MT Varzuga


MT Varzuga is a Russian product tanker operated by Murmansk Shipping Company. After her modernization in 1993 she became the first merchant ship to be equipped with Azipod, an electric azimuth thruster developed in Finland in the late 1980s. She was also the first non-Soviet ship to transit the Northern Sea Route.

History

Uikku, built in 1977 by Werft Nobiskrug GmbH in Rendsburg, Germany, was the last ship of a series of four arctic product tankers ordered by a Finnish oil and petroleum products company Neste Oyj in the 1970s. The ships were given names after Finnish seabirds and the silhouettes of their namesake birds were painted on the side of the ships' superstructure. Lunni and Sotka were delivered in 1976 and Tiira and Uikku in the following year. Until the 1990s the ships were used mainly to transport oil products in the Baltic Sea.
In 1993 Uikku was chartered to a newly founded Arctic Shipping Services to ship petroleum products in the Arctic Ocean. The new shipping company, based in Murmansk, was a joint operation between two Russian companies, Murmansk Shipping Company and Primorsk Shipping Company, and a Finnish company Nemarc Shipping Oy, which in turn was a joint venture shipping company owned by Neste and Kværner Masa-Yards. The ship's propulsion machinery was modernized for navigation in the harsh ice conditions of the Arctic Ocean in 1993 and her ice-strengthening was increased in 1998. In the following years Uikku operated in the Baltic Sea in winter and in the Northern Sea Route during summer months.
In 1997 Uikku became the first merchant ship under non-Soviet flag to navigate the entire Northern Sea Route. In the following year she took part in Arctic Demonstration and Exploratory Voyage, a research project funded by the European Union to determine the feasibility of year-around navigation in the Northern Sea Route. Uikku, accompanied by a Russian nuclear-powered icebreaker NS Rossiya to open the way and a research icebreaker Kapitan Dranitsyn to provide facilities to 70 researchers from different countries, carried a cargo of gas condensate from Ob river estuary to Europe.
Fortum sold Uikku, mainly due to her age exceeding 25 years, to Murmansk Shipping Company in 2003. She was renamed Varzuga after the Varzuga River. As Fortum is a state-owned company, the selling of two oil tankers capable of navigating in severe ice conditions resulted in a written question to the Parliament of Finland by Representative Pentti Tiusanen about whether the ships should be retained in Finnish control as they could be used to lighten a grounded oil tanker in harsh winter conditions.
The ship has since been used for oil transportation in the Arctic Ocean. Along with her sister ship Indiga, sold to Russians at the same time, she has been involved in transporting oil from an oil terminal in the Ob Bay of the Kara Sea through the Kara Gates, the strait between Vaygach and Novaya Zemlya, to FSO Belokamenka in the Kola Bay of the Barents Sea.

Incidents

On 19 July 2010 Varzuga collided with her sister ship Indiga while being assisted by two nuclear icebreakers in difficult ice conditions. The bow of Varzuga and the stern of Indiga were damaged, but neither vessel lost seaworthiness and there were no spills.

Design

Uikku and her sister ships were designed to be able to navigate in the ice conditions of the Baltic Sea independently without icebreaker assistance and maintain a moderately high speed in ice. For this purpose they had more power than an average Baltic tanker and were normally required to use only 50-75% of the full engine power in ice — in normal operation only one of the two main engines was coupled to shaft, with the other remaining in reserve for difficult ice conditions. The highly raked stem, similar to those in traditional icebreakers, was designed to break the ice by bending it downwards under the ship's weight. The ships were also equipped with an air bubbling system to reduce friction between the hull and ice. To prevent pollution in case of grounding the ships were also built with double hulls and conformed to the IMCO regulations in respect of segregated ballast tanks even though they were regarded only recommendations back then.

Modernization

Uikku was extensively modernized by Kværner Masa-Yards' Helsinki New Shipyard in 1993 and became the first merchant ship to receive a newly developed electronic azimuth thruster, Azipod. Before her retrofitting the only ship equipped with such propulsion was fairway maintenance vessel Seili owned by the Finnish Maritime Administration. Her original MaK 12M551AK main engines, reduction gearbox, shaft generators, controllable-pitch propeller and rudder were removed and replaced with Wärtsilä Vasa marine generating sets and an 11.4 MW electric propulsion unit. Being one of the early designs the Azipod unit in Uikku was of the so-called "pushing" type with an aft-facing propeller instead of the more efficient "pulling" set-up usually used in modern Azipod-equipped ships.
Upgrading the propulsion machinery dramatically improved her manoeuvering and icebreaking capabilities, especially when running astern. Even though the ship's stern wasn't originally designed or shaped for icebreaking, ice resistance astern in level ice was only 40% of that of when running ahead despite the icebreaking bow. The modernization of Uikku also further proved the feasibility of Azipod in icebreaking ships and the double acting tanker concept as navigation in the severe ice conditions in the Northern Sea Route sometimes required the ship to be turned around and run astern to break through ice. The refit also increased her speed from 14.5 to 17 knots despite the propulsion power remaining roughly the same.
Uikku's sister ship, Lunni, was similarly modernized in the following year.
In 1998 the ice-strengthening of Uikku was upgraded and increased for the severe ice conditions in the Arctic Ocean, making her hull strength exceed the demands for Finnish-Swedish ice class 1A Super. The hull was also instrumented with strain gauges for the ARCDEV research voyage.