Ohio-class submarine

Ohio-class submarine
Ohio-class SSBN profile
USS Ohio, during her commissioning ceremony in 1981.
Class overview
NameOhio class
BuildersGeneral Dynamics Electric Boat
Operators United States Navy
Preceded byBenjamin Franklin class
Succeeded byColumbia class
Cost$2 billion (late 1990s) ($3.4 billion in 2023 dollars)
Built1976–1997
In commission1981–present
Planned24
Completed18
Cancelled6
Active18
General characteristics
TypeSSBN/SSGN (hull design SCB-304)
Displacement
  • 16,764 tonnes (16,499 long tons) surfaced
  • 18,750 tonnes (18,450 long tons) submerged
Length560 ft (170 m)
Beam42 ft (13 m)
Draft35.5 ft (10.8 m) maximum
Propulsion
  • S8G PWR nuclear reactor
  • 2× geared turbines; 35,000 shp (26 MW)
  • 1x Fairbanks Morse auxiliary diesel
  • 1× 325 hp (242 kW) auxiliary motor
  • 1 shaft with seven-bladed screw
Speed
  • 12 knots (22 km/h; 14 mph) surfaced
  • 20 knots (37 km/h; 23 mph) submerged (official)
  • 25 knots (46 km/h; 29 mph) submerged (reported)
RangeLimited only by food supplies
Test depth+800 ft (240 m)
Complement15 officers, 140 enlisted
Sensors and
processing systems
  • BQQ-6 passive bow-mounted array (which includes BQS-13 fire control array)
  • BQR-19 navigation
  • TB-16 or BQR-23 towed array
  • BQR-25 conformal array
  • The AN/BPS-15J [1]
Armament4 × 21 inch (533 mm) Mark 48 torpedo tubes (Forward Compartment 4th level)
General characteristics (SSBN-726 to SSBN-733 from construction to refueling)
Armament20 × Trident I C4 SLBM with up to 8 MIRVed 100 ktTNT W76 nuclear warheads each, range 4,000 nmi (7,400 km; 4,600 mi)
General characteristics (SSBN-734 and subsequent hulls upon construction, SSBN-730 to SSBN-733 since refueling)
Armament20 × Trident II D5 SLBM with up to 12 MIRVed W76 or W88 (475 ktTNT) nuclear warheads each, range 6,100 nmi (11,300 km; 7,000 mi)
General characteristics (SSGN conversion)
Armament22 tubes, each with 7 Tomahawk cruise missiles, totaling 154

The Ohio class of nuclear-powered submarines includes the United States Navy's 14 ballistic missile submarines (SSBNs) and its four cruise missile submarines (SSGNs). Each displacing 18,750 tons submerged, the Ohio-class boats are the largest submarines ever built for the U.S. Navy. They are also the third-largest submarines ever built, behind the Russian Navy's Soviet era 48,000-ton Typhoon class, the last of which was retired in 2023, and 24,000-ton Borei class. Capable of carrying 24 Trident II missiles apiece, the Ohio class are equipped with just as many missiles as, if not more than, either the Borei class (16) or the deactivated Typhoon class (20).

Like their predecessors the Benjamin Franklin and Lafayette-class, the Ohio-class SSBNs are part of the United States' nuclear-deterrent triad, along with U.S. Air Force strategic bombers and intercontinental ballistic missiles. The 14 SSBNs together carry about half of U.S. active strategic thermonuclear warheads. Although the Trident missiles have no preset targets when the submarines go on patrol,: 392  they can be given targets quickly, from the United States Strategic Command based in Nebraska, using secure and constant radio communications links, including very low frequency systems.

All the Ohio-class submarines, except for USS Henry M. Jackson, are named for U.S. states, which U.S. Navy tradition had previously reserved for battleships and later cruisers. The Ohio class is to be gradually replaced by the Columbia class beginning in 2031.

Description

The Ohio-class submarine was designed for extended strategic deterrent patrols. Each submarine is assigned two complete crews, called the Blue crew and the Gold crew, each typically serving 70-to-90-day deterrent patrols. To decrease the time in port for crew turnover and replenishment, three large logistics hatches have been installed to provide large-diameter resupply and repair access. These hatches allow rapid transfer of supply pallets, equipment replacement modules, and machinery components, speeding up replenishment and maintenance of the submarines. Moreover, the "stealth" ability of the submarines was significantly improved over all previous ballistic-missile subs. Ohio was virtually undetectable in her sea trials in 1982, giving the U.S. Navy extremely advanced flexibility.

