Ordered December 1997 Length 65 m Displacement 1.853 million kg Builder Meyer Turku | Yard number 496497 Weight 2,076 tons Draft 2.9 m | |
 | ||
Name Arcticaborg (Арктикаборг)Antarcticaborg (Антарктикаборг) Completed 14 October 199817 October 1998 | ||
Arcticaborg (Арктикаборг) is an icebreaking platform supply vessel operated by Wagenborg Kazakhstan in the Caspian Sea. She and her sister ship, Antarcticaborg (Антарктикаборг), were built by Kværner Masa-Yards in Helsinki, Finland, in 1998. They are the first full developments of the double acting ship concept and among the first icebreakers equipped with Azipods, electric azimuth thrusters manufactured by ABB.
Contents
General characteristics
The 2,043-ton Arcticaborg and Antarcticaborg are 65.10 metres (213.6 ft) long and have a beam of 16.40 metres (53.8 ft). Designed to operate in shallow waters with a maximum depth of 5 metres (16 ft), their maximum operating draught is only 2.90 metres (9.5 ft). Furthermore, their main dimensions are limited by the Russian inland waterways, which had to be used to transport the ships to the Caspian Sea. The gross tonnage of Arcticaborg and her sister ship are 1,453, net tonnage 454, and deadweight tonnage 675 tons. The ships are served by a crew of 12 and have accommodation for 20.
Being supply ships, Arcticaborg and Antarcticaborg are equipped to carry a wide range of goods needed on the offshore platform. Each ship has a 350 m2 (3,800 sq ft) open aft decks for dry cargos and a cargo hold which has a hatch large enough the fit a twenty-foot container. For powderized goods such as cement and barite, they have five storage silos with a combined capacity of 51 m3 (1,800 cu ft). Furthermore, the ships have cargo tanks for 48 m3 (1,700 cu ft) of liquid drilling mud, 363 m3 (12,800 cu ft) of fuel, and 278 m3 (9,800 cu ft) of fresh water. On their way back from the platform, Arcticaborg and her sister ship can carry 67 m3 (2,400 cu ft) of sewage and wastewater. They are also equipped for firefighting, pollution control and rescue operations, and has towing and anchor handling equipment.
The ships are classified by Russian Maritime Register of Shipping with ice class UL, equivalent to the highest Finnish-Swedish ice class, 1A Super. However, the actual level of ice strengthening far exceeds the requirements of the ice class notations.
Power and propulsion
Arcticaborg and Antarcticaborg have a diesel-electric powertrain with two six-cylinder Wärtsilä 6L26 4-stroke medium-speed diesel engines, each with a maximum continuous rating of 1,950 kilowatts (2,610 hp), driving van Kaick DGS generators rated 2,250 kVA at 690 V. According to the power plant principle, the main generators in the forward engine room provide electrical power for all shipboard consumers, including propulsion. For emergency and harbour use the ships also have Valmet 612 diesel engines, rated at 130 kilowatts (170 hp), coupled to 163 kVA alternators. The vessels are propelled by two ABB Azipod VI1100A electric azimuth thrusters rated at 1,620 kW each. Arcticaborg and her sister ship were among the first icebreakers fitted with Azipod units that allow the ships to operate astern in heavy ice conditions with excellent maneuverability. In addition the ships have one 150 kW bow thruster for harbour operations.
Arcticaborg and her sister ship are one of the few ships capable of operating in the harsh ice conditions of the shallow Caspian Sea oil fields. They are able to break level ice up to 60 centimetres (24 in) thick at 3 knots (5.6 km/h; 3.5 mph) when moving ahead. However, the bow is designed with good seakeeping and open water characteristics in mind, and in heavy ice conditions the ships are turned around and operated stern first. In such way, their icebreaking capability increases to 1 metre (3.3 ft) of level ice. More importantly, by allowing the Azipod units to mill and crush the ice, Arcticaborg and Antarcticaborg are able to penetrate ice ridges that are thicker than the draught of the ship and sometimes reach the seabed without having to rely on backing and ramming. Their service speed in open water is 13 knots (24 km/h; 15 mph) and bollard pull 32 tons.
In addition to the four Azipod units installed on the ships ABB delivered a fifth spare unit, which allows the company to carry out a complete overhaul for all propulsors, one at a time, without having to dock the ships for extended periods.
Career
Arcticaborg and Antarcticaborg were ordered from Kværner Masa-Yards Helsinki New Shipyard in December 1997 following extensive research and model testing at the company's Arctic Technology Centre, nowadays known as Aker Arctic. Constructed in the covered dry dock at the same time, both ships were delivered to Wagenborg Kazakhstan BV, a subsidiary of the Dutch shipping company Wagenborg, within a week in October 1998 and sailed from Finland through the Mediterranean to the Black Sea and finally to the Caspian Sea through rivers Don and Volga. The final ice trials were conducted in the following spring. The ships were placed under long-term charter by Offshore Kazakhstan International Operating Company (OKIOC), a consortium which includes Royal Dutch Shell. Although initially classified by Bureau Veritas and flying the Dutch flag, the ships were reclassified by the Russian Maritime Register of Shipping and their port of registry was changed to Aktau, Kazakhstan, shortly after delivery.
Following the discovery of the Kashagan Field in July 2000, Arcticaborg and Antarcticaborg have since been operating for Agip KCO in the Northern Caspian Sea, where the water depth is only 4–7 metres (13–23 ft) and the ice conditions are particularly difficult. In 2000 dedicated ice-strengthened barges, pushed or towed by the icebreaking supply ships, were developed and constructed to allow uninterrupted cargo transportation to and from the platforms year round.