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Project 971 Shchuka-B class

NATO: Akula class


Akula class

Unknown Akula class submarine travelling at the surface.
Source: US Department of defense - © public domain

Soviet Union
Nuclear powered attack submarine
Entered service
In service
Early 1970's to 1979
Soviet Union - Malakhit Central Design Bureau
1983 - 2009
Soviet Union - Sevmash in Severodvinsk
Soviet Union - Amur shipyard in Komsomolsk
Russia - Sevmash in Severodvinsk
Russia - Amur shipyard in Komsomolsk
Unit cost
About $ 1.5 billion in 1995
Number produced
7 Project 971 / Akula I
5 Project 971M / Akula I Improved
3 Project 971U / Akula II
Project 971 Shchuka-B (official name)
Akula class (NATO reporting name)
Notable users
Soviet Union



The Project 971 Shchuka-B class is a late Cold War era nuclear powered attack submarine of Soviet origin. The NATO reporting name is Akula class. This class was developed in the early 1980's in response to the US Los Angeles class and is considered a quantum leap forward in Soviet submarine technology. The Project 971 class is the follow on to the Project 671RTM Shchuka (NATO: Victor III) and remained the most capable Soviet/Russian attack submarine until the commissioning of the Yasen class.


The Project 971 hull design has been inspired by the Project 945 (NATO: Sierra) class. The layout is conventional with the armament carried in the bow, the command and crew compartments in the bow and below the sail and the propulsion system at the rear. The sail has a hydrodynamic design and houses an escape pod for its crewmembers. Noise reduction has been a key element in the design. The floors are suspended within the hull and anechoic tiles cover the external hull. The original Project 971 (NATO: Akula) is reported to be nearly as silent as the original US Los Angeles class. The improved Project 971U (NATO: Akula II) has a longer hull to house noise cancelling equipment and is reportedly slightly quieter than the improved Los Angeles class.


The Project 971 class is fitted with four 650mm and four 533mm torpedo tubes. When using liners 533mm weapons can also be launched from the 650 mm tubes. Usually a mix of 12 650mm weapons and 28 533mm weapons is carried. The 650mm weapons consist of the 65-76 long range anti-shipping torpedo and 100 km range RPK-7 Veter anti-submarine cruise missiles. The 533mm tubes are used with various types of anti-submarine and anti-shipping torpedoes. The 533mm torpedo tubes are also used to launch the S-10 Granat (NATO: SS-N-21 Sampson) cruise missiles with a range of 3.000 km or the RPK-6 Vodopad anti-submarine cruise missile. From the improved model onwards there are six externally loaded single shot torpedo 533mm tubes in the upper bow. These are predominantly used with MG-74 Korund and other torpedo-based decoys.


The sail houses a variety of periscopes and other sensors. Hull mounted sonar systems are located at the lower bow and front sides. The sonar capabilities have been subsequently upgraded over time with at least three types of sonar installed on various ships in class. The large teardrop shaped bulb on the vertical stabilizer is a container for a passive towed array sonar.

Akula II artwork

Artwork showing Akula II hull shape above and below the waterline.
Source: Alexpl - © GNU Attribution - Share Alike license


The Project 971 is fitted with a single 190 MW OK-9VM pressurized water reactor that powers a single seven blade propeller. The maximum speed is 10 knots when surfaced and 28 knots under water. Maximum speed during sea trails was reportedly just over 33 knots. Two retractable propulsors are fitted for low speed maneuvering, for instance in port. The maximum operating depth is listed as 480 meters, although there are reports in the Project 971 can in theory dive up to 600 m. Operational range is practically unlimited due to using a nuclear reactor. Endurance at sea is 80 to 100 days.


The Project 971 class was produced for the Soviet navy. Of the 20 planned vessels 15 have been delivered and two additional hulls have been used for the Yasen class. All vessels that remained when the USSR collapsed ended up in the Russian navy. Four are in operation service with six vessels undergoing repair or modernization. The latest Project 971 is used by the Russian navy to train Indian crews and was leased to India from 2012 to 2021.


