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Why Did the USS Thresher Sink? Finally, the Navy Is Being Forced to Tell Us

dawp

Lifer
Jul 2, 2005
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curious to see their explanation but why 300 pages at a time?

I think it had to do with a new alloy steel and not doing thorough testing on it
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.
 
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pcgeek11

Lifer
Jun 12, 2005
17,776
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My understanding being a career bubblehead is that when they attempted to emergency blow, Ice formed in the Emergency Blow Valve(s) ( hammer Valves ) which prevented all ballast tanks from being blown clear. Emergency blow is done using 4500 psi high pressure air. This in turn caused the bow to rise to an angle too steep and the air vented out the open grates of the ballast tanks at the bottom. Once this angle is reached you cannot stop the ballast tanks from spilling the air and filling with seawater and you sink like a stone backwards. Stern first. When they reach crush depth it is over.

Many bad things happen with excessive angles, Reactors Shutdown, Lubrication Oil pumps lose suction ...

I served on several deep diving submarines with hulls made of HY80. It was routine to perform an emergency blow from test depth every sea trials before going on patrol.
 

pcgeek11

Lifer
Jun 12, 2005
17,776
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For a quick edit on my post above the angle could have been a bow up or stern up or even side to side depending on what blow valves froze. Regardless when the air spills out the bottom bad things are going to happen. High moisture content and high pressure air rushing through a restriction is bad news.

I also assumed they had lost propulsion, due to the fact that they could have driven up in a more controlled fashion with the screw turning.
 
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pcgeek11

Lifer
Jun 12, 2005
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Also the article stated that the Thresher contacted the ship with a radio transmission. A radio will not transmit through the water. Esp from 1,300 feet deep. It would have had to been a UQC Underwater telephone that was used. It uses a transducer to broadcast underwater and isn't real clear on the best of days, (think talking to Donald Duck).

The bright spot in the loss of the Thresher and the Scorpion. They are the only two Submarines lost not due to enemy action and we learned a lot from the loss of those poor souls. Specifically the SUBSAFE Program, which was a pain in the ass for all the paperwork and tracking of repairs. I am positive it saved many lives.

The USSR/Russia has lost 7. I think.
 
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TheVrolok

Lifer
Dec 11, 2000
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My understanding being a career bubblehead is that when they attempted to emergency blow, Ice formed in the Emergency Blow Valve(s) ( hammer Valves ) which prevented all ballast tanks from being blown clear. Emergency blow is done using 4500 psi high pressure air. This in turn caused the bow to rise to an angle too steep and the air vented out the open grates of the ballast tanks at the bottom. Once this angle is reached you cannot stop the ballast tanks from spilling the air and filling with seawater and you sink like a stone backwards. Stern first. When they reach crush depth it is over.

Many bad things happen with excessive angles, Reactors Shutdown, Lubrication Oil pumps lose suction ...

I served on several deep diving submarines with hulls made of HY80. It was routine to perform an emergency blow from test depth every sea trials before going on patrol.
Really interesting, thanks for the insight.
 
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pcgeek11

Lifer
Jun 12, 2005
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Really interesting, thanks for the insight.

If I could go back and re-live my younger days riding a Submarine with the guys I worked with back in the day. I would do it with no hesitation at all.

It was more a family than a crew. Much different than the military today.

Ballast Control Panel. The two handles above the dudes head are the chicken switches. These are the manual valves that control the emergency blowing of the ballast tanks. The one on the right is the Forward group, the left the After group.

Blow forward first and when the angle starts upward you blow the after group.

1583929797869.png
 
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IJTSSG

Golden Member
Aug 12, 2014
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For a quick edit on my post above the angle could have been a bow up or stern up or even side to side depending on what blow valves froze. Regardless when the air spills out the bottom bad things are going to happen. High moisture content and high pressure air rushing through a restriction is bad news.

