Ice resistance of ships in brash ice channel: calculation method

Abstract

Object and purpose of research. This paper discusses modern carrier ships and icebreakers operating in ice channels and harbours, typically filled with brash ice that always forms very quickly in regularly used passages due to harsh Arctic climate, thus seriously impeding navigation. The purpose of this study is to develop a calculation method for brash ice resistance that would facilitate theoretical estimates of ice propulsion performance for ships under design, and would also be helpful in planning their operation in Arctic conditions. Materials and methods. This paper theoretically describes the phenomena that accompany ship sailing in brash ice channel. Theoretical model is based on the data of full-scale trial data and the model tests performed in KSRC Ice Basin. Main results. Ice resistance calculation method for ship sailing in brash ice channel has been successfully developed. The effect of main parameters in the developed mathematical model has been thoroughly analysed. Calculation results have been compared versus available experimental data. Conclusion. The calculations performed as per this mathematical model for several notional large ice-going ships have shown that breadth and length of their parallel middlebodies, as well as bow shape, have the greatest effect upon resistance. Ice resistance tests performed in KSRC Ice Basin have shown a good correlation between experimental data and calculation results obtained as per the suggested procedure.

Keywords

• brash ice
• ice channel
• ice resistance
• friction force
• buoyancy force