The Ohio, US Navy's nuclear-powered ballistic missile submarine

The Ohio, US Navy's nuclear-powered ballistic missile submarine

Strategic deterrence has been the sole mission of the Nuclear-Powered Fleet Ballistic Missile Submarine (SSBN) since its inception in 1960. The SSBN provides the US most survivable and enduring nuclear strike capability.

The original requirement for the Ohio class came from a need to replace the SSBNs- Ballistic Missile Nuclear Powered Submarine, of the Gorge Washington and Ethan Allen classes, which were incapable of conversion to fire the Poseidon, the ballistic missile of that time and Trident the projected successor. Initially the new SSBN design was to have been an enlarged and improved Lafayette, employing the same S5W reactor for a max speed of 19-20 knots. However the navy was anxious to install a natural circulation reactor. The design for sophisticated noise reduction techniques led in turn to a proposal that the expense involved in efficient quieting could be better justified if the missile complement was raised from the original 16 to 24. The result was a submarine more then twice the size of the Lafayette class.

The 18 Trident SSBNs (each carrying 24 missiles), carry 50 percent of the total US strategic warheads. Although the missiles have no pre-set targets when the submarine goes on patrol, the SSBNs are capable of rapidly targeting their missiles should the need arise, using secure and constant at-sea communications links, and fire all 24 of them in less then a minute.

Specifications, USS Ohio SSBN-726, Ohio class:
A total of 18 hulls were ordered under this class. All laid down by Electric Boat Div., General Dynamics Corp., Groton, CT, and launched between April 1979 and July 1996.

Displacement (srf/sub tons): 16,765/18,750
Dimensions (L*B*D feet): 560'0*42'0*36'4
Propulsion: 1*General Electric S8G Pressurized Water Reactor (PWR) 60,000hp, 2*geared steam turbine, one screw
Speed (sub knots): 25
Range (srf/sub miles@knots): not relevant
Diving depth (feet): 1000 (1200)
Complement: 15 officers 140 enlisted
Missile: 24*SLBM (Submarine Launch Ballistic Missile) located aft of the fin structure capable of launching Lockheed Trident I C-4 (4,000 n/miles up to 8 thermonuclear warheads) or Trident II D-5 (6,5000 n/miles up to 12 thermonuclear warheads)
Torpedo: 4*21" (533 mm) torpedo tubes for MK 48 torpedoes located amidship beneath the fin, total of 12 torpedo reloads.
Armament: none
Mines:
none

Construction
The first eight Ohio class submarines were originally equipped with 24 Trident I C-4 ballistic missiles. Beginning with the ninth submarine, USS Tennessee, SSBN 734, all new ships are equipped with the Trident II D-5 missile system as they are built, and the earlier ships are being retrofitted to Trident II. Trident II can deliver significantly more payload than Trident I C-4 and more accurately.

The Ohio class submarines are specifically designed for extended deterrent patrols. 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 and modern main concepts allow the submarines to operate for 15+ years between overhauls.

The first four Ohio class submarines are scheduled for conversion starting in 2002 over  five years to Guided Missile Submarines (SSGN) with an additional capability to transport and support Navy special operations forces.