Virginia class submarine
Overview
 
The Virginia class (or SSN-774 class) is a class of nuclear-powered
Nuclear marine propulsion
Nuclear marine propulsion is propulsion of a ship by a nuclear reactor. Naval nuclear propulsion is propulsion that specifically refers to naval warships...

 fast attack submarine
Submarine
A submarine is a watercraft capable of independent operation below the surface of the water. It differs from a submersible, which has more limited underwater capability...

s (SSN
Hull classification symbol
The United States Navy, United States Coast Guard, and United States National Oceanic and Atmospheric Administration use hull classification symbols to identify their ship types and each individual ship within each type...

) in service with the United States Navy
United States Navy
The United States Navy is the naval warfare service branch of the United States Armed Forces and one of the seven uniformed services of the United States. The U.S. Navy is the largest in the world; its battle fleet tonnage is greater than that of the next 13 largest navies combined. The U.S...

. The submarines are designed for a broad spectrum of open-ocean
Blue-water navy
The term blue-water navy is a colloquialism used to describe a maritime force capable of operating across the deep waters of open oceans. While what actually constitutes such a force remains undefined, there is a requirement for the ability to exercise sea control at wide ranges...

 and littoral
Littoral
The littoral zone is that part of a sea, lake or river that is close to the shore. In coastal environments the littoral zone extends from the high water mark, which is rarely inundated, to shoreline areas that are permanently submerged. It always includes this intertidal zone and is often used to...

 missions. They were conceived as a less expensive alternative to the Seawolf class attack submarines
Seawolf class submarine
The Seawolf class is a class of nuclear-powered fast attack submarines in service with the United States Navy. The class was the intended successor to the , ordered at the end of the Cold War in 1989. At one time, an intended fleet of 29 submarines was to be built over a ten-year period, later...

, designed during the Cold War
Cold War
The Cold War was the continuing state from roughly 1946 to 1991 of political conflict, military tension, proxy wars, and economic competition between the Communist World—primarily the Soviet Union and its satellite states and allies—and the powers of the Western world, primarily the United States...

 era, and they are planned to replace the older of the Los Angeles-class submarines
Los Angeles class submarine
The Los Angeles class, sometimes called the LA class or the 688 class, is a class of nuclear-powered fast attack submarines that forms the backbone of the United States submarine fleet. With 43 submarines on active duty and 19 retired, the Los Angeles class is the most numerous nuclear powered...

, nineteen of which, from a total of 62 built, have already been decommissioned.
The Virginia class incorporates several innovations not previously incorporated into other submarine classes.
Instead of a traditional periscope
Periscope
A periscope is an instrument for observation from a concealed position. In its simplest form it consists of a tube with mirrors at each end set parallel to each other at a 45-degree angle....

, the class utilizes a pair of telescoping photonics mast
Photonics mast
A photonics mast is a sensor similar in concept to a submarine periscope, except that it doesn't require a periscope tube thus freeing design space duringconstruction and limiting risks of water leakage in the event of damage...

s located outside the pressure hull.
Encyclopedia
The Virginia class (or SSN-774 class) is a class of nuclear-powered
Nuclear marine propulsion
Nuclear marine propulsion is propulsion of a ship by a nuclear reactor. Naval nuclear propulsion is propulsion that specifically refers to naval warships...

 fast attack submarine
Submarine
A submarine is a watercraft capable of independent operation below the surface of the water. It differs from a submersible, which has more limited underwater capability...

s (SSN
Hull classification symbol
The United States Navy, United States Coast Guard, and United States National Oceanic and Atmospheric Administration use hull classification symbols to identify their ship types and each individual ship within each type...

) in service with the United States Navy
United States Navy
The United States Navy is the naval warfare service branch of the United States Armed Forces and one of the seven uniformed services of the United States. The U.S. Navy is the largest in the world; its battle fleet tonnage is greater than that of the next 13 largest navies combined. The U.S...

. The submarines are designed for a broad spectrum of open-ocean
Blue-water navy
The term blue-water navy is a colloquialism used to describe a maritime force capable of operating across the deep waters of open oceans. While what actually constitutes such a force remains undefined, there is a requirement for the ability to exercise sea control at wide ranges...

 and littoral
Littoral
The littoral zone is that part of a sea, lake or river that is close to the shore. In coastal environments the littoral zone extends from the high water mark, which is rarely inundated, to shoreline areas that are permanently submerged. It always includes this intertidal zone and is often used to...

 missions. They were conceived as a less expensive alternative to the Seawolf class attack submarines
Seawolf class submarine
The Seawolf class is a class of nuclear-powered fast attack submarines in service with the United States Navy. The class was the intended successor to the , ordered at the end of the Cold War in 1989. At one time, an intended fleet of 29 submarines was to be built over a ten-year period, later...

