USS Thresher (SSN 593)

On 10 April 1963, while engaged in a deep test dive, the nuclear submarine USS THRESHER (SSN 593) was lost at sea with all persons aboard. Based on the findings of a Court of Inquiry and the subsequent Joint Congressional Committee on Atomic Energy hearings into the loss of the THRESHER, it was concluded that a flooding casualty in the engine room, resulting from a piping failure in one of the salt water systems, was the most probable cause for the loss.

A THRESHER Design Appraisal Board determined that, although the basic design of this submarine class was sound, measures should be taken to improve the level of confidence in the material condition of the hull integrity boundary and in the ability of submarines to control and recover from flooding casualties. Thus the genesis of the Level I/SUBSAFE Program. The program establishes control for procurement, inspection, certification, test, identification, documentation, record control, storage, issue, turn-in, recall and disposal. Level I/SUBSAFE Stock Program materials are intensively managed and controlled. They require certification with traceable objective quality evidence. Items include submarine hull pressure boundary fittings, high pressure air and gas components, high pressure/temperature steam system components and selected safety related equipment on surface ships and submarines.

Loss of F-4 Leads to Creation of Submarine School

The USS F-4 was an “F” class submarine, and was built in Seattle, Washington. Originally named Skate, her name was changed to F-4 in November 1911, while she was under construction. The new submarine was commissioned in May 1913 and operated along the U.S. west coast until mid-1914, when she was transferred to Hawaii. On 25 March 1915, during a routine dive a few miles off Honolulu, F-4 sank in 51 fathoms of water, with the loss of her 21 crew members.

The ensuing rescue attempts and successful recovery of the sunken submarine were major events in the history of Navy diving and salvage. Raising F-4 was done under the technical direction of Naval Constructor Julius A. Furer in April-August 1915. Initially, cables were dragged under her hull and she was lifted and towed into shallower water during May. While taking part in the extremely deep diving activities involved in this phase of the operation, Navy Diver Frank W. Crilley performed an act of heroism for which he received the Medal of Honor.

As F-4‘s weakened hull could not withstand further measures of the type used in the initial lifting, the final part of the recovery effort had to await construction of special salvage pontoons. On 29 August 1915, after the pontoons had been brought to Hawaii from the west coast, and following extensive additional diving work, the submarine was raised from the bottom and taken into Honolulu Harbor for dry-docking. Examination of the wreck revealed design defects that were corrected in existing and future Navy submarines, greatly enhancing the safety of the undersea service. F-4 was not repaired. Her remains were buried near the Pearl Harbor Submarine Base in 1940.

On another historical note, this great tragedy in the Submarine Force resulted in the creation of a school dedicated to teaching the art of submarine warfare. The sinking of the submarine F-4 off the coast of Hawaii with the loss of all hands in 1915 caused the Secretary of the Navy to direct the establishment of a formal school to instruct submariners in the operation and maintenance of these specialized boats. The commanding officer of the Submarine Base in New London, Connecticut, was directed to establish the Naval Submarine School, which began operation on 1 July 1916. After six months of training, the first officer class graduated on 23 December 1916. The first enlisted class graduated one year later.