USS Michigan (SSBN-727) at a dry-dock in November 2002, before its conversion to an SSGN

The class's design allows the boat to operate for about 15 years between major overhauls. These submarines are reported to be as quiet at their cruising speed of 20 knots (37 km/h; 23 mph) or more as the previous Lafayette-class submarines at 6 knots (11 km/h; 6.9 mph), although exact information remains classified. Fire control for their Mark 48 torpedoes is carried out by Mark 118 Mod 2 system, while the Missile Fire Control system is a Mark 98.

The Ohio-class submarines were constructed from sections of hull, with each four-deck section being 42 ft (13 m) in diameter. The sections were produced at the General Dynamics Electric Boat facility, Quonset Point, Rhode Island, and then assembled at its shipyard at Groton, Connecticut.

The US Navy has a total of 18 Ohio-class submarines which consist of 14 ballistic missile submarines (SSBNs), and four cruise missile submarines (SSGNs). The SSBN submarines provide the sea-based leg of the U.S. nuclear triad. Each SSBN submarine is armed with up to 20 Trident II submarine-launched ballistic missiles (SLBM). Each SSGN is capable of carrying 154 Tomahawk cruise missiles, plus a complement of Harpoon missiles to be fired through their torpedo tubes.

History

The Ohio class was designed in the 1970s to carry the concurrently designed Trident submarine-launched ballistic missile. The first eight Ohio-class submarines were armed at first with 24 Trident I C4 SLBMs. Beginning with the ninth Trident submarine, Tennessee, the remaining boats were equipped with the larger, three-stage Trident II D5 missile. The Trident I missile carries eight multiple independently targetable reentry vehicles, while the Trident II missile carries 12, in total delivering more destructive power than the Trident I missile and with greater accuracy. Starting with Alaska in 2000, the Navy began converting its remaining ballistic missile submarines armed with C4 missiles to carry D5 missiles. This task was completed in mid-2008. The first eight submarines had their home ports at Bangor, Washington, to replace the submarines carrying Polaris A3 missiles that were then being decommissioned. The remaining 10 submarines originally had their home ports at Kings Bay, Georgia, replacing the Poseidon and Trident Backfit submarines of the Atlantic Fleet.

SSBN/SSGN conversions

Ohio-class SSGN profile
Black submarine with orange paint from cheatline down in drydock at nightfall
USS Ohio being converted from an SSBN to an SSGN in March 2004

In 1994, the Nuclear Posture Review study determined that, of the 18 Ohio SSBNs the U.S. Navy would be operating in total, 14 would be sufficient for the strategic needs of the U.S. The decision was made to convert four Ohio-class boats into SSGNs capable of conducting conventional land attack and special operations. As a result, the four oldest boats of the class—Ohio, Michigan, Florida, and Georgia—progressively entered the conversion process in late 2002 and were returned to active service by 2008. The boats could thereafter carry 154 Tomahawk cruise missiles and 66 special operations personnel, among other capabilities and upgrades. The cost to refit the four boats was around US$1 billion (2008 dollars) per vessel. During the conversion of these four submarines to SSGNs (see below), five of the remaining submarines, Pennsylvania, Kentucky, Nebraska, Maine, and Louisiana, were transferred from Kings Bay to Bangor.[citation needed] Further transfers occur as the strategic weapons goals of the United States change.

Artist's concept of an Ohio-class SSGN launching Tomahawk Land Attack Missiles

In 2011, Ohio-class submarines carried out 28 deterrent patrols. Each patrol lasts around 70 days. Four boats are on station ("hard alert") in designated patrol areas at any given time. From January to June 2014, Pennsylvania carried out a 140-day-long patrol, the longest to date.

The conversion modified 22 of the 24 88-inch (2.2 m) diameter Trident missile tubes to contain large vertical launch systems, one configuration of which may be a cluster of seven Tomahawk cruise missiles. In this configuration, the number of cruise missiles carried could be a maximum of 154, the equivalent of what is typically deployed in a surface battle group. Other payload possibilities include new generations of supersonic and hypersonic cruise missiles, and Submarine Launched Intermediate Range Ballistic Missiles, unmanned aerial vehicles, the ADM-160 MALD, sensors for antisubmarine warfare or intelligence, surveillance, and reconnaissance missions, counter mine warfare payloads such as the AN/BLQ-11 Long Term Mine Reconnaissance System, and the broaching universal buoyant launcher and stealthy affordable capsule system specialized payload canisters.[citation needed]