, designed during the Cold War
Cold War
The Cold War was the continuing state from roughly 1946 to 1991 of political conflict, military tension, proxy wars, and economic competition between the Communist World—primarily the Soviet Union and its satellite states and allies—and the powers of the Western world, primarily the United States...

 era, and they are planned to replace the older of the Los Angeles-class submarines
Los Angeles class submarine
The Los Angeles class, sometimes called the LA class or the 688 class, is a class of nuclear-powered fast attack submarines that forms the backbone of the United States submarine fleet. With 43 submarines on active duty and 19 retired, the Los Angeles class is the most numerous nuclear powered...

, nineteen of which, from a total of 62 built, have already been decommissioned.

Innovations

The Virginia class incorporates several innovations not previously incorporated into other submarine classes.

Photonics Masts

Instead of a traditional periscope
Periscope
A periscope is an instrument for observation from a concealed position. In its simplest form it consists of a tube with mirrors at each end set parallel to each other at a 45-degree angle....

, the class utilizes a pair of telescoping photonics mast
Photonics mast
A photonics mast is a sensor similar in concept to a submarine periscope, except that it doesn't require a periscope tube thus freeing design space duringconstruction and limiting risks of water leakage in the event of damage...

s located outside the pressure hull. Each mast contains high-resolution cameras, along with light-intensification and infrared sensors, an infrared laser rangefinder, and an integrated Electronic Support Measures (ESM) array. Signals from the masts' sensors are transmitted through fiber optic data lines through signal processors to the control center. Visual feeds from the masts are displayed on LCD interfaces in the command center.

Propulsor

The class also makes use of pump-jet
Pump-jet
A pump-jet, hydrojet, or water jet, is a marine system that creates a jet of water for propulsion. The mechanical arrangement may be a ducted propeller with nozzle, or a centrifugal pump and nozzle...

 propulsors, which significantly reduces the risks of cavitation
Cavitation
Cavitation is the formation and then immediate implosion of cavities in a liquidi.e. small liquid-free zones that are the consequence of forces acting upon the liquid...

, allowing for quieter and faster operations.

Improved sonar systems

The Virginia class submarines are equipped with a bow-mounted spherical active/passive sonar array, a wide aperture lightweight fiber optic sonar array (three flat panels mounted low along either side of the hull), as well as two high frequency active sonars mounted in the sail and keel (under the bow). The submarines are also equipped with a low frequency towed sonar array and a high frequency towed sonar array.

The will be the first Virginia-class submarine with the advanced electromagnetic signature reduction system built into it, but this system will be retrofitted into the other submarines of the class.

Other Improved Equipment

  • The high speed, turbocharged Caterpillar 3512B V-12 replaced the venerable medium speed Fairbanks-Morse
    Fairbanks-Morse
    Fairbanks Morse and Company was a manufacturing company in the late 19th and early 20th century. Originally a weighing scale manufacturer, it later diversified into pumps, engines, windmills, locomotives and industrial supplies until it was merged in 1958...

     38D81/8 Opposed Piston engines used since the pre-World War II Tambor class submarine
    Tambor class submarine
    The Tambor class submarine was a United States Navy submarine design, used primarily during World War II. It was the USN's first practical fleet submarine and formed the core of the United States Pacific submarine fleet at the time of the US entry into World War II.-Design history:Early U.S...

     in the Virginia class diesel generator.

  • Fiber-optic fly-by-wire Ship Control System replaces electro-hydraulic systems for control surface actuation.

  • According to a Congressional Research Service
    Congressional Research Service
    The Congressional Research Service , known as "Congress's think tank", is the public policy research arm of the United States Congress. As a legislative branch agency within the Library of Congress, CRS works exclusively and directly for Members of Congress, their Committees and staff on a...

     report, magnetic bearings are used on the Ship Service Turbine Generator (SSTG)s.

