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.[18]
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.[19] Fire control for their Mark 48 torpedoes is carried out by Mark 118 Mod 2 system,[9] while the Missile Fire Control system is a Mark 98.[9]
The Ohio class was designed in the 1970s to carry the concurrently designed Tridentsubmarine-launched ballistic missile. The first eight Ohio-class submarines were armed at first with 24 Trident I C4 SLBMs.[6] Beginning with the ninth Trident submarine, Tennessee, the remaining boats were equipped with the larger, three-stage Trident II D5 missile.[9] 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 profileUSS 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.[20] The boats could thereafter carry 154 Tomahawk cruise missiles and 66 special operations personnel, among other capabilities and upgrades.[20] The cost to refit the four boats was around US$1 billion (2008 dollars) per vessel.[21] 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.
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.[22] From January to June 2014, Pennsylvania carried out a 140-day-long patrol, the longest to date.[23]
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 USMCMARSOC teams. Improved communications equipment installed during the upgrade allows the SSGNs to serve as a forward-deployed, clandestine Small Combatant Joint Command Center.[24]
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.[25][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-classsubmarine.[26]
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.[27]
Detailed cross-section
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
The U.S. Department of Defense anticipated a continued need for a sea-based strategic nuclear force.[citation needed] The first of the current Ohio-class SSBNs was expected to be retired by 2029,[citation needed] 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.[3] 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.[citation needed]
With the cooperation of both Electric Boat and Newport News Shipbuilding, in 2007, the U.S. Navy began a cost-control study.[citation needed] 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 SecretaryRobert M. Gates stated that the U.S. Navy was expected to begin such a program in 2010.[3] 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.[citation needed][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).[52] The Navy wants to procure the first Columbia-class boat in FY2021,[53] though it is not expected to enter service until 2031.[54][55]
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.[56]
In popular culture
As ballistic-missile submarines, the Ohio class has occasionally been portrayed in fiction books and films.
^Adcock, Al. (1993). U.S. Ballistic Missile Submarines. Carrolltown, Texas: Squadron Signal. pp. 4, 40. ISBN978-0-89747-293-7.
^ abcdefAdcock, Al (1993). U.S. Ballistic Missile Submarines. Carrolltown, Texas: Squadron Signal. p. 40. ISBN978-0-89747-293-7.
^"Part II.6 Trident". Appendices: Commission on the Organization of the Government for the Conduct of Foreign Policy. Vol. IV: Appendix K: Adequacy of Current Organization: Defense and Arms Control. U.S. Government Printing Office. June 1975. pp. 177–179. Retrieved 14 January 2023. The projected boat would have a 30,000 ton displacement and would be powered by two 30,000 shp reactors... ...both the submarine and the missile grew incrementally in size to their current dimensions — the missile by six inches in diameter and four to five feet in length; the submarine by 5,000 shp in reactor output...
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