I also assumed they had lost propulsion, due to the fact that they could have driven up in a more controlled fashion with the screw turning.
The theory that the guys who are suing for the report is that there was a loss of propulsion due to a primary electrical bus failure. The bus frequency changes can be heard on SOSUS data. That bus failure caused the loss of the main coolant pumps, which caused a SCRAM and the obvious loss of power. The procedures at the time did not include a fast rcovery startup or the use of residual steam. You isolated the the main and switched to battery. When losing propulsion at that depth, the procedure is to blow to the surface. The temporary dryers in the airlines failed, the system iced over and very little air reached the ballast tanks. If she was trimmed for negative buoyancy . . . the eventual outcome is obvious.

What the SOSUS data did not reveal was flooding. No acoustic data was recorded that indicated flooding. You've been in the wet trainer at Groton and know how loud flooding is in the trainer. Imagine what it would be like at test depth. If there was flooding, it would've been heard. By everyone.

My least favorite thing to do as a Diving Officer was to operate at or near test depth. It's mentally and sometimes physically exhausting.
 
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pcgeek11

Lifer
Jun 12, 2005
17,776
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The theory that the guys who are suing for the report is that there was a loss of propulsion due to a primary electrical bus failure. The bus frequency changes can be heard on SOSUS data. That bus failure caused the loss of the main coolant pumps, which caused a SCRAM and the obvious loss of power. The procedures at the time did not include a fast rcovery startup or the use of residual steam. You isolated the the main and switched to battery. When losing propulsion at that depth, the procedure is to blow to the surface. The temporary dryers in the airlines failed, the system iced over and very little air reached the ballast tanks. If she was trimmed for negative buoyancy . . . the eventual outcome is obvious.

What the SOSUS data did not reveal was flooding. No acoustic data was recorded that indicated flooding. You've been in the wet trainer at Groton and know how loud flooding is in the trainer. Imagine what it would be like at test depth. If there was flooding, it would've been heard. By everyone.

My least favorite thing to do as a Diving Officer was to operate at or near test depth. It's mentally and sometimes physically exhausting.

Yes, it can be very tense. Been there at the BCP standing Chief of the Watch (COW). The worse one is the first deep dive out of the shipyard. :eek:

You always want to be positive at those depths.

I didn't know you were a Bubblehead too. Good to know a fellow Squid.
 
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Feb 4, 2009
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Yes, it can be very tense. Been there at the BCP standing Chief of the Watch (COW). The worse one is the first deep dive out of the shipyard. :eek:

You always want to be positive at those depths.

I didn't know you were a Bubblehead too. Good to know a fellow Squid.
Alright so off topic questions.

Why don’t subs become super cold being in deep water for extended periods of time?
I know this is movies not real life but they are always portrayed as being really warm. Does the engine/reactor/batteries put out that much heat?
How often were you able to shower or clean yourself underwater? How was hygiene enforced? I imagine if one dude smells like ass it is bad for moral or does everyone smell like ass and nobody notices until you get fresh air?
Any weird noises happen like something contracting that puts you on edge? Is it a regular occurrence?
 

hal2kilo

Lifer
Feb 24, 2009
16,368
4,322
136
My understanding being a career bubblehead is that when they attempted to emergency blow, Ice formed in the Emergency Blow Valve(s) ( hammer Valves ) which prevented all ballast tanks from being blown clear. Emergency blow is done using 4500 psi high pressure air. This in turn caused the bow to rise to an angle too steep and the air vented out the open grates of the ballast tanks at the bottom. Once this angle is reached you cannot stop the ballast tanks from spilling the air and filling with seawater and you sink like a stone backwards. Stern first. When they reach crush depth it is over.

Many bad things happen with excessive angles, Reactors Shutdown, Lubrication Oil pumps lose suction ...