Construction and controversy

The Virginias were intended, in part, as a cheaper ($1.8 billion vs, $2.8 billion) alternative to the Seawolf class sumbarines
Seawolf class submarine
The Seawolf class is a class of nuclear-powered fast attack submarines in service with the United States Navy. The class was the intended successor to the , ordered at the end of the Cold War in 1989. At one time, an intended fleet of 29 submarines was to be built over a ten-year period, later...

, whose production run was stopped after just three boats had been completed. To reduce costs, the Virginia-class submarines use many "commercial off-the-shelf
Commercial off-the-shelf
In the United States, Commercially available Off-The-Shelf is a Federal Acquisition Regulation term defining a nondevelopmental item of supply that is both commercial and sold in substantial quantities in the commercial marketplace, and that can be procured or utilized under government contract...

" (or COTS) components, especially in their computers and data networks. In practice, they actually cost less than $1.8 billion (in fiscal year 2009 dollars) each, due to improvements in shipbuilding technology.

In hearings before both House of Representatives and Senate committees, the Congressional Research Service
Congressional Research Service
The Congressional Research Service , known as "Congress's think tank", is the public policy research arm of the United States Congress. As a legislative branch agency within the Library of Congress, CRS works exclusively and directly for Members of Congress, their Committees and staff on a...

 and expert witnesses testified that the current procurement plans of the Virginia class — one per year at present, accelerating to two per year beginning in 2012 — would result in high unit costs and (according to some of the witnesses and to some of the committee chairmen) an insufficient number of attack submarines. In a March 10, 2005 statement to the House Armed Services Committee, Ronald O'Rourke of the CRS testified that, assuming the production rate remains as planned, "production economies of scale for submarines would continue to remain limited or poor."

The Virginia class is built through an industrial arrangement designed to keep both GD Electric Boat
Electric Boat Corporation
The General Dynamics Electric Boat is a division of General Dynamics Corporation. It has been the primary builder of submarines for the United States Navy for over 100 years....

 and Newport News Shipbuilding and Drydock Company (the only two U.S. shipyards capable of building nuclear-powered vessels) in the submarine-building business. Under the present arrangement, the Newport News facility builds the stern, habitability and machinery spaces, torpedo room, sail and bow, while Electric Boat builds the engine room and control room. The facilities alternate work on the reactor plant as well as the final assembly, test, outfit and delivery.

O’Rourke wrote in 2004 that, "Compared to a one-yard strategy, approaches involving two yards may be more expensive but offer potential offsetting benefits." Among the claims of "offsetting benefits" that O'Rourke attributes to supporters of a two-facility construction arrangement is that it "would permit the United States to continue building submarines at one yard even if the other yard is rendered incapable of building submarines permanently or for a sustained period of time by a catastrophic event of some kind", including an enemy attack.

In order to get the submarine's price down to $2 billion per submarine in FY-05 dollars, the Navy instituted a cost-reduction program to shave off approximately $400 million in costs off each submarine's price tag. The project was dubbed "2 for 4 in 12," referring to the Navy's desire to buy two boats for $4 billion in FY-12. Under pressure from Congress, the Navy opted to start buying two boats a year earlier, in FY-11, meaning that officials would not be able to get the $2 billion price tag before the service started buying two submarines per year. However, program manager Dave Johnson said at a conference on March 19, 2008, that the program was only $30 million away from achieving the $2 billion price goal, and would reach that target on schedule.

In December 2008, the Navy signed a $14 billion contract with General Dynamics and Northrop Grumman to supply eight submarines. The contractors will deliver one submarine in each of fiscal 2009 and 2010, and two submarines on each of fiscal 2011, 2012 and 2013. This contract will bring the Navy's Virginia-class fleet to 18 submarines. And in December 2010, the United States Congress
United States Congress
The United States Congress is the bicameral legislature of the federal government of the United States, consisting of the Senate and the House of Representatives. The Congress meets in the United States Capitol in Washington, D.C....

 passed a defense authorization bill that expanded production to two subs per year. Two submarine-per-year production resumed on September 2, 2011 with commencement of SSN-787
SSN-787
SSN-787 will be a . The contract to build her was awarded to Electric Boat division of General Dynamics in Groton, Connecticut on December 22, 2008. This ship is the fourth of the Block III subs which will feature a revised bow, including some technology from SSGNs. Construction began on...

 construction.

