''Semyon Dezhnev'' ( rus, Семён Дежнёв) is a

Russia Russia (, , ), or the Russian Federation, is a List of transcontinental countries, transcontinental country spanning Eastern Europe and North Asia, Northern Asia. It is the List of countries and dependencies by area, largest country in the ...

n icebreaker. It is the last of twelve Project 97A icebreakers built by

Admiralty Shipyard The JSC Admiralty Shipyards (russian: link=no, Адмиралтейские верфи) (''formerly Soviet Shipyard No. 194'') is one of the oldest and largest shipyards in Russia, located in Saint Petersburg. The shipyard's building ways can ac ...

Leningrad Saint Petersburg ( rus, links=no, Санкт-Петербург, a=Ru-Sankt Peterburg Leningrad Petrograd Piter.ogg, r=Sankt-Peterburg, p=ˈsankt pʲɪtʲɪrˈburk), formerly known as Petrograd (1914–1924) and later Leningrad (1924–1991), i ...

Soviet Union The Soviet Union,. officially the Union of Soviet Socialist Republics. (USSR),. was a transcontinental country that spanned much of Eurasia from 1922 to 1991. A flagship communist state, it was nominally a federal union of fifteen national ...

, in 1961–1971.

Description

In the mid-1950s, the Soviet Union began developing a new diesel-electric icebreaker design based on the 1942-built steam-powered icebreaker ''Eisbär'' to meet the needs of both civilian and naval operators. Built in various configurations until the early 1980s, the Project 97 icebreakers and their derivatives became the largest and longest-running class of icebreakers and icebreaking vessels built in the world. Of the 32 ships built in total, the unarmed civilian variant Project 97A was the most numerous with twelve icebreakers built in 1961–1971. Project 97A icebreakers were

long overall __NOTOC__ Length overall (LOA, o/a, o.a. or oa) is the maximum length of a vessel's hull measured parallel to the waterline. This length is important while docking the ship. It is the most commonly used way of expressing the size of a ship, and ...

and had a beam of . Fully laden, the vessels drew of water and had a displacement of . Their three 10-cylinder 13D100

two-stroke A two-stroke (or two-stroke cycle) engine is a type of internal combustion engine that completes a Thermodynamic power cycle, power cycle with two strokes (up and down movements) of the piston during one power cycle, this power cycle being comple ...

opposed-piston

diesel engine The diesel engine, named after Rudolf Diesel, is an internal combustion engine in which ignition of the fuel is caused by the elevated temperature of the air in the cylinder due to mechanical compression; thus, the diesel engine is a so-call ...

s were coupled to generators that powered electric propulsion motors driving two propellers in the stern and a third one in the bow. Project 97A icebreakers were capable of breaking thick snow-covered ice at very slow but continuous speed.

History

The last of twelve Project 97A icebreakers was

laid down Laying the keel or laying down is the formal recognition of the start of a ship's construction. It is often marked with a ceremony attended by dignitaries from the shipbuilding company and the ultimate owners of the ship. Keel laying is one o ...

on 30 March 1971, launched on 31 August 1971, and delivered to the

Baltic Sea Shipping Company The Baltic Sea Shipping Company or B.S.S.C (russian: ОАО Балтийское морское пароходство, БМП) is a Russian sea transport engaged in the business of oil products storage via rail wagons within Russian link-able term ...

on 28 December 1971. It was named after the 17th century Russian explorer Semyon Ivanovich Dezhnyov and stationed in

. Following the

dissolution of the Soviet Union The dissolution of the Soviet Union, also negatively connoted as rus, Разва́л Сове́тского Сою́за, r=Razvál Sovétskogo Soyúza, ''Ruining of the Soviet Union''. was the process of internal disintegration within the Sov ...

, ''Semyon Dezhnev'' passed over to the successor state,

. The icebreaker was owned by Port of Saint Petersburg in 1996–2005 before joining Rosmorport's fleet. The original main engines were replaced with 6-cylinder Wärtsilä 6L26A units in 1999. , ''Semyon Dezhnev'' is one of the two Project 97A icebreakers still in service.

References

Icebreakers of the Soviet Union Icebreakers of Russia 1971 ships Ships built at Admiralty Shipyard {{ship-stub