Influence of bow design on ice breaking resistance

One of the main contributions to the resistance in level ice is the breaking force which is mainly influenced by the bow shape, beside ice properties and the ship's speed. Understanding the influence of the bow shape on the ice breaking resistance is essential for the assessment of the hull form in an early design stage. However, at a first glance the bow shapes of modern ice breaking vessels seem to be quite similar. Thus, a need exists to evaluate the contribution of the ice breaking force to the resistance in ice methodically for different bow shapes. Since model tests are still the most reliable resistance prediction method, they form the basis for the analysis of the ice breaking process at the bow. Specifically, breaking patterns and geometric bow parameters are investigated. The findings are compared with the selected semi-empirical method of Lindqvist. On this basis the Lindqvist approach is evaluated with further model test results and theoretical considerations. Finally, refinements of the Lindqvist formula are suggested where appropriate based on the analysis.