Ohio class USS Ohio SSGN-726

The Ohio class is a class of nuclear-powered submarines used by the United States Navy. The United States has 18 Ohio class submarines:

* 14 nuclear-powered SSBNs (ballistic missile submarines), each armed with 24 Trident II SLBMs; they are also known as "Trident" submarines, and provide the sea-based leg of the nuclear triad of the United States strategic nuclear weapons arsenal
* 4 nuclear-powered SSGNs (cruise missile submarines), each capable of carrying 154 Tomahawk cruise missiles with conventional warheads

The Ohio class is named after the lead submarine of this class, the USS Ohio (SSGN-726). The 14 Trident II SSBNs together carry around fifty percent of the total U.S. strategic warhead inventory. The exact number varies in an unpredictable and highly classified manner, at or below a maximum set by various strategic arms limitation treaties. Although the missiles have no pre-set targets when the submarine goes on patrol, the platform, when required, is capable of rapid targeting using secure and constant at-sea communications links. The Ohio class is the largest type of submarine ever constructed for the U.S. Navy, and are second only to the Russian Typhoon-class in displacement and size (the new Russian Borei class submarine has larger displacement when submerged, but not when surfaced).

The Ohio-class submarines were specifically designed for extended deterrence patrols. Each submarine is complemented by two crews, Blue and Gold, with each crew operating on a 100-day interval. To decrease the time in port for crew turnover and replenishment, three large logistics hatches are fitted to provide large diameter resupply and repair openings. These hatches allow sailors to rapidly transfer supply pallets, equipment replacement modules and machinery components, significantly reducing the time required for replenishment and maintenance. The class design allows the vessel to operate for over fifteen years between overhauls. The boats are purported to be as stealthy at their cruising speed of 20 knots (37 km/h; 23 mph) as previous subs were at a dead crawl of 6 knots (11 km/h; 6.9 mph), although exact information remains classified.

Except for the USS Henry M. Jackson (SSBN-730), the Ohio class submarines are named after states in the United States, preceded by the usual "USS".

History

The first eight Ohio-class submarines were originally equipped with 24 Trident-I (C4) submarine-launched ballistic missiles. Beginning with the ninth Trident submarine, USS Tennessee, the remaining boats were equipped with the upgraded Trident-II (D5) variant as they were constructed. The Trident-II missile carries eight multiple independently targetable reentry vehicles (MIRVs), in sum delivering more deterrence than the Trident-I and with much greater accuracy. Starting with USS Alaska in 2000, the navy began converting the remaining C4-equipped submarines to D5 missiles; this was completed in mid-2008.

The first eight boats were homeported in Bangor, Washington to replace the Polaris (A3) carrying submarines that were then being decommissioned. The remaining ten boats were originally homeported in Kings Bay, Georgia, replacing the Atlantic-based Poseidon and Trident Backfit submarines. During the conversion of the first four hulls to SSGNs (see below), five boats, Pennsylvania, Kentucky, Nebraska, Maine, and Louisiana, were shifted from Kings Bay to Bangor. Further shifts are occurring as the United States' strategic needs change.
[edit] SSBN/SSGN conversions
Ohio SSGN conversion

After the end of the Cold War, plans called for Ohio to be retired in 2002, followed by three of her sisters. However, Ohio, Michigan, Florida, and Georgia instead were slated for modification, to remain in service as conventional, guided missile submarines (SSGNs).

Beginning in 2002 through 2010, 22 of the 24 88-inch (2.2 m) diameter Trident missile tubes will be modified to contain large vertical launch systems (VLS), 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 (SLIRBM)[3], unmanned air vehicles (UAVs), the ADM-160 MALD, sensors for anti-submarine warfare or intelligence, surveillance and reconnaissance missions, counter-mine warfare payloads such as the AN/BLQ-11 Long Term Mine Reconnaissance System (LMRS), and the broaching universal buoyant launcher (BUBL) and stealthy affordable capsule system (SACS) specialized payload canisters.

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 Advanced SEAL Delivery System and the Dry Deck Shelter can be mounted on lock out chamber and the boat will be able to host up to 66 special operations sailors or Marines, such as Navy SEALs. Improved communications equipment installed during the upgrade allows the SSGNs to serve as a forward-deployed, clandestine Small Combatant Joint Command Center.[4]

On 26 September 2002, the Navy awarded the Electric Boat company a $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. Advanced 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.

In November 2002, the USS Ohio entered drydock, 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 the USS Florida in April 2006. The converted USS Michigan was delivered in November 2006. The converted Ohio went to sea for the first time in October 2007. The Georgia returned to the fleet in March 2008 at Kings Bay.[5] These four SSGNs are expected to remain in service until about 2023-2026.
[edit] Next class of SSBN

The Department of Defense anticipates a continued need for a sea-based strategic nuclear force.[6] The current Ohio class Trident SSBNs are expected to retire its first vessel by 2029[6] meaning a platform must already be sea worthy by that time. A replacement may cost over $4billion per unit compared to the Ohio's $2billion per unit.[2] The Navy is exploring two options. The first is a variant of the Virginia class nuclear attack submarines and the second is a dedicated SSBN either a new hull or an overhaul of the current Ohio class.

With the cooperation of both Electric Boat and Newport News Shipbuilding in 2007 the Navy had already begun a cost control study.[6] Then in December 2008 the 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. Though the Navy has yet to confirm an Ohio class replacement program Defense Secretary Robert M. Gates as of April 2009 confirms that the Navy should begin such a program in 2010.[2] The new vessel is scheduled to enter the design phase by 2014. It is anticipated that if a new hull design is used the program must be initiated by 2016 in order to meet the 2029 deadline.[6]
[edit] Popular culture
Artist concept of an Ohio class SSBN launching Trident ICBMs.

As ballistic missile submarines, the Ohio-class has occasionally played a pivotal role in fiction books and films.

USS Alabama plays a pivotal role in the film Crimson Tide, when an attack interrupts an incoming message regarding the potential launch of the submarines SLBMs, ultimately resulting in mutiny centered around the captain and executive officer.[7]

The sinking of the fictional USS Montana is the inciting incident in James Cameron's 1989 film The Abyss.

In Tom Clancy's novels, these missile submarines play important roles. For example, the fictional Akula-class submarine Admiral Lunin sinks the USS Maine (SSBN-741) near the end of Tom Clancy's novel The Sum of All Fears. Also interestingly in Debt of Honor, the Ohio class submarines of the US Pacific fleet are used as attack submarines due to their availability from nuclear disarmament, paralleling what the US navy has done.
[edit] Boats of the class
[edit] Guided Missile Submarines

* USS Ohio (SSGN-726)
* USS Michigan (SSGN-727)
* USS Florida (SSGN-728)
* USS Georgia (SSGN-729)

[edit] Ballistic Missile Submarines

* USS Henry M. Jackson (SSBN-730)
* USS Alabama (SSBN-731)
* USS Alaska (SSBN-732)
* USS Nevada (SSBN-733)
* USS Tennessee (SSBN-734)
* USS Pennsylvania (SSBN-735)
* USS West Virginia (SSBN-736)
* USS Kentucky (SSBN-737)
* USS Maryland (SSBN-738)
* USS Nebraska (SSBN-739)
* USS Rhode Island (SSBN-740)
* USS Maine (SSBN-741)
* USS Wyoming (SSBN-742)
* USS Louisiana (SSBN-743)