Akula-class submarine

Project 971 Щука-Б (Shchuka-B, 'Shchuka' meaning pike, NATO reporting name "Akula"), is a nuclear-powered attack submarine (SSN) first deployed by the Soviet Navy in 1986. The class is also known under the name Bars (eng. snow leopard). There are four sub-classes or flights of Shchuka, consisting of the original seven "Akula I" submarines which were commissioned between 1984 and 1990, six "Improved Akula" submarines commissioned between 1991 and 2009, one "Akula II" submarine commissioned in 1995 and one Akula III commissioned in 2001. The Russians call all of the submarines Schuka-B, regardless of modifications.

The name Akula (Акула meaning "shark" in Russian) is the Soviet designation of the ballistic missile submarine class designated by NATO as the Typhoon class submarine. The name Akula was used as the NATO designation of the Projekt 971 because the first of the class was the K-284 christened Akula.

Construction
The Akula incorporates a double hull system composed of an inner pressure hull and an outer "light" hull. This allows more freedom in the design of the exterior hull shape, resulting in a submarine with more reserve buoyancy than its western analogs. This design requires more power than single-hull submarines because of the greater wetted surface area, which increases drag.

The distinctive "bulb" or "can" seen on top of the Akula's rudder houses its towed sonar array, when retracted. Most Akulas have the SOCKS hydrodynamic sensors, which detect changes in temperature and salinity. They are located on the leading edge of the sail, on the outer hull casing in front of the sail and on the bottom of the hull forward of the sail. All Akulas have two T-shaped doors on the aft bottom of the hull, on either side. These are where the OK-300 auxiliary propulsion devices are located, which can propel the submarine at up to 5 kn.



All Akulas are armed with four 533 mm torpedo tubes which can use Type 53 torpedoes or the SS-N-15 Starfish missile, and four 650 mm torpedo tubes which can use Type 65 torpedoes or the SS-N-16 Stallion missile. These torpedo tubes are arranged in two rows of four tubes each. Improved Akulas, Akula IIs have an additional six 533 mm torpedo tubes mounted externally, capable of launching possibly up to 6 decoys each. The external tubes are mounted outside the pressure hull in one row, above the torpedo tubes, and can only be reloaded in port or with the assistance of a submarine tender. The 650 mm tubes can be fitted with liners to use the 533 mm weaponry. The submarine is also able to use its torpedo tubes to deploy mines.

Current status
As with many Soviet/Russian craft, information on the status of the Akula Class submarines is sparse, at best. Information provided by sources varies widely.

Akula-I (project 971)
Of the seven original Akula-I submarines, only three are known to still be in service. These boats are equipped with MGK-500 Skat sonar system (with NATO reporting name Shark Gill). The lead boat of the class, K-284 'Akula' was decommissioned in 2001, apparently to help save money in the cash-strapped Russian Navy. K-322 'Kashalot' and K-480 'Bars' [Currently Ak Bars] are in reserve. K-480 'Bars' was put into reserve in 1998, and is being dismantled in February 2010. 'Pantera' returned to service in January 2008 after a comprehensive overhaul. All were retrofitted with the SOCKS hydrodynamic sensors except Volk. All submarines before K-391 Bratsk have reactor coolant scoops that are similar to the ones of the Typhoon class SSBNs, long and tubular. Bratsk and subsequent submarines have reactor coolant scoops similar to the ones on the Oscar IIs, short and (the Typhoon, Akula and Oscar classes use the similar OK-650 reactor).

Akula-I Improved (project 971 and 971I)
The six Akulas of this class are all thought to be in service. They are quieter than the original MGK-500 Skat sonar system on Akula-I is upgraded to the MGK-501 Skat-MS. Sources also disagree as to whether construction of this class has been suspended, or if there are a further two units planned.

Improved Akula-I Hulls: K-328 Leopard, K-461 Volk, K-154 Tigr, K-419 Kuzbass, K-295 Samara and K-152 Nerpa''. These submarines are much quieter than early Akula class submarines and all have the SOCKS hydrodynamic sensors except Leopard''. The Akula-I Improved submarines have 6 533 mm decoy launching tubes, as do subsequent submarines. They have a different arrangement of limber holes on the outer hull than Akula Is. Nerpa and Iribis (not completed) have a different rescue chamber in the sail. I can be distinguished by the large dome on the top surface.''

