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

November 23, 2010

   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,