Does the limiting ice-going capability actually correlate with RS ice class notation signs?

Many shipbuilders believe that there is an unambiguous correlation between class notation signs and the main characteristic of ship propulsion in ice, i.e. the limiting ice-going capability (speed vs ice thickness). This paper analyses current RS rules to bring to light this relationship. It is shown that the ice class notation sign may only correlate with the limiting ice-going capability if the minimum horsepower of the ship powerplant required by RS is taken into account. The analysis is performed for generic ice-going vessels with typical principal particulars and bow shapes. The study results show that it is not possible to predict the limiting ice-going capability based on the relationship of ship characteristics under consideration, therefore it cannot be used in the ship design process.

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