Columbia-class submarine - Wikipedia

Columbia class
Artist rendering of a Columbia-class ballistic missile submarine, 2019 (190306-N-N0101-125).jpg
Artist's rendering of the planned Columbia-class submarine (Naval Sea Systems Command)
Class overview
Preceded byOhio class
  • US$109.8 billion for 12 boats (FY2021, projected)[1]
  • US$9.15 billion per unit (FY2021, projected)
On order2
General characteristics
TypeBallistic missile submarine (SSBN)
Displacement20,810 long tons (21,140 t) (submerged)[4]
Length560 ft (171 m)[4]
Beam43 ft (13 m)[4]
Installed powerNuclear reactor
PropulsionTurbo-electric drive, pump-jet[4]
Complement155 (accommodation)[4]
Sensors and
processing systems
Enlarged version of the Virginia-class LAB sonar[4]
Armament16 × Trident D5[5] and twin torpedo tubes

The Columbia-class submarine (formerly known as the Ohio Replacement Submarine and SSBN-X Future Follow-on Submarine) is an upcoming class of nuclear submarines designed to replace the Ohio-class ballistic missile submarines in the United States Navy.[6] The first submarine officially began construction on 1 October 2020,[7] and is scheduled to enter service in 2031.[8][9][10]

On 3 June 2022, the Navy announced that this first boat will be named USS District of Columbia (SSBN-826), because there currently exists an attack submarine named USS Columbia (SSN-771).[11] The Navy did not say whether the name of the class will also be changed.[12]


The Columbia class is to replace the Ohio class of UGM-133 Trident II–armed ballistic missile submarines, whose remaining boats will be decommissioned, one per year, beginning in 2027. The Columbia class will take over the role of submarine presence in the United States’ strategic nuclear force.[5]

Electric Boat designed the new class with help from Newport News Shipbuilding. A total of 12 submarines are planned,[2] with construction of the lead boat began in 2021. Each submarine will have 16 missile tubes, each carrying one Trident II D5LE missile. The submarines will be 560 feet (170.7 m) long and 43 feet (13.1 m) in diameter, as long as the Ohio-class design, and 1 foot (30 cm) larger in diameter.[5]

In studies to determine how many submarines would be needed to support the United States' strategic nuclear force, the U.S. Navy looked at the number of missiles required to be at sea and on station at any given time, the number of missiles each submarine should be armed with and the likelihood that a submarine will remain undiscovered by the enemy and be capable of launching its missiles. Also taken into consideration was how the maintenance schedule of each submarine will affect that boat’s availability to be deployed on mission.[13] Cost-reduction studies explored design and construction possibilities, including adding missile tubes to the design of the Virginia-class attack submarine, building Ohio-class replacement submarines using updated Ohio-class designs, and developing an entirely new Ohio Replacement Submarine design.[5][14]

Ohio Replacement Submarine

Using the information from these studies, the Navy concluded that a new design would be the least expensive option that could meet all of the technical requirements.[13] For example, both the modified Virginia-class and updated Ohio-class design options would have required an expensive mid-life refueling,[5] whereas each Columbia-class nuclear core will last as long as the submarine is in service.[15][16]

The design and technology development of the Columbia-class is projected to cost $4.2 billion (fiscal 2010 dollars), although technology and components from the Ohio and Virginia classes are to be included where possible, to save money. The cost to build Columbia, the lead boat of the class, will be an estimated $6.2 billion (fiscal 2010 dollars).[5] The Navy has a goal of reducing the average cost of the remaining 11 planned hulls in the class to $4.9 billion each (fiscal 2010 dollars).[15] The total lifecycle cost of the entire class is estimated at $347 billion.[15] The high cost of the submarines is expected to cut deeply into Navy shipbuilding.[17]

In April 2014, the Navy completed a 300-page specification report for the Ohio Replacement Program submarines. There are 159 specifications including weapons systems, escape routes, fluid systems, hatches, doors, sea water systems, and a set length of 560 ft (170 m), partly to allow for sufficient volume inside the pressure hull.[18]

In March 2016, the U.S. Navy announced that General Dynamics Electric Boat was chosen as the prime contractor and lead design yard.[19] Electric Boat will carry out the majority of the work, on all 12 submarines, including final assembly.[20] All 18 Ohio-class submarines were built at Electric Boat as well.[21] Huntington Ingalls Industries’ Newport News Shipbuilding will serve as the main subcontractor, participating in the design and construction and performing 22 to 23 percent of the required work.[22]

