14 Shipgaz No 6 2010
Newcomer Loke Viking Photo: rabt
Moving icebergs is one of the challenges for the Loke Viking. pull of 220 tons and is equipped with a 400-tons (550 tons brake) towing/ working winch of Rolls-Royce design and a similar sized anchor handling winch. Loke Viking has two secondary winches located above the main winch in a sheltered area. Deck operations are supported by two 5-tons sliding cranes port and starboard of the 750 square metres work deck.
The drums can handle up to 13 kilometres of wire, 9,000 metres of 84 mm wire on the main winch and 4,000 metres of 8-inch wire on the secondary. Alternatively, the latter can be replaced with 3,200 metres of synthetic rope. The 14,000-kW propulsion machinery consists of four MAK engines, two 4,000 kW and two 3,000 kW, in father-and-son arrangements that drives two Berg CPP propellers through Flender reduction gears. For manoeuvring and positioning purposes the vessel has two Becker spade rudders, with a 2 x 70 degree range split or synchronized, and four Brunvoll tunnel thrusters of 830 kW placed in pairs fore and aft, and one
830 kW azimuth thruster forward. The vessel has a total cargo capacity of 6,700 cubic metres of wet and dry cargoes in 11 tanks. The bulk cargo is loaded and discharged with compressed air. When Loke Viking was delivered, the vessel joined two other company AHTS’s on a charter for Cairn Energy west of Greenland, assisting two Stena Drilling rigs in the undrilled Buffin Bay Basin. In arctic waters, an important task for an AHTS is to protect the rig from drifting icebergs. This can be done in several ways.
The vessel is equipped with a powerful fire fighting system. Two water cannons placed on the bridge roof with a capacity of 4,351 cubic metres/h can reach a throw length of about 220 meters at a pressure of 13–14 bar. This is not only sufficient to move smaller icebergs, it is also sufficient to move the ship at a speed of 5–6 knots in calm waters. Larger icebergs are actually lassoed. The end of a floating rope is attached to a buoy. The vessel then
greenland Loke Viking, Balder Viking and Vidar Viking assisted Stena Don and Stena Forth in the exploration west off Greenland for Cairn Energy. Of three wells drilled, one was suspended for a possible re-entry and two were abandoned, lacking commercial discoveries. Total drilling cost for the last two is around USD 185 million. Findings of oil and gas are however ”extremely encouraging”, Cairns claims.
circles around the iceberg. Back at the buoy, the rope is connected to a towing wire, a couple of kilometres of the wire are played out and the vessel starts to pull. It is actually not a towing operation, more a way to change the drift angle to make the iceberg pass on a safe distance to the rig. Normally, the Swedish-flagged ship is manned by a crew of 14–15, mainly Scandinavians, but with total accommodation capacity for 45 persons, to cater for oil company representatives and other specialists. After having finished the Greenland venture, Loke Viking headed to the Oresund Drydocks in Landskrona, Sweden for upgrading and alternation works, before heading off to the new charter.
At the shipyard, the vessel was also used for measuring and to find the most favourable way to fit a ROV system on the next vessel in the series, the Njord Viking that is scheduled for delivery before the end of this year. Norwegian ENI Norge has chartered Njord Viking for four years to support exploration and development in the Barents Sea, including the Goliat field. The NOK 430-million charter will commence in May next year with Hammerfest as the vessel’s base. After the yard break, Loke Viking has headed off to the Arctic waters of Barents Sea where the vessel will support drilling of three wells for Statoil during some 200 days. The first well will be drilled by the rig Polar Pioneer at the Skrugard field, between Bjørnøya and the Snøhvid field. Also Loke Viking will have Hammerfest as base port. rolf P Nilsson
Motor spare parts and good customer service Motor-Service Sweden AB Address: Mölna Fabriksväg 8, SE-610 72 Vagnhärad, Sweden Phone: +46 (0)156 34040 Fax: +46 (0)156 209 40 sales@motor-service.se www.motor-service.se Annons 1 - 61x185.indd 1
2010-07-30 10:49:25