Recent contracts have provided the commercial confirmation of the success of the technological breakthroughs made by Aker Finnyards, as Kvaerner Masa-Yards will be known from 2005 onwards, in the design of ships for use on Arctic shipping routes. Aker Finnyards' double-acting technology is now set to become an industry standard for ships navigating in ice – making regular service at high latitudes a practical reality at very reasonable cost.
Double-acting technology showed its superiority at full scale for the first time in 2003, when two 106,000 dwt oil tankers, the 'Tempera' and the 'Natura', operated independently the entire winter in the eastern Gulf of Finland, loading crude at the newly opened Primorsk terminal north of St. Petersburg. Both vessels exceeded all performance criteria in conditions that saw up to 70 cm of level ice and ice ridges up to 13 metres deep.
More recently, Aker Finnyards has won contracts for a 14,500 dwt Arctic container vessel to be delivered in winter 2006 to JSC GMK Norilsk Nickel in Russia, and for the initial design of two 70,000 dwt Arctic shuttle tankers for a Gazprom and Rosneft subsidiary.
The Norilsk Nickel ship will be used to guarantee year-round transport of nickel and palladium from the Yenisei river port of Dudinka to a new distribution centre in Murmansk; while the two shuttle tankers will be used for offshore production on the Northern Russian shelf.
|Aker Finnyards is building a doubleacting 13 MW icebreaker to serve ExxonMobil's Orlan oil production platform in the Sakhalin offshore field.|
Arctic navigation and icebreakers represent one of Aker Finnyards' core businesses. The company's Helsinki shipyard has built more than 60% of all the world's icebreakers. The latest, a 13 MW double-acting supply and stand-by icebreaker, will be delivered in spring 2005 to Russia's Far East Shipping Company (FESCO), and will be the first newly built icebreaker in use in the Sakhalin offshore oil field.
Aker Finnyards assisted the Norwegian Coast Guard in the design of the latest patrol icebreaker for Spitzbergen recently, and is providing input for a new icebreaker for the U.S. Coast Guard for use on the Great Lakes.
Aker Finnyards' Arctic Technology Unit – MARC – is the only research centre of its type worldwide run by a private company, and plays an important role in providing shipowners and shipyards with access to new technologies for Arctic conditions. Recent customers include oil companies such as ExxonMobil, Shell, BP, Norsk Hydro, ConocoPhillips, Agip, Marathon, Statoil, Sakhalin Energy, Gazprom, LUKoil, Fortum, and China's Bohai Oil (CNOOC). Many engineering groups, including Bechtel and Tecnomare, also rely on Finnish expertise.
|Fortum Shipping's two new 105,000 dwt DAS crude carriers have performed very well in ice, and have very low fuel consumption in open water as well.|
A new propulsion system
Another important part of Aker Finnyards' work has been the development of an azimuthing electric propulsion system. The first prototype of the system, marketed under the Azipod® brand today, was built and installed in 1990.
The first full-size unit, rated at 11.4 MW, was installed in 1993 in the 'Uikku', a 16,000 dwt Finnish tanker. This was followed two years later by a second unit in her sister ship, the 'Lunni'. To date, these two ships have put in some 100,000 hours of trouble-free operation using the system.
Since then, Azipods have been installed in several new icebreakers: the AFY-built Caspian supply icebreakers, the 'Arcticaborg' and the 'Antarticaborg', the newest Finnish Baltic icebreaker, the 'Botnica', as well as the Norwegian 'Svalbard'. Several new icebreakers with electrical pod drives are currently building, among them a 13 MW twin-pod supply icebreaker due to enter service in spring 2005 and a twin-pod 9 MW terminal icebreaker for Exxon Neftegaz, and two 15 MW supply icebreakers for Sevmorneftegaz.
|Aker Finnyards recently won contracts to build the world's first Arctic container carrier, and design the first true Arctic crude oil carriers.|
Onwards to double-acting and oblique ships
Combining the advantages of electric propulsion with superb manoeuvrability, very low noise and vibration levels, and valuable savings in machinery space, Azipod drives represent a major step forward in ship propulsion. They have also provided the inspiration for a totally new concept – the double-acting ship.
Traditionally, when designing a bow, designers have always had to balance the needs of open water and ice operation requirements. If they focus on good icebreaking capability, the result will be poor open water performance and bad sea-keeping properties, and vice versa. Pod drives change all this, however.
A fully rotating pod gives the designer a unique possibility to design the bow of a ship to be good in open water, and the stern to be good at breaking ice The result: the 'doubleacting ship' (DAS) concept.
The bow design of Aker Finnyards' DAS concept incorporates experience built up with conventional vessels, and is an efficient, ice-strengthened open-water bow, offering open water performance some 10-15% better than that of a conventional ice-breaking bow. In icebreaking mode, a DAS vessel enters a ridge field at slow or moderate speed, and lets its pulling propeller chew up the ridge and slowly pull the vessel through.
As a new, cost-efficient technology, DAS opens up a number of possibilities in Russia's Far North, as well as in Alaska and Northern Canada. Studies have shown that maritime transport using DAS vessels is cheaper and more reliable than conventional tankers assisted by icebreakers, not to mention new pipelines.
Aker Finnyards have now gone even further, and created the 'oblique icebreaker'. Based on the idea of breaking ice with the entire side of a vessel, using a new oblique hull form and three propeller units, a ship of this type could be capable of breaking a channel 50 metres wide.
|Underwater view of an ice model test, showing the flushing stream created by the forward propeller. Reducing ice friction in this way is central to cutting power needs in modern icebreaking.|