Announcement

Collapse
No announcement yet.

Retired Submarine Commander Sues Navy to Release USS Thresher Investigation

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • Mountain Man
    replied
    I have read that air compressing at that speed literally ignites into a fireball. Is that the case?

    What do you see as the goal of the sub com's inquiry? Given what you've posted it appears that this was merely a tragic and unfortunate accident.

    Leave a comment:


  • Achtung Baby
    replied
    Originally posted by Mountain Man View Post

    I was thinking in terms of the size of the debris field. That's why I wondered how deep it was.
    She broke up in six major sections, the majority of the debris field is around 400 hundred yards square. She imploded around 2,400 ft, and is resting at 8,400 feet. And given how far down she reached before the implosion, the quality of her construction cannot be dismissed.
    The pressure of the water at 2,400 ft was immense, it is estimated that the velocity of the water ram entering her compartments was 2,600 mph, or about 4 feet per millisecond. At those speeds, the ram would have traversed the maximum internal diameter of the pressure hull in about 0.008 seconds. The initial breach would have also generated a shock wave that propagated through the entire hull at the velocity of the speed of sound in steel, about 20,000 feet per second... five times the velocity of the water ram.
    That shockwave, acting on a structure that is already stressed to the point of collapse, probably triggered additional failure points before the flooding reached those points. This can tear the pressure hull longitudinally and vertically.
    USS Thresher was destroyed in 47 milliseconds, half the minimum time required for human cognitive perception of the event.
    Last edited by Achtung Baby; 24 Sep 19, 16:42.

    Leave a comment:


  • Mountain Man
    replied
    Originally posted by Achtung Baby View Post

    USS Thresher was 2,400ft when she imploded, her collapse depth was 1,950ft. So the personal at Portsmouth Naval Shipyards actually did a commendable job in building the sub. The original court of inquiry's suggestion of flooding doesn't add up, I'll go into more detail about that later.
    I was thinking in terms of the size of the debris field. That's why I wondered how deep it was.

    Leave a comment:


  • Achtung Baby
    replied
    The meaning of "900 North"

    '900 North' was Thresher's last UQC(underwater telephone) transmission to her escort ship USS Skylark.

    At 075 Thresher advised Skylark that her depth was 400ft.

    At 0754 Thresher advised Skylark that(for security reasons) all future references to depth would be given relative to test depth. The number 900 was thus an indirect reference by Thresher to her depth at 0917: 900ft below her test depth of 1300ft or 2200ft. The word 'north' is assessed to have been a direction. In this case 'up' as north is on a map, i.e. test depth was above Thresher by 900ft at 0917.

    This explanation was dismissed in the court of inquiry, because it required the Thresher's hull pressure to have survived greater than the crush depth of 1950ft. Furthermore, it would have invalidated their conclusion that flooding had occurred at test depth(1300 feet).

    The idea of flooding didn't add up then, nor is it even credible now. Thresher made no mention of flooding during her decent, nor did Skylark hear it. A test demonstration at dry dock No 2 at Portsmouth naval shipyard was held for the court of inquiry. A stream of water was released to atmosphere at Thresher's test depth pressure(580 psi) against a piece of electronic equipment. One witness Russell Preble, CDR USN (ret) observed that test, and said the noise was overwhelming, nothing could be heard over the noise. No orders could be heard over the roar of the water striking anything in it's way. This would have been heard by the men on Skylark, and observed on the underwater hydrophones that picked up the entire event.
    And given the size of the pipes that the court of inquiry claimed to have leaked, they don't seem to have calculated the amount of water that would have entered the sub in those six minutes(from 1300ft(at 0911) to the 900 north(0917) quote). Why the court of inquiry blame silver blazing when no reports of flooding was recorded, or reported, and Thresher survived without breach to almost twice test depth... it seems the court of inquiry was deflecting blame. It appears relying on the nuclear power plant alone without a designed or tested backup appears to be Thresher's demise.

    Leave a comment:


  • Achtung Baby
    replied
    Originally posted by Mountain Man View Post

    How far above bottom was the implosion?
    USS Thresher was 2,400ft when she imploded, her collapse depth was 1,950ft. So the personal at Portsmouth Naval Shipyards actually did a commendable job in building the sub. The original court of inquiry's suggestion of flooding doesn't add up, I'll go into more detail about that later.

    Leave a comment:


  • Mountain Man
    replied
    Originally posted by Achtung Baby View Post
    Just started reading a detailed analysis of the accident... book arrived just a few hours ago. I must say I'm already overwhelmed with the amount of issues overlooked in the original navy inquiry. I can now understand why the retired commander wants this rectified.

    One thing that repeatedly stands out, USS Thresher was already negatively buoyant at test-depth. She was sinking at a rate of 120ft/min, Scorpion was more neutrally buoyant and is estimated to have had a lower average sink rate of 52ft/min. It was assessed that the noise of Thresher's implosion could have been detected at ranges equal to the circumference of the earth. No wonder she was found in many pieces.
    How far above bottom was the implosion?

