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Tugger
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Lost Argentine sub ARA San Juan found!

Sat Nov 17, 2018 6:24 pm

The Argentinian submarine ARA San Juan that went missing just over one year ago has been located as confirmed by the Argentine Navy and government.

A submarine that went missing over a year ago together with 44 crewmen aboard has been found, the Argentinian navy said early Saturday.

The ARA San Juan submarine disappeared on Nov. 15 last year, sparking an international search operation assisted by the United States and other countries.
[...]

The submarine was detected more than 2,600 feet deep in the waters off the Valdes Peninsula in Argentine Patagonia, the navy’s statement said.

https://www.foxnews.com/world/argentina ... sappearing

Image

It was located by the Ocean Infinity ship Seabed Constructor which had also been involved in the hunt for flight MH370.
Image

Ocean Infinity is using five autonomous underwater vehicles (AUVs) to carry out the search, which will be conducted by a team of approximately 60 crew members on board Seabed Constructor.

https://www.maritime-executive.com/arti ... uan-search
Image
Image

The sad thing is that the area it has been found was one that had previously been identified as the likely location for the lost sub.
http://en.mercopress.com/2018/11/11/nav ... uad-admits


The loss was originally discussed in this thread: viewtopic.php?f=11&t=1379099

RIP to all the lost sailors.

Tugg
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DeltaMD90
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Re: Lost Argentine sub ARA San Juan found!

Sun Nov 18, 2018 1:51 am

My bad Tugg, I accidentally resurrected the previous thread. Mods should sort it out (your post has a lot of good info, I'll suggest locking the other.)

People wonder how things like planes and subs remain unfound for long stretches of time. If you've ever been on a search like this, the vast size of the ocean will amaze you. The mind can't comprehend it without seeing it.

RIP to the sailors, the mood in Argentina when it happened was heartbreaking. It hit the Navy hard as well... the navy being the size it is, a large chunk (if not the majority) of the officers and sailors knew someone on the crew

:tombstone:
 
910A
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Re: Lost Argentine sub ARA San Juan found!

Sun Nov 18, 2018 2:22 pm

a complicated process in which the submarine was cut in half before the engines and batteries were replaced,

https://www.washingtonpost.com/world/20 ... 1bb888c20c

I'm not a seaman, and I'm much too tall ever to sail of a submarine, but sailing on a submarine that was cut in half and then reassembled just doesn't sound safe to me..

One more step in solving the mystery. The Washington Post link has some pictures of the sub at it's resting place.
 
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cjg225
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Re: Lost Argentine sub ARA San Juan found!

Sun Nov 18, 2018 2:47 pm

910A wrote:
https://www.washingtonpost.com/world/2018/11/17/submarine-that-vanished-with-sailors-found-near-argentina-search-bodies-answers-begins/?utm_term=.9e1bb888c20c

I'm not a seaman, and I'm much too tall ever to sail of a submarine, but sailing on a submarine that was cut in half and then reassembled just doesn't sound safe to me..

One more step in solving the mystery. The Washington Post link has some pictures of the sub at it's resting place.

From the Argentine navy's twitter: https://twitter.com/Armada_Arg

Some photos of actual wreckage in there.
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bennett123
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Re: Lost Argentine sub ARA San Juan found!

Sun Nov 18, 2018 8:08 pm

910A

Doing that on a surface vessel would be risky.

But on a sub, just crazy.
 
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cjg225
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Re: Lost Argentine sub ARA San Juan found!

Sun Nov 18, 2018 9:55 pm

bennett123 wrote:
910A

Doing that on a surface vessel would be risky.

But on a sub, just crazy.

It happens with surface vessels more often than you'd think.
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THS214
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Re: Lost Argentine sub ARA San Juan found!

Sun Nov 18, 2018 10:04 pm

"a submarine that was cut in half and then reassembled just doesn't sound safe to me."

I Don't know about submarines but ships are all the time cut and lengthen and then put together. I think that when everything is strong enough (where cut and put together) its enough. Of course that can be the problem here.
 
Okie
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Re: Lost Argentine sub ARA San Juan found!

