particular shipping route, given known profiles of open water, pack ice and level ice.