DETERMINATION OF THE CALCULATED RANGE OF THE VALUES OF ICE RESISTANCE OF THE ICEBREAKERS OPERATED IN THE VOLGA-CASPIAN SEAWAY CANAL AND IN THE NORTHERN CASPIAN
The method to calculate the ice resistance is extremely important while designing the propulsion systems of icebreakers and ice ships, as it affects the accuracy of the calculated values of the power of the vessel and the optimal choice of the main engine. The method to determine the calculated ice resistance, used when designing the vessel itself and the propulsion system for an icebreaker, in particular, is developed. The structure of the method is presented; an example of its use while designing the propulsive complex for icebreakers operating in the Volga-Caspian seaway canal and in the Northern Caspian is considered. Ice resistance values are determined for a range of statistical values presented as an operational zone for designing the propulsion system of the icebreaker. That allows you to work with a wider range of possible design solutions, in which you can select the optimal values. Taking into account the specific features of the operational area, there were calculated the values of icebreaker resistance in unbroken ice, slightly broken ice and shallow waters for the initial range of the values of the main dimensions and hull lines of the vessel. While determining the resistance in slightly broken ice, the different intensity of ice concentration is taken into account. In order to determine the power of the vessel, there were chosen the calculated values of ice resistance as a result of the comparison of all kinds of the vessel resistance in ice. The choice is explained from the practical and operational points of view, the calculated values are compared with the values of ice resistance of icebreakers operating in the predetermined area of navigation. The calculated values correspond to the ice resistance in slightly broken ice due to 8 points of ice concentration.