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Argentinean Submarine down - USN rescue team mobilised

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Argentinean Submarine down - USN rescue team mobilised

Old 3rd Dec 2017, 08:08
  #201 (permalink)  
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TrimStab - the seismologists who look at this stuff are the worlds greatest experts on detecting & classifying explosions - they have 60 years of experince of N-test, conventional explosions, earthquakes, landslides

from the article:_
ANALYSIS OF ACOUSTIC DETECTION OF THE LOSS OF THE ARGENTINE SUBMARINE SAN JUAN
By Bruce Rule

An analytical review of all information released by the Comprehensive Nuclear-Test-Ban Treaty Organization on the acoustic signal associated with the loss of the Argentina Submarine ARA SAN JUAN confirms the following:

That acoustic signal originated near 46-10S, 59-42W at 1358Z (GMT) on 15 November 2017. It was produced by the collapse (implosion) of the ARA SAN JUAN pressure-hull at a depth of 1275-feet. Sea pressure at the collapse depth was 570 PSI. The frequency of the collapse event signal (bubble-pulse) was about 4.4 Hz.

The energy released by the collapse was equal to the explosion of 12,500 pounds of TNT at the depth of 1275-feet. That energy was produced by the nearly instantaneous conversion of potential energy (sea-pressure) to kinetic energy, the motion of the intruding water-ram which entered the SAN JUAN pressure-hull at a speed of about 1800 mph.

The entire pressure-hull was completely destroyed (fragmented/compacted) in about 40 milliseconds (0.040s or 1/25th of a second), the duration of the compression phase of the collapse event which is half the minimum time required for cognitive recognition of an event.

Although the crew may have known collapse was imminent, they never knew it was occurring. They did not drown or experience pain. Death was instantaneous.
The SAN JUAN wreckage sank vertically at an estimated speed between 10 and 13 knots. Bottom impact would not have produced an acoustic event detectable at long range.

The open question is: why was no corrective action - such as blowing ballast - taken by the SAN JUAN crew before the submarine sank to collapse depth? According to Argentine Navy spokesman Gabriel Galeazzi, the Commanding Officer of the SAN JUAN reported a "failure" in the submarine's "battery system," The time of that report was 0730 on 15 November, assumed to have been GMT. Subsequently, the problem was reported to have been "fixed." The SAN JUAN intended to submerged and continued its transit north. The SAN JUAN pressure-hull collapsed at 1358 GMT on 15 November.

In the case of the loss of the US nuclear submarine SCORPION (SSN 589), hydrogen out-gassed by the main battery exploded at 18:20:44 GMT on 22 May 1968 incapacitating/killing the crew with an atmospheric over-pressure in the battery well estimated to have been 7-10 times the fatal value. The pressure-hull was not breached. This assessment was based on analysis of acoustic detections of the event and damage observed in pieces of the fragmented battery recovered from the wreckage at a depth of 11,100 feet by the US submersible TRIESTE, e.g., microscopic, spectrographic and x-ray diffraction analyses. (There was no flooding of the pressure-hull before the battery exploded.) SCORPION lost power and sank slowly over nearly 22 minutes to collapse at a depth of 1530-feet at 18:42:34 GMT on 22 May 1968. There is the possibility that a similar sequence of events occurred aboard the SAN JUAN. If the wreck is located and efforts are made to recover components, emphasis should be placed on the battery system.

The author of this assessment was the lead acoustic analyst at the US Office of Naval Intelligence for 42 years, analyzed acoustic detectors of the loss of the USS THRESHER (SSN 593) on 10 April 1963 and testified before that Court of Inquiry. The author expresses his appreciation to those who supported this assessment with research and calculations.
Initial reports from the Argentine Navy indicate that they had a problem with their snorkle which allowed water to enter the hull and shorted out the forward battery. What transpired after that to cause the sub to sink is only speculation at this time. As the author of this report indicates, it's not beyond the realm of possibility that the forward battery exploded. A similarly accident occurred on the USS Bonefish (SS-582) in April of 1988. She was able to surface, and the captain ordered the ship evacuated. Incidentally, the CO, CDR Mike Wilson was my Executive Officer at Trident Training Facility Kings Bay following this incident.
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Old 3rd Dec 2017, 12:59
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I still can't find an authoritative published source for that article - it is in the same style as Bruce Rule's other articles on the IUSS link I posted earlier (e.g. IUSSCAA Message Board) but I can't find a first instance of the exact txt.