I served on several deep diving submarines with hulls made of HY80. It was routine to perform an emergency blow from test depth every sea trials before going on patrol.
Yea, that's been the official reason for a couple decades, and I have no reason to doubt it. Use to walk past a poster in the hall everyday that honored the people who went down on the Thresher. Part of my work involved going out on sea trials to collect weapon system data used for analysis. If it had been a different time, I could have been one of those souls who ended up on the bottom.
As a matter of fact, a couple years ago, we supported some testing to determine the temperature drop when the forward ballast tanks were vented, to support some studies for the Trident replacement.
 

pcgeek11

Lifer
Jun 12, 2005
17,776
1,868
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Alright so off topic questions.

Why don’t subs become super cold being in deep water for extended periods of time?
I know this is movies not real life but they are always portrayed as being really warm. Does the engine/reactor/batteries put out that much heat?
How often were you able to shower or clean yourself underwater? How was hygiene enforced? I imagine if one dude smells like ass it is bad for moral or does everyone smell like ass and nobody notices until you get fresh air?
Any weird noises happen like something contracting that puts you on edge? Is it a regular occurrence?
I'll try and give you some insight.

1.) Why don’t subs become super cold being in deep water for extended periods of time?

There is a ton of electronic gear inside of a sealed tube. It gets as hot as hell without air conditioning. Once we were at sea on patrol and lost a heat exchanger. To do repairs they had to take the entire system off line. It was 112 degrees in the control room forward. The engine room was well over that. They relieved the watch every two hours. Uniform of the day was underwear and tennis shoes. And this is with turning off all non essential equipment.

2.) I know this is movies not real life but they are always portrayed as being really warm. Does the engine/reactor/batteries put out that much heat?

Yes, even the lights.

3.) How often were you able to shower or clean yourself underwater? How was hygiene enforced?
Yes, a short shower every day or so as long as the freshwater evaporators and stills are working properly. I have seen when one goes down and we went for a week or so with no shower water. The reactor always gets first dibs on the water, then the galley, then the crew...

Standard Submarine Shower:
Turn on the water, get wet.
Turn off the water, soap up.
Turn on the water, rinse off.
Turn off the water. ~ 3 minutes tops.

4.) I imagine if one dude smells like ass it is bad for moral or does everyone smell like ass and nobody notices until you get fresh air?

On a Submarine everybody smells like ass anyway from the oil, amine, hydraulics and enclosed environment for months at a time.

5.) Any weird noises happen like something contracting that puts you on edge? Is it a regular occurrence?

The decks are not attached to the hull, but slide as they float on beams. When you go down the hull contracts and when you go up it expands. Short answer it creaks whenever you change depths. You get used to it and usually pay no attention.

The only hairy dives are the first out of the shipyards or the test depth emergency blows.

Take it into account that I retired in 1993. I'm sure things have improved a lot since I rode the boats. They are much fancier now. I worked on some of the Trident Hull boats before I retired and they were like a Lincoln in comparison to an old 608 class boat that I cut my teeth on.

 
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hal2kilo

Lifer
Feb 24, 2009
16,368
4,322
136
I'll try and give you some insight.

1.) Why don’t subs become super cold being in deep water for extended periods of time?

There is a ton of electronic gear inside of a sealed tube. It gets as hot as hell without air conditioning. Once we were at sea on patrol and lost a heat exchanger. To do repairs they had to take the entire system off line. It was 112 degrees in the control room forward. The engine room was well over that. They relieved the watch every two hours. Uniform of the day was underwear and tennis shoes. And this is with turning off all non essential equipment.

2.) I know this is movies not real life but they are always portrayed as being really warm. Does the engine/reactor/batteries put out that much heat?

Yes, even the lights.

3.) How often were you able to shower or clean yourself underwater? How was hygiene enforced?
Yes, a short shower every day or so as long as the freshwater evaporators and stills are working properly. I have seen when one goes down and we went for a week or so with no shower water. The reactor always gets first dibs on the water, then the galley, then the crew...

