Military Factory logo
Icon of F-15 Eagle military combat fighter aircraft
Icon of Abrams Main Battle Tank
Icon of navy warships
Icon of AK-47 assault rifle

USS Permit (SSN-594)

Nuclear-Powered Attack Submarine

With the loss of USS Thresher to a diving trial accident, USS Permit assumed the lead of the now-renamed Permit-class nuclear-powered attack submarine group of the USN.
Authored By: Staff Writer | Edited: 9/12/2018
National Flag Graphic


Year: 1962
Status: Decommissioned, Out-of-Service
Ships-in-Class: 13
Named Ships: USS Permit (SSN-594); USS Plunger (SSN-595); USS Barb (SSN-596); USS Pollack (SSN-603); USS Haddo (SSN-604); USS Jack (SSN-605); USS Tinosa (SSN-606); USS Dace (SSN-607); USS Guardfish (SSN-612); USS Flasher (SSN-613); USS Greenling (SSN-614); USS Gato (SSN-615); USS Haddock (SSN-621);
Roles: Blue Water Operations; Hunter; Direct-Attack; Long-Range;
Complement: 105
Length: 278.4 ft (84.86 m)
Width: 31.6 ft (9.63 m)
Height: 25.1 ft (7.65 m)
Displacement (Surface): 3,759 tons
Displacement (Submerged): 4,369 tons
Propulsion: 1 x S5W Pressurized Water Reactor, nuclear; 2 x Steam turbines delivering up to 15,000 shaft horsepower to 1 x shaft.
Speed (Surface): 22 kts (25 mph)
Speed (Submerged): 20 kts (23 mph)
Range: Essentially Unlimited
Operators: United States
With the loss of USS Thresher (SSN-593) during a deep sea trials on April 10th, 1963, the United States Navy (USN) retired the "Thresher" name in remembrance and revised the Thresher-class to become the Permit-class after the second boat in the group. USS Permit (SSN-594) was ordered on January 27th, 1958 and built by the Mare Island Naval Shipyard in Vallejo, California. Her keel was laid down on May 1st, 1959 and she was launched to sea on July 1st, 1961. The boat was formally commissioned for service on May 29th, 1962.

USS Permit Walk-Around

USS Permit typically carried a crew of 105 and had a displacement of 3,760 tons (short) when surfaced and 4,370 tons when submerged. Dimensions included an overall length of 278.4 feet, a beam of 31.6 feet and a draught of 25.1 feet. Power was from a single S5W (Submarine, 5th Gen, Westinghouse) nuclear reactor tied to 2 x geared steam turbines developing 15,000 horsepower to a single shaft astern. 15 knots were attainable when surface running and nearly 30 knots could be reached when submerged. The hull was tested to a depth of 1,300 feet. Armament was 4 x 21" (533mm) torpedo tubes fitted amidships.

The Thresher-class

The Thresher-class was an important addition to the USN during this part of the Cold War period. The type was designed with noise reduction qualities to make her more resistant to sonar detection and the nuclear powerpack gave them essentially unlimited range under water - restricted mainly by crew fatigue and onboard food stores. The boats were also fast and appropriately armed for the purpose of engaging enemy forces on the sea and under it. The group served for some three decades and were succeeded by the Sturgeon-class.

Service History

On March 28th, 1963, USS Permit became the first USN submarine to successfully fire the in-development SUBROC missile and was used in testing the weapon at length. When USS Thresher was tragically lost in April of 1963, USS Permit stood up to take the lead of the Thresher-class - now renamed to Permit-class. An overhaul greeted her career during late 1966 and in May of the following year she joined with WESTPAC in the Pacific Theater before returning stateside to the American West Coast. The boat was given another overhaul in 1967 before returning to active service in the Pacific.

USS Permit was decommissioned on July 23rd, 1991 after several decades of faithful service and her name was struck from the Naval Register soon after. With her nuclear powerpack properly disposed of and her hull stripped of its military usefulness, the boat was sold off for scrap, bringing about her official end on September 30th, 1991.


4 x 21-inch (533) torpedo tubes amidships.

Air Wing

Site Disclaimer  |  Privacy Policy  |  Cookies  |  Site Map Site content ©2003-, All Rights Reserved.

The "Military Factory" name and logo are registered ® U.S. trademarks protected by all applicable domestic and international intellectual property laws. All written content, illustrations, and photography are unique to this website (unless where indicated) and not for reuse/reproduction in any form. Material presented throughout this website is for historical and entertainment value only and should not to be construed as usable for hardware restoration, maintenance, or general operation. We do not sell any of the items showcased on this site. Please direct all other inquiries to militaryfactory AT

Part of a network of sites that includes, GlobalFirepower, a data-driven property used in ranking the top military powers of the world, and, the World Directory of Modern Military Aircraft.

Facebook Logo YouTube Logo