Argentine navy lost contact with sub [UPDATE: SUB FOUND]

[ACR]

Originally Posted by fitzcarraldo

The ARA San Juan had been called back to port after the commander informed of a complication with one of the batteries. "Entry of seawater by ventilation system to battery tank No. 3 caused a short circuit and the beginning of a fire in the balcony of battery bars, bow batteries out of service, at the time of immersion, propelling with a split circuit. I will keep staff informed," Pedro Martín Fernández informed in a message via radio frequency.
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.

do you have a source for this ? when you scroll up this thread it is close to what i assumed earlier but i,m wondering if this is some credible data . the only thing i see officially is the CTBTO at their homepage now speeks of an IMPLOSIVE not an explosive sound .

if that happened the only consolation for the families is the fact nobody suffered pain or a survival fight and the fact no rescue operation of this world could have saved them regardless how quick they would have found the boat.

also a very interesting question i have no clue of an answer : is an emergency blow loud enough to be detected by the microphones ? the question is if they ever tried to blow the ballast .

another thing to remember : the german shipyard can surely help with closely estimating the actual crush depth of a tr 1700 and should the first sound be indeed the crush of the hull and the second sound ( roughly 40 seconds later ) the wreckage hitting the bottom they can calculate the ocean depth where the sub is . now take the search area and look at depth charts which areas match the ocean depth . i,m sure such calculation are already made beyond media release.

of course still pure speculation and many open questions .

[Falkirion]

The information is freely available via the CTBTO, what investigators/sonar techs really need is the recordings of the events if any exist. Using those it would possibly lead to a better analysis than is currently available.
That said, if they find the boat any investigation results would probably be more accurate than what can be speculated only at this point and that's exactly what Rule is doing using incomplete data, which for me makes it hard to trust his opinion on the matter. I don't debate his credentials, I debate the accuracy of the information released.

[ACR]

the sound recorded is such low frequency over the huge discance that its beyond capabilities of the human ear so i guess any audio recordings have no use .

media claims russian rov,s are investigating two or three objects in about 3000ft waterdepth , further the russian spy/intelligence ship 'yantar' keeps on going from south africa to the search area with equipment on board capable to reach depths of 18000 feet ( at least russia claims it ) . i hope and believe they will find the sub .

does the usa still search for the sub ?

[ikalugin]

I thought that GUGI was on this case more or less from the begining?

[Gargamel]

From the SubSim Front page:

https://www.telesurtv.net/english/ne...0406-0018.html

Investigators told the Nacion newspaper that the fires most likely spread throughout the stricken submarine, forcing the crew to battle the blaze in ferocious weather conditions.

Did I miss something and they find the boat? It seems to me from this brief article they are closing the book on the investigation. Without more facts, I feel they are jumping to conclusions.

[HunterICX]

She's been found:

The wreckage of a submarine which went missing with 44 crew on board a year ago has been found, the Argentine navy says.

The ARA San Juan submarine disappeared 430km (270 miles) off the Argentine coast on 15 November 2017.

The navy stopped its rescue mission two weeks after the sub's disappearance.

However, a year and a day after it went missing, officials announced it had been found 800m (2,620ft) below the surface of the Atlantic Ocean.

https://www.bbc.com/news/world-latin-america-46245686

[Onkel Neal]

And https://www.bbc.com/news/world-latin-america-46245686

However, a year and a day after it went missing, officials announced it had been found 800m (2,620ft) below the surface of the Atlantic Ocean.

According to a tweet from the Argentine navy, the ARA San Juan had been positively identified under the water by a US company.

The navy had earlier shared a picture from the seabed, suggesting a 60m-long object might be the missing submarine.

[golfvictorwhiskey]

BBC says US company (salvage?) located 60m long object subsequently confirmed ARA San Juan.

Twitter image here:
https://twitter.com/Armada_Arg/statu...59859511115776

Debris field looks quite concentrated. Can anyone quote crush depth for this type?

What degree of recovery wil be possible is moot, but this will provide some closure and certainty for the families. RIP.
GVW

[Pirate]

Originally Posted by golfvictorwhiskey

Debris field looks quite concentrated. Can anyone quote crush depth for this type?

For a TR-1700, possibly between 300 and 400m.

[Jimbuna]

Hopefully a great many people will soon be able to find some form of closure.

[Catfish]

"The wreckage of the submarine which went missing with 44 crew on board a year ago has been found, the Argentine navy says."

https://www.bbc.com/news/world-latin-america-46245686

I did not find the original thread, nor with "ARA" nor with "San Juan", in the advanced search

[vienna]

http://www.subsim.com/radioroom/showthread.php?t=235528
















<O>

[Mr Quatro]

Subsim Front page news: http://www.subsim.com/radioroom/show...55#post2577655

Originally Posted by HunterICX

She's been found:

Quote:
The wreckage of a submarine which went missing with 44 crew on board a year ago has been found, the Argentine navy says.

The ARA San Juan submarine disappeared 430km (270 miles) off the Argentine coast on 15 November 2017.

The navy stopped its rescue mission two weeks after the sub's disappearance.

However, a year and a day after it went missing, officials announced it had been found 800m (2,620ft) below the surface of the Atlantic Ocean.
https://www.bbc.com/news/world-latin-america-46245686

__________________

[Cybermat47]

Originally Posted by Bleiente

This submarine was clearly torpedoed. A German submarine can withstand more pressure than depth, than the ridiculous Virgina class.

Armada Argentina is reporting that the boat imploded. Probably something to do with the battery malfunction - maybe other systems were affected?

[Jimbuna]

Threads merged.