Investigation of ship ice-resistance in the marginal ice zone

Abstract

Under the influence of global warming, the Arctic ice sheet area has been decreasing. As a consequence, vessel traffic has been increasing rapidly in the Arctic. Most Arctic traffic occurs in summer when ice coverage is at its lowest level. Therefore, the impact of brash ice and broken ice on ship resistance is relevant to study during the Arctic summer. The aim of this thesis was to compare ice resistance prediction models for brash ice conditions and broken ice conditions, respectively. Three groups of experiment data from literatures were compared in a case study. By comparing the model estimates and the experiment results, the applicability of each model was discussed and summarized. The Spencer and Jones model for brash ice and broken ice was found to give rather good performance prediction and was thus applied for calculation of ship performance of Arctic transit ships. In addition, a sensitivity study was carried out to investigate the impact on the ice resistance from the various parameters of ice and ship hull. It was found that the ice thickness and ice concentration have the greatest influence on the resistance in all the models. With the selected models, the corresponding fuel consumptions and sailing time for a part of the Northern Sea Route was simulated and compared under different ice conditions. The ice was real-life records of July, October, and November in 2018. The results indicated that severe ice conditions and a higher speed lead to significant increases of fuel consumption.