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Home / Issue Archive / 2010 / November #11 / Double Acting Tanker Set for Pechora Sea Debut The first of two new Arctic double acting shuttle tankers for the Prirazlomnoye project has entered service

№ 11 (November 2010)

Double Acting Tanker Set for Pechora Sea Debut The first of two new Arctic double acting shuttle tankers for the Prirazlomnoye project has entered service

   The result of a unique collaboration involving an overseas designer and a Russian shipbuilder, the 70,000 dwt Mikhail Ulyanov (IMO Number: 9333670, photo) was delivered to Sovcomflot by Admiralty Shipyard at the end of February. The-state-of-the-art vessel, designed by Aker Arctic Technology, is currently undertaking general duties in the spot market, but her destiny lies in plying one of the harshest of trades, shuttling oil from the Prirazlomnoye oil field development in the Pechora Sea to a Floating Storage and Offloading (FSO) unit moored off Murmansk.

By John Balfe

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   Sister ship Kirill Lavrov is also soon to be delivered to service an area which is covered in ice during the entire winter navigation season, with ice first forming in November and lasting until June. During hard winter seasons ice can of over 1.2 meters in thickness can form.

   Operations will continue all year round in an area where the average number of ice period days is 213, and the minimum air temperature is minus 46 degrees Celsius. Oil production is expected to last for 22 years.
Originally envisaged as an Aframax design, the eventual selection of smaller ships came about due to concern with the draught and the stern loading effects in the shallow platform location, where there was a risk of flushing of the supporting berm for the ice resistant platform. Consequently the concept ship was reduced to feature a draught less than 14 meters and with a bow loading system adopted.

   At 257.33 meters long and 34.04 meters wide, Mikhail Ulyanov features a draft of 14.0 meters and a depth of 21.6 meters. The ship features a total cargo tank capacity of 87,029 cu. m and separated ballast tanks of 35,200 cu. m. She is fitted with ten Marflex electrically driven deepwell type pumps for cargo tanks and two electrically driven deepwell type pumps for slop tanks.

   The ship features a tailor made bow loading system for the Prirazlomnoye platform Direct Oil Offloading Complex (DOOC). The 10,000 cu. m/hour capacity Maritime Pusnes AS system is fully compatible with all other offshore loading facilities requiring “North Sea Type” bow loading.

   To meet their exacting tasks, the hull form for the Prirazlomnoye tankers was developed by Aker Arctic Technology Inc. (AARC), based on the double acting operation principle, for year round independent navigation in seasonal “average” ice conditions.

   Pioneered by Aker Arctic Technology, the double acting concept found first form in the shape of the tankers Mastera and Tempera, delivered by Sumitomo Heavy Industries to Neste Shipping. Sovcomflot, meanwhile, already has three Aker Arctic-designed double acting tankers in service delivered by Samsung Heavy Industries, while Norilsk Nickel is operating the first five double acting containerships ever to be built, and is in the process of taking on a sixth double acting ship, this time a product tanker from Nordic yards of Germany.  
According to Mikko Niini, president of Aker Arctic Technology Inc., for the Prirazlomnoye shuttle tankers, the hull form has been optimised for two modes of operation in first-year ice conditions. Those are astern operation in medium and thick first-year ice and ahead operation in thin and young ice conditions and open water.

   In Niini’s words, a double acting ship draws on operating experience and knowledge of the improved ice going performance of existing icebreakers arranged with bow propellers. The two basic hull-ice interaction mechanisms for improved ice going performance are decreased hull ice resistance, due to “washing”, or “lubrication”, of the hull by the wake of the bow propeller, and improved hull icebreaking performance, due to the slight pressure drop that occurs just ahead of the icebreaker due to water flow into the bow propeller.
Dimensioning of hull structures for ice strengthening for the ships is in accordance with Russian Maritime Register of Shipping ice category LU6 (Arc 6), with the stern of the vessel strengthened for bow design ice loads for double acting operation. The shuttle tankers are dual classed by RMRS and Lloyd’s Register, with a class notation of KM * Arc6 [2] AUT1 EPP Oil Tanker (ESP).
Here, the shell in the forward region of hull ice strengthening is transversely framed throughout; with built section main and intermediate ice frames at 400 mm spacing. A 60 mm thickness stem bar is arranged with a 45 mm radius stem plate.

   The bottom shell in the forward intermediate region of ice strengthening is longitudinally framed. At the edge of each of the vertical regions on the ship side there is a 4 mm step down in shell plating thickness.