    Leave a comment:


  • Achtung Baby
    replied
    Just started reading a detailed analysis of the accident... book arrived just a few hours ago. I must say I'm already overwhelmed with the amount of issues overlooked in the original navy inquiry. I can now understand why the retired commander wants this rectified.

    One thing that repeatedly stands out, USS Thresher was already negatively buoyant at test-depth. She was sinking at a rate of 120ft/min, Scorpion was more neutrally buoyant and is estimated to have had a lower average sink rate of 52ft/min. It was assessed that the noise of Thresher's implosion could have been detected at ranges equal to the circumference of the earth. No wonder she was found in many pieces.

    Leave a comment:


  • T. A. Gardner
    replied
    Originally posted by slick_miester View Post
    The Mk 37 torpedo, was it fueled by H2O2?
    No, it had silver-zinc batteries that tended to overheat if charged too fast or wrong. Sort of like Lithium batteries do lately...



    Sort of the same thing...

    Leave a comment:


  • Achtung Baby
    replied
    It appears that the inquiry wasn’t considering the evidence of the SOSUS recordings, which conflicts with the official version of events.

    Leave a comment:


  • slick_miester
    replied
    The Mk 37 torpedo, was it fueled by H2O2?

    Leave a comment:


  • Snowygerry
    replied
    Originally posted by T. A. Gardner View Post
    Thresher wreckage:
    The subscript says "Mosaic" of sail and debrir there, does that mean several pictures are made into one for clarity ?
    Last edited by Snowygerry; 29 Aug 19, 04:55.

    Leave a comment:


  • Mountain Man
    replied
    Originally posted by T. A. Gardner View Post

    The likely cause there was flooding due to improper brazing of seawater piping. I've seen the sloppy job sandcrabs do of that. AAA (West coast) did an AFFF system upgrade in phosphor bronze piping to connect all the stations on the hangar bay on the 'prise. They hired anyone who could spell brazing. Then they lit the system off to test the piping rather than use an air test.
    The results were as appalling as they were hilarious. A lot of the piping ran through senior officer's state rooms on the third deck and there's nothing like saltwater and AFFF to ruin your day!

    Thresher had issues with her seawater piping being right out of the yards but the issues weren't considered serious enough to keep trials from happening.



    Most likely in her case was a Mk 37 torpedo, known to have issues, started running hot and they tried to jettison it but it detonated or caused a fire and much like the Kursk, Scorpion went to the bottom. At least, that's the most plausible explanation.
    Then the Scorpion would be shattered and widely scattered like the Thresher, so that did not happen.. Whenever an accident is kept classified for so long, intelligent people always want to know why.

    Leave a comment:


  • T. A. Gardner
    replied
    Originally posted by Achtung Baby View Post

    Of course, but SOSUS evidence suggests a failure of an electrical bus for the coolant pumps. Which is why I guess the retired sub commander wants answers.
    The likely cause there was flooding due to improper brazing of seawater piping. I've seen the sloppy job sandcrabs do of that. AAA (West coast) did an AFFF system upgrade in phosphor bronze piping to connect all the stations on the hangar bay on the 'prise. They hired anyone who could spell brazing. Then they lit the system off to test the piping rather than use an air test.
    The results were as appalling as they were hilarious. A lot of the piping ran through senior officer's state rooms on the third deck and there's nothing like saltwater and AFFF to ruin your day!

    Thresher had issues with her seawater piping being right out of the yards but the issues weren't considered serious enough to keep trials from happening.

    USS Scorpion probably deserves another thread, she was commonly called USS Scrap iron because she had so many faults and issues.
    Most likely in her case was a Mk 37 torpedo, known to have issues, started running hot and they tried to jettison it but it detonated or caused a fire and much like the Kursk, Scorpion went to the bottom. At least, that's the most plausible explanation.

    Leave a comment:


  • Achtung Baby
    replied
    Originally posted by T. A. Gardner View Post

    Except, that Thresher was on trials and the USS Skylark, a submarine rescue ship was on the surface with her. The two were in communication using underwater telephone. The communications became garbled just before Thresher went down, so there's every indication of what likely happened. The follow on investigation was as thorough as it could be.
    Of course, but SOSUS evidence suggests a failure of an electrical bus for the coolant pumps. Which is why I guess the retired sub commander wants answers.

    USS Scorpion probably deserves another thread, she was commonly called USS Scrap iron because she had so many faults and issues.

    Leave a comment:


  • T. A. Gardner
    replied
    Originally posted by Achtung Baby View Post
    The theory that makes this story intriguing is that the seafloor sound surveillance system (SOSUS) detected sounds that suggested another reason to why she may have sunk, but SOSUS was highly classified, thus never talked about openly. But they did find that there were issues using emergency blow at her test depth, thus rectifying that problem for future subs.
    Except, that Thresher was on trials and the USS Skylark, a submarine rescue ship was on the surface with her. The two were in communication using underwater telephone. The communications became garbled just before Thresher went down, so there's every indication of what likely happened. The follow on investigation was as thorough as it could be.

    Leave a comment:

Latest Topics

Collapse

Working...
X