Posted on 03/11/2020 2:39:05 PM PDT by Red Badger
The submarine mysteriously went down in 1963, killing everyone on board. Thanks to a lawsuit, we're about to learn why.
A retired U.S. Navy submarine commander sued the Navy to release an official report on the sinking of the USS Thresher—and won.
Thresher sank in April 1963, lost with all hands, but there has never been an official explanation as to why.
The loss of Thresher lead to an improved culture of safety in the Navy, and since 1968, the service hasn’t lost a single submarine.
==================================================================
A retired U.S. Navy submarine commander has won a lawsuit forcing the Navy to release its report on what happened to the USS Thresher, a nuclear-powered attack submarine that sank during diving tests in 1963. The loss of the submarine has never been fully explained, and the Navy has never released the report on the sub’s sinking.
Diagram of Thresher showing off its teardrop hull.
=====================================================================
USS Thresher was the first of its class, a new type of fast, deep diving attack submarine. The Thresher-class subs used a streamlined hull designed for fast underwater travel. With a torpedo-like hull design and a S5W nuclear reactor, the Thresher class could make 20 knots on the surface and 30 knots underwater—the reverse of World War II-era submarines designed to spend most of their time on the surface. The submarines were 278 feet long, 31 feet wide, and carried Mk. 37 homing torpedoes for use against surface and subsurface targets, SUBROC anti-submarine torpedoes, and sea mines.
On April 9, 1963, the Thresher was 220 miles east of Cape Cod, conducting diving tests. It was the first submarine to use the new HY-80 steel alloy, and the Navy was eager to determine how deep the new design could safely dive. At 9:13 a.m., while at a depth of 1,300 feet, the submarine radioed the submarine rescue ship USS Skylark, waiting above:
“Experiencing minor difficulties. Have positive up angle. Am attempting to blow (ballast tanks). Will keep you informed.”
But Thresher never surfaced, and the Navy later found the sub in six pieces on the bottom of the Atlantic Ocean. All 129 personnel on board were killed. People have come up with many theories about how the sub sank, including blaming the faulty welds that failed during the tests, shorting out the sub's critical electrical systems and sapping its power.
Capt. Jim Bryant, a retired Navy submarine officer, wanted to see the Navy’s 1,700-page report on the Thresher’s sinking, but the Navy refused to release it. So Bryant, Stars and Stripes reports, sued the Navy, and last month a federal judge ordered the service to release it in 300-page chunks.
The Navy has long been extremely protective of the report. The Navy submarine force is notoriously tight-lipped; submariners say the nickname “the silent service” not only applies to the quiet nature of subs, but the secretive nature of the sub community as a whole.
The service first said it would release the Thresher report in 1998, but released only 19 of 1,700 pages, claiming that keeping it classified was to protect serving submarine crews. The problem with that explanation? The accident happened during normal dive tests. More than 50 years have passed since the sinking, and the submarine’s technology is obsolete.
The loss of the Thresher led to a sea change in the Navy submarine force. After the sinking, the service instituted SUBSAFE, a program that ensures the safe operation of submarines. SUBSAFE monitors the design and construction of new subs to ensure ships can remain watertight and survive accidents at sea. (The Navy lost another submarine, the USS Scorpion, in 1968, but it wasn't built to SUBSAFE standards.)
In 2005, the attack submarine USS San Francisco collided with an underwater seamount at the equivalent of 30 miles an hour—and was still able to sail to Guam for repairs. The culture of safety spawned by SUBSAFE—and indirectly Thresher—is credited for ensuring the San Francisco’s survival.
The Navy will begin releasing the Thresher report in segments on May 15 and will continue until Oct. 15.
I saw that documentary. They might have started taking seawater through the reactor cooling pipes and begun flooding aft. Trying to blow ballast at depth, where it is very cold, they found the valves froze up and they couldn't empty the ballast tanks and losing depth the hull imploded.
This fellow Momsen was present on the surface and he personally knew some of the men on the sunken sub. It tore him apart that the boat was in fairly shallow water but that they had no means of rescuing the crew; it was this incident that pushed him to develop a specialized "lung" that would allow one to escape a submarine and come to the surface without an external source of air. (If you're familiar with the movie "Das Boot", there are a couple of scenes where the crew puts these on in response to the captain's call to don "escape gear"; they look like inflatable life vests that have not yet had the CO2 cartridge activated.)
It's been years since I've read the book, but my understanding is that the men of the Squalus owe their lives to Momsen's pioneering efforts. (An actual submariner on this thread might correct me on this; I don't know.)
I was told that the introduction of the Engine Room Fresh Water system was a direct result of the Thresher. The SSMGs on 688’s for example were cooled by ERFW, but I heard that they were cooled directly by seawater on 593/594’s. So not just stronger seawater pipe connections, but also less seawater piping overall.
I know what you're trying to say, but the way you're saying it is incredibly awkward.
The reactor coolant system is a pressurized closed loop freshwater system that does not have any connections to a seawater system (with the possible exception of some type of emergency cooling system).
If the Thresher had an emergency cooling system that cooled coolant via a seawater heat exchanger, it wouldn't make it into the reactor coolant system. That reactor coolant system pressure is much higher than any seawater system pressure. If there was a leak between those two systems, it would be an outward one, and once pressure equalized, the reactor coolant system could withstand the pressure of the sea without rupturing.
Under normal circumstances, the reactor coolant system exchanges heat in steam generators. The steam produced powers turbines and then is cooled and condensed by the main seawater cooling system. So ultimately, the reactor is cooled by seawater, but I don't recommend you calling the main seawater cooling system "reactor cooling pipes."
Regardless, from what I've heard, the seawater rupture was in an auxilary seawater cooling system which had nothing to do with the reactor.
This is what I’ve heard. I have a son on a boat so I have interest in this.
Interesting recent review of the scorpion?
I also am very interested in the truth.
We were a military family outside DC at the time, I was in 5th grade. All things military were always news in our home.
I worked for B&W NPGD in Lynchburg back in the 70’s. Got fire fighting training at the Naval Nuclear Fuels division on the James River. I lived in Appomattox and Lynchburg at the time.
Failure to maintain buoyancy is my guess
Well, that one was likely sunk by the Soviets.
Thank you.
I was told by a nuclear engineer about twenty years ago that the computer shut down the reactor/engine because it sensed a malfunction and the crew could not override the computer code.
Sort of.
1. There was no computer.
2. Procedures were revised to allow propulsion turbines to stay running after a scram.
3. Procedures were revised to allow for a rapid scram recovery.
BS!
I was a young girl when that happened and I remember it like it was yesterday. So sad. I was in the newspapers for weeks it seemed like....
Disclaimer: Opinions posted on Free Republic are those of the individual posters and do not necessarily represent the opinion of Free Republic or its management. All materials posted herein are protected by copyright law and the exemption for fair use of copyrighted works.