A historian who for years has been studying one of the most devastating maritime disasters in history and its investigation calls for a more sophisticated analysis of acoustic data.
The U.S. Navy experienced its worst submarine disaster when the nuclear-powered attack submarine USS Thresher (SSN-593) was lost on 10 April 1963 with 129 men on board. Although the specific cause was never established, the Navy theorized that a flooding casualty short-circuited electrical equipment that caused the nuclear reactor to shut down. Operating at a depth of about 1,300 feet, the crew tried to blow her ballast tanks. At that point, a phenomenon known as Venturi cooling took place: moisture in the deballasting systems accumulated and froze in the boat's reducing valve strainers, blocking the passage of compressed air into the ballast tanks. These strainers, installed by the manufacturer to protect sensitive reduction valves from particulate matter, proved the sub's undoing. 1 Unable to blow her tanks or restart her reactor in time, the Thresher passed beyond collapse depth and imploded.