Sun Nov 18, 2018 10:35 pm

910A wrote:
I'm not a seaman, and I'm much too tall ever to sail of a submarine, but sailing on a submarine that was cut in half and then reassembled just doesn't sound safe to me..


You will have to enlighten me on how you would build a submarine without welding together metal materials in the first place.

We have not approached Additive Manufacturing (printing) to the scale to build a submarine much less high pressure vessels of which a submarine would be considered.

********
It would be interesting if they can get enough resoltion to the pictures and or enough pictures to determine if the intial cause was from an explosion or just a fire that incapacitated the crew and then the water pressure caused an impolsion.

Okie
 
salttee
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Re: Lost Argentine sub ARA San Juan found!

Sun Nov 18, 2018 11:36 pm

The USN "cut a sub in half" and in fact they replaced the front end of a nuke sub, the USS San Francisco, with the bow section from a different sub.

In June 2006, it was announced that San Francisco's bow section would be replaced at the Puget Sound Naval Shipyard with the bow of USS Honolulu, which was soon to be retired. San Francisco is four years older than Honolulu, but she had been refueled and upgraded in 2000–2002. The cost of her bow replacement has been estimated at $79 million, as compared with the estimated $170 million to refuel and overhaul the nuclear reactor of Honolulu.
https://en.wikipedia.org/wiki/USS_San_F ... o_(SSN-711)
 
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neutrino
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Re: Lost Argentine sub ARA San Juan found!

Mon Nov 19, 2018 5:56 am

910A wrote:
a complicated process in which the submarine was cut in half before the engines and batteries were replaced,

https://www.washingtonpost.com/world/20 ... 1bb888c20c

I'm not a seaman, and I'm much too tall ever to sail of a submarine, but sailing on a submarine that was cut in half and then reassembled just doesn't sound safe to me..

One more step in solving the mystery. The Washington Post link has some pictures of the sub at it's resting place.

So subs assembled from many many pieces of metal would be very safe to you?
Ok, so chances for you to "sail" in a sub is practically zilch but wait.......airplanes are also built from many many pieces of metal, so do you feel safe to fly? Granted the new clean sheet widebodies, being chiefly of CFRP, have way less pieces but they are still many times more pieces than being reassembled from a cut-in-half body.
Don't ever get into a pressure vessel. They do not come in a single continuous monolithic construct.
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meecrob
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Re: Lost Argentine sub ARA San Juan found!

Mon Nov 19, 2018 4:21 pm

To echo what others are saying, cutting a vessel in half and re-assembling it (IF done correctly) will result in a weight penalty as opposed to reduced structural integrity. Welding/fastening steel is well understood and the calculations are straightforward. Of course we are all human, and mistakes can be made, but I think this is one of those things that sounds insane on first look, but makes more sense when you see the process behind it.

Back to topic: I saw a headline regarding this but the article was subscription only. It mentioned that the Argentine Navy does not have sufficient funds to salvage this sub...has there been any news on this front? I imagine the world's Naval community will be more than happy to help fellow seamen.
 
Flighty
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Re: Lost Argentine sub ARA San Juan found!

Mon Nov 19, 2018 4:29 pm

IIRC all submarines are welded together in the first place. The same can happen with airplanes. You can assemble one from parts.
 
WIederling
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Re: Lost Argentine sub ARA San Juan found!

Mon Nov 19, 2018 5:55 pm

910A wrote:
I'm not a seaman, and I'm much too tall ever to sail of a submarine, but sailing on a submarine that was cut in half and then reassembled just doesn't sound safe to me..
.


They are produced that way.
... and major refurbishing/redesign goes the same way.
established tech.
IMU the HDW yard at Kiel had a depth testing "chamber" to do final weld quality testing.
https://translate.google.com/translate? ... i%2FDock_C

nowadays quality control seems to be good enough to not need it anymore. scrapped.
Murphy is an optimist
 
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Gonzalo
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Re: Lost Argentine sub ARA San Juan found!

Mon Nov 19, 2018 8:40 pm

WIederling wrote:
910A wrote:
I'm not a seaman, and I'm much too tall ever to sail of a submarine, but sailing on a submarine that was cut in half and then reassembled just doesn't sound safe to me..
.


