|
Ballistic Missile Submarines (SSBNs) |
| Ballistic Missile Submarines (SSBNs) are the most survivable leg of the Triad. This is because of the submarine's ability to disappear in the ocean's depths and its great mobility. The submarine's Trident missiles provide launch capability from around the globe. SSBNs are constantly on patrol, with each patrol area totaling more than one million square miles. Currently there are 18 SSBNs based between Kings Bay, Ga., and Bangor, Wash., each capable of carrying 24 Trident missiles. These units are organized into Task Forces, each with a unique area of responsibility. |  |
| Description Nuclear-powered submarines armed with long-range strategic missiles. Background Strategic deterrence has been the sole mission of the fleet ballistic missile submarine (SSBN) since its inception in 1960. The SSBN provides the nation's most survivable and enduring nuclear strike capability. The Ohio class submarine replaced aging fleet ballistic missile submarines built in the 1960s and is far more capable. Ohio-class/Trident ballistic missile submarines provide the sea-based "leg" of the triad of U.S. strategic deterrent forces. The 18 Trident SSBNs (each carrying 24 missiles), carry 50 percent of the total U.S. 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. Features The first eight Ohio class submarines (Tridents) were originally equipped with 24 Trident I C-4 ballistic missiles. Beginning with the ninth Trident 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.
Builders: General Dynamics Electric Boat Division. |
| Trident Fleet Ballistic Missile |
Description Intercontinental ballistic missiles launched from submarines. Background Submarine launched ballistic missiles (SLBMs) have been an integral part of the strategic deterrent for six generations, starting in l956 with the U.S. Navy Fleet Ballistic Missile (FBM) Polaris (A1) program. Since then, the SLBM has evolved through Polaris (A2), Polaris (A3), Poseidon (C3) and today’s force of Trident I (C4) and Trident II (D5). Each generation has been continuously deployed at sea as a survivable retaliatory force and has been routinely operationally tested and evaluated to maintain confidence and credibility in the deterrent. |
 |
| Trident I (C4) was first deployed in 1979 and is planned to be deployed until phased out in the early 2000s. Trident II (D5) was first deployed in 1990 and is planned to be deployed past 2020. The Trident II (D5) missile is also provided to the United Kingdom which equips the missile with UK warheads and deploys the missile on Vanguard Class UK submarines. Features Trident I (C4) and Trident II (D5) missiles are deployed in Ohio- class (Trident) submarines, each carrying 24 missiles. The Trident II (D5) is a three-stage, solid-propellant, inertially guided FBM with a range of more than 4,000 nautical miles (4,600 statute miles). Trident II is more sophisticated than Trident I (C4) with a significantly greater payload capability. All three stages of the Trident II are made of lighter, stronger, stiffer graphite epoxy, whose integrated structure means considerable weight saving. The missile’s range is increased by the aerospike, a telescoping outward extension that reduces frontal drag by about 50 percent. Trident II is launched by the pressure of expanding gas within the launch tube. When the missile attains sufficient distance from the submarine, the first stage motor ignites, the aerospike extends and the boost stage begins. Within about two minutes, after the third stage motor kicks in, the missile is traveling in excess of 20,000 feet (6,096 meters) per second. General Characteristics, Trident I (C4) Primary Function: Strategic Nuclear Deterrence General Characteristics, Trident II (D5)Primary Function: Strategic Nuclear Deterrence |