In late 2016, some 3,000 employees were involved, in Electric Boat alone, in the detailed design phase of the program,[23] with the procurement of the first submarine scheduled for 2021.[5] Completion of the first submarine is scheduled for 2030, followed by its entry into service in 2031. All 12 submarines are expected to be completed by 2042 and remain in service until 2085.[5][18]

On 28 July 2016, it was reported that the first submarine of the class will be named Columbia, to commemorate the District of Columbia, the capital of the United States.[24] The Columbia-class was officially designated on 14 December 2016, by Secretary of the Navy Ray Mabus, and the lead submarine will be USS Columbia (SSBN-826).[25] The Navy wants to procure the first Columbia-class boat in FY2021.[26]

On 28 October 2020, U.S. Navy Secretary Kenneth J. Braithwaite announced that the second submarine would be named USS Wisconsin (SSBN-827), after the U.S. state.[27]

On 7 June 2021, the U.S. Navy Budget office announced that the total cost for the first submarine, Columbia, would reach $15.03 billion, but that also includes planning costs for entire program.[28]

General characteristics[edit]

Graphic artist concept, 2012
Cutaway image

Although still evolving, the following are some of the characteristics for the SSBN(X) design:[9][29]

  • Expected 42-year service life (it is planned that each submarine will carry out 124 deterrent patrols during its service life)[30]
  • Life-of-the-ship nuclear fuel core that is sufficient to power the submarine for its entire expected service life, unlike the Ohio-class submarines, which require a mid-life nuclear refueling[16]
  • Missile launch tubes that are the same size as those of the Ohio class, with a diameter of 87 inches (2,200 mm) and a length sufficient to accommodate a D-5 Trident II missile
  • Beam at least as great as the 42-foot (13 m) beam of the Ohio-class submarines
  • 16 missile launch tubes instead of 24 missile launch tubes on Ohio-class submarines.[5][31][32][33]
  • Although the SSBN(X) is to have fewer launch tubes than the Ohio-class submarine, SSBN(X) is expected to have a submerged displacement about the same as that of Ohio-class submarines

The U.S. Navy has also stated that "owing to the unique demands of strategic relevance, SSBN(X)s must be fitted with the most up-to-date capabilities and stealth to ensure they are survivable throughout their full 40-year life span."[5]

In November 2012, the U.S. Naval Institute, citing Naval Sea Systems Command, revealed additional design information:[33]

  • X-shaped stern control surfaces (hydroplanes)
  • Sail-mounted dive planes
  • Electric drive
  • Off-the-shelf equipment developed for previous submarine designs (Virginia-class SSNs), including a pump-jet propulsor, anechoic coating and a Large Aperture Bow (LAB) sonar system.

The Columbia-class submarine may also be equipped with a Submarine Warfare Federated Tactical System (SWFTS), a cluster of systems that integrate sonar, optical imaging, weapons control etc.[34][35][36]

Electric drive[edit]

Electric drive is a propulsion system that uses an electric motor that turns the propeller of a vessel. It is part of a wider (Integrated electric power) concept whose aim is to create an "all electric vessel".[37][38] Electric drive should reduce the life-cycle cost of submarines while at the same time reducing acoustic signature.[39][40]

Turbo-electric drive had been successfully used on U.S. capital ships (battleships and aircraft carriers) in the first half of the 20th century,[41] and on the small nuclear-powered submarine USS Tullibee in the late 1950s.[42] Another larger nuclear-powered submarine, the USS Glenard P. Lipscomb, was equipped with a turboelectric drive but proved to be underpowered and experienced reliability and maintenance issues.[43][44] As of 2013, only the French Navy uses turboelectric drive on its nuclear-powered Triomphant-class submarines.[45]

Conceptually, electric drive is only a segment of the propulsion system (it does not replace the nuclear reactor or the steam turbines). Instead, it replaces reduction gearing (mechanical drive) used on earlier nuclear-powered submarines.[37] In 1998, the Defense Science Board envisaged a nuclear-powered submarine that would use direct energy conversion, eliminating the need for both reduction gearing as well as steam turbines.[46]

In 2014, Northrop Grumman was chosen as the prime designer and manufacturer of the turbine generator units.[47] The turbines convert thermal energy in the steam into mechanical energy, and the generators convert that mechanical energy into electrical energy.[48] The electrical energy is then used for powering onboard systems as well as for propulsion via electric motor.[47][49]

