Argentinian Submarine Lost? News?

[emoreira]

Here from Argentina.
The submarine ARA San Juan was reported missing after 2 days without communication to the home base in Mar del Plata where she was heading. That was Nov 17th. The last report from the sub captain said that they were having problems with the batteries, however they could isolate the problem and could go on but at a reduced speed of 5 knots.
Three hours after that, a submerged explosion was captured by the hydrophones from the CTBTO (Comprehensive Test-Ban-Treaty Organization) triangled from 2 stations ( Ascension island and Crozet island) to a position 30 miles from the position where the sub did the last communication. The position is aproximate as it was detected by hydrophones located many many miles away.
The sub was going from Usuahia to Mar del Plata. The route goes by the limit of the national submerged platform which goes up to the abyssal slope. The search zone goes from 200 meters depth to up to 1000 meters depth and more.
This sub was rated to 250 meters as max operating depth. No official data was released concerning crush depth, but all estimations say that 600 meters should be the crush depth.
Up to now, the remains of the sub has not been found.
Sea and weather conditions in the search zone are way more than "bad" with wave heights of 6 meters and winds near 100 km/hour. Those bad conditions have been seen all this week and the past week.
If the hull was crushed under pressure, oil and diesel stains should have been visible in the sea surface, but considering the sea condition, it's like a drop of oil in a blender tumbler full of water at maximum speed. After 12 days of the explosion, there is no hope to find them alive, in spite that the US search team requested for life jackets and warm clothes. It was more a gesture than a need.
I, as Argentine citizen, am very grateful for the help received from many countries. I understand that this is a very good opportunity for every one to test the search and rescue gear that every Navy should have. I hope that the sub remains could be found for the peace of mind of all the families.
I guess that raising the sub remains from the depths is something that is far from possible. Besides, as this is a conventional diesel electric sub, there is very little risk of long term contamination, a different situation of what happened with the Kusks, sunk in less that 100 meters depth with a nuclear engine and nukes inside.

 

[emoreira]

ARA San Juan was the only operational sub of the Argentine Navy. The other two ARA San Luis and ARA Santa Cruz are not operational.
ARA San Juan was refurbished (half life repair) and returned to operational service in 2014. The repair lasted almost 7 years. This mission was not the first, and the problem she had was also not the first.
ARA Santa Cruz is twin of the ARA San Juan, while ARA San Luis is way older. Both are under repairs. Endless repairs.
ARA San Juan was cut in halves, new diesel engines, new electric motors, new piping, hydraulic systems, electrical systems. Batteries were refurbished, not replaced.
A lot of complains are now appearing in the press, corruption, over-prices and works not done but paid. Repair was done in the state owned shipyard TANDANOR, again with a sad history of corruption and over-prices.

 

[Lorenzoid]

Thank you for the perspectives, Eduardo. Very sad.

 

[Schwob]

Argentina missing sub: Water entered snorkel causing short circuit -

Water led to missing sub's battery failure

 

[Akimbo]

Argentina missing sub: Water entered snorkel causing short circuit -

Water led to missing sub's battery failure

Good link. Depressing but informative. Assuming the implosion hypothesis is correct, at least it is a merciful way to die.

Some members on my dive team in the navy worked on a project to study how subs implode. They took two WWII era diesel boats and sank them, unmanned of course. They sent a submersible down (I can't remember if it was the Alvin, Sea Cliff, or Turtle) to study the debris fields. I never saw the images but was told that both hulls failed like a steam piston -- meaning that the catastrophic failure point in the hull caused the atmosphere to instantly turn to steam and the all internal pressure bulkheads acted like pistons and crammed everything to the end(s) within milliseconds.

If I remember correctly, one boat failed amidships and drove bulkheads fore and aft while and the second failed at the stern and smashed everything into the forward torpedo room. I understand that the submersible could fly into one of them like a big empty pipe.

 

[Bubblesong]

It is sad for their families, but better to know they didn’t suffer.

 

[Bob DBF]

ARA San Juan was cut in halves, new diesel engines, new electric motors, new piping, hydraulic systems, electrical systems. Batteries were refurbished, not replaced.

This is standard operating procedure for submarines. The major maintenance is impossible to do when in service because all tools and equipment would have to fit through a 30" hatch. I never rode or served on any submarine that didn't have this happen to them at least once. My qual boat had a big hole in the pressure hull to replace equipment when I reported aboard.

I did read one article that the engines and batteries were replaced. As far as refurbished, the battery components can be disassembled and replaced as necessary, so it depends on what they actually did, but one properly refurbished is as good as new.

A lot of complains are now appearing in the press, corruption, over-prices and works not done but paid. Repair was done in the state owned shipyard TANDANOR, again with a sad history of corruption and over-prices.

Having served on submarines, I'm with the "string 'em up" crowd if substandard work was done.

I don't know how its done in Argentina, but in the US all the shops that work on the boats have to send a representative out on sea trials. It was to take notes on any issues found, but we just refered to them as hostages.



Bob

 

[scubafanatic]

Argentina missing sub: Water entered snorkel causing short circuit -

Water led to missing sub's battery failure

Is it a good idea to keep operating/diving the sub with a known hull water penetration ?

 

[DavBuc]

Is it a good idea to keep operating/diving the sub with a known hull water penetration ?

Apparently not.

 

[Bob DBF]

Is it a good idea to keep operating/diving the sub with a known hull water penetration ?

The issue is that there were gale force winds and large seas causing water to enter the snorkel so the diesels could not be used as well as water causing electrical problems while on the surface. The best way to deal with that hull penetration is to shut down and house the snorkel and quit trying to use it.

Submarines are miserable on the surface in bad weather so normally they are submerged to avoid the surface action of the storm and proceed underwater. At the time the skipper figured that was the best course of action. When a submarine is being dived all watchstations have to check and report that they are ready to dive. I would say under the adverse conditions, both casualty and sea state, by this time was an all hands evolution and highly unlikely that a mistake was made during the dive.

If the battery/electrical casualty became worse than they anticipated as they were operating submerged, there are a number of ways to get to a bad outcome, including getting to the surface and not being able to remain there.


USS COCHINO (SS-345) and USS TUSK (SS-426)
The Cochino made it to the surface after a battery explosion and fire, all hands were out on the deck because of fire and chlorine gas. Luckily it was in contact with the USS Tusk which rescued all but one from the Cochino and lost six of there own.

Read the first few paragraphs and it may give a look into how things can go wrong.



Bob