   The side shell in the midship region ice belt between the ice load waterline and ballast waterline is strengthened with bulb sections for the main and intermediate ice frames at 400 mm spacing. Within the double side skin space there are platforms decks arranged vertically every 3.4 meters with intermediate ice stringers.

   The underwater hull form incorporates an icebreaking bow for operation ahead in young ice and thin first year ice conditions. However, as the tanker has also been designed for international trade, the bow shape is derived from a compromise between performance in ice and open water sea-keeping and performance in the Barents Sea and North Atlantic (for possible shuttle voyages from Murmansk in open water to European refineries).

   Mikhail Ulyanov is driven by four nine-cylinder (380 mm bore) Wärtsilä 9L 38 main engines, with maximum continuous ratings of 6,525 kW apiece. For harbour use, the ship is equipped with one Wärtsilä 4 L 20 auxiliary engine, while the emergency engine is an MTU 12V 2000 P82 unit.

   The ship is equipped with two equal “pulling” Azipod propulsion units from ABB Marine with a solid fixed pitch propellers of 5.6 meters diameter. Classed to LU 6 and with a maximum output of 8.5 MW, each system consists of a azimuthing rudder propeller and an electric propulsion motor installed inside the propeller’s submerged pod.

   Azipods enable a ship to penetrate cross ridged ice when running astern with a continuous slow speed, where conventional ships ram when running ahead. The basic hull-ice interaction mechanisms, for ridge penetration and crossing ridges in astern operation with Azipods, is the flushing and milling of the submerged surface of the ice ridge by side to side turning of the Azipod units.

   ABB Azipod units were selected for Mastera and Tempera. Equipped with one 16MW Azipod unit apiece, these vessels operate in Baltic ice conditions. However, the higher power twin Azipod solution was preferred for Mikhail Ulyanov and Kirill Lavrov because these ships will need to be able to achieve three knots speed astern in first year level ice, of 1.2 meters thickness with 0.2 meters of snow layer and three knots speed ahead in first year level ice of 0.5 m thickness.

   The ship is also equipped with two electrically-driven bow thrusters with controllable pitch propellers, while its 10,750 cu. m/hour capacity inert gas system has been supplied by Hamworthy Moss. She is equipped with a Sotznia Ustka Free Fall type lifeboat for 39 persons, while her helicopter deck for MI-8 type helicopter has been built in line with the latest International Chamber of Shipping (ICS) recommendations.

   As with every other aspect of the design of the ship, the bridge has been outfitted with state-of-the-art equipment, in this case supplied by Transas. The electronics will include communication equipment for GMDSS area (A4), two radars for extreme temperatures, two ECDIS 3000-I systems, six information displays with Navi-Conning, Automatic Identification System, Voyage Data Recorder, log, and echosounder. Meanwhile, a fully redundant Kongsberg Maritime dynamic positioning system based on two control computers (one on-line and one standby) is also installed.  
Mikhail Ulyanov’s Main Dimensions:
Length overall, abt.    257.33 m
Length betw. perp.    235.94 m
Breadth mld.    34.04 m
Depth mld.    21.59 m
Draught summer load line    14.00 m
Main Particulars:
Deadweight    69,830 tons
Trial Speed    16 knots
Cargo tank capacity, incl. slop tanks    87,029 cu.m
Ballast tank capacity    36,361 cu.m
Bunker capacity    2,332 cu.m
DO capacity    122 cu.m
Fresh water capacity    514 cu.m
Ice breaking, DAS mode    Three knots speed in level ice of 1.2 m thick
    and 0.2 m snow layer on top of the ice
Ice breaking, bow ahead    Three knots speed in level ice of 0.5 m
Classification

The Vessel, including its machinery, equipment and outfitting constructed in accordance with rules of dual Classification by Russian Maritime Register of Shipping (RS) and Lloyd’s Register of Shipping (LR).
The relevant class notations of Russian register and Lloyd’s Register are described below.
The vessel(s) have the following RS class notation:
Class: KM + Arc6 [2] AUT1 EPP Oil Tanker (ESP).
The vessel(s) have the following LR class notations:
+100A1 Double Hull Oil Tanker, ESP, ShipRight (SDA, FDA, CM), LI, +LMC, UMS, IGS, NAV1, IBS, ICC, SPM, BLS, Helicopter Landing Area, EP(P), DP(AA)1, Winterization D(-40)2.
LR descriptive class notations:
Pechora Sea (Prirazlomnoye) to Murmansk Service, part higher tensile steel, Ice Class (RMRS LU6), Centralized Operation Station for Liquid Cargoes, ShipRight (PCWBT), ETA.

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