On 21 June 2008, the Navy christened the , the first Block II submarine. This boat was delivered eight months ahead of schedule and $54 million under budget. Block II boats are built in four sections, compared to the ten sections of the Block I boats. This enables a cost saving of about $300 million per boat, reducing the overall cost to $2 billion per boat and the construction of two new boats per year. Beginning in 2010, new submarines of this class will include a software system that can monitor and reduce their electromagnetic
Electromagnetism
Electromagnetism is one of the four fundamental interactions in nature. The other three are the strong interaction, the weak interaction and gravitation...

 signatures when needed.

In September 2010, it was found that urethane tiles, applied to the hull to dampen internal sound and absorb rather than reflect sonar pulses, were falling off while the subs were at sea.

Ross Babbage
Ross Babbage
Professor Ross Babbage is currently Managing Director of Strategy International and chair of The Kokoda Foundation. He has also formerly held the position as Head of Strategic Analysis in the Office of National Assessments and as advisor to various government ministers and departments Babbage...

 has called on Australia to buy or lease a dozen Virginia class submarines from the United States.

The Royal Canadian Navy
Royal Canadian Navy
The history of the Royal Canadian Navy goes back to 1910, when the naval force was created as the Naval Service of Canada and renamed a year later by King George V. The Royal Canadian Navy is one of the three environmental commands of the Canadian Forces...

 is also believed to be exploring the feasibility of acquiring up to eight Virginia class submarines.

Tango Bravo

Because of the slow rate of Virginia production, the Navy entered into a program with DARPA to overcome Technology Barriers (TB or Tango Bravo) to lower the cost of attack submarines so that more could be built to keep up the size of the fleet.

These include:
  • Propulsion concepts not constrained by a centerline shaft.
  • Externally stowed and launched weapons (especially torpedoes).
  • Conformal alternatives to the existing spherical sonar array.
  • Technologies that eliminate or substantially simplify existing submarine hull, mechanical and electrical systems.
  • Automation to reduce crew workload for standard tasks

Specifications

  • Builders: GD Electric Boat
    Electric Boat Corporation
    The General Dynamics Electric Boat is a division of General Dynamics Corporation. It has been the primary builder of submarines for the United States Navy for over 100 years....

     and Northrop Grumman Newport News
    Northrop Grumman Newport News
    Newport News Shipbuilding , originally Newport News Shipbuilding and Drydock Company , was the largest privately-owned shipyard in the United States prior to being purchased by Northrop Grumman in 2001...

  • Length: 377 ft (114.91 m)
  • Beam: 34 ft (10.36 m)
  • Displacement: 7800 LT
  • Payload: 40 weapons, special operations forces, unmanned undersea vehicles, Advanced SEAL Delivery System (ASDS)
  • Propulsion: The S9G nuclear reactor
    S9G reactor
    The S9G reactor is a naval reactor used by the United States Navy to provide electricity generation and propulsion on Virginia class submarines...

  • Maximum diving depth: greater than 800 ft (244 m)
  • Speed: 25+ knots
  • Planned cost: about US$1.65 billion each (based on FY95 dollars, 30-ship class and two ship/year build-rate)
  • Actual cost: about $1.8 billion each (as of 2009)
  • Crew: 120 enlisted and 14 officers
  • Armament: 12 VLS
    Vertical Launching System
    A vertical launching system is a system for holding and firing missiles on surface ships and submarines used by many navies around the world. Each VLS system consists of a number of cells, which can hold one or more missiles ready for firing...

     & four torpedo
    Torpedo
    The modern torpedo is a self-propelled missile weapon with an explosive warhead, launched above or below the water surface, propelled underwater towards a target, and designed to detonate either on contact with it or in proximity to it.The term torpedo was originally employed for...

     tubes, capable of launching Mark 48 torpedo
    Mark 48 torpedo
    The Mark 48 and its improved ADCAP variant are heavyweight submarine-launched torpedoes. They were designed to sink fast, deep-diving nuclear-powered submarines and high-performance surface ships.-History:...

    es, UGM-109 Tactical Tomahawks
    BGM-109 Tomahawk
    The Tomahawk is a long-range, all-weather, subsonic cruise missile. Introduced by General Dynamics in the 1970s, it was designed as a medium- to long-range, low-altitude missile that could be launched from a surface platform. It has been improved several times and, by way of corporate divestitures...

    , Harpoon missiles and the new advanced mobile mine
    Naval mine
    A naval mine is a self-contained explosive device placed in water to destroy surface ships or submarines. Unlike depth charges, mines are deposited and left to wait until they are triggered by the approach of, or contact with, an enemy vessel...

     when it comes available.

