Abstract: Polar ships need to meet stringent safety and environmental requirements. Usually those ships are classified by different ice classes based on ice operation capability. However, the polar ships are also trapped by severe ice condition due to low propulsion power. Therefore, it is a realistic question to design the appropriate minimum propulsion power for ice operation. This paper focuses on the ice resistance and its related propulsion power for the ships with polar code (PC) classes. In consideration of seven typical polar ice conditions related to the PC rule of International Association of Classification Societies (IACS), a prediction method of ice resistance is developed by Lindqvist’s model. The results are compared with those of Lindqvist’s model and Riska’s model by using two real ship lines. The comparison among propulsion requirements of representative classification societies is made, and a formula of minimum propulsion power is presented on the basis of ice resistance by revised Finnish-Swedish Ice Class Rules (FSICR) method. The results are verified by the actual values from seven ice class ships. A relatively good agreement is achieved. As a conclusion, the presented prediction method of ice resistance and minimum propulsion power is recommended for evaluation of ice resistance and its related propulsion power during the process of developing polar ships.

Key words: polar ship, level ice| ice resistance| propulsion power| ship classification

摘要： Polar ships need to meet stringent safety and environmental requirements. Usually those ships are classified by different ice classes based on ice operation capability. However, the polar ships are also trapped by severe ice condition due to low propulsion power. Therefore, it is a realistic question to design the appropriate minimum propulsion power for ice operation. This paper focuses on the ice resistance and its related propulsion power for the ships with polar code (PC) classes. In consideration of seven typical polar ice conditions related to the PC rule of International Association of Classification Societies (IACS), a prediction method of ice resistance is developed by Lindqvist’s model. The results are compared with those of Lindqvist’s model and Riska’s model by using two real ship lines. The comparison among propulsion requirements of representative classification societies is made, and a formula of minimum propulsion power is presented on the basis of ice resistance by revised Finnish-Swedish Ice Class Rules (FSICR) method. The results are verified by the actual values from seven ice class ships. A relatively good agreement is achieved. As a conclusion, the presented prediction method of ice resistance and minimum propulsion power is recommended for evaluation of ice resistance and its related propulsion power during the process of developing polar ships.

关键词: polar ship, level ice| ice resistance| propulsion power| ship classification