The helm of the Ohio-class guided-missile submarine, USS Florida (SSGN-728), in March 2010

The missile tubes also have room for stowage canisters that can extend the forward deployment time for special forces. The other two Trident tubes are converted to swimmer lockout chambers. For special operations, the Dry Combat Submersible (which replaced the Advanced SEAL Delivery System), as well as the dry deck shelter, can be mounted on the lockout chamber and the boat will be able to host up to 66 special-operations sailors or Marines, such as Navy SEALs, or USMC MARSOC teams. Improved communications equipment installed during the upgrade allows the SSGNs to serve as a forward-deployed, clandestine Small Combatant Joint Command Center.

On 26 September 2002, the Navy awarded General Dynamics Electric Boat a US$442.9 million contract to begin the first phase of the SSGN submarine conversion program. Those funds covered only the initial phase of conversion for the first two boats on the schedule. Advance procurement was funded at $355 million in fiscal year 2002, $825 million in the FY 2003 budget and, through the five-year defense budget plan, at $936 million in FY 2004, $505 million in FY 2005, and $170 million in FY 2006. Thus, the total cost to refit the four boats is just under $700 million per vessel.[citation needed]

In November 2002, Ohio entered a dry-dock, beginning her 36-month refueling and missile-conversion overhaul. Electric Boat announced on 9 January 2006 that the conversion had been completed. The converted Ohio rejoined the fleet in February 2006, followed by Florida in April 2006. The converted Michigan was delivered in November 2006. The converted Ohio went to sea for the first time in October 2007. Georgia returned to the fleet in March 2008 at Kings Bay.[failed verification] These four SSGNs are expected to remain in service until about 2023–2026. At that point, their capabilities will be replaced with Virginia Payload Module-equipped Virginia-class submarine.

Missile tube reduction

As part of the New START treaty, four tubes on each SSBN were deactivated in 2017, reducing the number of missiles to 20 per boat.

Detailed cross-section

Line drawing of submarine with circled numbers denoting different submarine components and compartments.
Line drawing of the Ohio class in its original SSBN configuration. (1) Sonar dome, (2) Main ballast tanks, (3) Computer room, (4) Integrated radio room, (5) Sonar room, (6) Command and control center, (7) Navigation center, (8) Missile control center, (9) Engine room, (10) Reactor compartment, (11) Auxiliary machinery room no. 2, (12) Crew's berthing, (13) Auxiliary machinery room no. 1, (14) Torpedo room, (15) Wardroom, (16) Chief petty officer quarters, (17) Missile compartment