Some of it (e.g. the implosion/cognitive recognition time) appears in other posts on that site.
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Old 3rd Dec 2017, 13:37
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Heathrow Harry
Initial reports from the Argentine Navy indicate that they had a problem with their snorkle which allowed water to enter the hull and shorted out the forward battery. What transpired after that to cause the sub to sink is only speculation at this time. As the author of this report indicates, it's not beyond the realm of possibility that the forward battery exploded.

That acoustic signal originated near 46-10S, 59-42W at 1358Z (GMT) on 15 November 2017. It was produced by the collapse (implosion) of the ARA SAN JUAN pressure-hull at a depth of 1275-feet. Sea pressure at the collapse depth was 570 PSI. The frequency of the collapse event signal (bubble-pulse) was about 4.4 Hz.

The energy released by the collapse was equal to the explosion of 12,500 pounds of TNT at the depth of 1275-feet. That energy was produced by the nearly instantaneous conversion of potential energy (sea-pressure) to kinetic energy, the motion of the intruding water-ram which entered the SAN JUAN pressure-hull at a speed of about 1800 mph.

The entire pressure-hull was completely destroyed (fragmented/compacted) in about 40 milliseconds (0.040s or 1/25th of a second), the duration of the compression phase of the collapse event which is half the minimum time required for cognitive recognition of an event.

What I don't understand is, if the boat took on water through the snorkel which led to a battery short then a possible explosion in the forward battery bay, why would it implode ?

A cylinder filling with water from an explosion is then not going to implode with the force being described in the article, and if filled with sufficient water to over come the blast tanks and sink then the amount of water involved would surely cause the inside hull pressure to start equalising near to the outside pressure.

An explosion in the forward battery bay opening up the hull and sinking rapidly to the bottom would make more sense.
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Old 3rd Dec 2017, 13:40
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Originally Posted by Trim Stab View Post
I don't deny that the submarine probably imploded, all I am saying is that I doubt that the quoted narrative has much academic credibility. Here is an academic paper on the mechanics of an imploding cylinder which may give you some insight.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3857872/
Bulkheads.
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Old 3rd Dec 2017, 15:22
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Originally Posted by Above The Clouds View Post
What I don't understand is, if the boat took on water through the snorkel which led to a battery short then a possible explosion in the forward battery bay, why would it implode ?
It wouldn't, directly. However it seems plausible that a battery short could, via any number of means, lead to loss of control of the ship. If this loss of control allowed it to sink below the hull's crush depth, it could then implode.
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Old 3rd Dec 2017, 15:46
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It was produced by the collapse (implosion) of the ARA SAN JUAN pressure-hull at a depth of 1275-feet.
Is that a determined fact....or an assumption based upon the Design Crush Depth for the Boat?

I am still trying to absorb the fact that something serious enough...and sudden enough to prevent the Crew from blowing all tanks using compressed air....and thus take the Boat to the surface....no matter how rough the seas and uncomfortable the ride would be....just what could it have been?

My first guess would be a Hydrogen Gas explosion.

Some of you scoff at surfacing being a valid option.....I very much differ.

If you get enough seawater into a battery compartment to short out the batteries....you would have to fear that it could get into contact with the Battery Acid and that would produce both Hydrogen and Toxic Gases.

Ventilating the Boat becomes the primary preventative measure and that could only be done on the surface.
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Old 3rd Dec 2017, 23:43
  #207 (permalink)  
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I believe that the statement that the hull imploded at 1275 feet is based on the experience of the writer and the fact that the writer has studied the sound recording and compared it to others rather than just quoting a mathematical conclusion.
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Old 4th Dec 2017, 05:39
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The logical explanation would be that he compared the known intensity of sound with energy needed and calculated the known displacement of the submarine in the equations.

