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Thresher: Going Quietly

Thresher: Going Quietly

Thresher on April 30, 1961
Photograph courtesy U.S. Navy
At 9:18 a.m. on April 10, 1963, sonar operators aboard the U.S. Navy submarine rescue ship Skylark, which was accompanying the nuclear attack submarine Thresher, heard a chilling sound “like air rushing into an air tank,” and Thresher was no more. Its deep-dive trials southeast of Cape Cod, Massachusetts, had come to a cataclysmic end and all 129 men aboard perished in 8,400 feet (2,560 meters) of water.

Five minutes prior to the implosion, Thresher had radioed that it was having minor problems. Skylark received several fragmentary, garbled messages, followed by silence. Moments later the chilling sounds of a submarine breaking apart and imploding were heard.

According to U.S. military reviews of the accident, the most likely explanation is that a piping joint in a sea water system in the engine room gave way. The resulting spray shorted out electronics and forced an automatic shutdown of the nuclear reactor.

Creaking Death

When the accident occurred, Thresher was near its maximum test depth, which, though classified, was probably around 1,300 feet (396 meters). Most submarines are built to survive down to a “crush depth,” which can be 20 to 35 percent greater than their maximum test depth. However, without the reactor, the sub would not have had enough power to stop itself from sinking to the bottom.

As they sank, the men aboard would have heard piping and fittings giving way. They would have listened as the ship’s hull creaked and groaned, until it finally, deafeningly gave way to massive water pressure. All lives were likely extinguished within a matter of seconds.

Next: “The Greatest Submarine Rescue in History” >>



Thresher at Sea 1

in 1961

Thresher at Sea 2

(Markings Visible)

Slow Going: The Search for Thresher

To find Thresher in 1963, the U.S. Navy brought in the circa-1953 Trieste, a bathyscaphe (a navigable underwater vehicle with a spherical observation chamber on the underside of a relatively massive buoyancy tank).

The bathyscaphe’s embarrassing performance convinced many, including a Navy review committee, that U.S. deep-ocean access capabilities were severely and unacceptably deficient. The incident spurred the formation of the Deep Submergence Systems Project, which eventually led to such remotely operated deep-sea vehicles as Alvin, which explorer Robert Ballard used to view Titanic’s remains firsthand.