List of boats

Boat Hull number Ordered Laid down Launched Delivered Commissioned Homeport Service life
(status)
Ref.
Guided-missile submarines (SSGN)
Ohio SSGN-726 1 July 1974 10 April 1976 7 April 1979 28 October 1981 11 November 1981 Naval Base Kitsap, Washington 42 years, 4 months and 17 days
(in active service)
Michigan SSGN-727 28 February 1975 4 April 1977 26 April 1980 28 August 1982 11 September 1982 Naval Base Kitsap, Washington 41 years, 6 months and 17 days
(in active service)
Florida SSGN-728 28 February 1975 19 January 1981 14 November 1981 17 May 1983 18 June 1983 Naval Submarine Base Kings Bay, Georgia 40 years, 9 months and 10 days
(in active service)
Georgia SSGN-729 20 February 1976 7 April 1979 6 November 1982 17 January 1984 11 February 1984 Naval Submarine Base Kings Bay, Georgia 40 years, 1 month and 17 days
(in active service)
Ballistic missile submarines (SSBN)
Henry M. Jackson
(ex Rhode Island)
SSBN-730 6 June 1977 19 November 1981 15 October 1983 11 September 1984 6 October 1984 Naval Base Kitsap, Washington 39 years, 5 months and 22 days
(in active service)
Alabama SSBN-731 27 February 1978 27 August 1981 19 May 1984 23 April 1985 25 May 1985 Naval Base Kitsap, Washington 38 years, 10 months and 3 days
(in active service)
Alaska SSBN-732 27 February 1978 9 March 1983 12 January 1985 26 November 1985 25 January 1986 Naval Submarine Base Kings Bay, Georgia 38 years, 2 months and 3 days
(in active service)
Nevada SSBN-733 7 January 1981 8 August 1983 14 September 1985 7 August 1986 16 August 1986 Naval Base Kitsap, Washington 37 years, 7 months and 12 days
(in active service)
Tennessee SSBN-734 7 January 1982 9 June 1986 13 December 1986 18 November 1988 17 December 1988 Naval Submarine Base Kings Bay, Georgia 35 years, 3 months and 11 days
(in active service)
Pennsylvania SSBN-735 29 November 1982 2 March 1987 23 April 1988 22 August 1989 9 September 1989 Naval Base Kitsap, Washington 34 years, 6 months and 19 days
(in active service)
West Virginia SSBN-736 21 November 1983 18 December 1987 14 October 1989 10 September 1990 20 October 1990 Naval Submarine Base Kings Bay, Georgia 33 years, 5 months and 8 days
(in active service)
Kentucky SSBN-737 13 August 1985 18 December 1987 11 August 1990 27 June 1991 13 July 1991 Naval Base Kitsap, Washington 32 years, 8 months and 15 days
(in active service)
Maryland SSBN-738 14 March 1986 22 April 1986 10 August 1991 31 May 1992 13 June 1992 Naval Submarine Base Kings Bay, Georgia 31 years, 9 months and 15 days
(in active service)
Nebraska SSBN-739 26 May 1987 6 July 1987 15 August 1992 18 June 1993 10 July 1993 Naval Base Kitsap, Washington 30 years, 8 months and 18 days
(in active service)
Rhode Island SSBN-740 15 January 1988 15 September 1988 17 July 1993 22 June 1994 9 July 1994 Naval Submarine Base Kings Bay, Georgia 29 years, 8 months and 19 days
(in active service)
Maine SSBN-741 5 October 1988 3 July 1990 16 July 1994 21 June 1995 29 July 1995 Naval Base Kitsap, Washington 28 years, 8 months and 9 days
(in active service)
Wyoming SSBN-742 18 October 1989 8 August 1991 15 July 1995 20 June 1996 13 July 1996 Naval Submarine Base Kings Bay, Georgia 27 years, 8 months and 15 days
(in active service)
Louisiana SSBN-743 19 December 1990 23 October 1992 27 July 1996 14 August 1997 6 September 1997 Naval Base Kitsap, Washington 26 years, 6 months and 22 days
(in active service)

Note: Boats based at Naval Base Kitsap, Washington are operated by the U.S. Pacific Fleet, while boats based at Naval Submarine Base Kings Bay, Georgia are operated by U.S. Fleet Forces Command, (formerly the U.S. Atlantic Fleet).

Replacement

The U.S. Department of Defense anticipated a continued need for a sea-based strategic nuclear force. The first of the current Ohio-class SSBNs was expected to be retired by 2029, so the replacement submarine would need to be seaworthy by that time. A replacement was expected to cost over $4 billion per unit compared to Ohio's $2 billion. The U.S. Navy explored two options. The first option was a variant of the Virginia-class nuclear-powered attack submarines. The second option was a dedicated SSBN, either with a new hull or based on an overhaul of the current Ohio-class.

With the cooperation of both Electric Boat and Newport News Shipbuilding, in 2007, the U.S. Navy began a cost-control study. Then in December 2008, the U.S. Navy awarded Electric Boat a contract for the missile compartment design of the Ohio-class replacement, worth up to $592 million. Newport News is expected to receive close to 4% of that project. In April 2009, U.S. Defense Secretary Robert M. Gates stated that the U.S. Navy was expected to begin such a program in 2010. The new vessel was scheduled to enter the design phase by 2014. If a new hull design was to be used, the program needed to be initiated by 2016 to meet the 2029 deadline.[needs update]

The Columbia-class was officially designated on 14 December 2016, by Secretary of the Navy Ray Mabus, and the lead submarine will be USS District of Columbia (SSBN-826). The Navy wants to procure the first Columbia-class boat in FY2021, though it is not expected to enter service until 2031.

In 2020, Navy officials first publicly discussed the idea of extending the lives of select Ohio-class boats at the Naval Submarine League's 2020 conference. During the 2022 conference, Rear Admiral Scott Pappano, the program executive officer for strategic submarines, and Rear Admiral Douglas G. Perry, the director of undersea warfare on the Chief of Naval Operations' staff, discussed the Columbia-class program, and also touched on the possibility of finding Ohio-class boats that had sufficient remaining nuclear fuel and were in good enough material state to be given a further extension to their lives.

In popular culture

As ballistic-missile submarines, the Ohio class has occasionally been portrayed in fiction books and films.

See also


This page was last updated at 2024-03-28 03:27 UTC. Update now. View original page.

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