Figure 1: USS Thresher (SSN-593) bow-on view, taken at sea on 24 July 1961. Official US Navy Photograph, from the collections of the NHHC. Click on photograph for larger image.
Figure 2: USS Thresher (SSN-593) starboard bow view, taken at sea on 24 July 1961. Official U.S. Navy Photograph, from the collections of the NHHC. Click on photograph for larger image.
Figure 3: USS Thresher (SSN-593) stern-on view, taken at sea on 24 July 1961. Note upper rudder in the foreground, with draft markings painted on its side and navigation light at its top. Official US Navy Photograph, from the collections of the NHHC. Click on photograph for larger image.
Figure 4: USS Thresher (SSN-593) starboard broadside view, taken while the submarine was underway on 30 April 1961. Photographed by J.L. Snell. Official US Navy Photograph, from the collections of the NHHC. Click on photograph for larger image.
Figure 5: USS Thresher (SSN-593) port broadside view, taken while the submarine was underway on 30 April 1961. Photographed by J.L. Snell. Official US Navy Photograph, from the collections of the NHHC. Click on photograph for larger image.
Figure 6: USS Thresher (SSN-593) port broadside view, taken while the submarine was underway with water surging over her bow, 30 April 1961. Photographed by J.L. Snell. Official US Navy Photograph, from the collections of the NHHC. Click on photograph for larger image.
Figure 7: Loss of USS Thresher (SSN-593), April 1963. Navy ships circle in the vicinity of the site of Thresher's sinking, 15 April 1963, five days after her loss. Ships are (left to right): USS Thomas Jefferson (SSBN-618); USS Sunbird (ASR-15); USS Warrington (DD-843), group flagship; and USS Redfin (SS-272). Photographed by PHCS Parker. Official US Navy Photograph, from the collections of the NHHC. Click on photograph for larger image.
Figure 8: US Navy Bathyscaphe Trieste (1958-1963) under tow and en route to a deep-water dive in the Pacific, 15 September 1959. She is flying both the United States and Swiss flags. Trieste was used in the search for the wreck of Thresher. US NHHC Photograph. Click on photograph for larger image.
Figure 9: U.S. Navy Bathyscaphe Trieste (1958-1963) is hoisted out of the water in a tropical port, circa 1958-1959, soon after her purchase by the Navy. Photograph was released by the US Navy Electronics Laboratory, San Diego, California. Trieste was used in the search for the wreck of Thresher. US NHHC Photograph. Click on photograph for larger image.
Figure 10: USNS Mizar (T-AGOR-11) photographed on a winter day in the middle or later 1960s. Mizar was used in the search for the wreck of Thresher. US NHHC Photograph. Click on photograph for larger image.
Figure 11: USNS Mizar (T-AGOR-11), which was used in the search for the wreck of Thresher. Here she is photographed circa 1970, by the US Naval Research Laboratory, for which the ship was operated by the Military Sealift Command. The original caption, received with this photograph under date of October 1970, states: "... The ship has been used to investigate the ocean depths and to locate lost ships and, most recently, to find the site of the scuttled Liberty Ship Le Baron Russell Briggs which sank during August 1970 in 16,000 feet of water about 230 miles off the coast of Florida with 418 concrete and steel coffins of nerve-gas rockets aboard." Official US Navy Photograph, from the collections of the NHHC. Click on photograph for larger image.
Figure 12: Loss of USS Thresher (SSN-593), April 1963. "Debris on the ocean floor 8,400 feet below the surface may be a clue to the final resting place of the nuclear submarine USS Thresher. Taken last week by an underwater camera system operated by the oceanographic research vessel Atlantis II, these photographs show scattered bits of unidentified debris. The round objects are sea urchins which may range in size from four to twelve inches in diameter. The Navy states that the photographs in themselves are not conclusive evidence of the location of the missing submarine which sank on April 10, 1963, 220 miles east of Cape Cod. Ships of the searching force are continuing a minute search of the area with underwater cameras, sonar and other detection devices." Quoted from the original caption released with this photograph on 22 May 1963. Official US Navy Photograph, from the collections of the NHHC. Click on photograph for larger image.
Figure 13: Wreck of USS Thresher (SSN-593). "Starboard side of the USS Thresher sail with portions of the hull number '593' visible." Photographed from a deep-sea vehicle deployed from USNS Mizar (T-AGOR-11). The original photograph bears the date October 1964. Quoted text is from the caption released with that print. Official US Navy Photograph, from the collections of the NHHC. Click on photograph for larger image.
Figure 14: Wreck of USS Thresher (SSN-593). Overhead view of Thresher's upper rudder, photographed from a deep-sea vehicle deployed from USNS Mizar (T-AGOR-11). The view shows draft markings on the rudder side and a navigation light at its top. The original photograph bears the date October 1964. Thresher was lost on 10 April 1963. Official US Navy Photograph, from the collections of the NHHC. Click on photograph for larger image.
Figure 15: Wreck of USS Thresher (SSN-593). "Sonar Dome -- A section of a sonar dome from the bow of a Thresher class submarine photographed August 24 during the second series of dives by the bathyscaph Trieste. The bathyscaph has completed 10 dives some 220 miles east of Cape Cod where the nuclear-powered submarine Thresher sank April 10." The original view, from whose caption the quoted text is taken, was released on 5 September 1963. Official US Navy Photograph, from the collections of the NHHC. Click on photograph for larger image.
Figure 16: Wreck of USS Thresher (SSN-593). "Sonar Dome -- An external portion of a sonar dome used exclusively in Thresher class submarines was photographed by the bathyscaph Trieste August 24 during the second series of dives in the area where the nuclear-powered submarine Thresher sank April 10." The original view, from whose caption the quoted text is taken, was released on 5 September 1963. Official US Navy Photograph, from the collections of the NHHC. Click on photograph for larger image.
