Argentine navy loses contact with submarine

That's very unfortunate. I'll confess to not knowing the Argentinians had a submarine force prior to this incident. I guess it makes sense given the "got to fight the British" thing.
 
Red Flag 1 said:
The take water in via the snorkel. The battery shorts. The travel home submerged. Then Boom.

Why did they not surface and run on diesel power back to base? It just seems screwy to me to stay submerged and still run on the batteries. Seems smarter to surface, ventilate the boat and motor to shore without relying on the compromised electrical propulsion system.
Click to expand...
What was the sea state?
Modern subs do not handle well on the surface.
 
ThunderHorse said:
Article from WSJ:
The San Juan’s Final Hours: The Loss of an Argentine Submarine

Oof.
Click to expand...

Not everyone has a subscription to WSJ. Always nice to share a paragraph or two:



MAR DEL PLATA, Argentina— Susana Miguens last spoke with her son in early November, when he called from the world’s southernmost city, Ushuaia, to say the submarine he served on would soon set out to chase down illegal fishing vessels in the frigid waters off southern Argentina.

Argentine Navy Seaman Leandro Cisneros told her the vessel was in good shape, its 44-member crew well trained and prepared for any surprises. “We have everything we need to live underwater,” he reassured her.

But just over a week later, the ARA San Juan dropped off the map, stunning Argentina’s navy and prompting the U.S. and 16 other nations to join it in what Argentine officials describe as an unprecedented international effort to find the sub and figure out what went so drastically wrong.

Calamity on the San Juan

216 FEET

1 Water enters the snorkel while sub is running its diesel engine on surface.

2 The water causes a short circuit and fire in batteries, which the crew manages to isolate.

3 Backup batteries kick in, but three hours after fire was out, vessel experiences what officials believe was a major explosion.

On Thursday, Argentina’s Navy said it was officially giving up hope of finding the sailors alive and was looking only for wreckage.

In recent days, Argentine authorities have gathered crucial evidence to piece together a theory of what happened after the San Juan left Ushuaia on Nov. 8, bound for its home base of Mar del Plata about 260 miles south of Buenos Aires. They believe the sub took on water that caused a short circuit and a subsequent fire in a key battery compartment. The crew got the fire under control, but hours later there was a loud noise consistent with an explosion near the sub’s last reported location.

Top Argentine officials now believe a blast instantly killed the sailors and sent the vessel to the seafloor. While no one knows for sure what caused the explosion, the batteries are the likeliest culprit, Argentine naval officials and outside experts say.

“It looks like a very possible cause,” said Mike Fabey, a naval expert at Jane’s by IHS Markit, a defense consulting firm. “Battery issues of all types with submersibles are something people have been trying to deal with since submarines first went into the water. Water plus electricity equals fire.”

A federal judge in Argentina has opened an investigation into the submarine’s disappearance. Maintenance is one area likely to come under scrutiny. La Nación newspaper reported that an internal Defense Ministry review in 2015 and 2016 determined that Navy personnel servicing the submarine’s batteries “tried to direct the purchase to benefit certain providers and, in the process, they likely acquired materials with expired warranties and committed crimes,” the newspaper reported.

A Defense Ministry official declined to comment on internal investigations.

The battery-and-diesel-powered submarine, delivered by its German manufacturer, Thyssenkrupp, in 1985, was being used by the Argentine Navy to track illegal fishing in the South Atlantic Ocean, an area rich in seafood sought by trawlers from China and other countries. Last year, Argentina’s coast guard sank a Chinese fishing ship in those waters after it tried to elude authorities.

On the San Juan’s last mission, nothing seems to have gone wrong until the captain ordered the vessel to surface sometime on Nov. 14, a week after it first set out.

That would normally have been a routine decision. Diesel-electric subs rely on a giant bank of batteries to glide silently underwater, making them hard to detect, said William Craig Reed, a former U.S. Navy diver and submariner. Nuclear subs, which have long made up the entire U.S. submarine fleet, can go for months at a time underwater.

A diesel-electric sub’s batteries only hold a charge for about a week while submerged, so it must surface and “snorkel,” running its engines to recharge the batteries and ventilate stale air.

In this case, the sub surfaced amid rough seas, with 23-foot-high waves that may have caused the sub to take on too much water through its snorkel, Argentine Navy spokesman Capt. Enrique Balbi said. The snorkel is equipped with a flap to keep water out, but water can sometimes get in anyway, navy officials said.

The Argentine military submarine San Juan and crew leaving Buenos Aires on June 2, 2014. PHOTO: ARMADA ARGENTINA/REUTERS

At 30 minutes after midnight on Nov. 15, sometime after resurfacing, the ship sent a report saying seawater came through the ventilation system and into contact with the batteries, “causing a short-circuit and the beginning of a fire in the batteries tray,” according to a transcript of the crew’s message.

