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Ohio class Ballistic Missile Submarine - SSBN
Ohio class Guided Missile Submarine - SSGN



SSBN/SSGN 726 USS Ohio (1981)
SSBN/SSGN 727 USS Michigan (1982)
SSBN/SSGN 728 USS Florida (1983)
SSBN/SSGN 729 USS Georgia (1984)
SSBN 730 USS Henry M. Jackson (1984)
SSBN 731 USS Alabama (1985)
SSBN 732 USS Alaska (1986)
SSBN 733 USS Nevada (1986)
SSBN 734 USS Tennessee (1988)
SSBN 735 USS Pennsylvania (1989)
SSBN 736 USS West Virginia (1990)
SSBN 737 USS Kentucky (1991)
SSBN 738 USS Maryland (1992)
SSBN 739 USS Nebraska (1993)
SSBN 740 USS Rhode Island (1994)
SSBN 741 USS Maine (1995)
SSBN 742 USS Wyoming (1996)
SSBN 743 USS Louisiana (1997)
Builder: General Dynamics Electric Boat, Groton, Connecticut, USA
Displacement: 16764 tons (surfaced) / 18750 tons (submerged)
Length: 170 meters (560 feet)
Beam: 13 meters (42 ft)
Draft: 10,8 meters (35 ft 5 in)
Speed: 12 knots (22 km/h) surfaced / 20 knots (37 km/h) submerged
Range: unlimited / Endurance: approx. 60 days with food supplies
Complement: 15 officers, 140 enlisted

1 x S8G pressurized water nuclear reactor
2 x geared turbines - 60000 shp / 45 MW
1 x auxilary diesel engine - 325 hp / 242 kW
1 shaft with 7-bladed propeller

Armament / SSBN 726-733:
4 x 21 inches (533mm) torpedo tubes for Mk-48 heavy weight torpedo / ADCAP
24 x
launching tubes for ballistic missiles
> Trident I C4 Submarine-Launched Ballistic Missile (SLBM)
> with up to 8 W76 100 kilo-tons nuclear warheads / range 4000 NM (7400 km)

Armament / SSBN 734-743 and 730-733 after refueling:
4 x 21 inches (533mm) torpedo tubes for Mk-48 heavy weight torpedo / ADCAP
24 x
launching tubes for ballistic missiles
> Trident II D5 Submarine-Launched Ballistic Missile (SLBM)
> with up to 12 W76 or W88 300-475 kilo-tons nuclear warheads / range 6100 NM (11300 km)

Armament / SSGN 726-729:
4 x 21 inches (533mm) torpedo tubes for Mk-48 heavy weight torpedo / ADCAP
22 x launching tubes each with 7 UGM-109 Tomahawk cruise missiles = total 154

BQQ-6 bow mounted sonar
BQR-19 navigation
BQS-13 active sonar
TB-16 or BQR-23 towed array
The Ohio class is a class of nuclear-powered submarines currently used by the United States Navy. The navy has 18 Ohio-class submarines: 14 ballistic missile submarines (SSBN) and 4 that were later converted to guided missile submarines (SSGN).

The Ohio-class submarines are the largest submarines ever built for the U.S. Navy. Two classes of the Russian Navy's submarines have larger total displacements: the Soviet-designed Typhoon-class submarines have more than twice the total displacement, and Russia's Borei-class submarines have roughly 25 percent greater displacement, but the Ohio-class boats carry more missiles than either: 24 Trident missiles per boat, versus 16 missiles for the Borei class (20 for the Borei II) and 20 for the Typhoon class.

The Ohio-class submarines were designed specifically for extended war-deterrence patrols. Each of these submarines is provided with two complete crews, called the Blue crew and the Gold crew, with each crew serving typically on 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, significantly reducing the time required for replenishment and maintenance of the submarines.

The class's design allows the warship to operate for about fifteen 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 than 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 (MFC) 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 are also known as "Trident" submarines, and provide the sea-based leg of the U.S. nuclear triad. Each SSBN submarine is armed with up to 24 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.

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 (MIRV), while the Trident II missile carries twelve, 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 the Polaris A3 missile that were then being decommissioned. The remaining ten submarines originally had their home ports at Kings Bay, Georgia, replacing the Poseidon and Trident Backfit submarines of the Atlantic Fleet. During the conversion of the first four submarines to SSGNs (see below), five of the submarines, Pennsylvania, Kentucky, Nebraska, Maine, and Louisiana, were transferred from Kings Bay to Bangor. 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. From January to June 2014, Pennsylvania carried out a 140-day-long patrol, the longest to date.

SSBN/SSGN conversions:

After the end of the Cold War, plans called for Ohio to be retired in 2002, followed by three of her sister boats. However, Ohio, Michigan, Florida, and Georgia instead were slated for modification, to remain in service carrying conventionally armed guided missiles, and were redesignated as SSGNs.

The conversion modified 22 of the 24 88-inch (2.2 m) diameter Trident missile tubes 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), unmanned aerial vehicles (UAVs), the ADM-160 MALD, sensors for anti-submarine warfare or intelligence, surveillance, and reconnaissance missions, countermine 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 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 the Electric Boat company 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. 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, Ohio entered a 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 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. 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 submarines.

source: wikipedia (2017)


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