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Ice is no problem – when you know how

Aker Arctic Technology Inc.
Thanks to its advanced testing facilities and decades of experience, Aker Arctic Technology understands the challenges involved in designing ships capable of navigating in ice very well. Its unique technologies, such as double-acting vessels, lead the field and are winning new customers.

Aker Arctic Technology (AARC) recently celebrated the 40th anniversary of ice model testing at Western Europe’s first dedicated test basin, and the company has over 50 years of experience in developing ships capable of operating efficiently in ice.

AARC was the first ship designer to bring electric azimuthing thrusters (Azipods) to icegoing vessel, for example. Used in combination with modern hull forms optimised for ice conditions, these units have revolutionised vessel operations in ice, overcoming the shortcomings associated with conventional shafts and propellers in areas such as steering capabilities. Azipods were central to the development of AARC’s revolutionary double-acting principle, which allows vessels to proceed ahead in thinner ice and astern in heavier ice.

The Kirill Lavrov, launched in December 2009 at the Admiralty Shipyard in St. Petersburg, is the fifth Aker Arctic DAS™ shuttle tanker designed to transport crude from new offshore oilfields in the Pechora Sea to Murmansk without icebreaker assistance.

When double-acting vessels operate astern, the milling action of the propeller helps cut a path for the ship through the ice, and the water flow automatically flushes the hull, easing progress. Until this type of operation became possible, ice-going ships needed to be designed with an ice bow, which is much less hydrodynamic than an open-water bow, leading to higher fuel consumption.

The first ships to incorporate the doubleacting principle – the Arcticaborg and the Antarcticaborg supply vessels – have operated successfully in the Caspian Sea for more than 10 years. Two 1AS ice-classified Aframax-class tankers, the Tempera and the Mastera, featuring pod drives and a double-acting hull, were delivered by Sumitomo Heavy Industries to Neste Oil in 2002 and 2003.

The 13 MW Fesco Sakhalin – an ice-breaking platform support and standby vessel based on a double-acting design for Exxon Neftegaz’ Sakhalin 1 project in the Sea of Okhotsk – has proved very capable of dealing with conditions there, where 1.5 metre-thick ice can create rubble formations 20 metres deep.

A new-generation Arctic oil export system

Norilsk Nickel’s fleet of five modern vessels – completed with the Norilskiy Nickel Arctic container vessel, featuring a 13 MW electric pod and built to the highest ARC 7 Arctic ice class so far – has ushered in a completely new logistics system capable of operating independently of high-cost icebreaker assistance through the Kara Sea and the River Yenisei.

AARC is currently designing a new generation of shallow-draught icebreakers for operations in the northern Caspian to be built by STX Romania for Caspian Offshore Construction (COC).

Transporting oil by tanker in the Arctic used to be handled by nuclear-powered icebreakers and relatively small oil tankers. After electric pod propulsion was tested in the region by retrofitting two existing tankers, Naryanmarneftegaz launched a project with Aker Arctic to develop a direct marine export system for onshore oil production in the Timan-Pechora region, which is now in its second winter of operation.

This work led to a pioneering pair of Arctic icebreaking shuttle tanker types for Sovcomflot built by Samsung Heavy Industries and Russia’s Admiralty Shipyards under a cooperation agreement signed with AARC in 2004.

These new designs are able to break ice up to 1.5 metres thick covered by 0.2 metres of snow at a speed of approximately 3 knots moving either forward or astern. Powered by twin pods and featuring a hull that has been ice-strengthened in accordance with RMRS Ice Class ARC 6, these ships are fully winterised to cope with temperatures down to -45 °C and incorporate a bow loading system capable of spill-free loading/ unloading at 10,000m3/h.

Taking on new challenges

The latest fruits of AARC ’s intensive product development programme have been reflected in a number of contracts for the design of a new generation of multipurpose and ice management icebreakers. Work includes the development of the conceptual and basic designs and preparation of the tender documents needed for yard contracts, together with construction supervision in some cases.

AARC’s new ice management icebreaker for Rederi AB Transatlantic, designed to work in harsh environments affected by multi-year ice inclusions.

Ice management is very useful in exploration drilling in harsh Arctic environments, where dedicated icebreakers can break up heavy ice as it approaches a drilling site, ensuring that ice loads on floaters are kept to an acceptable level.

AARC has also been awarded a design contract for five shallow-draught Icebreaker tugs for the northern Caspian. These will be fitted with three 1,600 kW azimuthing electric thrusters to provide efficient ice milling in the world’s largest oil field development, the Kashagan field in the Kazakhstan sector of the Caspian Sea.

AARC is also working on innovative drill ship designs that could open up new opportunities at very high latitudes, such as the Beaufort Sea, by offering new solutions based on dynamic positioning to reduce ice loads.

> Mikko Niini
(Published in HighTech Finland 2010)