Sierra-class submarine

	A Sierra II-class submarine underway
Class overview
Name	Sierra class
Builders	Krasnoye Sormovo, designed by Lazurit
Operators	Soviet Navy; Russian Navy;
Preceded by	Alfa class, Victor class
Succeeded by	Akula class
Built	1979–1992
In commission	1984–present
Planned	5
Completed	4
Cancelled	1
Active	4
General characteristics
Type	Nuclear attack submarine
Displacement	Sierra I:; 7,200 tons (surfaced); 8,300 tons (submerged); Sierra II:; 7,600 tons (surfaced); 9,100 tons (submerged);
Length	Sierra I: 107.16 m (351.6 ft); Sierra II: 110 m (360 ft);
Beam	Sierra I: 12.28 m (40.3 ft); Sierra II: 14.2 m (47 ft);
Draft	Sierra I: 8.8 m (29 ft); Sierra II: 8.8 m (29 ft);
Propulsion	Sierra I & II: 1 × PWR, 190 MW (HEU <= 45%); 2 × 1,002 hp (747 kW) emergency motors; 1 shaft, 2 spinners;
Speed	Sierra I & II: 10 knots (18.5 km/h) (surfaced); Sierra I: 34 knots (63.0 km/h) (submerged); Sierra II: 32 knots (59.3 km/h) (submerged);
Range	Effectively unlimited, except by food supplies
Complement	Sierra I & II: 61 & 72
Armament	Sierra I & II:; 4 × 650 mm (26 in) torpedo tubes (only Sierra I); 4 × 530 mm (21 in) torpedo tubes ( 6 x Sierra II); SS-N-21 Sampson SLCM; SS-N-15 Starfish anti-submarine weapon: 200 kt depth charge or 90 kg HE Type 40 torpedo; SS-N-16 Stallion, 200 kt depth charge or 90 kg HE Type 40 torpedo; Minelaying configuration: 42 mines instead of torpedoes;

The Sierra class, Soviet designations Project 945 Barrakuda and Project 945A Kondor, (NATO reporting names Sierra I and Sierra II respectively), are a series of nuclear-powered attack submarines intended for the Soviet Navy and currently in service with the Russian Navy.

The class resembles the Alfa-class submarine in having a light and strong titanium pressure hull which enables the submarines of the class to dive to greater depths, reduce the level of radiated noise and increase resistance to torpedo attacks. It is powered by a single OK-650 pressurized water reactor.

The upgraded version, the Sierra II class was specifically developed for search and destroy missions against US nuclear submarines. It has speeds and diving depth greater than its American counterparts at the time it was designed. It has also improved quieting and sonar.^[2]

^ "Marine Nuclear Power:1939 – 2018" (PDF). July 2018. Retrieved 30 December 2022.
^ Polmar, Norman; Moore, Kenneth J. (2004). Cold War Submarines: The Design and Construction of U.S. and Soviet Submarines. Washington, DC: Brassey's. p. 283. ISBN 978-1-57488-594-1. Archived from the original on 13 September 2016. Retrieved 28 August 2016 – via Google Books.

[1] "Marine Nuclear Power:1939 – 2018" (PDF). July 2018. Retrieved 30 December 2022.

[CWs-2] Polmar, Norman; Moore, Kenneth J. (2004). Cold War Submarines: The Design and Construction of U.S. and Soviet Submarines. Washington, DC: Brassey's. p. 283. ISBN 978-1-57488-594-1. Archived from the original on 13 September 2016. Retrieved 28 August 2016 – via Google Books.

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