Standard Submarine Shower:
Turn on the water, get wet.
Turn off the water, soap up.
Turn on the water, rinse off.
Turn off the water. ~ 3 minutes tops.

4.) I imagine if one dude smells like ass it is bad for moral or does everyone smell like ass and nobody notices until you get fresh air?

On a Submarine everybody smells like ass anyway from the oil, amine, hydraulics and enclosed environment for months at a time.

5.) Any weird noises happen like something contracting that puts you on edge? Is it a regular occurrence?

The decks are not attached to the hull, but slide as they float on beams. When you go down the hull contracts and when you go up it expands. Short answer it creaks whenever you change depths. You get used to it and usually pay no attention.

The only hairy dives are the first out of the shipyards or the test depth emergency blows.

Take it into account that I retired in 1993. I'm sure things have improved a lot since I rode the boats. They are much fancier now. I worked on some of the Trident Hull boats before I retired and they were like a Lincoln in comparison to an old 608 class boat that I cut my teeth on.

PCgeek was never a navigator. One of the guys that was my boss at one time said he spent most of the time in his jacket in NAV. It was like working in a refrigerator. This is Poseidon, not Trident.
 

tweaker2

Lifer
Aug 5, 2000
11,825
3,059
136
My understanding being a career bubblehead is that when they attempted to emergency blow, Ice formed in the Emergency Blow Valve(s) ( hammer Valves ) which prevented all ballast tanks from being blown clear. Emergency blow is done using 4500 psi high pressure air. This in turn caused the bow to rise to an angle too steep and the air vented out the open grates of the ballast tanks at the bottom. Once this angle is reached you cannot stop the ballast tanks from spilling the air and filling with seawater and you sink like a stone backwards. Stern first. When they reach crush depth it is over.

Many bad things happen with excessive angles, Reactors Shutdown, Lubrication Oil pumps lose suction ...

I served on several deep diving submarines with hulls made of HY80. It was routine to perform an emergency blow from test depth every sea trials before going on patrol.

I work quite often with HY80 being a machinist making parts and repairs for/on Navy ships. That's some really tough stuff to shave chips off of, especially so when deep threading into that metal. For this material the "slow is fast" method of machining it along with the hastelloy/inconel family of HP alloys is about the only practical way of shaping that stuff without damaging equip't and expendables.

That being said, it's pretty amazing how deep sea pressure can mess with its cylindrical structural integrity in such a nasty way.
 

pcgeek11

Lifer
Jun 12, 2005
17,776
1,868
126
PCgeek was never a navigator. One of the guys that was my boss at one time said he spent most of the time in his jacket in NAV. It was like working in a refrigerator. This is Poseidon, not Trident.

I agree Nav Center was like working in a freezer most of the time. I think it had mostly to do with the (SINS) Ship’s Inertial Navigation System Computers. Turn off the chilled water and the Quartermasters will be plotting ships location by hand for a while. They may even have to surface at night to get a star shot.
LOL.

The Tridents also use SINS just a touch newer.

I did work on all the Nuclear Weapons from A2 Polaris, A3 Polaris, C3 Poseidon, and D5 Trident.

I also worked with the older Mark 45 Nuclear Warhead Torpedoes.
 

hal2kilo

Lifer
Feb 24, 2009
16,368
4,322
136
I agree Nav Center was like working in a freezer most of the time. I think it had mostly to do with the (SINS) Ship’s Inertial Navigation System Computers. Turn off the chilled water and the Quartermasters will be plotting ships location by hand for a while. They may even have to surface at night to get a star shot.
LOL.

The Tridents also use SINS just a touch newer.

I did work on all the Nuclear Weapons from A2 Polaris, A3 Polaris, C3 Poseidon, and D5 Trident.

