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reytuerto
Post subject: About the explossion of the ssk San Juan.Posted: November 24th, 2017, 5:59 am
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Good morning:

I have some doubts about this sad accidente, and I would be very pleased if you can give me some light in the matter.
1. The explosion could be an ignition of hidrogen from a spoiled battery?
2. An explosion in the torpedo section could ignite the torpedo warheads?
3. A diesel electric submarine could navigete in the surface in a stormy weather (sea state 5 o 6)?
4. Which thing is more risky: a surface navigation in a severe gale or a submerged navigation with electric problems?
Thanks a lot, and cheers.

PS: Edited this sunday. Awfully misspelled words.


Last edited by reytuerto on November 26th, 2017, 4:46 pm, edited 1 time in total.

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odysseus1980
Post subject: Re: About the explossion of the ssk San Juan.Posted: November 24th, 2017, 6:46 am
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1. Possible, if spark occurs. Hydrogen is very flammable and explosive.
2. Not sure, but if the torpedoes are not maintained properly warhead might ignite.
3. In theory yes, but with much rolling and pitching. A modern submarine is designed for underwater and its surface seakeeping capabilites are limited.
4. Second, because electric faults in submerged navigation are dangerous.


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heuhen
Post subject: Re: About the explossion of the ssk San Juan.Posted: November 24th, 2017, 3:01 pm
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Here's the long version ;)


There are many circumstances around this.

What we know:
1. She was cut in two, when they replaced Diesel engine/generator and batteries. After the engine refit, she was welded together again.
- A weld on a submarine hull have to be 100% perfect. Are there a minor defect in an weld, you can get problems.

2. Electric short circuit on some of her batteries.
- She have two main banks of batteries, so if one goes, should be a big problem.
- could the electric problem she experienced also caused problems with some off here pumps, eventually freeze over. (something that was put up as an alternative theory of USS Thresher, when it sunk and imploded)
- Gas from batteries that have experienced problems, and not been vented out probably (because a bad sensor for example). build up of that gas in a room full of batteries with problems...
- Can the short circuit made other type of damage?

3. Reports of mechanical problems.
- are an mechanical problems a pump, how would an short on the batteries affect pumps that are already worn out.

4. Crew members talk about that there is problem with the submarine, long before the accident.
- what are those problems? bad valves, old torpedoes, maintenance problems

5. The Submarine is 32+ years old.
- past it's hull life, without proper maintenance you can get problems.

"when Norway did a reift on there Ula class between 2012-2017, they used over 50 million dollar. in two batches. among the refit for the 4 last submarine that have to be operational until new 212CD class are build, was total removal of the outer hull, basicly a total stripdown of the submarine, just to get access to the pressure hull. then the entire pressure hull was scanned tested and re-welded in many location, including replacement of several valves. they was also striped back to original state internally, and rebuild internally. All this to get 10+ year out of them, until new submarine are operational"

6. The Argentinian military is quit underfunded and struggle with keeping equipment maintained.
- not so long ago, a Argentinian Navy vessel sunk at dock, and the military used 2 years to get it up.
- Refit of the submarine was slowed down due to not enough funding for the refit.


There are so many circumstances, that when they find here and start the investigation. They will most likely find many things that contributed to the event ARA San Juan have been trough.

My short list would be:
- defect batteries, temporary fixed before they dived again.
- hydrogen build up in battery hold
- spark on hydrogen batteries
- sever damage to either aft or front pressure hull
- if front, torpedoes with low maintenance... unstable
- no electricity to operate valves
- valves perhaps frozen or stuck, lock by an electric locking mechanism (mechanical problems)
- Can't emergency blow
- no power or not enough power for propulsion.
- sink to a new crush depth, due to bad maintenance. (the crush depth would not be around 800-900 meter but less, due to not good enough maintenance (crush dept: German built submarine have often there crush depth of the double of there test dive depth)) (not a submarine that are deeper than a certain point, and have no power. a emergency blow of the ballast, would not be enough to help the submarine up, due to the pressure on the hull from before)


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Hood
Post subject: Re: About the explossion of the ssk San Juan.Posted: November 24th, 2017, 4:04 pm
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According to a report I've read in the Guardian the Comprehensive Nuclear Test-Ban Treaty Organisation are being guarded whether the sound picked up was an explosion.

It was noted the area is near the edge of the Continental Shelf where the depth goes from 200 metres to around 1,000 metres and further out as far deep as 5,000 metres. So its not impossible had their been a problem with the diving planes or trim control that the submarine has descended beyond its structural limits and suffered an implosion.

An implosion is perhaps more likely than an explosion, poor maintenance aside there are very few conventional submarines (any?) that have suffered catastrophic battery failure involving explosions.

https://www.theguardian.com/world/2017/ ... y-confirms

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reytuerto
Post subject: Re: About the explossion of the ssk San Juan.Posted: November 24th, 2017, 5:03 pm
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Thanks for your answers, guys!


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Hood
Post subject: Re: About the explossion of the ssk San Juan.Posted: November 28th, 2017, 1:01 pm
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It seems that my implosion hypothesis was sadly not so wrong after all.
The Argentine Navy is now admitting that the snorkel was leaking, which caused the battery to short-circuit. It seems they switched to the unaffected battery and carried on. Presumably at some point the snorkel must have failed and the sub sank. Its possible some may have survived if they had time to seal off compartments but the volume of water would have quickly overwhelmed the crew.

https://www.theguardian.com/world/2017/ ... rt-circuit

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heuhen
Post subject: Re: About the explossion of the ssk San Juan.Posted: November 28th, 2017, 2:55 pm
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Hood wrote: *
It seems that my implosion hypothesis was sadly not so wrong after all.
The Argentine Navy is now admitting that the snorkel was leaking, which caused the battery to short-circuit. It seems they switched to the unaffected battery and carried on. Presumably at some point the snorkel must have failed and the sub sank. Its possible some may have survived if they had time to seal off compartments but the volume of water would have quickly overwhelmed the crew.

https://www.theguardian.com/world/2017/ ... rt-circuit
Some newsagents report that the short-circuit caused a fire. that most likely was fixed. The implosion thesis I had for a while, is due to the location and that it go from just deep to holy shit it's deep, very fast. that they are using long time to find here, specially when they are using modern submarine hunter equipment and many other vessel, so if she was intact, and as old as she was and large, they would have found here within days, but since they have not.. they are most likely looking for something that are flat and twisted


one of the earlier news-text around this accident, said that after they had fixed the problem, they dived again. (quit often a submarine dive to 50 meters when traveling between places) I can understand why they dived again, the weather wasn't good at the time, and a submarine are better underwater than on surface.

But after an accident with batteries and a possible fire... I would not dive at all, you have already had problems, then you decide to dive again, eh. I find it also weird that they didn't go for the nearest port.


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Hood
Post subject: Re: About the explossion of the ssk San Juan.Posted: November 28th, 2017, 4:18 pm
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The thing is find puzzling is why the Argentine Navy is being so slow to reveal information it must have had days ago.

If the snorkel was defective or leaky, enough to affect the battery compartments, then as you say why would you dive again knowing the battery hazards (smoke, impurities in the air), let alone also knowing the snorkel is defective. Regardless of weather (its always bad weather done there) those are big risks to take.

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reytuerto
Post subject: Re: About the explossion of the ssk San Juan.Posted: November 30th, 2017, 7:14 pm
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An INTL SUBMARINERS GROUP... #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.


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