Attack Submarines - SSN

Last updated: 26 Feb 2019


Attack submarines are designed to seek and destroy enemy submarines and surface ships; project power ashore with Tomahawk cruise missiles and Special Operation Forces (SOF); carry out Intelligence, Surveillance and Reconnaissance (ISR) missions; support battle group operations; and engage in mine warfare.



With the number of foreign diesel-electric/air-independent propulsion submarines increasing, the United States Submarine Force relies on its technological superiority and the speed, endurance, mobility, stealth and payload afforded by nuclear power to retain its preeminence in the undersea battlespace.


The Navy has three classes of SSNs in service. Los Angeles-class (SSN 688) submarines are the backbone of the submarine force, with approximately 40 now in commission. Thirty of those are equipped with 12 Vertical Launch System (VLS) tubes for firing Tomahawk cruise missiles.


The Navy also has three Seawolf-class submarines. Commissioned July 19, 1997, USS Seawolf (SSN 21) is exceptionally quiet, fast, well-armed, and equipped with advanced sensors. Though lacking VLS, the Seawolf class has eight torpedo tubes and can hold up to 50 weapons in its torpedo room. The third ship of the class, USS Jimmy Carter (SSN 23), has a 100-foot hull extension called the multi-mission platform. This hull section provides for additional payloads to accommodate advanced technology used to carry out classified research and development and for enhanced warfighting capabilities.


The Navy continues to build the next-generation attack submarine, the Virginia (SSN 774) class. More than a dozen Virginias have been commissioned to date, and they will replace Los Angeles Class submarines as they retire. The Virginia class has several innovations that significantly enhance its warfighting capabilities, including in littoral -- or coastal -- operations. Virginia class SSNs have a fly-by-wire ship control system that provides improved shallow-water ship handling. The class has special features to support SOF, including a reconfigurable torpedo room which can accommodate a large number of SOF and all their equipment for prolonged deployments and future off-board payloads. The class also has a large lock-in/lock-out chamber for divers. In Virginia-class SSNs, traditional periscopes have been supplanted by two photonics masts that host visible and infrared digital cameras atop telescoping arms. With the removal of the barrel periscopes, the ship's control room has been moved down one deck and away from the hull's curvature, affording it more room and an improved layout that provides the commanding officer with enhanced situational awareness. Additionally, through the extensive use of modular construction, open architecture, and commercial off-the-shelf components, the Virginia class is designed to remain state-of-the-practice for its entire operational life through the rapid introduction of new systems and payloads.


As part of the Virginia-class' third, or Block III, contract, the Navy redesigned approximately 20 percent of the ship to reduce their acquisition costs. Most of the changes are found in the bow where the traditional, air-backed sonar sphere has been replaced with a water-backed Large Aperture Bow (LAB) array which reduces acquisition and life-cycle costs while providing enhanced passive detection capabilities. The new bow also replaces the 12 individual Vertical Launch System (VLS) tubes with two large diameter 87-inch Virginia Payload Tubes (VPTs), each capable of launching six Tomahawk cruise missiles. The VPTs simplify construction, reduce acquisition costs, and provide for more payload flexibility than the smaller VLS tubes due to their added volume. The design changes were successfully proven out during USS North Dakota's (SSN 784) builder sea trials in August 2014. Block III hulls include the eight ships procured from 2008 through and 2013 (SSNs 784-791.)


Block IV submarines (SSNs 792-801) incorporate design changes focused on reduced total ownership cost (RTOC). By making these smaller-scale design changes to increase the component-level lifecycle of the submarine, the Navy will increase the periodicity between depot maintenance availabilities and increase the number of deployments. Blocks I-III Virginias are planned to undergo four depot maintenance availabilities and conduct 14 deployments. Block IV RTOC efforts are intended to reduce planned availabilities by one to three, and increase deployments to 15. The Navy refers to this as 3:15.


The next major change will be incorporation of the Virginia Payload Module (VPM), planned for the Block V submarines (2019-2022). VPM, currently in the early concept development phase, will add four additional payload tubes -- each capable of carrying seven Tomahawk cruise missiles -- into the Virginia class design. The VPM tubes will be very similar to the VPTs utilized on Block III and forward ships. By using these tubes in the VPM, the Navy will leverage mission-proven components for the new module, thereby minimizing design and cost risk.

