Rational Approach to Integrate the Design of Propulsion Power and Propeller Strength for Ice Ships

The current tendency shows that ship designers prefer to apply advanced methodologies, such as direct calculation and model test, to rationalize the propulsion system and propeller design. In this paper, two critical design issues for ice ship propulsion, namely engine powering and propeller strength, are discussed. Comparison of designs based on Finnish-Swedish Ice Class Rules (FSICR) formulae and a direct calculation method is presented. This paper documents detailed direct calculation procedures to estimate the engine power based on propeller performance in ice operation. Finite element analysis results of propeller blade are presented for strength assessment based on the ice loads and failure criteria in the proposed new FSICR. In addition, propeller cavitation and its induced surface force due to thicker blades used in ice class ships are also studied.