Thresher/Permit-class submarine

Thresher/Permit-class submarine
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Name	Thresher/Permit-class submarine
Caption	USS Thresher (SSN-593)
Country	United States United States Navy
Builder	Electric Boat Company; Newport News Shipbuilding
Laid down	1958
Launched	1960
Commissioned	1961
Fate	various
Class before	Tench-class submarine
Class after	Sturgeon-class submarine
Displacement	4,000–4,500 tons (surfaced/submerged)
Length	278 ft (84.7 m)
Beam	31 ft (9.4 m)
Propulsion	S5W nuclear reactor, steam turbine
Armament	torpedoes, Mark 37 torpedo, later SUBROC and Harpoon (missile)
Complement	~100 officers and enlisted

Thresher/Permit-class submarine The Thresher/Permit-class submarine was a United States United States Navy nuclear-powered attack submarine program introduced during the Cold War era. Conceived to advance submerged speed, stealth, and sensor performance beyond preceding Skipjack-class submarine and Tang-class submarine designs, the class influenced subsequent generations such as the Sturgeon-class submarine and Los Angeles-class submarine. Built by Electric Boat Company and Newport News Shipbuilding, the class included vessels that served in ASW, surveillance, and deterrence roles during theaters ranging from the Atlantic Ocean to the Pacific Ocean.

Design and development

The design and development pivoted on lessons from the USS Nautilus (SSN-571), experience at Naval Reactors under Admiral Hyman G. Rickover, and analysis by Bureau of Ships and Naval Ship Research and Development Center. Engineers prioritized hull form and quieting measures informed by studies at the David Taylor Model Basin and acoustic research at the Naval Underwater Sound Laboratory. Structural innovations incorporated HY-80 steel standards from the Bureau of Ships and influenced by pressure hull research associated with the Office of Naval Research. Program management involved coordination with the Chief of Naval Operations and congressional oversight through committees such as the United States Senate Committee on Armed Services.

Technical specifications

Specifications drew on nuclear propulsion technology licensed via Naval Reactors and the S5W reactor plant developed by Westinghouse Electric Corporation. The submarines featured a teardrop hull influenced by USS Albacore (AGSS-569) hydrodynamics, with dimensions and displacement optimized for submerged endurance and maneuverability as examined at the David Taylor Model Basin. Sensor suites included sonar systems derived from projects at the Naval Research Laboratory and fire-control components interoperable with weapons like the Mark 37 torpedo and later integration trials with SUBROC and anti-ship missiles evaluated in coordination with Naval Sea Systems Command. Command-and-control accommodations reflected doctrine from Commander, Submarine Force Atlantic and Commander, Submarine Force Pacific staffs.

Operational history

Vessels of the class operated in patrols supporting NATO anti-submarine operations during crises such as heightened tensions around the Cuban Missile Crisis aftermath and Cold War shadowing missions against Soviet Navy units including Project 627 and Project 645 submarine classes. Deployments touched major maritime regions including the North Atlantic Ocean, Mediterranean Sea, and western Pacific Ocean near Sea of Japan and East China Sea, often coordinating with task forces under United States Sixth Fleet and United States Seventh Fleet. Crew training, readiness cycles, and acoustic trials were conducted with institutions like Submarine School (United States Navy) and research collaboration with the Applied Physics Laboratory at Johns Hopkins University.

Accidents and loss of USS Thresher

The loss of USS Thresher in 1963 prompted extensive investigation led by the Admiralty-equivalent Board of Inquiry and involvement by Naval Reactors under Admiral Hyman G. Rickover. The incident—occurring during deep-dive trials east of the United States coast—resulted in major policy responses including the establishment of the SUBSAFE program administered by Naval Sea Systems Command. The subsequent inquiries engaged agencies and entities such as the United States Coast Guard for recovery coordination and procedural reviews by the United States Congress, reshaping inspection, quality assurance, and emergency protocols across the United States Navy submarine force.

Upgrades and modernization

Throughout service life, ships of the class underwent refits influenced by evolving requirements from the Chief of Naval Operations and technological advances from contractors like Raytheon and General Dynamics Electric Boat. Modernization campaigns added quieting treatments inspired by Albacore research, sonar upgrades tied to AN/BQQ-5 family developments, and integration of weapons management systems reflecting work by Naval Sea Systems Command laboratories. Mid-life overhauls were performed at yards including Naval Shipyard Portsmouth and Puget Sound Naval Shipyard, often coordinated with fleet commanders such as Commander, Submarine Force Atlantic for operational availability scheduling.

Legacy and influence on submarine design

The class left an enduring legacy by catalyzing the SUBSAFE safety regime, advancing hydrodynamic forms validated by David Taylor Model Basin, and informing reactor reliability standards promoted by Naval Reactors. Lessons fed directly into successor designs including the Sturgeon-class submarine and Los Angeles-class submarine, and influenced allied programs in the Royal Navy and West German Navy procurement dialogues. Doctrinally, the class affected tactics developed by Submarine Force Atlantic and sonar employment concepts later codified at institutions like the Naval Undersea Warfare Center.

Category:United States Navy submarine classes Category:Cold War submarines of the United States