General Characteristics, Virginia Class
Builder: General Dynamics Electric Boat Division and Huntington Ingalls Industries Inc. - Newport News Shipbuilding
Date Deployed: USS Virginia commissioned Oct. 3, 2004
Propulsion: One nuclear reactor, one shaft
Length: 377 feet (114.8 meters)
Beam: 34 feet (10.36 meters)
Displacement: Approximately 7,800 tons (7,925 metric tons) submerged
Speed: 25+ knots (28+ miles per hour, 46.3+ kph)
Crew: 132: 15 officers; 117 enlisted
Armament: Tomahawk missiles, twelve VLS tubes (SSNs 774-783) or two VPTs (SSNs 784 and beyond), Mk 48 ADCAP torpedoes, four torpedo tubes.
USS Virginia (SSN 774), Groton, Connecticut
USS Texas (SSN 775), Pearl Harbor, Hawaii
USS Hawaii (SSN 776), Pearl Harbor, Hawaii
USS North Carolina (SSN 777), Pearl Harbor, Hawaii
USS New Hampshire (SSN 778), Groton, Connecticut
USS New Mexico (SSN 779), Groton, Connecticut
USS Missouri (SSN 780), Pearl Harbor, Hawaii
USS California (SSN 781), Groton, Connecticut
USS Mississippi (SSN 782), Pearl Harbor, Hawaii
USS Minnesota (SSN 783), Groton, Connecticut
USS North Dakota (SSN 784), Groton, Connecticut
USS John Warner (SSN 785), Norfolk, Virginia
USS Illinois (SSN 786), Pearl Harbor, Hawaii
USS Washington (SSN 787), Norfolk, Virginia
USS Colorado (SSN 788), Groton, Connecticut
USS Indiana (SSN 789), Groton, Connecticut
USS South Dakota (SSN 790), Groton, Connecticut
USS Delaware (SSN 791) - Commissioned April 4, 2020
USS Vermont (SSN 792) - Commissioned April 18, 2020
Oregon (SSN 793) - Keel laid July 8, 2017
Montana (SSN 794) - Keel laid May 16, 2018
Hyman G. Rickover (SSN 795) - Keel laid May 11, 2018
New Jersey (SSN 796) - Construction began March 2016
Iowa (SSN 797) - Construction began September 2016
Massachusetts (SSN 798) - Construction began March 2017
Idaho (SSN 799) - Construction began September 2017
Arkansas (SSN 800) - Construction began March 2018
Utah (SSN 801) - Construction began March 2018
General Characteristics, Seawolf Class
Builder: General Dynamics Electric Boat Division.
Date Deployed: USS Seawolf commissioned July 19, 1997
Propulsion: One nuclear reactor, one shaft
Length: SSNs 21 and 22: 353 feet (107.6 meters) SSN 23: 453 feet (138.07 meters)
Beam: 40 feet (12.2 meters)
Displacement: SSNs 21 and 22: 9,138 tons (9,284 metric tons) submerged; SSN 23 12,158 tons (12,353 metric tons) submerged
Speed: 25+ knots (28+ miles per hour, 46.3+ kph)
Crew: 140: 14 Officers; 126 Enlisted
Armament: Tomahawk missiles, MK48 torpedoes, eight torpedo tubes.
USS Seawolf (SSN 21), Bremerton, Washington
USS Connecticut (SSN 22), Bremerton, Washington
USS Jimmy Carter (SSN 23), Bangor, Washington
General Characteristics, Los Angeles Class
Builder: Newport News Shipbuilding Co.; General Dynamics Electric Boat Division
Date Deployed: Nov. 13, 1976 (USS Los Angeles)
Propulsion: One nuclear reactor, one shaft
Length: 360 feet (109.73 meters)
Beam: 33 feet (10.06 meters)
Displacement: Approximately 6,900 tons (7011 metric tons) submerged
Speed: 25+ knots (28+ miles per hour, 46.3 +kph)
Crew: 16 officers; 127 enlisted
Armament: Tomahawk missiles, VLS tubes (SSN 719 and later), MK 48 torpedoes, four torpedo tubes
USS Bremerton (SSN 698), Pearl Harbor, Hawaii
USS Jacksonville (SSN 699), Pearl Harbor, Hawaii
USS Dallas (SSN 700), Groton, Connecticut
USS San Francisco (SSN 711), Norfolk, VA (Moored Training Ship)
USS Olympia (SSN 717), Pearl Harbor, Hawaii
USS Providence (SSN 719), Groton, Connecticut
USS Pittsburgh (SSN 720), Groton, Connecticut
USS Chicago (SSN 721), Pearl Harbor, Hawaii
USS Key West (SSN 722), Guam
USS Oklahoma City (SSN 723), Guam
USS Louisville (SSN 724), Pearl Harbor, Hawaii
USS Helena (SSN 725), Norfolk, Virginia
USS Newport News (SSN 750), Norfolk, Virginia
USS San Juan (SSN 751), Groton, Connecticut
USS Pasadena (SSN 752), San Diego, California
USS Albany (SSN 753), Norfolk, Virginia
USS Topeka (SSN 754), Guam
USS Scranton (SSN 756), San Diego, California
USS Alexandria (SSN 757), San Diego, California
USS Asheville (SSN 758), Guam
USS Jefferson City (SSN 759), Pearl Harbor, Hawaii
USS Annapolis (SSN 760), San Diego, California
USS Springfield (SSN 761), Groton, Connecticut
USS Columbus (SSN 762), Pearl Harbor, Hawaii
USS Santa Fe (SSN 763), Pearl Harbor, Hawaii
USS Boise (SSN 764), Norfolk, Virginia
USS Montpelier (SSN 765), Norfolk, Virginia
USS Charlotte (SSN 766), Pearl Harbor, Hawaii
USS Hampton (SSN 767), San Diego, California
USS Hartford (SSN 768), Groton, Connecticut
USS Toledo (SSN 769), Groton, Connecticut
USS Tucson (SSN 770), Pearl Harbor, Hawaii
USS Columbia (SSN 771), Pearl Harbor, Hawaii
USS Greeneville (SSN 772), Pearl Harbor, Hawaii
USS Cheyenne (SSN 773), Pearl Harbor, Hawaii
General Characteristics, Decommissioned
Buffalo (SSN 715) - Bremerton, Washington

Point of Contact
Naval Sea Systems Command

Office of Corporate Communication (SEA 00D)
Washington, D.C. 20376

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