Akula-II (project 971U)
K-157 Vepr is the only completed Akula II. The Akula II is some meters longer and displaces about 700 tons (submerged displacement) more than the Akula I. The added space was used for additional quieting measures. The MGK-501 Skat sonar system on Akula-I is replaced to a new MGK-540 Skat-3 sonar system,. K-157 Vepr became the first Soviet submarine that was quieter than the latest U.S. attack submarines of that time, which was the Improved Los Angeles class (SSN 751 and later). Two of these submarines were used to build the Borei class SSBNs.

Akula-III (project 971M)
K-335 Gepard is the only completed Akula III (see table for others)(There is no AKULA III NATO classification). It is longer and has a larger displacement compared to the Akula II. Also, it has an enlarged sail and a different towed-array dispenser on the vertical fin. Again, more noise reduction methods were employed. The Gepard is the most advanced Russian submarine before the submarines of the Severodvinsk and Borei classes are commissioned. One of this class was used to complete the Borei SSBNs.

The Soviet advances in sound quieting were of considerable concern to the West, for acoustics was long considered the most significant advantage in U.S. submarine technology compared to the Soviets.

In 1983–1984 the Japanese firm Toshiba sold sophisticated, nine axis milling equipment to the Soviets along with the computer control systems, which were developed by Norwegian firm Kongsberg Vaapenfabrik. U.S Navy officials and Congressmen announced that this technology enabled the Soviet submarine builders to produce more accurate and quieter propellers.

Due to the breakup of the Soviet Union in 1991, production of all Akulas slowed.

The 1999–2000 edition of Jane's Fighting Ships incorrectly listed the first Akula-II as Viper (the actual name is "Vepr", "wild boar" in Russian), commissioned November 25, 1995, Gepard (Cheetah), launched 1999 and commissioned December 5, 2001, and Nerpa, laid down in 1993 began sea trials in October, 2008 and was commissioned by the Indian Navy as INS Chakra II in April 2012.

Lease to India
Three hundred Indian Navy personnel are being trained in Russia for the operation of the Akula II submarine Nerpa. India has finalized a deal with Russia, in which at the end of the lease of these submarines, it has an option to buy them. The submarine will be named INS Chakra as was the previous India-leased Soviet Charlie-I SSGN. INS Chakra was officially inducted into the Indian Navy on April 4, 2012.

Whereas the Russian Navy's Akula-II could be equipped with 28 nuclear-capable cruise missiles with a striking range of 3000 km, the Indian version was reportedly expected to be armed with the 300 km-range 3M-54 Klub nuclear-capable missiles. Missiles with ranges greater than 300 km cannot be exported due to arms control restrictions, since Russia is a signatory to the MTCR treaty.

Nerpa 2008 accident
On 27 October 2008, it was reported that K-152 Nerpa of the Russian Pacific Fleet had begun her sea trials in the Sea of Japan before handover under a lease agreement to the Indian Navy. On 8 November 2008, while conducting one of these trials, an accidental activation of the halon-based fire-extinguishing system took place in the fore section of the vessel. Within seconds the halon gas had displaced all breathable air from the compartment. As a result, 20 people (17 civilians and 3 seamen) were killed by asphyxiation. Dozens of others suffered freon-related injuries and were evacuated to an unknown port in Primorsky Krai. This was the worst accident in the Russian navy since the loss of the submarine K-141 Kursk in 2000. The submarine itself did not sustain any serious damage and there was no release of radiation.

Recent overseas deployments
In August 2009, the news media reported that two Akula-class submarines operated off the East Coast of the United States, with one of the submarines being identified as a Project 971 Shchuka-B type. U.S. military sources noted that this was the first known Russian submarine deployment to the western Atlantic since the end of the Cold War, raising concerns within U.S. military and intelligence communities. The U.S. Northern Command confirmed that this 2009 Akula-class submarine deployment did occur.

In August 2012, the news media reported that another Akula-class submarine operated in the Gulf of Mexico purportedly undetected for over a month, sparking controversy within U.S. military and political circles, with U.S. Senator John Cornyn of the Senate Armed Services Committee demanding details of this deployment from Admiral Jonathan W. Greenert, the Chief of Naval Operations. ; ; ; and