Various electric motors have and are being developed for both military and non-military vessels.[50] Those being considered for application on future U.S. Navy submarines include permanent magnet motors (PMM) (being developed by General Dynamics and Newport News Shipbuilding) and a high-temperature superconducting (HTS) synchronous motors, being developed by American Superconductors as well as General Atomics.[50][51][52]

More recent data shows that the U.S. Navy appears to be focusing on permanent-magnet, radial-gap electric propulsion motors (although the Zumwalt-class destroyer design switched from PMM to an advanced induction motor).[53] Permanent magnet motors are being tested on the Large Scale Vehicle II for possible application on late production Virginia-class submarines, as well as future submarines.[54][55] Permanent magnet motors, developed by Siemens AG, are used on Type 212 submarines, in service with the German and Italian navies.[56]

Reports on the Royal Navy's Dreadnought-class submarine, the class slated to replace the Vanguard class of ballistic missile submarines, state that the boats may have submarine shaftless drive (SSD) with an electric motor mounted outside the pressure hull.[57][unreliable source?] SSD was evaluated by the U.S. Navy as well, but it remains unknown whether the Ohio-class replacement will feature it.[58][59] On contemporary nuclear submarines, steam turbines are linked to reduction gears and a shaft rotating the propeller/pump-jet propulsor. With SSD, steam would drive electric turbogenerators, powered by steam turbines, that would be connected to a non-penetrating electric junction at the aft end of the pressure hull, with a watertight electric motor mounted externally, possibly an Integrated Motor Propulsor arrangement,[60] powering the pump-jet propulsor,[57] although SSD concepts without pump-jet propulsors also exist.[61] More recent data, including an Ohio Replacement scale model displayed at the Navy League’s 2015 Sea-Air-Space Exposition, indicates that the Ohio Replacement will feature a pump-jet propulsor visually similar to the one used on Virginia-class.[62][33] The class will share components from the Virginia-class in order to reduce risk and cost of construction.[62][5]

Common missile compartment[edit]

In December 2008, General Dynamics Electric Boat Corporation was selected to design the Common Missile Compartment that will be used on the Ohio-class successor.[31] In 2012, the U.S. Navy announced plans for its SSBN(X) to share a common missile compartment (CMC) design with the Royal Navy's Dreadnought-class ballistic missile submarine.[5] The CMC will house SLBMs in "quad packs".[63][64]

Ships in class[edit]

Name Hull Number Builder Ordered Laid down Launched Commissioned Homeport Status
District of Columbia SSBN-826 General Dynamics Electric Boat, Groton, CT 30 March 2016[65][failed verification] 4 June 2022[66][67] Under construction[66]
Wisconsin SSBN-827 30 November 2020[65] Ordered[68]


