Benjamin Franklin-class submarine

USS Benjamin Franklin
Class overview
Name	Benjamin Franklin class
Builders	General Dynamics Electric Boat Newport News Shipbuilding Mare Island Naval Shipyard[1]
Operators	United States Navy
Preceded by	James Madison class
Succeeded by	Ohio class
Built	1963–1967[1]
In commission	1965–2002[2]
Completed	12
Retired	12
General characteristics
Type	Nuclear-powered ballistic missile submarine
Displacement	Surfaced: 7,325 long tons (7,443 t) Submerged: 8,251 long tons (8,383 t)[3]
Length	425 ft (130 m)[3]
Beam	33 ft (10 m)[3]
Draft	28 ft 6 in (8.69 m)[3]
Propulsion	1 × S5W PWR 2 geared steam turbines (15,000 shp (11,000 kW)), 1 shaft[3]
Speed	16 kn (30 km/h; 18 mph) surfaced 21 kn (39 km/h; 24 mph) submerged[3]
Test depth	1,300 feet (400 m)[3]
Complement	Two crews of 14 officers and 126 enlisted[3]
Armament	16 Polaris A3 or Poseidon C3 or Trident I C4 missiles 4 × 21-inch (533 mm) torpedo tubes, 13 torpedoes[3]

The Benjamin Franklin class of US ballistic missile submarines were in service from the 1960s–2000s. The class was an evolutionary development from the earlier James Madison class of fleet ballistic missile submarine. Having quieter machinery and other improvements, it is considered a separate class. A subset of this class is the re-engineered 640 class starting with USS George C. Marshall. The primary difference was that they were built under the new SUBSAFE rules after the loss of USS Thresher, earlier boats of the class had to be retrofitted to meet SUBSAFE requirements. The Benjamin Franklin class, together with the George Washington, Ethan Allen, Lafayette, and James Madison classes, comprised the "41 for Freedom" that was the Navy's primary contribution to the nuclear deterrent force through the late 1980s. This class and the James Madison class are combined with the Lafayettes in some references.