Experimental Study of Ship Oblique Motion in Floating Ice of Different Concentrations

This study presents a model experiment on the oblique maneuvering of a ship in a floating ice environment. A series of captive model tests was conducted in both open-water and synthetic ice fields at concentrations of 60%, 70%, and 80%. The model was tested in a conventional towing tank using non-refrigerated polypropylene ice floes to simulate a broken ice field. Surge force, sway force, and yaw moment on the hull were measured under various drift angles and three speeds. Results show that in oblique motion, ice floes around the hull experience significant overturning and piling up, especially on the drift side, leading to random collisions with the hull. These interactions markedly affect the hydrodynamic forces. As the drift angle increases, the surge, sway, and yaw forces on the hull increase nonlinearly. The comparison between open-water and ice conditions indicates that floating ice can significantly increase the resistance and maneuvering forces. Higher ice concentrations lead to more frequent and more extensive contact between the hull and the ice floes, thereby further amplifying all components of the hydrodynamic forces. This work provides experimental data for validating calculation methods of ship resistance and maneuvering in broken ice. It demonstrates a feasible experimental approach for studying ship maneuvers in a floating ice channel.