Argentine Sub Missing

Hope came in the sign of 7 pings:

By Sunday, the pursuit to pinpoint the pings will be bolstered by the might of the U.S. Navy and Air Force, which are deploying more resources into the massive rescue mission already underway to locate the missing submarine, Pentagon officials told ABC News.

On Saturday, the Undersea Rescue Comand, or URC, shipped out two "independent rescue assets" from San Diego en route to the Southern Atlantic, where the Argentine Navy lost communications with one of its submarines. They are expected to arrive on Sunday, officials said.

The highly trained American sailors will employ advanced technology on the Submarine Rescue Chamber, or SRC, which has already been in touch with the family members of the 44 on board, and will utilize an underwater system called Remotely Operated Vehicle, or ROV. It can climb down to depths of 850-feet and pull to safety "up to six persons at a time," the Pentagon officials said.
See abcnews link

Source:
ABC News
 
Not looking good, a diesel/electric boat after this time missing? Even if it is intact and there are sections that remain water tight the air is unlikely to be breathable by now. Not good news.
 
Foo Fighter said:
Not looking good, a diesel/electric boat after this time missing? Even if it is intact and there are sections that remain water tight the air is unlikely to be breathable by now. Not good news.

They do have air purifiers, you realise?

A much greater danger is that of chlorine gas - when sea water comes in contact with lead-acid batteries it produces chlorine. A common problem with Dieso-Electric subs.

I've been following this story since last Thursday (my time). It does not look good. There is a lot of misinformation in Argentina about what is going on. The length of time is the problem. The longer it goes on, the less likely are the crew to be alive.
 
How does chlorine gas not affect air quality? What would be the power source for the pumps running air purifiers when power is out? If they still had power would they still be missing? I do realise.
 
TomcatViP said:
Hope came in the sign of 7 pings:

By Sunday, the pursuit to pinpoint the pings will be bolstered by the might of the U.S. Navy and Air Force, which are deploying more resources into the massive rescue mission already underway to locate the missing submarine, Pentagon officials told ABC News.

On Saturday, the Undersea Rescue Comand, or URC, shipped out two "independent rescue assets" from San Diego en route to the Southern Atlantic, where the Argentine Navy lost communications with one of its submarines. They are expected to arrive on Sunday, officials said.

The highly trained American sailors will employ advanced technology on the Submarine Rescue Chamber, or SRC, which has already been in touch with the family members of the 44 on board, and will utilize an underwater system called Remotely Operated Vehicle, or ROV. It can climb down to depths of 850-feet and pull to safety "up to six persons at a time," the Pentagon officials said.
See abcnews link

Source:
ABC News

A shame they retired the DSRV. ???
 
Kadija_Man said:
A much greater danger is that of chlorine gas - when sea water comes in contact with lead-acid batteries it produces chlorine. A common problem with Dieso-Electric subs.

Curious as to the batteries selected for San Juan's MLU; the US Navy began retrofitting valve-regulated lead acid
batteries back in 2006 which don't have the chlorine-gas-on-contact with-sea-water problem.

They still have the hydrogen-gas-on-overcharge-or-overheat problem.
 
sferrin said:
TomcatViP said:
Hope came in the sign of 7 pings:

By Sunday, the pursuit to pinpoint the pings will be bolstered by the might of the U.S. Navy and Air Force, which are deploying more resources into the massive rescue mission already underway to locate the missing submarine, Pentagon officials told ABC News.

On Saturday, the Undersea Rescue Comand, or URC, shipped out two "independent rescue assets" from San Diego en route to the Southern Atlantic, where the Argentine Navy lost communications with one of its submarines. They are expected to arrive on Sunday, officials said.

The highly trained American sailors will employ advanced technology on the Submarine Rescue Chamber, or SRC, which has already been in touch with the family members of the 44 on board, and will utilize an underwater system called Remotely Operated Vehicle, or ROV. It can climb down to depths of 850-feet and pull to safety "up to six persons at a time," the Pentagon officials said.
See abcnews link

Source:
ABC News

A shame they retired the DSRV. ???

The new SRDRS might actually be more flexible in important ways. For starters, it doesn't depend on a submarine carrier platform (as DSRV did after Pigeon and Ortolan retired). It can be bolted onto a range of vessels of convenience -- basically any large offshore oil rig support vessel should do. The PRM element can dock with an incident sub at more extreme angles than the DSRV (up to 60 degrees versus 40 degrees).