They are produced that way.
... and major refurbishing/redesign goes the same way.
established tech.
IMU the HDW yard at Kiel had a depth testing "chamber" to do final weld quality testing.
https://translate.google.com/translate? ... i%2FDock_C

nowadays quality control seems to be good enough to not need it anymore. scrapped.



There are several non destructive testing methods precisely created to ensure quality of manufacturing and assembly of basically anything you can imagine, and that includes submarines, airplane parts, pressure vessels of very very different size and use. If you follow the welding procedures, the heat treatments, work with certified materials and qualified personnel, you can cut a submarine in four parts and then assembly again without any problem.
Sadly, there are suspicions and rumours about the ARA San Juan, probably because the works were made during the Cristina K government, and her name is basically the equivalent of corruption, funds bleeding from institutions ( including the Argentinian Navy ), and mismanagement of resources at various levels. I would love to see the reports of the works performed, and the reports of all the non destructive testing associated. If a third party audited all that and found nothing, would be different, but AFAIK is not the case.

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WIederling
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Re: Lost Argentine sub ARA San Juan found!

Mon Nov 19, 2018 11:54 pm

Gonzalo wrote:
Sadly, there are suspicions and rumours about the ARA San Juan, probably because the works were made during the Cristina K government, and her name is basically the equivalent of corruption, funds bleeding from institutions ( including the Argentinian Navy ), and mismanagement of resources at various levels. I would love to see the reports of the works performed, and the reports of all the non destructive testing associated. If a third party audited all that and found nothing, would be different, but AFAIK is not the case.


The boat was located at about 900m depth. Design spec diving depth is 300m. I'd assume that anything beyond 600..700m would 100% cause failure of the hull.
Murphy is an optimist
 
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Aesma
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Re: Lost Argentine sub ARA San Juan found!

Tue Nov 20, 2018 7:44 am

The problem arose during snorkeling initially so definitely nothing to do with the pressure vessel.
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Jouhou
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Re: Lost Argentine sub ARA San Juan found!

Wed Nov 21, 2018 6:02 am

salttee wrote:
The USN "cut a sub in half" and in fact they replaced the front end of a nuke sub, the USS San Francisco, with the bow section from a different sub.

In June 2006, it was announced that San Francisco's bow section would be replaced at the Puget Sound Naval Shipyard with the bow of USS Honolulu, which was soon to be retired. San Francisco is four years older than Honolulu, but she had been refueled and upgraded in 2000–2002. The cost of her bow replacement has been estimated at $79 million, as compared with the estimated $170 million to refuel and overhaul the nuclear reactor of Honolulu.
https://en.wikipedia.org/wiki/USS_San_F ... o_(SSN-711)


I was gonna mention the 711! There were also plans to do something similar to salvage the USS Miami (SSN 755) before those plans were scrapped due to budget constraints. There's a lot of inspections and certifications involved in doing such a thing, and that's how we can be sure the vessel is safe prior to sea trials.

DeltaMD90 wrote:
My bad Tugg, I accidentally resurrected the previous thread. Mods should sort it out (your post has a lot of good info, I'll suggest locking the other.)

People wonder how things like planes and subs remain unfound for long stretches of time. If you've ever been on a search like this, the vast size of the ocean will amaze you. The mind can't comprehend it without seeing it.

RIP to the sailors, the mood in Argentina when it happened was heartbreaking. It hit the Navy hard as well... the navy being the size it is, a large chunk (if not the majority) of the officers and sailors knew someone on the crew

:tombstone:


I would like to point out this was a military vessel and was likely clad in a sonar absorbing material, further frustrating the search. It's not meant to be detected by sonar at all, but that's exactly how you search the seafloor for a wreckage.
 
VSMUT
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Re: Lost Argentine sub ARA San Juan found!

Wed Nov 21, 2018 1:43 pm

Jouhou wrote:
I would like to point out this was a military vessel and was likely clad in a sonar absorbing material, further frustrating the search. It's not meant to be detected by sonar at all, but that's exactly how you search the seafloor for a wreckage.


