James Madison class submarine
Encyclopedia
The James Madison class of submarine was an evolutionary development from the 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 , , , and classes, comprised the "41 for Freedom."
, 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 4000 lbs more, and had a range 1000 nautical miles (1,852 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.
Ballistic missile submarine
A ballistic missile submarine is a submarine equipped to launch ballistic missiles .-Description:Ballistic missile submarines are larger than any other type of submarine, in order to accommodate SLBMs such as the Russian R-29 or the American Trident...
. 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
Trident missile
The Trident missile is a submarine-launched ballistic missile equipped with multiple independently-targetable reentry vehicles . The Fleet Ballistic Missile is armed with nuclear warheads and is launched from nuclear-powered ballistic missile submarines . Trident missiles are carried by fourteen...
(C-4) missiles. This class, together with
the , , , and classes, comprised the "41 for Freedom."
Class Improvements
Improvements in the James Madison class included the ballistic missileBallistic missile
A ballistic missile is a missile that follows a sub-orbital ballistic flightpath with the objective of delivering one or more warheads to a predetermined target. The missile is only guided during the relatively brief initial powered phase of flight and its course is subsequently governed by the...
, guidance
Missile guidance
Missile guidance refers to a variety of methods of guiding a missile or a guided bomb to its intended target. The missile's target accuracy is a critical factor for its effectiveness...
, fire control
Fire-control system
A fire-control system is a number of components working together, usually a gun data computer, a director, and radar, which is designed to assist a weapon system in hitting its target. It performs the same task as a human gunner firing a weapon, but attempts to do so faster and more...
, navigation
Inertial navigation system
An inertial navigation system is a navigation aid that uses a computer, motion sensors and rotation sensors to continuously calculate via dead reckoning the position, orientation, and velocity of a moving object without the need for external references...
, 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 4000 lbs more, and had a range 1000 nautical miles (1,852 km) farther than the A2. Additionally, the number of reentry systems was increased from 1 to 3, making this the first multiple reentry vehicle
Multiple Reentry vehicle
A Multiple Reentry vehicle payload for a ballistic missile deploys multiple warheads in a pattern against a single target. The advantage of an MRV over a single warhead is that the damage produced in the center of the pattern is far greater than the damage possible from any single warhead in the...
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
Polyurethane
A polyurethane is any polymer composed of a chain of organic units joined by carbamate links. Polyurethane polymers are formed through step-growth polymerization, by reacting a monomer with another monomer in the presence of a catalyst.Polyurethanes are...
foam.
See also
- 41 for Freedom Fleet Ballistic Missile submarines