Ethan Allen-class submarine

Ethan Allen-class submarine
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Name	Ethan Allen-class submarine
Operator	United States Navy
Class before	Skate-class submarine (1955)
Class after	Lafayette-class submarine
Built	Cold War
In service	1960–1983
Retired	1983

Ethan Allen-class submarine The Ethan Allen-class submarine was a class of nuclear-powered ballistic missile submarines (SSBNs) operated by the United States Navy during the Cold War. Introduced as the second generation of American strategic submarine-launched ballistic missile platforms, the class bridged developments between the early George Washington (SSBN-598) type and later Lafayette and James Madison classes. Designed to carry the Polaris missile system, these submarines played a central role in strategic deterrence and nuclear triad posture through patrols within the Atlantic Ocean and Pacific Ocean.

Design and Development

The Ethan Allen design emerged from requirements set by the Chief of Naval Operations and Secretary of the Navy offices to field a more optimized SSBN following experience with the George Washington and Skipjack designs. Naval architects at Electric Boat and the Newport News Shipbuilding yard incorporated lessons from trials involving USS Nautilus (SSN-571), USS Seawolf (SSN-575), and the Skipjack-class submarine hydrodynamic refinements. Collaborations with researchers at the David Taylor Model Basin and engineers from Brookhaven National Laboratory and Oak Ridge National Laboratory informed reactor layout choices to house the S5W reactor and to improve acoustic quieting. The class featured a hull form adapting the teardrop hull pioneered on USS Albacore (AGSS-569), while internal arrangement prioritized missile compartment expansion and habitability for extended deterrent patrols ordered by Joint Chiefs of Staff planners.

Specifications and Performance

Ethan Allen boats displaced approximately 6,900–8,000 long tons submerged and measured about 410 feet in length with a beam near 33 feet—dimensions influenced by Naval Ship Research and Development Center studies. Propulsion centered on a single S5W reactor driving one shaft with a geared turbine and skeg arrangements reminiscent of contemporary Skipjack-class submarine engineering. Top submerged speeds exceeded 20 knots and surfaced transit speeds were significantly lower; endurance was effectively limited only by provisions and crew endurance, enabling months-long patrols as guided by Strategic Air Command and Submarine Force Atlantic. Acoustic signatures were reduced relative to earlier SSBNs through machinery isolation techniques developed with input from Naval Undersea Warfare Center scientists. Habitability and crew complement conformed to standards overseen by the Bureau of Ships and Office of Naval Research directives.

Armament and Sensors

Primary armament consisted of 16 vertical launch tubes configured for Polaris A-2 and later compatible missiles, reflecting missile development sequences at Lockheed Corporation and Douglas Aircraft Company divisions. The missile compartment arrangement derived from integration studies with the Polaris missile program office and Naval Ordnance Test Station. Secondary armament included torpedo tubes compatible with wire-guided and unguided torpedoes produced by General Dynamics and ordnance standards maintained by Naval Sea Systems Command. Sensors suite integrated sonar systems developed at Naval Research Laboratory facilities, including bow-mounted active/passive arrays and flank arrays informed by acoustic research at Scripps Institution of Oceanography. Navigation relied on inertial navigation systems influenced by Northrop Grumman and earlier work at Massachusetts Institute of Technology's Instrument Laboratory.

Operational History

Commissioned during heightened tensions associated with crises like the Cuban Missile Crisis aftermath and ongoing Vietnam War operations, Ethan Allen-class submarines carried out deterrent patrols assigned by Submarine Force Pacific and Submarine Force Atlantic. Deployments emphasized continuous at-sea deterrence posture coordinated with Strategic Arms Limitation Talks era policy shifts and fleet ballistic missile patrol doctrines. Crews drew on training regimens from Naval Submarine School and operational evaluation by Commander, Submarine Force, U.S. Atlantic Fleet. These boats participated in tests of missile reliability, under-ice transits influenced by exercises with Naval Support Facility units, and joint operations with carrier task forces flagged by Commander, U.S. Sixth Fleet and Commander, U.S. Pacific Fleet.

Notable Incidents and Losses

While the class suffered no wartime losses, several boats experienced notable incidents involving reactor, propulsion, or collision risks during Cold War operations reported by entities such as the Navy Department. Events prompted investigations by the Naval Investigative Service and review panels from General Accounting Office and the Congressional Research Service. Specific mishaps led to repairs at yards including Puget Sound Naval Shipyard and Portsmouth Naval Shipyard, with subsequent policy changes in maintenance and safety under oversight from the Secretary of Defense and Chief of Naval Operations.

Decommissioning and Disposal

As newer SSBN types like the Lafayette-class submarine and missile upgrades rendered earlier platforms less capable under Strategic Arms Reduction Treaty-era constraints, Ethan Allen-class units were gradually converted, decommissioned, and recycled under programs managed by the Naval Sea Systems Command and the Nuclear Powered Ship and Submarine Recycling Program. Hulls were defueled and disposed of at facilities including Puget Sound Naval Shipyard, following statutes and directives issued by the Department of Defense and environmental regulations overseen by the Environmental Protection Agency. Several former submarines entered reserve before final scrapping, aligning with broader fleet modernization overseen by United States Congress appropriations and Presidents of the United States administration-level defense reviews.

Category:United States Navy submarine classes