From the photos, the pressure vessel is exposed, so any anechoic tiles will have been shed.

It isn't guaranteed that the ARA San Juan had any though. Detail photos of her don't indicate that the hull is covered with anything, it's just welded and painted metal.

Image
 
Okie
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Re: Lost Argentine sub ARA San Juan found!

Wed Nov 21, 2018 4:22 pm

Aesma wrote:
The problem arose during snorkeling initially so definitely nothing to do with the pressure vessel.



Basic question I had way up. Questioning whether they had a hydrogen explosion from the salt water leaking on the batteries or the battery issue incapacitated the crew or vessel causing the it to implode from the pressure as it sunk.

Okie
 
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Jouhou
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Re: Lost Argentine sub ARA San Juan found!

Wed Nov 21, 2018 5:53 pm

Okie wrote:
Aesma wrote:
The problem arose during snorkeling initially so definitely nothing to do with the pressure vessel.



Basic question I had way up. Questioning whether they had a hydrogen explosion from the salt water leaking on the batteries or the battery issue incapacitated the crew or vessel causing the it to implode from the pressure as it sunk.

Okie

Usually submarine hull losses at sea involve a catastrophic loss of power and recoverability and sink towards crush depth where they eventually implode. This boat definitely imploded- if the pressure hull flooded there Would be nothing to implode due to the equalization of sea pressure.

Also wow that thing had a lumpy sail. I think that might be poorly faired in tile.
 
salttee
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Re: Lost Argentine sub ARA San Juan found!

Wed Nov 21, 2018 6:07 pm

Jouhou wrote:
Also wow that thing had a lumpy sail. I think that might be poorly faired in tile.

It looks like it was made out of scrap metal pieces.
 
WIederling
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Re: Lost Argentine sub ARA San Juan found!

Wed Nov 21, 2018 6:11 pm

Jouhou wrote:
Also wow that thing had a lumpy sail. I think that might be poorly faired in tile.


I had wondered about that too.
Did they operate it in (ant)arctic drift ice conditions ?

They don't look that way when they are new.
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Jouhou
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Re: Lost Argentine sub ARA San Juan found!

Wed Nov 21, 2018 6:24 pm

salttee wrote:
Jouhou wrote:
Also wow that thing had a lumpy sail. I think that might be poorly faired in tile.

It looks like it was made out of scrap metal pieces.


That's definitely tile on the sail. They probably don't have the maintenance infrastructure necessary to properly install tiles in a way that doesn't risk them peeling off.

WIederling wrote:
Jouhou wrote:
Also wow that thing had a lumpy sail. I think that might be poorly faired in tile.


I had wondered about that too.
Did they operate it in (ant)arctic drift ice conditions ?

They don't look that way when they are new.


I doubt that thing was fitted out with proper ice-breaking capability, despite having Antarctic waters near-by. That would be expensive for a small navy like this.
 
WIederling
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Re: Lost Argentine sub ARA San Juan found!

Wed Nov 21, 2018 6:35 pm

Jouhou wrote:
I doubt that thing was fitted out with proper ice-breaking capability, despite having Antarctic waters near-by. That would be expensive for a small navy like this.


it would explain the banged up exterior of the sail ( and parts of the visible hull ).

regular use doesn't show similar deformation:
http://deacademic.com/pictures/dewiki/1 ... nforde.jpg
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Jouhou
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Re: Lost Argentine sub ARA San Juan found!

Wed Nov 21, 2018 6:48 pm

WIederling wrote:
Jouhou wrote:
I doubt that thing was fitted out with proper ice-breaking capability, despite having Antarctic waters near-by. That would be expensive for a small navy like this.


it would explain the banged up exterior of the sail ( and parts of the visible hull ).

regular use doesn't show similar deformation:
http://deacademic.com/pictures/dewiki/1 ... nforde.jpg


Lol, Argentinian navy: Fuck it, icebreaking capability is just an expensive scam for pansies, let's just ram through the ice with our sail! No wonder their snorkel started to take on water.

Do you work for the german shipbuilding industry? This thing was german made it seems.
 
WIederling
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Re: Lost Argentine sub ARA San Juan found!

