Virginia Class Submarine, US Navy attack submarine

The Virginia class subamrine (or SSN-774 class) of attack submarines are U.S. submarines designed for a broad spectrum of open-ocean and littoral missions. They were designed as a less expensive alternative to the Cold War-era designed Seawolf class attack submarines, and they are slated to replace the aging Los Angeles class submarines, seventeen of which (from a total of 62) have already been decommissioned.

Innovations of Virginia Class Submarine

The Virginia-class incorporates several innovations not previously seen in other submarine classes.

Photonics Masts

Instead of a traditional periscope, the class utilizes a pair of telescoping photonics masts 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.

Propulsion

The class also makes use of pump-jet propulsors, which significantly reduces the risks of cavitation, allowing for quieter and faster operations.

Sonar

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.

USS California will be the first Virginia with the advanced electromagnetic signature reduction system built in, but this will be retrofitted into the other submarines of the class.

Specifications of Virginia class submarine

• Builders: GD Electric Boat and Northrop Grumman Newport News
• Length: 377 ft (114.91 m)
• Beam: 34 ft (10.36 m)
• Displacement: 7,800 long tons (7,900 t)
• Payload: 40 weapons, special operations forces, unmanned undersea vehicles, Advanced SEAL Delivery System (ASDS)
• Propulsion: The S9G nuclear reactor
• 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, which has not yet been authorized)
• Actual cost: about $1.8 billion each (as of 2009)
• Crew: 120 enlisted and 14 officers
• Armament: 12 VLS & four torpedo tubes, capable of launching Mark 48 torpedoes, Harpoon missiles, UGM-109 Tactical Tomahawks, and the new advanced mobile mine when it comes available.

Virginia Class Submarine overview
Name:	Virginia
Builders:	General Dynamics Electric Boat Northrop Grumman Newport News
Operators:	United States Navy
Preceded by:	Seawolf class attack submarine Los Angeles class attack submarine
Cost:	$1.8 billion per unit 2009
Built:	2000 – present
In commission:	2004 – present
Building:	3
Planned:	30
Completed:	7
Active:	7
General characteristics
Type:	Attack submarine
Displacement:	7,900 metric tons (7,800 long tons)
Length:	377 feet (115 m)
Beam:	34 feet (10 m)
Propulsion:	S9G reactor
Speed:	25+ knots (45+ km/h)
Range:	unlimited except by food supplies
Test depth:	800+ ft (250+ m)
Complement:	134
Armament:	12 × VLS (BGM-109 Tomahawk cruise missile) & 4 × 533mm torpedo tubes (Mk-48 torpedo)
Notes:	Ships in class include: Virginia, Texas, Hawaii, North Carolina, New Hampshire, New Mexico, Missouri, California, Mississippi, Minnesota, North Dakota, John Warner