Arctic Marine Transportation: State Of The Art

Abstract

ABSTRACT This Paper illustrates that safe and cost-effective Arctic tanker transportation on a year-round basis is feasible in both the North American and Russian Arctic areas. An overview of existing icebreaking tankers is followed by a review of recent advances in icebreaking technology, proposed improvements to ice regulations, and the environmental impact of Arctic tankers. A year-round transportation system is described, including a discussion on tanker loading in the Arctic. A voyage analysis is used to demonstrate the positive economic effects of improved technology on transportation costs. INTRODUCTION Icebreakers and open water tankers have quite different characteristics. It is worth considering those differences as an introduction to the design of icebreaking tankers. Icebreakers are small, powerful, highly manoeuvrable multi-propeller ships (Average Horsepower Displacement Ratio HP/?=2. 1)[Ref. (1)]. They are also extremely strong, double-hulled, built of ductile steel and have excellent safety and environmental records. Open water tankers are large, relatively low powered, single-screw ships with poor manoeuvring characteristics (Average HP/?=O.2). They are usually built with a single skin of about one inch of steel. These large vessels have a less than favorable safety and environmental performance record. What is needed for the transportation of oil in an Arctic setting is a tanker which has more of the useful characteristics of an icebreaker. Very few icebreaking tankers exist today; all of them operate safely and successfully. But for year-round operation in the Arctic waters of Russia and North America, a synthesis of the characteristics of each is required. This Paper will show that such icebreaking tankers can be designed and built. ICEBREAKING TANKERS Key examples of icebreaking tankers are presented below. It should be noted that extensive icebreaking research has been undertaken in association with each. A major research program in the North American Arctic in 1969 and 1970 with the modified open water tanker Manhattan proved successful [Ref. (2)], when it was demonstrated that safe tanker navigation through the Arctic is possible. The large propulsion power, 43000 hp (HP/?=O.3), made efficient icebreaking possible. Four icebreaking tankers (Lunni et al, HP/?=O.7), intended primarily for service in the Northern part of the Baltic Sea, were built in Germany in the 1970s [Ref. (3)]. Their design incorporated features such as an icebreaking hull form with a new bow shape, and an ice-strengthened structure that included double-bottom tanks and a double-skin side shell. These vessels have proven to be able to transit level ice of 1 m (3 ft.) continuously. They have been profitably employed in independent icebreaking in trips to the North American and Russian Arctic regions without incident. The MV Arctic was built in Canada in 1978 as a double-hull Ice Class 2 bulk carrier (HP/?=O.4). During the winter of 1984/1985, the ship was modified to an OBO carrier to facilitate the shipment of crude oil from the Bent Horn field in the Canadian Arctic Islands.