The effect of icebreaker power capacity on the calculated ice load (methodology)

Abstract

The article outlines the main provisions of the methodology for accounting for the effect of icebreaker power capacity on the calculated ice loads. In the current RS Rules, this is implemented by adjusting the calculated intensity of the ice load on the bow area of the ice belt by introducing a correction factor, which is determined by a simplified formula depending on the ratio of the actual total power on the propeller shafts and the base power value. The correction factor is assumed to be constant within the ice class and independent of the displacement of the icebreaker. It is shown that when designing advanced icebreakers of high capacity, where the actual total power on the propeller shafts significantly exceeds the base value for the ice class, the approach proposed in the current requirements of the RS Rules may lead to an unjustified increase in the estimated intensity of the ice load. A methodology and algorithm for eliminating this disadvantage of the requirements of the Rules are proposed, based on the accounting of statistical information on the energy capacity of Russian icebreakers. It is shown that for individual projects with significantly increased energy capacity for their class, the transition to the developed recommendations solves the problem of excess calculated ice pressures.