  1. ^ O'Rourke, Ronald (1 May 2020). "Navy Columbia (SSBN-826) Class Ballistic Missile Submarine Program: Background and Issues for Congress". Congressional Research Service. p. 7. Retrieved 14 May 2020.
  2. ^ a b "Columbia-class Program Upping Oversight of Vendors, Components to Stave Off Further Delays". 8 November 2018. Retrieved 9 November 2018.
  3. ^ "US Navy begins construction of Columbia Class ballistic missile submarines". 10 November 2020. Retrieved 16 April 2021.
  4. ^ a b c d e f "Ohio Replacement Program". United States Naval Institute. 18 October 2012. Retrieved 1 November 2012.
  5. ^ a b c d e f g h i j k l O'Rourke, Ronald (17 September 2017). "Navy Navy SSBN(X) Ballistic Missile Submarine Program: Background and Issues for Congress" (PDF). Congressional Research Service. R41129. Retrieved 23 September 2017 – via Federation of American Scientists.
  6. ^ "SSBN-X Future Follow-on Submarine". 24 July 2011. Retrieved 24 July 2011.
  7. ^ "Navy: USS Columbia Will Have Most Complete Design Ever at Official Construction Start". 8 May 2019.
  9. ^ a b "SENEDIA Defense Innovation Days" (PDF). 5 September 2014. Retrieved 20 August 2016.
  10. ^ This story was written by Lt. Rebecca Rebarich, Commander Submarine Group Ten Public Affairs. "1,000 Trident Patrols: SSBNs the Cornerstone of Strategic Deterrence". Retrieved 20 August 2016.
  11. ^ DC Congresswoman Pushes DC Statehood at Keel-Laying for Navy Submarine
  12. ^ "SECNAV Names SSBN 826 USS District of Columbia". United States Navy. Retrieved 4 June 2022.
  13. ^ a b Kristensen, Hans M. (24 July 2013). "SSBNX Under Pressure: Submarine Chief Says Navy Can't Reduce". FAS Strategic Security Blog. Federation of American Scientists. Archived from the original on 6 September 2013. Retrieved 17 August 2013.
  14. ^ Kelly, Jason. "Facts We Can Agree Upon About Design of Ohio Replacement SSBN". Retrieved 17 August 2013.
  15. ^ a b c "U.S. Nuclear Modernization Programs". Arms Control Association. Archived from the original on 5 April 2010. Retrieved 1 November 2012.
  16. ^ a b "Ohio-class Replacement Will Carry "Re-packaged and Re-hosted" Weapons System". Defense Media Network. 4 February 2011. Retrieved 6 February 2013.
  17. ^ Ratnam, Gopal; Capaccio, Tony (9 March 2011). "U.S. Navy Sees 20-Year, $333 Billion Plan Missing Ship Goals". Bloomberg. Retrieved 9 March 2011.
  18. ^ a b Kris Osborn (8 April 2014). "Navy Finishes Specs for Future Nuclear Sub". Archived from the original on 15 May 2016. Retrieved 20 August 2016.
  19. ^ Grace Jean (30 March 2016). "USN taps General Dynamics Electric Boat as prime contractor for Ohio Replacement Programme". IHS Jane's 360, Retrieved 20 August 2016.
  20. ^ "Ohio Replacement Plan Is Good News For Electric Boat". Breaking Defense. 29 March 2016. Retrieved 20 August 2016.
  21. ^ "SSBN / SSGN Ohio Class Submarine". Naval Technology. 15 June 2011. Retrieved 20 August 2016.
  22. ^ "Newport News Shipbuilding's share of Virginia-class submarine deliveries to grow | Defense & Shipyards". 29 March 2016. Retrieved 20 August 2016.
  23. ^ Bergman, Julia (10 December 2016). "Navy contracts mean Electric Boat will hire 14,000 over next 13 years". The Day.
  24. ^ Sam LaGrone (28 July 2016). "New U.S. Navy Nuclear Sub Class to Be Named for D.C." Retrieved 20 August 2016.
  25. ^ "SECNAV Mabus to Officially Designate First ORP Boat USS Columbia (SSBN-826)". USNI News, 13 December 2016.
  26. ^ "Report on the Columbia-class Nuclear Ballistic Missile Submarine Program". USNI News, 20 May 2020.
  27. ^ Santos, Babs (29 October 2020). "U.S. Navy to name submarine after Wisconsin". WLUK-TV. Archived from the original on 5 November 2020.
  28. ^ "Cost Estimates for Lead Boat in Columbia-class Program Grow by $637M". USNI News. 7 June 2021. Retrieved 18 August 2021.
  29. ^ OHIO Replacement Program Naval Submarine League
  30. ^ "Ohio Replacement Submarine Starts Early Construction". 24 October 2013.
  31. ^ a b "CMC Program to Define Future SSBN Launchers for UK, USA". Defense Industry Daily. 25 November 2012. Retrieved 3 December 2012.
  32. ^ "An Analysis of the Navy's Fiscal Year 2013 Shipbuilding Plan" (PDF). Congressional Budget Office. Retrieved 3 December 2012.
  33. ^ a b c "Ohio-class Replacement Details". US Naval Institute. 1 November 2012. Retrieved 3 December 2012.