Wed Nov 21, 2018 9:55 pm

Jouhou wrote:
WIederling wrote:
Jouhou wrote:
I doubt that thing was fitted out with proper ice-breaking capability, despite having Antarctic waters near-by. That would be expensive for a small navy like this.


it would explain the banged up exterior of the sail ( and parts of the visible hull ).

regular use doesn't show similar deformation:
http://deacademic.com/pictures/dewiki/1 ... nforde.jpg


Lol, Argentinian navy: Fuck it, icebreaking capability is just an expensive scam for pansies, let's just ram through the ice with our sail! No wonder their snorkel started to take on water.

Do you work for the german shipbuilding industry? This thing was german made it seems.


I have one line of work touching commercial and recreational shipping.

The TR1700 units were built at Thyssen Nordseewerke, Emden. enlarged version of the small coastal 206/209/212 series.

Interesting (for me) research result: at one time a plan existed to upgrade these to be nuclear powered ( 25MW electric output reactor) :
https://en.wikipedia.org/wiki/CAREM

addendum, some basic info on the type:
https://en.wikipedia.org/wiki/TR-1700-class_submarine
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Jouhou
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Re: Lost Argentine sub ARA San Juan found!

Thu Nov 22, 2018 5:23 am

WIederling wrote:
Jouhou wrote:
WIederling wrote:

it would explain the banged up exterior of the sail ( and parts of the visible hull ).

regular use doesn't show similar deformation:
http://deacademic.com/pictures/dewiki/1 ... nforde.jpg


Lol, Argentinian navy: Fuck it, icebreaking capability is just an expensive scam for pansies, let's just ram through the ice with our sail! No wonder their snorkel started to take on water.

Do you work for the german shipbuilding industry? This thing was german made it seems.


I have one line of work touching commercial and recreational shipping.

The TR1700 units were built at Thyssen Nordseewerke, Emden. enlarged version of the small coastal 206/209/212 series.

Interesting (for me) research result: at one time a plan existed to upgrade these to be nuclear powered ( 25MW electric output reactor) :
https://en.wikipedia.org/wiki/CAREM

addendum, some basic info on the type:
https://en.wikipedia.org/wiki/TR-1700-class_submarine


I was curious because you seemed to recognize that sails don't tend to look so... lumpy. I've seen many and I've never seen one like that. For the people here who are more familiar with aircraft, this would be sort of like allowing the vertical stabilizer to get banged up and misshapen and continuing to fly with it like that. It would sort of mess with the fluid dynamics of the design.
 
VSMUT
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Re: Lost Argentine sub ARA San Juan found!

Thu Nov 22, 2018 8:04 am

Jouhou wrote:
salttee wrote:
Jouhou wrote:
Also wow that thing had a lumpy sail. I think that might be poorly faired in tile.

It looks like it was made out of scrap metal pieces.


That's definitely tile on the sail. They probably don't have the maintenance infrastructure necessary to properly install tiles in a way that doesn't risk them peeling off.


Those aren't tiles. You can clearly see the weld-lines. Anechoic tiles are made of a rubber-compound, and glued to the side. They are also over 10 cm thick, so you don't just blend them. In fact, the ARA San Juan completely predates the use of anechoic tiles in the west.

The tiles are also pretty distinct, you can clearly see them on this Trafalgar class submarine:

Image
 
WIederling
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Re: Lost Argentine sub ARA San Juan found!

Thu Nov 22, 2018 9:00 am

Jouhou wrote:
I was curious because you seemed to recognize that sails don't tend to look so... lumpy. I've seen many and I've never seen one like that. For the people here who are more familiar with aircraft, this would be sort of like allowing the vertical stabilizer to get banged up and misshapen and continuing to fly with it like that. It would sort of mess with the fluid dynamics of the design.


not really. not in a meaningful way I'd guess.
the outer form of the sail is not pressurized. Same for the visible hull.
The actual pressure hull is "inside".

