MISSION BASED SHIP DESIGN UNDER UNCERTAIN ARCTIC SEA ICE CONDITIONS

For the design of an ice-going ship, determining its ice capability is one of the key design aspects. Excessive ice capability increases the ship's acquisition cost and reduces its deadweight capacity. On the other hand, less ice-capability limits its serviceable area and it decreases the probability for the ship to complete its given/expected missions successfully. The ice conditions, which the ship would encounter during its operations, are dependent on its route planning, and they become a basis for the determination of its ice-capability. For the design of an ice-going ship, which is going to be operated under constant operational conditions, static route analysis or use of historical voyage data is sufficient to estimate its required ice-capability. However, if the operational conditions change dynamically, like the Arctic sea ice conditions, a dynamic route analysis is needed. Otherwise, the required ice-capability tends to be over-estimated by the static analysis. Sea ice conditions in the Arctic change dynamically from hour-to-hour. In addition, the forecast of its operational conditions has a high uncertainty due to lack of understanding of the Arctic sea ice. Thus, for the design of a ship for Arctic operation, we carry out transit simulations in a dynamic and stochastic manner in this paper and estimate the required ice-capability from the simulations' result.