Kvaerner Unveils New Double Hull Arctic Tanker
To help unlock the oil and gas reserve potential from the severe environmental conditions in the Arctic continental shelf, Kvaerner Masa-Yards debuted a special tanker vessel designed to operate in both open water and ice conditions. The new tanker design also has a propulsion arrangement option—incorporating either a pair of diesel engines (top) or an Azipod propulsion unit (bottom).
The arctic tanker design is 120,000-dwt, with an overall length of 915 feet (279 m), a breadth of 141 feet (43 m) and a draft of 56 feet (17 m). According to the shipyard, 120,000 dwt is the maximum practical size for vessels operating in the shallow coastal waters of the Russian Arctic Shelf.
PROPULSION The vessel is designed for medium speed diesel or Azipod propulsion options. The medium speed diesel alternative consists of a pair of15,600-kW diesels driving a single controllable-pitch propeller through twin input, single output reduction gear with a built-in thrust bearing. The Azipod propulsion alternative comprises a new generation ACAC power plan and two 15 MW Azipod propulsion units. The system, according to the yard, is ideally suited for operation in ice, and the compact arrangement allows more space for cargo tanks, or perhaps a shorter vessel length.
THE HULL The double hull design fulfills the new requirements of Marpol 73/78 Annex I regulation 13 F. Ice strengthening is in accordance to DNV Ice-10; the tanker's double bottom and sides are ice-strengthened. Two alternative hull forms have been developed by Kvaerner Masa-Yards. Hull A, with its bulbous bow, performs better in open water, whereas Hull B, with its icebreaking stern, performs best in ice. Hull A is capable of operating independently in level ice of up to 2.3 ft. (.7 m); Hull B in ice up to 3.3 ft. (1 m).
CARGO HANDLING The ship is mainly intended to carry crude oil in seven tanks. It features three cargo segregates and can also transport oil products as return cargo to service distant arctic communities. Each cargo tank is fitted with its own variable-speed electric deep-well pump. The tanks are heated by a thermal oil system to reduce the risk of icing up of the heat exchangers and pipes. The cargo piping on the weather deck is placed under protective cover. The ballast water pumps are also of the deepwell type, so no separate ballast water pump room is needed. The basic vessel design can be altered for shuttle tanker service with relatively minor modifications, the yard reports. For more information from Kvaerner Masa-Yards, Circle 119 on Reader Service Card