The downside is that the miserable weather happening down there right now might make a recovery difficult, assuming they find the sub at all.
 
Foo Fighter said:
How does chlorine gas not affect air quality? What would be the power source for the pumps running air purifiers when power is out? If they still had power would they still be missing? I do realise.

It kills quicker than "poor air quality" (ie greater concentrations of CO^2). They use air purifying candles to clean the air and generate oxygen in emergencies.
 
My point is that air stuffed with chlorine gas is of poor quality.
 
Very sadly the 7 pings proved to be a false alarm. They are still trying to localize the sub.

On the BBC

Although SRC and ROV have been airlifted already

Two C-17 Globemaster IIIs and a C-5M Super Galaxy were dispatched to Argentina on Saturday, bringing with them two underwater rescue systems to aid in the search for A.R.A. San Juan, an Argentine navy submarine that went missing in the South Atlantic Ocean on Nov. 15.

The three aircraft were scheduled to arrive Sunday in Comodoro Rivadavia, Argentina, according to Air Mobility Command.

The aircraft first stopped at Marine Corps Air Station Miramar, California, to pick up a Submarine Rescue Chamber (SRC) and an underwater Remotely Operated Vehicle (ROV), according to the statement from AMC.

DefenseNews
 
Weather conditions in the general search area are making things tough.

https://www.youtube.com/watch?v=-jfOS596ldU
 
Also, the reports of banging noises that were initially attributed to the sub's crew are now being described as likely biological sounds.

https://www.theguardian.com/world/2017/nov/20/missing-argentina-submarine-running-out-of-air-as-search-enters-critical-phase

Sadly, as we approach one week after the initial mishap, the chances of a successful recovery look pretty slim.
 
Developments . . .

http://www.dailymail.co.uk/news/article-5106689/Missing-Argentine-submarine-located-Navy.html?ITO=1490&ns_mchannel=rss&ns_campaign=1490


cheers,
Robin.
 
I thought an implosion was more likely than an explosion and sadly it seems I was 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 completely and the sub sank. It 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/nov/27/argentinas-missing-submarine-water-caused-battery-to-short-circuit
 
We could be looking at a hydrogen explosion in the battery compartment. Just because they thought the fire was out doesn't mean it couldn't reflash.
 
An edited report I received from a US Sub Forum.

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.
 
Sure, it'd give them a more detailed picture of what went wrong.
 
At that depth, with the hull a mess, recovery would be very complex and expensive. Argentina would need someone to take the project pro bono, or at least to take a big chunk out of the cost, for it to happen. If a country wealthy enough and with enough technical skill wanted to improve their relations with Argentina that much, and wanted to use it as an excuse for training plus R&D, it could happen. But I'm pretty skeptical.
 
Moose said:
At that depth, with the hull a mess, recovery would be very complex and expensive. Argentina would need someone to take the project pro bono, or at least to take a big chunk out of the cost, for it to happen. If a country wealthy enough and with enough technical skill wanted to improve their relations with Argentina that much, and wanted to use it as an excuse for training plus R&D, it could happen. But I'm pretty skeptical.

Hello. As Argentinian I've say a lot of people would like the rescue the sub but right now but my country is in serious economic problems. Mainly because of the fiscal deficit.
I've a lot of respect for the pain of families but with an 30% of poor population isn't very wise to expend a lot of money on that operation.
 
Hobbes said:
Sure, it'd give them a more detailed picture of what went wrong.

Not guaranteed. The wreck is described as catastrophically broken up with wreckage broadly dispersed/crushed.
 
Agreed, there are no guarantees, but it never ceases to amaze me how much information professionals can get from a mangled wreck.
 
Scared me for a moment, I thought this was another Argentine sub lost, not a fresh post on the ARA San Juan.

Part of what happened once the snorkel mast leak was reported to HQ was the captain submerging to 40m or so to work on the batteries. Modern submarines roll like a drunken pig on the surface, the cylindrical hull does not do anything to stop roll angles.

Being deep would minimize rolls and allow the crew to work in the battery well a lot safer. Thing is, lead acid batteries make up about 1/4 the weight of a sub like the San Juan. Because the batteries are so heavy, they're put in the bottom of the hull. Unfortunately, water leaking from anywhere in that compartment would also go towards the battery well.

Seawater plus batteries equals chlorine gas, hydrogen gas, and oxygen. And usually comes with a side order of sparks, to provide an ignition source. minor boom that disables the crew and controls. Then the sub takes on water until she implodes.
 

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