April 10, 2020 – Lessons from the Loss of the USS Thresher (SSN 593), April 10, 1963

You are currently viewing April 10, 2020 – Lessons from the Loss of the USS Thresher (SSN 593), April 10, 1963

On the morning of April 10, 1963, at approximately 9:18 a.m., USS Thresher was lost with all 129 crew and civilian riders on board. Thresher had just completed a nine-month overhaul and modernization availability at Portsmouth Naval Shipyard in which she received new electronic and sonar equipment as well as other upgrades and repairs. She had departed from the shipyard just the day before. Wives and children waved to the crew members, as three tugs nuzzled against her and guided her away from her berth, anxious for them to return after completion of the planned two-day trial.

Conducting several successful shallow dives along the way, Thresher transited east-southeast to her dive point 220 miles off of Cape Cod where the Continental Shelf ends and the ocean’s depth plummets to 8400 feet. As her controlled dive began in 100-foot increments, Thresher sent routine messages to the rescue ship, USS Skylark. At 9:17 a.m., Skylark received a garbled message “…minor difficulties, have positive up-angle, attempting to blow.” Then Thresher went silent. Skylark attempted to regain contact by all means available, but to no avail. Thresher was lost.

Despite the Navy’s rigorous investigation, the exact cause of this tragedy is unknown; however, the following is the likely sequence of events:

•One or more silver-braze piping joints in sea water systems failed, resulting in engine room flooding.

•Due to the ship’s design and system arrangements, the crew was unable to access vital equipment to control the flooding.

•Saltwater spray on electrical components caused electrical panels to short circuit, the reactor plant to shut down and loss of propulsion power.

•The emergency main ballast tank blow system failed to operate properly. Restrictions in the piping system coupled with excessive moisture in the air led to ice formation and subsequently plugged of the airway.

The lives of the families that experienced this tragedy were forever changed. Wives were now widows; children fatherless. You may recall a WIB article I wrote back in October in which I discussed attending the dedication of the Thresher Memorial in Arlington National Cemetery and sitting amongst the surviving family members of the Thresher crew. The experience brought this event full circle in my mind and made me feel a personal, not just professional, tie to the Thresher disaster. The pain of this disaster is still with them–I saw it.

Multiple issues may have contributed to the loss of the 129 lives: perhaps poor workmanship, or testing, or a design or engineering error. Imagine what must have gone through the minds of the folks that worked on Thresher, wondering if it was their work that caused the loss.

This pivotal point in US Navy submarine history marks the event that sparked the inception of the Submarine Safety (SUBSAFE) program. Since the inception of the SUBSAFE program, no SUBSAFE certified submarine has ever been lost. In January of this year, the SUBSAFE, Fly-by-Wire Ship Control System and material condition certification of the PCU Vermont was revoked due to an undocumented condition on the ship. This loss of confidence in our certification process was unprecedented and a stark reminder of just how critical our jobs are to the safety of the ship, her crew, and their families.

We cannot lose sight of the fact that it is the robust material condition that we design into our ships, the expert craftsmanship, the technical rigor of engineering, the comprehensive testing and certified documentation combined with the Special Emphasis Program (SUBSAFE, DSS-SOC and Fly-by-Wire Ship Control System) requirements that provide the assurances that our submarines and their crews will be safe and on mission. We have the responsibility to maintain our vigil on the loss of the USS Thresher every day in all the work that we do, by applying the lessons learned and not losing sight of it despite the many distractions. It is especially tough this year with COVID-19 and all the challenges it brings to us. However, every job you complete, every document you sign, every decision you make, day-to-day, contributes to the material condition of our ships.

It is the sum of all your daily acts, as employees of the greatest submarine builder in the world, which ultimately allows the certification of our ships to go to sea. It allows their safe deployments and allows its sailors and their families to have the sacred trust and confidence that the ship will return safely, every time, no matter what.

Please stay safe and healthy.

Stephen Kirkup,
Director of Quality Assurance and Special Emphasis Programs

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