From a different mechanism you can see that on airplanes that had an excess of cycles.
( the skin between stringers and frames stretches from pressurization cycles and
from "diagonal" loading the skin. ( there is a name for the effect. can't remember.)
Looks like continental quilt :-)

With ships you see that effect mostly from banging into things ( ice, quay sides, tugs....)
skin gives except for the places where there is (stiffer, form giving) structure underneath.
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Jouhou
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Re: Lost Argentine sub ARA San Juan found!

Thu Nov 22, 2018 11:28 am

VSMUT wrote:
Jouhou wrote:
salttee wrote:
It looks like it was made out of scrap metal pieces.


That's definitely tile on the sail. They probably don't have the maintenance infrastructure necessary to properly install tiles in a way that doesn't risk them peeling off.


Those aren't tiles. You can clearly see the weld-lines. Anechoic tiles are made of a rubber-compound, and glued to the side. They are also over 10 cm thick, so you don't just blend them. In fact, the ARA San Juan completely predates the use of anechoic tiles in the west.

The tiles are also pretty distinct, you can clearly see them on this Trafalgar class submarine:

Image


It depends whose submarine it is, in terms of the tiles:

Image they are far less visible on U.S. subs. We "blend" them, why can't others? Also, the ARA San Juan entered service in 1985. The first Los Angeles class ship was commissioned in 1976. It did not predate the use of the tiles in the west.
 
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Jouhou
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Re: Lost Argentine sub ARA San Juan found!

Thu Nov 22, 2018 11:49 am

WIederling wrote:
Jouhou wrote:
I was curious because you seemed to recognize that sails don't tend to look so... lumpy. I've seen many and I've never seen one like that. For the people here who are more familiar with aircraft, this would be sort of like allowing the vertical stabilizer to get banged up and misshapen and continuing to fly with it like that. It would sort of mess with the fluid dynamics of the design.


not really. not in a meaningful way I'd guess.
the outer form of the sail is not pressurized. Same for the visible hull.
The actual pressure hull is "inside".

From a different mechanism you can see that on airplanes that had an excess of cycles.
( the skin between stringers and frames stretches from pressurization cycles and
from "diagonal" loading the skin. ( there is a name for the effect. can't remember.)
Looks like continental quilt :-)

With ships you see that effect mostly from banging into things ( ice, quay sides, tugs....)
skin gives except for the places where there is (stiffer, form giving) structure underneath.


I never implied the sail was a part of the pressure hull? Unless you thought my comment about the deformation of the sail being linked to the snorkel taking in water was saying that. I was saying the snorkel penetrates the hull at the base of the sail and if they've been going too rough on the sail, especially with the snorkel extended, It could possibly cause severe damage to the seal at the hull penetration. There's plenty of video that submarines can easily surface from under Ice as long as break through vertically. That's not what that damage looks like it's from though.

And as I was saying before, it's functional but sloppy to leave a sail deformed. Like a vertical stabilizer, the structure itself serves to stabilize the boat. When it's in motion, water flows past it. It's shaped the way it is to minimize impedance against the moving water. It works better when it's smooth.
 
ChrisKen
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Re: Lost Argentine sub ARA San Juan found!

Thu Nov 22, 2018 12:31 pm

Jouhou wrote:
It depends whose submarine it is, in terms of the tiles:

Image they are far less visible on U.S. subs. We "blend" them, why can't others? Also, the ARA San Juan entered service in 1985. The first Los Angeles class ship was commissioned in 1976. It did not predate the use of the tiles in the west.

Hate to break it to you but the picture you've posted has no tiles on the fin. You can see them on the on the side of pressure hull on the port side just aft of it though. And in this case, yes it's the pressure hull as US subs tend not to use a casing. Also, the tiles are a relatively recent retrofit, they weren't on the original spec.
 
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Jouhou
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Re: Lost Argentine sub ARA San Juan found!

Thu Nov 22, 2018 12:46 pm

ChrisKen wrote:
Jouhou wrote:
It depends whose submarine it is, in terms of the tiles:

Image they are far less visible on U.S. subs. We "blend" them, why can't others? Also, the ARA San Juan entered service in 1985. The first Los Angeles class ship was commissioned in 1976. It did not predate the use of the tiles in the west.

