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DNV identifies
the Arctic challenge
Booming Baltic oil exports have been the primary catalyst behind the current orderbook of ice-classed aframax tankers. The centre of action is the Gulf of Finland and particularly the Port of Primorsk. But owners are increasingly keeping an eye on the Northern Sea Routes and the Sakhalin area in the Russian Far East. Large, ice-strengthened tankers is not an entirely new idea. They were pioneered in the US 30 years ago with the conversion of the Manhattan for test navigation of the North West Passsage. Finnish company Neste built 16,000 DWT tanker in the 1970s to trade in icy waters. The first aframax vessels on the Baltic scene were Fortum’s Mastera and Tempera, both 106,000 DWT. They have the highest ice-class. Det Norske Veritas (DNV) is strongly committed to this area of shipping. According to DNV Forum demand is soaring for ice-class tankers resulting in a USD 4.5 billion investment in high-spec vessels. Conditions in “first-year ice” areas like the Baltic are fairly well-known, so most of the research is now going into navigation in Arctic waters.
Wilhelm Magelssen, head of DNV’s Maritime business and marketing department says:
– With the opening of new Arctic trade routes that encompass cold climates and heavier weather than before, we predict that ships in the future will most likely be specified with additional class notations to minimize risks and the environmental impact of shipping. We must make shipowners and crew recognize the challenges of operating in cold climates and icy conditions. DNV is prepared to support and to be a discussion partner for owners, yards and authorities in the further development of shipping activities in cold climates.
And this is not looking too far ahead.
Ice-classed vessels
According to Clarkson Research in London there are presently 262 Ice Class 1A ships in operation today, or 4.2 million DWT, but 70 to 80 per cent of them are below 20,000 DWT. However, there are another 234 vessels with ice strengthening on order, of which 165 with Ice Class 1A and 3 with Ice Class 1A Super. Stephen Gordon of Clarkson Research says to DNV Forum that “there is a debate about how to develop the crude oil network in the Arctic. The most likely development looks to shuttle through Murmansk”. Dr Igor V. Stepanov – a leading research scientist at the Arctic and Antarctic Research Insitute (AARI) – says that there is little experience in operating bigger vessels in ice-infested waters, but that the technical challenges are tested through fullscale trails to assess ice-performance and ice-loads for large vessels.
“Stena Antarctica”, one of two aframaxes built to highest ice-class, due to be delivered this year. CONNY WICKBERG/DAN HAMBE
Tanker ice trails
Tanker ice trails were begun in 2002 offshore Sakhalin, sponsored by Sakhalin Energy Investment Company and Exxon Mobil and they were carried out by AARI as the main contractor with Central Marine Design and Research Institute in Russia and the Science and Technology Group in the US. The vessel used in the trails were, according to DNV Forum, 106,000 DWT tanker Primorye, with DNV Ice Class 1C, owned by Frico and two icebreakers, Krasin and Magadan, operated by Fesco.
Primorye was full instrumented and huge amounts of ice-performance and ice-load data were obtained. Dr Stepanov says that the analysis of the data led to appropriate adjustments to ice-performance and ice-load models to make them applicable to large tankers and LNG carriers. Other research concerning Baltic aframax tankers show that the net steel weight will increase by around 2.5 per cent for Ice 1C vessels, 4 per cent for Ice 1B and over 5 per cent for Ice 1A vessels.
A challenge ahead
The challenge ahead for owners and classification societies is considerable. DNV is well ahead in the game with one third of all DNV classed tankers currently on order specified with ice strengthening and the proportion seems to increase.
To the predominately Far Eastern yards constructing these value-added tankers it is a technical challenge in order to meet very high specifications in fabrication and welding.
//Petter Arentz
Latest update 18-10-2006 8:49
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