Military Wiki
James Madison-class submarine
USS John C. Calhoun (SSBN-630).jpg
USS John C. Calhoun (SSBN-630)
Class overview
Builders: General Dynamics Electric Boat[1]
Mare Island Naval Shipyard[1]
Portsmouth Naval Shipyard[1]
Newport News Shipbuilding and Drydock Company[1]
Operators:  United States Navy
Preceded by: Lafayette-class submarine
Succeeded by: Benjamin Franklin-class submarine
Built: 1962–1964
In commission: 1964–1995
Completed: 10
Retired: 10
Preserved: 1 (As Training Vessel - SSBN-635)
General characteristics
Type: Ballistic Missile Submarine
Displacement: 7,250 long tons (7,370 t) surfaced [1]
8,250 long tons (8,380 t) submerged [2]
Length: 425 ft (130 m) [2]
Beam: 33 ft (10 m) [2]
Draft: 31 ft 6 in (9.60 m) [2]
Propulsion: 1 × S5W reactor - two geared steam turbines - 1 shaft [1]
Speed: 20 knots (37 km/h) surfaced [2]
25 knots (46 km/h) submerged [2]
Complement: Two crews of 13 officers and 130 enlisted [2]
Armament: • 4 × 21 in (530 mm) torpedo tubes for Mark 48 torpedoes[2]
• 16 × vertical tubes for Polaris or Poseidon ballistic missiles [2]

The James Madison class of submarine was an evolutionary development from the Lafayette class of fleet ballistic missile submarine. They were identical to the Lafayettes except for being designed to carry the Polaris A-3 missile instead of the earlier A-2. During the late 1970s and early 1980s, select units were further modified to carry Trident-I (C-4) missiles. This class, together with the George Washington, Ethan Allen, Lafayette, and Benjamin Franklin classes, comprised the "41 for Freedom."

Class Improvements

Improvements in the James Madison class included the ballistic missile, guidance, fire control, navigation, and launcher systems. The improved missile system introduced was the Polaris A3 missile. The A3 was restricted by size because it had to fit into the existing submarine launch tube. But it was 1.5 inches (3.8 cm) longer, weighed 4,000 pounds (1,800 kg) more, and had a range 1,000 nautical miles (1,900 km) farther than the A2. Additionally, the number of reentry systems was increased from 1 to 3, making this the first multiple reentry vehicle missile.

The guidance, fire control, and navigation systems were improved to account for the longer range of the A3 missile. The launcher system was improved by replacing the liquid springs on which the launch tube rested with polyurethane foam.


Submarines of the James Madison class:[3]

See also


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