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SubCommand Part II: SeaWolf and Akula
by Len "Viking1" HjalmarsonArticle Type: Preview / Real Military
Article Date: Apr. 25, 2001
<<== Back To Part I
Seawolf
Seawolf-class submarines were designed to operate autonomously against the world's most capable submarine and surface threats. The primary mission of the Seawolf was to destroy Soviet ballistic missile submarines before they could attack American targets.
SSN 21 SeaWolf
Soviet submarines are one of the most survivable elements of their intercontinental ballistic missile arsenal. In addition to their capabilities in countering enemy submarines and surface shipping, Seawolf submarines are suited for battlespace-preparation roles. Incorporation of sophisticated electronics produces enhanced indications and warning, surveillance, and communications capabilities. These platforms are capable of integrating into a battle group's infrastructure, or shifting rapidly into a land-battle support role.
The Seawolf features a strengthened sail, designed to permit operations under the polar ice cap for taking the fight to the Soviets in their own front yard. It sports an eight-tube, double-deck torpedo room to simultaneously engage multiple threats. It incorporates the latest in quieting technology to keep pace with the threat then posed by an aggressive Soviet Union.
Bow Array for SeaWolf
The Seawolf has the highest tactical speed of any US submarine. Much of the design effort was focused on noise reduction, and it is expected that the fully coated boat will restore the level of acoustic advantage which the US Navy enjoyed for the last three decades. The Seawolf's propulsion system makes it ten times more quiet over its full range of operating speeds than the Improved-688 class and 70 times more quiet than the initial generation of Los Angeles 688-class submarines.
The Seawolf's quieter propulsion system gives it twice the tactical speed as the I-688. Tactical speed is the speed at which a submarine is still quiet enough to remain undetected while tracking enemy submarines effectively. Overall, the Seawolf's propulsion system represents a 75-percent improvement over the I-688's -- the Seawolf can operate seventy-five percent faster before being detected. It is said that SEAWOLF is quieter at its tactical speed of 25 knots than a Los Angeles-class submarine at pierside.
SeaWolf Systems
With twice as many torpedo tubes and a thirty percent increase in weapons magazine size over the Los Angeles (SSN 688)-class submarines, Seawolf is capable of establishing and maintaining battlespace dominance. Seawolf's inherent stealth enables surreptitious insertion of combat swimmers into denied areas. SSN 23 will incorporate special-operations force capabilities, including a dry deck shelter (DDS) and a new, specially designed combat swimmer silo. The DDS is an air-transportable device that piggy-backs on the submarine and can be used to store and launch a swimmer delivery vehicle and combat swimmers.
A Construction Section for SeaWolf
Construction of the submarine has relied on a new welding material to join the steel into plates, hull subsections and large cylindrical sections. The Seawolf is the first American attack submarine to use a hull made entirely of high-pressure HY-100 steel—previous sumarines used HY80 steel. HY-100 steel was first used in submarines in the early 1960s in the Navy's deep-diving SEA CLIFF and TURTLE, which were capable of reaching depths in excess of 10,000 feet. More recently, the Moray, an advanced conventional submarine designed by the Dutch shipyard R.D.M. (Rotterdamsche Droogdok Maatschappij B.V), incorporated HY-100 steel to achieve an operational diving depth of 300 meters, and an incidental diving depth of 360 meters.
SSN 21 at her commissioning.
Seawolf (SSN 21) was commissioned on 19 July 1997 at Electric Boat Shipyard.
Seawolf was projected to be the most expensive ever built, with a total program cost for twelve submarines estimated in 1991 at $33.6 billion in current dollars. As many as twenty-nine submarines were planned. In the 1992 State of the Union address, President Bush proposed the rescission of $2,765,900,000 previously appropriated, and two Seawolf class submarines were authorized by Congress, which in 1995 agreed to terminate the program at three boats.
President Clinton endorsed the construction of SSN-23 as the most cost-effective method of retaining the vitality of the submarine industrial base while bridging the gap to the future New Attack Submarine. The Fiscal Year 1998 $153.4 million budget request was the final increment of funding required for the third SEAWOLF to complete the program. The program continues to be managed within the Congressionally mandated cost cap.
SeaWolf Crew at work.
Akula
The Project 971 Shuka-B 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, the submarine is officially designated Project 971 Shuka B (shuka is an aggressive breed of fresh water pike, a kind of fresh water shark).
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.
Akula at Sea
Double hull construction dramatically increases 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.
The Akula submarine design is 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 accommodate a quieter propulsion system.
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.
The improved Los Angeles class 688(I) retained the edge in silencing compared to the Akuka I. The Project 971A Akula II incorporated improved double layer silencing system for the power train and noise emissions are now roughly the level of the Improved Los Angeles Class at slow speeds. At medium or high speeds the improved Los Angeles design retains an acoustic advantage.
The Project 971 uses advanced sound insulation techniques that may not withstand Russian service conditions, and it may actually be noisier than earlier designs 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 688I systems).
Akula at Dock
The Akula can launch a range of anti-submarine and anti-surface vessel torpedoes. The submarine has eight torpedo launch tubes, four 650 millimeter and four 533 millimeter 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, 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 defense 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. Two auxiliary diesels rated at 750 hp provide emergency power.
The propulsion system drives a seven bladed fixed pitch propeller and provides a maximum submerged speed of 35 knots, with a surface speed of 10-12 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 seventy-three crew.
At least two and as many as four Improved Akulas entered service between 1992 and 1995. An additional Improved Akula I [K.267 Drakon] was launched in 1994 and delivered to the Russian Navy in 1995, though subsequently repossessed by the shipyard due to lack of payment.
The status of the Akula II program is less certain. The Vepr [probably an Akula II] was launched in December 1994 and according to some sources was commissioned in 1995. The Gepard was laid down in 1991, with the sub scheduled to enter active service in 1996. In fact, Gepard is still in the yard, and has been renamed Belgograd. The sub's crew was scheduled to arrive on board in early 1998 while the boat was still under construction. At least two and as many as four more Akula II units are being built.
Sources
- SeaWolf Systems Images from Federation of American Scientists
- Akula images from Federation of American Scientists
- Nick’s Submarine Base
- Sealion Submarine Journal
- Warships Website
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