  34. ^ "On Watch 2011". Archived from the original on 3 March 2013. Retrieved 6 February 2013.
  35. ^ Keller, John (15 April 2012). "Lockheed Martin to adapt submarine combat systems for network-centric warfare operations at sea". Military & Aerospace Electronics, Retrieved 2 February 2014.
  36. ^ NAVSEA News.
  37. ^ a b "An Integrated Electric Power System: the Next Step". Archived from the original on 28 November 2012. Retrieved 6 February 2013.
  38. ^ "Going Electric". Defense Media Network. 14 June 2010. Retrieved 6 February 2013.
  39. ^ "Propulsion Systems for Navy Ships and Submarines" (PDF). Government Accounting Office. 6 July 2006.
  40. ^ Technology for the United States Navy and Marine Corps, 2000–2035 Becoming a 21st-Century Force: Volume 2: Technology. 1 June 2003. doi:10.17226/5863. ISBN 978-0-309-05897-1. Retrieved 30 May 2013.
  41. ^ Tony DiGiulian. "Turboelectric Drive in American Capital Ships". Retrieved 6 February 2013.
  42. ^ Paul Lambert. "USS Tullibee – History". USS Tullibee SSN 597. Archived from the original on 17 May 2014. Retrieved 6 February 2013.
  43. ^ "Submarine Technology thru the Years". 19 July 1997. Archived from the original on 12 February 2012. Retrieved 6 February 2013.
  44. ^ Sam LaGrone (28 March 2013). "Secret Nuclear Redesign Will Keep U.S. Subs Running Silently for 50 Years". Wired. Danger Room, Retrieved 30 May 2013.
  45. ^ "SSBN Triomphant Class". Naval Technology. 15 June 2011. Retrieved 6 February 2013.
  46. ^ "Submarine of the Future". Retrieved 6 February 2013.
  47. ^ a b "News". Northrop Grumman.
  48. ^ "Electricity 101 – GE Power Generation".
  49. ^ Kris Osborn. "Ohio Replacement Subs To Shift To Electric Drive". Retrieved 20 August 2016.
  50. ^ a b Bogomolov, M.D. (22 January 2013). "Concept study of 20 MW highspeed permanent magnet synchronous motor for marine propulsion" (PDF). Eindhoven University of Technology.
  51. ^ O'Rourke, Ronald (11 December 2006). "Navy Ship Propulsion Technologies: Options for Reducing Oil Use — Background for Congress" (PDF). Federation of American Scientists. RL33360.
  52. ^ Sonal Patel (1 March 2009). "Superconductor Motor for Navy Passes Full-Power Test :: POWER Magazine". Retrieved 30 May 2013.
  53. ^ "DDG-1000 Zumwalt Class Destroyer". 1 November 2012. Retrieved 6 February 2013.
  54. ^ "Small Subs Provide Big Payoffs for Submarine Stealth". Archived from the original on 13 March 2013. Retrieved 6 February 2013.
  55. ^ Dan Petty. "The US Navy – Fact File: Large Scale Vehicle – LSV 2". Retrieved 6 February 2013.
  56. ^ "SINAVY CIS Permasyn" (PDF). Siemens. 2009. Archived from the original (PDF) on 20 February 2014. Retrieved 30 May 2013.
  57. ^ a b "SSBN "Strategic Successor Submarine" project". Harpoon Headquarters. Retrieved 17 August 2013.
  58. ^ "Tango Bravo: breaking down barriers in submarine design". 23 March 2007. Retrieved 30 May 2013.[permanent dead link]
  59. ^ "Tango Bravo R&D Project to Drive Down Sub Size". Retrieved 30 May 2013.
  60. ^ "Torpedoes and the Next Generation of Undersea Weapons". Archived from the original on 20 April 2015. Retrieved 1 June 2013.
  61. ^ Kuhn, Dave; Torrez, Joe; Fallier, William (2006). "The Rim Electric Drive – Internal Submarine" (PDF). Naval Construction and Engineering. Massachusetts Institute of Technology.
  62. ^ a b "GDEB Unveils New Ohio Replacement (SSBN-X) Detailed Model at Sea-Air-Space 2015 Exposition". 14 April 2015. Retrieved 20 August 2016.
  63. ^ "Navy Signs Specification Document for the Ohio Replacement Submarine Program, Sets forth Critical Design Elements". Navy News Service. 6 September 2012. NNS120906-13. Retrieved 21 April 2013.
  64. ^ Patani, Arif (24 September 2012). "Next Generation Ohio-Class". Retrieved 21 April 2013.
  65. ^ a b "Newport News Shipbuilding awarded $2.2B contract for construction of first two Columbia-class submarines". WTKR. 29 November 2020. Archived from the original on 30 November 2020.
  66. ^ a b "Naval Vessel Register - COLUMBIA (SSBN 826)". Retrieved 30 October 2020.
  67. ^ "Keel Laying Ceremony Held for First Columbia-Class Ballistic Missile Submarine".
  68. ^ "SECNAV Names Newest Columbia-class submarine USS Wisconsin". United States Navy. Retrieved 30 October 2020.


External links[edit]