I also worked with the older Mark 45 Nuclear Warhead Torpedoes.
They all went to ESGNs for the navigation source. Uses a electrostatically suspended beryllium ball milled oblique so when its spins a 30000 rpms it becomes round. They were supposed to be using ring laser tech by now, but lets just say that the first TEMPALT was a rousing failure. This is political. The Navy put all their eggs in Lockheed for this. Boeings had a workable unit for a couple years, but.... and there are no more spinning balls on the shelf. Lots of works arounds.
It's in the Navy museum already.
 
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pcgeek11

Lifer
Jun 12, 2005
17,776
1,868
126
They all went to ESGNs for the navigation source. Uses a electrostatically suspended beryllium ball milled obleke so when its spins a 30000 rpms it becomes round. They were supposed to be using ring laser tech by now, but lets just say that the first TEMPALT was a rousing failure. This is political. The Navy put all their eggs in Lockheed for this. Boeings had a workable unit for a couple years, but.... and there are no more spinning balls on the shelf. Lots of works arounds.
It's in the Navy museum already.

Cool info.
I've been out of the loop for too long. :(
 

hal2kilo

Lifer
Feb 24, 2009
16,368
4,322
136
I'm considering a second retirement in the next two years.

Congrats on your retirement and career!
Thanks. Did you get to a job related to what skills you had in the Navy? Anyway, thanks for your service.
 

pcgeek11

Lifer
Jun 12, 2005
17,776
1,868
126
Electronics and repair of automated assembly lines. Robotics and such. I was offered a job with Lockheed and a Government GS position in Kings Bay when I retired. I elected to try something new... :)
 

hal2kilo

Lifer
Feb 24, 2009
16,368
4,322
136
Electronics and repair of automated assembly lines. Robotics and such. I was offered a job with Lockheed and a Government GS position in Kings Bay when I retired. I elected to try something new... :)
Yea, I was a tech rep to those guys. If you really have any gumption, you don't want to work in one of those civil service support shops. I was at Bangor, but I supported several shot missions at KB because the west coast array (range) was shut down for several years due to lack of funding. Speaking of bottom mounted sonar arrays, all that stuff is going to go away. Under water UAVs and swarms of drones with GPS will replace a lot of the hardware we use to relay position data to the range support ship so the cameras and radar will be pointed at where the missile broaches out of the water. Damn I wish I had access to the presentation that explained how all of this data is transmitted and collected for live feed to the Washington Navy Yard's SP headquarters.
 
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Amused

Elite Member
Apr 14, 2001
53,735
6,514
126
Why Did the USS Thresher Sink?

Because it filled with water?

Just a guess.
 

pcgeek11

Lifer
Jun 12, 2005
17,776
1,868
126
Yea, I was a tech rep to those guys. If you really have any gumption, you don't want to work in one of those civil service support shops. I was at Bangor, but I supported several shot missions at KB because the west coast array (range) was shut down for several years due to lack of funding. Speaking of bottom mounted sonar arrays, all that stuff is going to go away. Under water UAVs and swarms of drones with GPS will replace a lot of the hardware we use to relay position data to the range support ship so the cameras and radar will be pointed at where the missile broaches out of the water. Damn I wish I had access to the presentation that explained how all of this data is transmitted and collected for live feed to the Washington Navy Yard's SP headquarters.

Wow that is so cool. UAVs and drone swarms. No need for the telemetry antenna sticking out of the water anymore. Crap; I feel like a Neanderthal now... Well actually I felt like that when I went on one of the Trident Boats and they were loading torpedoes into the tubes and there wasn't a block and tackle anywhere........................ :D

I do have some cool pictures of when the Trident did the loop de loop during some of the initial test firings when a nozzle actuator broke during launch. The nozzle locked over to one side when the water slapped it when exiting the water. They had to do the emergency destruct on it. Spooky having a trident missile doing loops and no control.

This image is from a web site. I have some original sequence launch photos when we were working at the Cape in support of the Tennessee.


https://www.reddit.com/r/submarines/comments/atrzoq
1584071039943.png

 
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