Apparently two (unidentified) ships in the search area have now picked up sonar signals that could be the sound of tools banged on the hull.

Looking at charts of the search area, depth is 100-200m so a lot shallower than the likely crush-depth of the hull.

Not impossibly deep for technical divers, but would likely require a ROV rescue. The USN have two in the area.

No mention of the batteries, could they could last for 2 weeks on the bottom.

Isn't the limitation CO2 scrubbing rather than O2 levels?

I well remember that was the problem when the two Rogers were stuck in the putty on the seabed of the Irish Sea back in the 1970s. To this day Roger Chapman doesn't like to sit down, even at business meetings. He prefers to stand up. If you've seen the inside dimensions of that sub you'll understand why!

Edited to add:
Wasn't that also the most pressing limitation on the Apollo 13 recovery too? That and the unholy cold of course.

Hello all,

We are very worried here and, in the other hand, we are very grateful for so much help Argentina received in such short time.

More or less, the submarine has a week of oxygen (including spare oxygen, oxygen candles and so on). ARA San Juan is probably the best unit of the Argentine Navy. The submarine was accepted in 2014, after a big refit.

Personally, I have big faith in some sonar contact from two surface units. Nothing official about it, but I want (or I need) to believe.

Regards to all,

True definition of madness, jump out of perfectly serviceable aircraft, land in water and then try to effect a submarine rescue. Seriously though best of luck chaps and stay safe.

Let's hope this has a successful outcome.

I can't think of anything worse than sitting on the sea bed in a cold steel hull, hoping and praying to be rescued.

I think politicians of countries that lose subs should immediately put into a cold metal can with no air until they approve the mobilization of anyone with the abilities to perform the rescue. Waiting for political reasons just turns out really bad later on.

I think some crew could have been rescued from the Kursk if feet hadn't been dragged.

A friend of mine was the dive master on the Kursk recovery he told me 2 things 1 they would have saved many if they had been mobilised earlier and 2 they never got paid.

NASA NP-3D joins in
 

Think this is one of the Wallops Island a/c joining in the search.

https://arstechnica.co.uk/informatio...tine-navy-sub/

Actually the fundamental problem on Apollo 13 was lack of (electrical) power. Everything else was a direct or indirect result of the fact that Apollo 13 had lost the ability to generate electricity and had to rely on the LEM batteries. Even the CO2 problem was because the Command Module had lost electrical power (aside from the batteries which they need to save for re-entry), and the lithium hydroxide canisters from the Command Module didn't fit the LEM (requiring the Rube Goldberg setup to use square canisters in a system designed for round ones).
It wouldn't surprise me if this sub is faced with the same problem - they can survive until the battery's give out.
Here's hoping they can be rescued before then.

Beeb this morning:-

Argentina's navy says its ARA San Juan submarine, which has been missing since Wednesday, reported a mechanical breakdown in its last communication.

"The vessel surfaced and it reported a breakdown," naval commander Gabriel Galeazzi said.

Argentina's navy said a "noise" picked up by sonar on Monday during the search did not come from the vessel. It is the second false alarm in the hunt for the submarine.

Capt Galeazzi, who heads the naval base in Mar del Plata, south of Buenos Aires, said that the fault reported earlier related to a "short circuit" in the sub's batteries.
The brother of a crew member earlier told local media that in a message before communications were lost his sibling had mentioned that the vessel was having problems with its batteries. This is the first time that an official has mentioned the sub encountering mechanical problems. However Capt Galeazzi said that mechanical problems were not uncommon and rarely posed a risk."A warship has a lot of backup systems, to allow it to move from one to another when there is a breakdown," he said.

The naval commander said that the submarine had been asked to cut short its mission, which was originally due to last until Monday, and go directly to Mar del Plata.
According to local media, the captain of the ARA San Juan contacted the naval base again after reporting the mechanical problem. In the message, he reportedly said the sub was heading towards Mar del Plata with all 44 crew members in perfect health.

Signals not from sub

The navy also announced on Monday that seven signals picked up at the weekend were not from the missing submarine's satellite phone.
The failed calls, lasting between four and 36 seconds, had been received on Saturday. They had raised hopes that the crew members were alive.

A huge search and rescue operation is continuing in the South Atlantic.

Specialist underwater rescue equipment has arrived in Argentina from the United States and more boats and planes have also joined the search, which has been hampered by heavy winds and high waves.

Kudos to your mate for having an amazing profession, but in this instance he is spinning a yarn, or just misinformed. Only 23 (out of a crew of 118) survived the initial explosion, and most Western sources believe only for few hours. This is all well-documented now.

If that short circuit became a genuine Battery fire...with the resulting problems of heat, smoke, and poisonous gases....driving the crew topside....in those seas and temperatures?

If it was/is on the surface...why is it so hard to find?

If it had a battery issue....why would it submerge having been on the surface and reporting the problem?

Lots of questions....hopefully the crew can be found safe....but each hour lessens the chances of that happening.

The nautical term for this is: sink.

It's not usually intentional, y'know.

Rough weather, battery problems, hatches open to vent sub? We might never know, my hat goes off to people in these situations, you would think in this day an age they would have proper diving gear for each crew member on subs.

Dunno about the sub in question, but RN subs provide an escape suit for every crewman.

I understand that, but they were a straight up to the surface job by, surely a full sub Aqua set up would allow greater freedom of escape.

The Argentine Navy bought new escape suits for all its boats a couple of years ago.

Still praying for good news. Or confirmation of some rumours.

Besides that, is really comforting people for all over the world is helping in the search or, at least, giving best wishes and praying. Thanks, really.

Regards,

What would you do with it that you couldn't with an escape suit? Pop up to the surface, have a quick look round to see if you can spot any ships, and then swim back down to give everyone a status update? Unless you're next to the beach, hard to envisage a scenario where you'd leave the submarine without knowing there was someone on the surface to pick you up.

Although (some) submarines do have the capability to deploy and recover divers at depth, the systems required to do so are a lot more complex than a basic escape trunk.

Best hopes and wishes for a successful outcome....

I think it's great that you Brits support them. Classy. Thumbs up!