Project 971 Shuka-B Bars-class
Attack Submarine (Nuclear Powered)
Submarines of Project 971 "Shchuka-B" (designation of NATO - "Akula") - a series of Soviet multi-purpose nuclear submarines of the third generation, designed according to the same technical specification as the titanium boats of Project 945 Barracuda, but with a steel hull.
Project 971 boats received the code name "Akula" in NATO countries. Later, the project was improved several times, and the boats built on the modified projects received the code names "Improved Akula" (Russian "Improved Shark") in the west, the 971M project corresponds to the designation "Akula-II". The last of the constructed boats, K-335 "Cheetah", the embodiment of the latest technical achievements, in the West is called "Akula-III".
The Project 971 Shuka-B Bars-class attack submarine multi-purpose submarine is capable of strikes against groups of hostile ships and against coastal installations. Designated the "Akula" class by the West, and also widely known as the Bars (Snow Leopard) class, the submarine is reported to be officially designated Project 971 Shuka B (shuka is an aggressive breed of fresh water pike -- the Shchuka-A was the Project 671 Victor class). Some 110 meters long, the Akula is double-hulled with considerable distance between the outer and inner hulls to reduce the possible damage to the inner hull. The hull is constructed of low magnetic steel, and divided into eight compartments, and features a distinctive high aft fin.
The Project 971, using a steel hull, was initiated in 1976 when it became evident that existing industrial infrastructure was inadequate to mass produce the expensive titanium hulls of the Project 945 Sierra class. The performance of the Project 971 boats was a close approximation to that of the Project 945 design, though the later was significantly more expensive to build and maintain. It has 650 mm and 533 mm torpedo tubes which can use mines as well as Granat cruise missiles, anti-submarine missiles, and torpedoes.
The submarines feature double hull construction, dramatically increasing the reserve buoyancy of the submarine by as much as three times over that of a single hull craft. Ballast tanks and other gear are located between the inner and outer hulls, and limber holes are provided for the free-flooding sections between the hulls. Akula class submarines incorporate limber hole covers that can be closed to reduce or eliminate this source of unwanted noise.
Built to engage surface task forces and coastal facilities, the Akula submarine design was under constant upgrade. NATO designated the Project 971 boats as Akula I, and the Project 971U as "Improved Akula I" while Project 971A was designated Akula II. According to some reports the 'Akula-II' class has a 3.7 meter longer hull to accomdate a quieter propulsion system.
Significant modifications were made to the original Project 971 Akula design beginning with the fifth unit. Classified as "Akula II", these modifications include a four-meter extension hull extension. They are sometimes called the "Walker-class," referring to John Anthony Walker, whose espionage data related to sonar detection was used to improve the submarine. Writing in 1999, Neal Stevens observed "The spying efforts of American naval personnel John Walker and radioman Jerry Whitworth made the Soviet Union's military chiefs aware of how far advanced American submarines were. Substantial efforts to marginalize the sound profile of the Akula can be traced to intelligence gained from the Walker spy ring. A separate but equally empowering sequence of events for the Russians was the illegal sale of propeller milling technology by the Japanese firm Toshiba and the Norwegian firm Kongsberg. The combined results generated a steep drop in broadband acoustic noise profiles."
The Akula is the quietest Russian nuclear submarine ever designed, and the low noise levels came as a surprise to Western intelligence. Russia claims the Akula is the quietest of its domestically built submarines and is fitted with acoustic countermeasure equipment. Noise reduction efforts include rafting the propulsion plant, anechoic tiles on the outside and inside of the hulls and possibly other measures such as active noise cancellation. Nonetheless, the American Improved Los Angeles class retained a decisive edge in silencing compared to the Akuka I.
The Project 971A Akula II incorporated an improved double layer silencing system for the power train. According to Russian sources, this variant had noise emissions that were roughly the level of a basic Los Angeles and that of the Improved Los Angeles at slow speeds. At medium or high speeds the Improved Los Angeles design retains an acoustic advantage according to Russian sources. The Project 971 uses advanced sound insulation techniques that may not withstand Russian service conditions, and it may actually be noiser than earlier designs using more basic quieting technologies if poorly built or improperly maintained. The Project 971 is said by Russian sources to be at a distinct disadvantage in sensors, with a sonar suite that is roughly one-third as sensitive as the Los Angeles, able to track only two targets simultaneously (as opposed to the multiple target tracking capabilities of the American system).
The Akula can launch a range of anti-submarine and anti-surface vessel torpedoes. The submarine has eight torpedo launch tubes, four 650 millimetre and four 533 millimetre tubes. The Improved Akula and Akula II have ten, with six 533 mm tubes. The four 650 mm tubes can be fitted with liners to provide additional 533 mm weapon launch capacity. The torpedo tubes can be used to launch mines instead of torpedoes. The Akula Class carry up to twelve Granat submarine launched cruise missiles. The missiles are fired from four 533 mm torpedo launch tubes. The submarine's anti-ship missiles are the Novator SS-N-15 Starfish and the Novator SS-N-16 Stallion and an air defence capability is provided by the Strela SA-N-5/8 portable missile launcher with 18 missiles.
The main propulsion machinery consists of a VM-5 pressure water reactor with a model OK-650 b high-density reactor core rated at 190 MW with a GT3A turbine developing 35 MW. Some sources credit Akula with two reactors, but it appears that the Akula has only one reactor, as opposed to older Russian subs, which had two. Two auxiliary diesels rated at 750 hp provide emergency power. The propulsion system drives a seven bladed fixed pitch propeller. The propulsion system provides a maximum submerged speed of 33 knots and a surface speed of 10 knots. A reserve propeller system, powered by two motors rated at 370 kw, provides a speed of 3 to 4 knots. The submarine is rated for a diving depth to 600 meters. The submarine carries sufficient supplies for an endurance of 100 days and is operated by a complement of 73 crew. On 17 August 2012 U.S. Senator John Cornyn (R-TX), a member of the Senate Armed Services Committee, sent a letter to Chief of Naval Operations Admiral Jonathan Greenert requesting more information after it was reported that a Russian nuclear-powered attack submarine recently traveled undetected in the Gulf of Mexico: "The submarine patrol, taken together with the air incursions, seems to represent a more aggressive and destabilizing Russian military stance that could pose risks to our national security." Bill Gertz broke the story, reporting that "It is only the second time since 2009 that a Russian attack submarine has patrolled so close to U.S. shores. ... Brazil’s O Estado de Sao Paoli reported Aug. 2 that Russia plans to sell Venezuela up to 11 new submarines, including one Akula."
In early August 2009, the New York Times reported that the Pentagon had been tracking 2 Akula II class submarines off the coast of the United States. One vessel was reported on 4 August 2009 to have been 320 kilometers (200 miles) off the coast, while the location of the second vessel was unclear. The Pengaton officially had no comment and the Russian Navy responded to the New York Times article saying that similar patrols had continued even through the 1990s, despite suggestions that this was the first patrol of its type in over a decade.
In late December 2009, the Russian Nerpa nuclear attack submarine, which had been damaged while undergoing sea trials in November 2009, entered service with the Russian Navy. The submarine is to be leased to the Indian Navy as the INS Chakra, for a reported $650 million for a duration of 10 years.
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