Hate to break it to you but the picture you've posted has no tiles on the fin. You can see them on the on the side of pressure hull on the port side just aft of it though. And in this case, yes it's the pressure hull as US subs tend not to use a casing. Also, the tiles are a relatively recent retrofit, they weren't on the original spec.


You're not looking hard enough then. They're rectangular and shaped to fit. How many others here actually specialize in these things for a living?

They weren't on the original 688? How sure are you about that? Also there's large cavities forward and aft of the boat that could serve as a "casing". No one calls them that. They're ballast tanks. You can see the exterior of the pressure hull from inside of them.
 
ChrisKen
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Re: Lost Argentine sub ARA San Juan found!

Thu Nov 22, 2018 1:37 pm

Jouhou wrote:
You're not looking hard enough then. They're rectangular and shaped to fit. How many others here actually specialize in these things for a living?

You don't need to look very hard to see they're not there. A couple of the mastheads have some RAM on them but that's your lot.
I have my Dolphins.
I've also frequented several 688 and none had tiles on the fin. They're a mixture of steel and fibreglass/GRP with a 'special coating'. A coating is not a tile. The USN did not start using their 'special hull coatings' until 1988. Anechoic tiles are a much later addition to the US fleet.

They weren't on the original 688? How sure are you about that?

Yes, very sure. Just a plain teardrop hull. Black paint topsides (Black Anti-slip in working areas), usual oxide anti-foul coating below the surfaced waterline. There's plenty of photographs about which show this too.

Also there's large cavities forward and aft of the boat that could serve as a "casing". No one calls them that. They're ballast tanks. You can see the exterior of the pressure hull from inside of them.

Casing, the non-watertight external structure around the pressure hull (usually upper surfaces) mainly used for hydrodynamics, mounting equipment, stowage and improved personnel mobility. US boats tend not use a casing, preferring to maintain their teardrop pressure hull's lines. If you prefer, you can interchange 'casing' with 'light hull'.
A ballast tank is not part of the casing but may be contained within it..
 
ChrisKen
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Joined: Tue Aug 05, 2008 11:15 pm

Re: Lost Argentine sub ARA San Juan found!

Thu Nov 22, 2018 2:20 pm

ARA San Juan has neither tiles or 'special' coatings with the exception of anti-slip a top the casing. It's simply painted.
The lumps and bumps in the fin are nothing special. It's a lightweight non-watertight structure. take a look at the superstructure of most surface warships, you'll see similar.

Being cut in half isn't necessarily a problem. Unless there's been poor oversight with regards to standards when reassembling the hull. The hull was built in sections to start with. Cutting in half to refit is not an unusual procedure, particularly on older boats where there's no provision for removing/replacing large items within in other ways.

It's commonplace on surface vessels too. I'd be surprised if any Anetter's that have been afloat at some point in their lives have not been on a vessel that's been cut.
 
VSMUT
Posts: 3231
Joined: Mon Aug 08, 2016 11:40 am

Re: Lost Argentine sub ARA San Juan found!

Thu Nov 22, 2018 7:53 pm

Jouhou wrote:
Also, the ARA San Juan entered service in 1985. The first Los Angeles class ship was commissioned in 1976. It did not predate the use of the tiles in the west.


ARA San Juan was designed in 1977, laid down in 1982 and launched in 1983. The Royal Navy and US Navy didn't start experimenting with anechoic tiles until 1980, when HMS Churchill and USS Batfish were equipped with them. Even then, it was several years before surface treatments like these tiles became widespread. The first 688s weren't equipped with the tiles. As ChrisKen says, they weren't equipped until some time in the 90s. Even much newer Type 209s lack the tiles, including those built in the 2000s.
 
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cedars747
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Joined: Sat Dec 10, 2005 8:04 am

Re: Lost Argentine sub ARA San Juan found!

Sun Nov 25, 2018 1:49 am

After finding the submarine, the Argentine government must pay 7.5 million dollars.to Ocean Infinity. Do they have the money? and how much money would it cost to get it out of the water?
Tengo una pasion por la aviacion /لدي شغف للطيران / I have a passion for aviation /Jeg har en lidenskap for luftfart/ J'ai une passion pour l'aviation.

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