One of the concerns that arise while navigating ice-covered waters is the magnitude of the ice load encountered by ships. However, the accurate estimation of ice load still remains as a rather difficult task in the design of icebreaking vessels. This paper focuses on the global ice load for the icebreaking vessels. The extreme ice loads are expected from large ice features and these loads are most likely to be concentrated at the bow area of a ship. Ice load data of six icebreaking vessels in public domain, from the model tests and also from full-scale sea trials, are collected and then organized in the same format to give an insight for trend in global ice load variation according to various ship-ice interaction processes. Global ice load prediction formulas are compared with these data and are applied to a newly constructed DWT 70,000 class icebreaking tanker. Based on collected data, a semi-empirical ice load prediction formula is recommended for large sized icebreaking cargo vessels.
Recent trends in the change of oil and gas prices have accelerated the development of natural resources in the Arctic region. Expansion of Russian economy, partly by world-wide high oil and gas prices, has boosted the transportation through the Northern Sea Route. Year-round navigation through the NSR requires powerful icebreaker fleets and the maximum width of sea route in ice-covered water, therefore the size of ships, depend on the breadth of escort icebreakers. These days the dimensions of newly constructed ice class cargo vessels are so increasing that even the most powerful Russian nuclear icebreaker alone may not perform the role of icebreaking escort. The lack of larger and more powerful escort icebreakers operating in Arctic Sea suggests that the construction of independent ice-capable cargo vessels will be necessary in shipping industries (Choi and Lee 2006).