Hours later, at 7:30 a.m., the sub sent another report through a satellite phone that the crew had got the fire under control but lost use of the batteries in the ship’s bow.

That was the San Juan’s last communication.

Back in Argentina’s naval headquarters in Buenos Aires, there wasn’t yet cause for major alarm, since there were backup batteries to charge the sub.

“They had to electrically isolate the [damaged] batteries and continue navigating to Mar del Plata with another battery circuit and stern,” said Capt. Balbi, a submarine specialist who has repeatedly stressed that the vessels often require attention for minor problems.

Jorge Villareal, a retired navy veteran, said his son, crew member Fernando Villareal, spoke proudly of his ability to fix daily problems as they arose on the ship.

“He never told me of any serious technical faults,” Mr. Villareal said. “For him, it was easy to fix the submarine’s problems because he was an electronics technician. He said it was like changing a lightbulb at home.”

When the crew reported the problem, a submarine commander on shore ordered the sub to continue sailing north to Mar del Plata instead of heading west on the shortest possible course to land. That decision may have kept the submarine in deeper waters, making it harder for search-and-rescue teams to find, some family members and Argentine media have said.

Capt. Balbi disputes that criticism.

“At no time did the commander of the ship, or his superior, see this as an emergency or an event of great magnitude because they were able to resolve the problem by using backup power systems,” he said. Other ports located due west of the submarine, he added, would have also been too shallow for it to dock.

At 10:51 a.m. on Nov. 15—some three hours after the ship reported it had solved the fire problem—a “violent, nonnuclear event” occurred some 35 miles north of the sub’s last known location, according to reports from acoustic experts in the U.S. and at the Comprehensive Nuclear Test Ban Treaty Organization in Vienna.

Most outside experts say the calamity likely arose from the batteries. Submarines like the San Juan use lead batteries that produce highly flammable hydrogen, which must be kept at low levels and closely monitored, said Ney Zanella dos Santos, CEO of Amazônia Azul Tecnologias de Defesa SA, a state company linked to Brazil’s navy and created to help the country build submarines.

Precisely how the battery problems may have led to an explosion isn’t clear, however. “It’s like in airplane disasters—normally it is because of a series of things that went wrong,” said Nestor Antunes de Magalhães, a Brazilian military researcher.

Naval personnels’ concerns grew when they heard no more from the San Juan the next day. By the night of Nov. 16, the navy alerted Argentine President Mauricio Macri. On Nov. 19, when the sub was due at Mar del Plata, there was no sign of the vessel.

Luis Tagliapietra’s 27-year-old son Alejandro was on his last training mission on the sub to become a weapons specialist. Mr. Tagliapietra, a 55-year-old criminal-defense lawyer, says he rarely visited his son during his two years on the base. “It’s something that now I’ll never forgive myself for,” he said. “I regret not spending more time with him and less with my work.”
 
Flap failures on snorkel-equipped boats goes back to WWII. Another problem is when water washes over the snorkel and triggers it sensor, the flap works but the crew pays a price. The sudden loss of air forces an overpressure in the boat until the flap opens again; Side effects run from discomfort to ruptured eardrums.

Water in a battery compartment has doomed a number of subs. When I was on a U-boat history kick a few years ago, I read how water-induced battery issues either killed a number of subs outright or caused the evacuation of a perfectly good sub. Even in cases where a crew could work through battle damage, battery issues usually resulted in a loss or evacuation.

The crew and equipment could be top-notch, but some activites have little margin for error. You simply die if you don't break the chain.

Blue Skies.
 
Red Flag 1 said:
I was on the same kick a few years ago. I just could not find enough to read about the German U-Boats. Here is a tour of one of the final batch of U-Boats that were made, a 900 series,
Click to expand...

I'm sorry old friend, but that's not accurate.

U-Boat classes:
U-boat Types - German U-boats of WWII - Kriegsmarine - uboat.net

U-995:
The Type VIIC/41 U-boat U-995 - German U-boats of WWII - uboat.net

U-Boat types were essentially "1" - "23" with boat numbering done randomly to confuse the Allies as to their exact numbers. -995 was laid down in 1942 and the IX series was first laid down in 1936.
 
I know I've mentioned him before, but look up Clay Blair's excellent series on U-boats. The second can be dry and flat at times, but both are excellent
 
Ooh-Rah said:
The battery-and-diesel-powered submarine, delivered by its German manufacturer, Thyssenkrupp, in 1985, was being used by the Argentine Navy to track illegal fishing in the South Atlantic Ocean, an area rich in seafood sought by trawlers from China and other countries. Last year, Argentina’s coast guard sank a Chinese fishing ship in those waters after it tried to elude authorities.
Click to expand...

Learn something new everyday. Had no idea Thyssenkrupp manufactured subs. I thought their main deal was elevators.

Makes sense. Both go up and down.......
 

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