Block I

, commissioned and in service., commissioned and in service., commissioned and in service., commissioned and in service.

Block II

Block II boats are built in four sections rather than ten sections, saving about $300 million per boat.
, commissioned and in service. commissioned and in service., commissioned and in service., commissioned and in service., keel laid down June 9, 2010, and expected to be delivered in April 2012., named July 15, 2008, keel laid down May 20, 2011 and expected to be delivered in April 2013.

Block III

through approximately SSN-791
SSN-791
SSN-791 will be a . The contract to build her was awarded to Electric Boat division of General Dynamics in Groton, Connecticut on December 22, 2008. This ship is the eighth and final ship of the Block III subs which will feature a revised bow, including some technology from SSGNs....

 are planned to make up the Third Block or "Flight" and began construction in 2009. Block III subs will feature a revised bow, including some technology from Ohio class
Ohio class submarine
The Ohio class is a class of nuclear-powered submarines used by the United States Navy. The United States has 18 Ohio-class submarines:...

 SSGN
SSGN
A cruise missile submarine is a submarine that can launch guided missiles. SSGN is the United States Navy hull classification symbol for a nuclear-powered cruise missile submarine. The SS denotes "Ship, Submersible" , the G denotes "guided missile," and the N denotes "nuclear powered"....

s.
, named July 15, 2008 and is contracted for delivery in August 2014., named January 8, 2009 and is contracted for delivery in August 2015.
  • SSN-786
    SSN-786
    SSN-786 will be a . The contract to build her was awarded to Electric Boat division of General Dynamics in Groton, Connecticut on December 22, 2008. This ship is the third of the Block III subs which will feature a revised bow, including some technology from SSGNs....

    , construction began March 2011.
  • SSN-787
    SSN-787
    SSN-787 will be a . The contract to build her was awarded to Electric Boat division of General Dynamics in Groton, Connecticut on December 22, 2008. This ship is the fourth of the Block III subs which will feature a revised bow, including some technology from SSGNs. Construction began on...

    , construction began Sep 2, 2011.
  • SSN-788
    SSN-788
    SSN-788 will be a . The contract to build her was awarded to Electric Boat division of General Dynamics in Groton, Connecticut on December 22, 2008. This ship is the fifth of the Block III subs which will feature a revised bow, including some technology from SSGNs....

  • SSN-789
    SSN-789
    SSN-789 will be a . The contract to build her was awarded to Electric Boat division of General Dynamics in Groton, Connecticut on December 22, 2008. This ship is the sixth of the Block III subs which will feature a revised bow, including some technology from SSGNs....

  • SSN-790
    SSN-790
    SSN-790 will be a . The contract to build her was awarded to Electric Boat division of General Dynamics in Groton, Connecticut on December 22, 2008. This ship is the seventh of the Block III subs which will feature a revised bow, including some technology from SSGNs....

  • SSN-791
    SSN-791
    SSN-791 will be a . The contract to build her was awarded to Electric Boat division of General Dynamics in Groton, Connecticut on December 22, 2008. This ship is the eighth and final ship of the Block III subs which will feature a revised bow, including some technology from SSGNs....


Block IV

No block IV submarines are yet under contract. The first block IV submarine is not scheduled to be procured until FY14. Based on the planned split between block IV and block V boats, the following hull numbers will comprise block IV procurement.
  • SSN-792
  • SSN-793
  • SSN-794
  • SSN-795
  • SSN-796
  • SSN-797
  • SSN-798
  • SSN-799
  • SSN-800
  • SSN-801


Block V

Block V subs may incorporate the Virginia Payload Module (VPM), which would give guided-missile capability when the SSGN
SSGN
A cruise missile submarine is a submarine that can launch guided missiles. SSGN is the United States Navy hull classification symbol for a nuclear-powered cruise missile submarine. The SS denotes "Ship, Submersible" , the G denotes "guided missile," and the N denotes "nuclear powered"....

s are retired from service.
  • SSN-802
  • SSN-803
  • SSN-804

See also

  • Astute-class submarine
    Astute class submarine
    The Astute-class is the latest class of nuclear-powered fleet submarines in service with the Royal Navy. The class sets a new standard for the Royal Navy in terms of weapons load, communication facilities and stealth. The boats are being constructed by BAE Systems Submarine Solutions at...

  • French Barracuda-class submarine
  • Yasen-class submarine

External links

The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
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