USS Thresher (SSN 593) underway in April 1961. U.S. Navy photo

Marking the 60th Anniversary of the USS Thresher Tragedy

Published April 5, 2023

USS Thresher (SSN 593) was lost at sea 60 years ago on April 10 during its sea trials off the coast of New England. The anniversary is a sober reminder of the dangers faced by the submarine community, and a time to honor the 129 lives lost and to consider advances in safety since the tragedy.

Those lessons learned are embodied in the Submarine Safety (SUBSAFE) Program, established eight months after Thresher was lost. Today, SUBSAFE remains central to all submarine design, construction and maintenance work at Newport News Shipbuilding.

“The Thresher accident happened before most of our current designers and builders were born, but it is important to keep the memory alive, and to continue to learn lessons from it, because we are the first line of defense against the loss of life at sea,” said Phil Stephens, NNS SUBSAFE program director. “At NNS, that is our mission every day.”

Design, construction and testing problems contributed to the April 10, 1963, Thresher disaster. Since then, a number of improvements have made Navy submarines safer and saved the lives of sailors. Here is just a sample:

  • Eliminating restrictions in the Emergency Main Ballast Tank blow system, which lightens a submarine and allows it rapidly rise to the surface.
  • Eliminating silver-brazed joints, which are more difficult to inspect than welded joints for a similar cost.
  • Electrical equipment made water resistant against sea water spray.
  • Better management of test procedures and programs.
  • Improved configuration management so the as-built condition matches the corresponding drawings.

Over decades, SUBSAFE has paid untold dividends. In the 48 years before SUBSAFE, the Navy incurred 16 non-combat-related submarine losses, about one every three years. In the 57 years since the SUBSAFE program was stood up, the Navy has not lost a single SUBSAFE-certified boat.

The work of the SUBSAFE Program, along with the skill of NNS employees, has been credited with saving the lives of more than 200 sailors aboard the USS Montpelier (SSN 765) and the USS San Francisco (SSN 711).

Montpelier was damaged after colliding with a Ticonderoga-class cruiser in 2012, and returned to port under its own power with no loss of life. San Francisco struck an undersea mountain in 2005. While one member was lost, the crew’s skill and quality of craftsmanship saved further loss of life.

Safety is hallmark on all programs at NNS. During April, shipbuilders across programs will hear more about quality work and how it protects lives. NNS will sound the shipyard whistle at 9:15 a.m. Monday, April 10, to honor the 129 lives lost during the Thresher tragedy.