Ship performance in ice channels narrower than ship beam: Model test and numerical investigation

Abstract

During escort and convoy operations, an icebreaker opens a channel while the escorted or convoyed ships follow the path along the channel. If the assisted ship is wider than the channel which the icebreaker creates, the created channel cannot fit the assisted ship. Thus, the assisted ship has to break some ice by itself. This is herein referred to as navigation in ‘narrow ice channel’. The performance of ships in narrow ice channel is investigated here. For this aim, model-scale test of a ship going through ice channels with different widths and ice thicknesses is firstly conducted. After that, numerical simulation of the model test scenarios is implemented with an in-house simulation program dedicated for ship operation in ice. The simulation correctly captured the main features of ship resistance change as a function of channel width, which indicates its validity as a simulation tool. Subsequentially, numerical simulations are implemented with several other ships in order to gain general insights into performance of ships in narrow ice channel. Focus is given to the influence of channel width on ships' encountered resistance and attainable speed in ice. The general findings through these simulations are useful for decision making tools.