Author: O.V. Tarovik
Abstract
The article presents a formula to estimate a safe distance for icebreaker escorting of ships with azimuth thrusters. The formula has been obtained using a simplified representation of the processes that occur during ship stopping in ice. Ice resistance of a ship in the channel behind the icebreaker has been calculated using empirical formulae that include the main design parameters of a ship, such as bollard pull, maximum speed in open water, and others. The article also contains an analysis of the influence of various factors on safe distance. The formula has been verified by the model experiment on the stopping of Yamalmax-type LNG carrier in the channel behind the Leader-type icebreaker in 1,5 m thick ice. In addition, the calculation results were compared the full-scale distances between the Christophe de Margerie LNG-carrier and leading icebreaker during a transit voyage along the Northern Sea Route in February 2021. Average full-scale distances have been found to be significantly higher than calculated safe distance, and more corresponding to safe distance in open water conditions.
Keywords: icebreaker assistance, distance to icebreaker, safe distance, ship inertia, operation in channel.
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About author:
O.V. Tarovik - PhD, LLC Bureau Hyperborea, St. Petersburg, e-mail: oleg.tarovik@bureauhyperborea.ru
Issue: 66/67 (2022)
For citation: O.V. Tarovik. Safe distance for icebreaker escorting of ships with podded propulsors. Research Bulletin by Russian Maritime Register of Shipping. 2022, No. 66/67, pp. 4-18.
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