50th Anniversary of the Loss of USS THRESHER (SSN 593)
“Fifty years ago, on April 10, 1963, while engaged in a deep test dive, the USS THRESHER (SSN 593) was lost at sea with 129 Officers and men on board. Based on the findings of a Court of Inquiry and the Joint Congressional Committee on Atomic Energy hearings into the loss, it was concluded that a flooding casualty in the engine room, resulting from a piping failure in one of the sea water systems, was the most probable cause of the loss.
From this tragic event, the SUBSAFE Program was established in July, 1963 to ensure implementation of recommendations resulting from findings of the THRESHER Court of Inquiry and THRESHER Design Appraisal Board. Today, the technical and administrative requirements of the SUBSAFE Program continue to evolve, and the most current are contained in the Submarine Safety (SUBSAFE) Requirements Manual, NAVSEA.
Simply stated, the purpose of the SUBSAFE Program is to provide maximum reasonable assurance seawater is kept out of the submarine and the submarine and crew can recover if there is a seawater casualty.”
Statements above are from Vice Admiral Kevin McCoy
"A tragic event, the incident is especially poignant for naval shipbuilders as Thresher was on her initial post-overhaul dive trials with Portsmouth Naval Shipyard engineers supplementing the crew."
From a BIW employee.
It should be noted that the Sealab program got a lot of its funding in response to the Thresher disaster. The Navy saw the need to have better deep diving capability.
The incident also spurred the formation of the Deep Submergence Systems Project, which eventually led to remotely operated deep-sea vehicles and the Alvin deep research sub, which explorer Robert Ballard used to view Titanic’s remains firsthand.