Figure 17: Lieutenant John Wesley Harvey, USN. Portrait photograph taken 14 November 1955 by Farber. Lieutenant Commander Harvey took command of the nuclear-powered attack submarine Thresher (SSN-593) in January 1963,while she was in the shipyard for overhaul. He took his "boat" to sea for the first time for post-overhaul trials. On 10 April 1963, Lieutenant Commander John W. Harvey lost his life when Thresher accidently sank during diving tests. Official US Navy Photograph, from the collections of the Naval Historical Center. Click on photograph for larger image.
Figure 18: Insignia: USS Thresher (SSN-593). Emblem adopted in 1960 and received in October of that year. It was accompanied with this description: "The fish depicted in the subject insignia is a THRESHER shark, which is characterized by a tail that is approximately one-half of its total length. The THRESHER shark reportedly attacks its prey by flailing the long tail. The horizontal lines signify the deep diving capability of THRESHER. The circles represent her sonar capability. The motto, 'Vis Tacita', describes the overall characteristics of the ship, 'Silent strength'." US Naval Historical Center Photograph. Click on photograph for larger image.
Named after a type of shark, the 3,700-ton USS Thresher (SSN-593) was a lead ship in a class of nuclear-powered attack submarines that was built by the Portsmouth Naval Shipyard at Kittery, Maine, and was commissioned on 3 August 1961. The ship was approximately 278 feet long and 31 feet wide, had a top speed of more than 20 knots, and had a crew of 112 officers and men. Thresher was armed with four torpedo tubes.
After being commissioned, Thresher conducted lengthy trials in the western Atlantic and Caribbean oceans in 1961 and 1962. She completed a thorough evaluation of her many new technological features and weapons. The ship seemed to operate normally and without any major complications. Once these tests were completed, Thresher returned to her builders for an overhaul.
After her overhaul was completed, Thresher sailed out to sea on 10 April 1963 for post-overhaul trials. She was accompanied by the submarine rescue ship USS Skylark (ASR-20) and moved to a location roughly 220 miles east of Cape Cod, Massachusetts. Thresher then initiated deep-diving tests as part of her shakedown exercises. As the ship dove deep into the Atlantic, garbled communications were received by Skylark, indicating that there was trouble on board the submarine. Suddenly, the radio operators on board Skylark heard a noise “like air rushing into an air tank” and then silence. Those garbled transmissions were the last anyone ever heard from Thresher as well as the 112 officers, crewmen, and 17 civilian technicians that were on board the ship. Something had gone terribly wrong.
All efforts by Skylark to re-establish contact with Thresher failed. Five days after the loss of Thresher, a small search group was formed, which included USS Thomas Jefferson (SSBN-618), USS Sunbird (ASR-15), USS Warrington (DD-843) (the group’s flagship), and USS Redfin (SS-272). But nothing was found. The US Navy then called in reinforcements to search for the lost submarine. The remarkable bathyscaphe Trieste was brought into action along with the oceanographic ship Mizar (T-AK-272). A bathyscaphe is a small, modified submarine used for deep-sea exploration. It usually has a spherical observation chamber designed to hold two people placed underneath the ship’s main buoyancy chamber. Trieste was designed to go deep into the ocean without being literally crushed by the water above it. In January 1960, Trieste dove a record 35,791 feet into the Marianas Trench in the western Pacific Ocean, reaching the deepest part of any ocean on earth. Mizar was an oceanographic research ship with a deep-submergence support capability. Her specialty was locating and examining the wrecks of lost ships.
Soon
after Trieste and Mizar went into action, what was left of
Thresher was found. Thresher’s shattered remains were
located on the sea floor roughly 8,400 feet below the surface. Numerous
pictures were taken of the disaster site and many pieces of the actual
submarine were recovered as well. Eventually, a Court of Inquiry was convened
and after studying all of the photographs and retrieved physical evidence, it
was determined that Thresher was
probably lost due to a silver-brazed piping joint welding failure that flooded
the engine room with water. Salt water spray on electrical components caused
short circuits, reactor shutdown, and the loss of propulsion power. The main
ballast tank blow system then malfunctioned, most probably owing to ice
formation in the piping, and inadequate blow rate could not overcome the
flooding in the engine room. The submarine broke up as she hit the ocean floor,
leaving Thresher in six major
sections, with the majority of the debris concentrated in a roughly 400 square
yard area. The major sections are the “sail,” sonar dome, bow section,
engineering spaces, operations spaces, and the tail section. Fortunately, there
was no major radiation leakage from the nuclear reactors.
Over
the next several years, a massive program was undertaken to correct design and
construction problems on the Navy’s existing nuclear submarines, as well as those
under construction and in planning. After making these critical changes to its
nuclear submarine fleet, the US Navy suffered no further losses of the kind
that so tragically ended the brief service career of USS Thresher. In 1968, the nuclear submarine USS Scorpion
(SSN-589) was also lost at sea, but the actual cause of its loss was never
clearly determined. To date, these are the only two American nuclear submarines
lost at sea. Some interesting footnotes to this story are that the bathyscaphe Trieste was taken out of service soon after the mission to locate Thresher was completed. She is now on exhibit at the US Navy museum at the Washington Navy Yard at Washington, DC. The oceanographic research ship Mizar went on to locate several other important sunken ships, including the nuclear submarine USS Scorpion, the French submarine Eurydice, and the Soviet “Golf” class submarine K-129. Mizar also located an American thermonuclear bomb that was accidentally lost off the coast of Spain. Mizar was withdrawn from active service in the 1990s and reclassified as AK-272. Currently she is part of the National Defense Reserve Fleet in the James River, Virginia, and is listed for disposal.