From the mid 1980's to the 2000's a total of 15 Akulas have been produced. Due to subsequent improvements no Akula is completely identical to the other. Mainly the noise level differs per ship. Three subtypes of Akula are identified based on sonar, additional torpedo tubes and longer hull.

Akula class

The K-152 Vepr, one of two Akula II submarines, travelling at the surface.
Source: Ilya Kurganov - © GNU Attribution - Share Alike license

List of variants

Project 971 class
Known by NATO as Akula I. The original seven boats are fitted with the MGK-500 Skat sonar system and have no additional decoy launchers above the eight torpedo tubes.
Project 971M class
Known by NATO as Akula I Improved. Five of these boats have been built. These feature six additional single shot 533mm decoy torpedo tubes and the improved MGK-501 Skat-MS sonar system.
Project 971I class
Final vessel of the Project 971M class is the K-152 Nerpa which was in construction for over 15 years. This was completed to a modified Project 971I for lease to India and may feature some Project 971U components.
Project 971U class
Known by NATO as Akula II. This design features a 3 meter longer hull to house additional noise cancelling equipment. The sonar system used is the MGK-540 Skat-3. Project 971U may apply to two hulls modified during construction and Project 971A is often associated with the single hull produced to this standard from the start. Two additional hulls under construction were reused in the Yasen class.


Facts Project 971 class
Soviet Union
Nuclear powered attack submarine
80 max, 73 normal, 62 incl 31 officers minimum
Displacement (surface)
7.500 t
Displacement (submerged)
9.100 t
110 m overall
114 m for Project 971U
103 m at waterline
13.6 m
10.4 m
Single reactor connected to steam turbine
Power source
1x OK-9VM PWR, 190 MW
2x DG-300 diesel, 750 hp
1 shaft, 7 blade propeller
2x propulsor with auxiliary electric motor, 560 hp each
Speed (surface)
28 - 33 kt
Speed (submerged)
10 - 11 kt
480 m operational
600 m reported
80 to 100 days
MGK-500 Skat main sonar (NATO: Shark Gill)
MGK-501 Skat-MS main sonar on Project 971M
MGK-503 Skat-M on Project 971U
MG-519 Arfa mine detection sonar (NATO: Mouse Roar)
MGK-540 Skat-3 towed array
Passive detection
Surface search
MRKP-58 or MRKP-59 radar
Signal-3 and Lebed-11
Combat management
MVU-132 Omnibus fire control system
Molniya communication suite
Electronic warfare
MRP-21A or MRP-23 ESM system (NATO: Rim Hat)
6x 533mm tube for MG-74 Korund-2 [on Project 971M and U only]
Tube arrangement
4x 650mm torpedo tube
4x 533mm torpedo tube
Weapon types
650mm 65-73 and 65-76 torpedoes
533mm TEST-71, USET-80, VA-111 Shkval, SAET-60M, 53-65K torpedoes
650mm RPK-7 Veter anti-submarine cruise missile
533mm RPK-6 Vodopad anti-submarine cruise missile
533mm S-10 Granat land attack cruise missile
Weapon load
40 in total
12x 650mm and 28x 533mm



650mm nuclear tipped torpedo.
650mm long range wake homing anti-shipping torpedo.
RPK-7 Veter
650mm torpedo launched anti-submarine cruise missile.
533mm passive/active homing universal torpedo.
533mm wire guided passive/active homing anti-submarine torpedo.
533mm SAET-60M passive acoustic homing anti-ship torpedo.
533mm 53-65K wake following anti-shipping torpedo.
VA-111 Shkval
533mm supercavitating rocket powered torpedo.
S-10 Granat
533mm torpedo launched land attack cruise missile. 3.000 km range with nuclear warhead. Reportedly converted to conventional warheads.
RPK-6 Vodopad
533mm torpedo launched anti-submarine cruise missile.


SAET-60A torpedo on display in the museum of the Gidropribor research institute.

Source: V. Zamyatin and E. Erokhin, - © Copyright lies with original owner