The TERRIFYING Last Minutes Of The USS Thresher

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SSN-593, more commonly known as USS Thresher, was a sight to behold. A nuclear-powered attack submarine comprising the latest technology and the finest engineering. She was a force to be reckoned with. Able to travel faster and further than a conventional sub, USS Thresher was only limited by the rations on board and the needs of the crew. Named after the Thresher shark due to its characteristic shape and ability to seek out and destroy, the Navy's newest submarine could travel deeper and more quietly than any other underwater vessel making it nigh on impossible to detect. Its revolutionary sonar system was the most comprehensive detection system ever devised for a submarine.

USS Thresher had served the US Navy before but in 1962 it was hauled out of the water and sat in Portsmouth shipyard in New Hampshire. There, it went an extensive overhaul. Panels were sealed closed, piping connected, and dials and equipment trialled. She was lowered into the water, held fast by cables and the propeller was tested.

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Music by: CO.AG

[markwestergren]

I served aboard the SSN-595 from 1973 - 1975, a sister ship and same design as the SSN-593 Thresher. The Subsafe system was being installed when I reported aboard SSN-595 in the shipyard in 1973. The key points (much of this which is also available to the public on the internet) for the loss of the Thresher, which were corrected on SSN-595, were as follows:

1) They experienced a seawater leak (at this point no major flooding) which sprayed water on reactor control equipment resulting in an automatic reactor scram (shutdown). The Thresher had no automatic remote isolation valves to rapidly isolate a seawater leak.
2) As a result of the scram, procedures at the time stated to shut the Main Steam Isolation Valves (MSIVs) to preserve heat in the reactor. However, this led to a loss of normal steam turbine propulsion and loss of speed.
3) The Thresher at this point was slightly negatively buoyant causing it to slowly sink.
4) The Emergency Propulsion Motor (EPM), an electric motor designed to slowly turn the propellor in emergency, did not provide the sub with enough speed to ascend to the surface.
5) An emergency blow of the main ballast tanks was ordered, however, ice formed in the piping near the valves (called Marotta valves) used to allow high pressure air into the ballast tanks, preventing the emergency blow.
6) The result was a slow descent of the Thresher to the sea floor which was well beyond crush depth.

The Subsafe system and procedures that were implemented on the SSN-595 and other US submarines after that included;

1) Remotely operated hull isolation valves to rapidly close all seawater inlets to prevent a leak or flooding.
2) Following an unplanned reactor scram, the MSIVs were allowed to remain open to permit the remaining steam pressure to provide enough energy to drive the main turbines and the sub back to the surface.
3) The emergency blow system was re-designed to prevent air pipe freezing, operate at higher air pressure and with larger piping to ensure a successful emergency blow.

[jimhorton]

I couldn't even imagine how those men felt sinking and hearing the sub breaking up, pipes bursting, hull groaning and creaking! RIP to all those brave And patriotic submariner's that died, God bless ALL VETERANS AND WE CITIZENS OF UNITED STATES ARE ETERNALY GRATEFUL FOR YOUR

[billyandrews]

I was eight years old, and Mom was teaching me to Pray. The crew of Thresher was our subject for a week. R.I.P.

[GaryHendrickson-uyfp]

I was a young boy in.1963, and remember the accident. I could not imagine the terror that the subs crew went through in their final minutes of life. We learn from our accidents and failures. Rest In Peace.

[titanxlegion]

Anticipation of death is worse than death itself. They knew exactly what was going to happen…a horror beyond all comprehension. Glad it was painless. God bless all of our brave military personnel past, present, & future. You all are the reason we have an America.

[debbiebarr]

A friend of mine lost her husband, last name Musselwhite, on the Thresher. Here she was a widow with 4 small children. She received a hand written letter from President Kennedy after the disaster. I would assume all the families received letters from the President.

[landtuna]

In April of 1963 I was in the process of graduating from the Navy's RM 'A' school. I had been accepted into the submarine school but had changed my mind at the last moment. The sinking of the Thresher was obviously the main topic of discussion at my base.

The first question I had asked was "why didn't the Navy test the max depth at a location where the Thresher could not exceed crush depth?" Seems like a reasonable fail safe precaution.

As the remainder of my enlistment proceeded I came to learn there were some real idiots, both political and military, in leadership positions and elected to get out at the first opportunity. My attitude in subsequent years has not changed.

[robertolesen]

I remember hearing some television show I was watching as a child being interrupted with the news of the loss. I was a soldier later in life but it takes a special person with a bravery I never had to serve on a sub. Peace to those lost and their families and gratitude for those today with the nerve I never had to cruise beneath the waves to keep our country safe and in the forefront of technology and training.

[armadillotoe]

Most civilians are unaware of the dangers of being in the military even when not engaged in combat. I was a child of 11 when this event happened, and barely remembered hearing about it on the news.

[RONALDB]

I served on the last Submarine of this class USS Haddock SSN-621. We held the memory of Thresher in high regard. SubSafe was the result of this disaster and has prevented further accidents in the Submarine community.

[shirleyk]

My father-in-law worked on that Sub he was offered the chance to go out on it for its shake down cruse. But he turned it down seams that he had gone out with the ship before it for shake down cruse he said he had gone out on the other ship so he turned the big Brass down and staked in port.
He told me what happened to it before the Gov. told every one what it thought happened.
It seams the ship yard had installed new Ele. Values to blow balist to come back up he said the new values were sticking so they wasn’t able to blow baslest to surface. He was right it imploded.
He died of cancer from all the asbestos he was exposed with while working in the ship yard. He was only 50 when he died. Very hard working man.

[andrewweitzel]

I wasn't even born when this horrible loss happened to the men on the Thresher, my father was assigned to be on the Thresher but instead they asked him to go take a class. Im here today because of that fact or my father would have been with the crew on that final decent that took 129 souls, may they rest in peace.🙏

[johnwells]

Progress is often written in blood. Subsafe was created out of this accident. Only the Scorpion was lost after Subsafe. 16 were lost before then.

[LakshyaSaxenaTheBest]

It's horrifying to imagine that you're trying to ascend but due to power failure you're slowly going down into the unknown abyss.

[originalgoldengoddess]

This is really sad. I pray these souls have found peace. Rip to everyone who lost their lives 🙏🏽 🕊❤️

[hotrodbob]

I remember when the Thresher was lost. My dad worked at Portsmouth Navel Shipyard, in later yrs I worked there, 4th generation to work there.

[francestomic]

I wS very young when when this happened. I remember crying myself to sleep over the horror& praying for them all night. It still haunts me to this day

[vilemint]

I am in LOVE with this video. It's beautifully made, right to the point, descriptive details that you don't normally see on other disaster videos, no loud annoying music (imo the ominous single playing notes of this video really hit home) wonderful job!! I've literally just discovered this channel and I'm glad to say you've gained another subscriber ☺️. This will satisfy my hyperfixation on aviation/Maritime disasters!

[genehunsinger]

you did a fine job of telling the story.

[davewinter]

A friend of our family lost a son in the Thresher disaster.