Speed of the final event made me think that instant death was the result in milliseconds however I can’t stop thinking of the sounds which is produced by the hull as it goes over the construction limits. I studied quite some portion of books about submarines and final moments make me sleepless at times. The percentage of losses of the U-boot crews was horrifying and the number of all-hands fatalities in most of the cases popped up in my memory when I heard about this recent tragedy. If they lost control they knew what was coming. That thought is painful and even more for the families. Godspeed.
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Old 21st Dec 2017, 14:54
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Angel 100+ years on - HMAS AE1 located

First World War submarine lost with 35 British and Allied crew on board is finally found - ending 103-year mystery

PZU - Out of Africa (Retired)
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Old 24th Dec 2017, 22:09
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New contact detected in search for missing Argentine submarine in South Atlantic | Fox News

Fingers crossed.
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Old 25th Dec 2017, 08:27
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An awful Christmas for their famillies.

Hope they get closure soon
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Old 25th Dec 2017, 13:43
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Originally Posted by Pali View Post
The logical explanation would be that he compared the known intensity of sound with energy needed and calculated the known displacement of the submarine in the equations.

Speed of the final event made me think that instant death was the result in milliseconds however I can’t stop thinking of the sounds which is produced by the hull as it goes over the construction limits. I studied quite some portion of books about submarines and final moments make me sleepless at times. The percentage of losses of the U-boot crews was horrifying and the number of all-hands fatalities in most of the cases popped up in my memory when I heard about this recent tragedy. If they lost control they knew what was coming. That thought is painful and even more for the families. Godspeed.
Would agree that the sonic event suggests that the final collapse of any watertight compartments was almost instantaneous, and the german engineers who designed the pressure capsule would also have sought to make collapse depth structurally conformal, so the final moment would have been near instantaneous. But the final moments once buoyancy control was lost must have been terrifying. Am thinking of the families this Christmas.
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Old 25th Dec 2017, 16:42
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I am also thinking about the families this Christmas. It looks like the primary focus with the ongoing search is still close to the shelf.
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Old 26th Dec 2017, 11:45
  #214 (permalink)  
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West Coast, I am appalled by the comments in that Fox link. Clearly they have no idea of the comradeship that exists between Servicemen of all nations that share similar ethos even if on opposing sides.
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Old 26th Dec 2017, 21:47
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PN,

I just read the linked Fox Article.....exactly what is it you find problematic?

It seemed awfully bland and a mere recitation of facts as known.

As I am a bit sensitive to Sub losses...I knew one of the crew aboard the USS Thresher....Jimmy Musselwhite.....I did not find that article offensive in any way.

Jimmy was older than me but had family in my hometown and I got to know him during his visits there. His family was devastated when the Thresher was lost with him aboard.



James Alton Musselwhite
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Old 27th Dec 2017, 00:19
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Originally Posted by SASless View Post
PN,

I just read the linked Fox Article.....exactly what is it you find problematic?
SASless, I suspect PN is referring to some of the cretinous individuals who posted 'comments' in the conversation section below the article, not the article itself...

-RP
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Old 27th Dec 2017, 00:45
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I did not bother to look at the Comments....and generally do not for any article no matter the source.

There are plenty of stupid people with access to the internet and thus able to make stupid assed comments.
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Old 27th Dec 2017, 04:27
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Originally Posted by SASless View Post
There are plenty of stupid people with access to the internet and thus able to make stupid assed comments.
I couldn't agree more, PN's reference to the comments on West Coast's linked FOX News article are a case in point!

-RP
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Old 27th Dec 2017, 08:38
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RP, correct, thank you. It is often instructive to read what Joe Public make of articles which have a totally different meaning to the brotherhood.
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Old 2nd Jan 2018, 08:03
  #220 (permalink)  
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US Navy ends search for missing Argentine sub

WASHINGTON — The U.S. Navy is wrapping up its search for a missing Argentine submarine that disappeared in November with 44 crew aboard, according to a release from U.S. Southern Command.

At the height of its efforts, the U.S. had more than 200 personnel assigned to the mission, including P-8 Poseidon aircraft, four submersibles, an underwater rescue unit and various equipment. The U.S. Navy dropped more than 400 sonobuoys during the effort to locate the submarine San Juan. SOUTHCOM did a complete sweep of its assigned areas twice and were unable to locate the sub, the release said.

“On behalf of the people of the United States, we offer our respects to the families of the crew of ARA San Juan and the people of Argentina,” said Rear Adm. Daniel B. Abel, director of operations for SOUTHCOM.

The two assets, the Research Vessel Atlantis and a cable-controlled Undersea Recovery Vehicle are being recalled, said SOUTHCOM spokesman Cmdr. Erik Reynolds.........
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