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N965UW
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Indonesian Navy Submarine Missing

Thu Apr 22, 2021 6:30 pm

https://apnews.com/article/indonesia-mi ... c99016db64

KRI Nanggala (402), a diesel-electric attack sub, has gone missing following a torpedo drill north of Bali. Time is limited and there are challenges to a possible rescue. Brings back memories of the ARA San Juan in 2017. Let's hope for a positive outcome.
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casinterest
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Re: Indonesian Navy Submarine Missing

Thu Apr 22, 2021 7:07 pm

This is horrible, and I hope for the best. It seems like they are going to have trouble getting the right equipment in place.
Twenty years from now you will be more disappointed by the things you didn't do than by the ones you did..So throw off the bowlines. Sail away from the safe harbor. Catch the trade winds in your sails. Explore. Dream. Discover.--Mark Twain
 
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cjg225
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Re: Indonesian Navy Submarine Missing

Thu Apr 22, 2021 10:50 pm

Yuck. The shelf must drop quickly there if there are two different points described that are 2,000+ feet apart in depth.
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cskok8
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Re: Indonesian Navy Submarine Missing

Fri Apr 23, 2021 12:17 pm

The oil slick doesn't sound good
 
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casinterest
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Re: Indonesian Navy Submarine Missing

Fri Apr 23, 2021 12:40 pm

cskok8 wrote:
The oil slick doesn't sound good



No it doesn't. but i am hopeful the detection of the object at 50-100m is the sub. Hopefully they can reach it in time.

https://www.bbc.com/news/world-asia-56851487
Twenty years from now you will be more disappointed by the things you didn't do than by the ones you did..So throw off the bowlines. Sail away from the safe harbor. Catch the trade winds in your sails. Explore. Dream. Discover.--Mark Twain
 
Okie
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Re: Indonesian Navy Submarine Missing

Fri Apr 23, 2021 12:49 pm

N965UW wrote:
KRI Nanggala (402), a diesel-electric attack sub, has gone missing following a torpedo drill north of Bali.


Torpedo Drill sounds like another HTP (high test peroxide) accident. HTP is part of the propellent mix for torpedo's

Thinking Kursk.

Okie
 
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flyingturtle
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Re: Indonesian Navy Submarine Missing

Fri Apr 23, 2021 5:22 pm

casinterest wrote:
cskok8 wrote:
The oil slick doesn't sound good



No it doesn't. but i am hopeful the detection of the object at 50-100m is the sub. Hopefully they can reach it in time.

https://www.bbc.com/news/world-asia-56851487


A Swiss news portal said

"Laut Marine-Stabschef Yudo Margono wurde in der Region ein metallisches Objekt in 50 bis 100 Metern Tiefe geortet, das «sehr magnetisch» sei."

...so they've found a "very magnetic" object at this depth. But doesn't that refute the very point of a submarine?

I'm thinking of a translation error.
Reading accident reports is what calms me down
 
petertenthije
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Re: Indonesian Navy Submarine Missing

Fri Apr 23, 2021 6:16 pm

flyingturtle wrote:
A Swiss news portal said

"Laut Marine-Stabschef Yudo Margono wurde in der Region ein metallisches Objekt in 50 bis 100 Metern Tiefe geortet, das «sehr magnetisch» sei."

...so they've found a "very magnetic" object at this depth. But doesn't that refute the very point of a submarine?

I'm thinking of a translation error.

Not necesarily a mis-translation.

A common way to hunt for submarines is by using airplanes, such as the P-3 Orion, equiped with a MAD boom. This Magnetic Anomaly Detector can identify changes in the magnetic field, which are caused by the metals a submarine is made of.
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ThePointblank
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Re: Indonesian Navy Submarine Missing

Fri Apr 23, 2021 6:51 pm

Okie wrote:
N965UW wrote:
KRI Nanggala (402), a diesel-electric attack sub, has gone missing following a torpedo drill north of Bali.


Torpedo Drill sounds like another HTP (high test peroxide) accident. HTP is part of the propellent mix for torpedo's

Thinking Kursk.

Okie

Only the Russians still use high test peroxide in their torpedoes.

Western torpedoes tend to use either battery electric, or monopropellent propulsion (typically, Otto fuel II). These are considered stable propellent systems.

The Indonesian submarine from what I can remember uses German SUT torpedoes, which are battery electric.
 
GDB
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Re: Indonesian Navy Submarine Missing

Fri Apr 23, 2021 7:28 pm

Okie wrote:
N965UW wrote:
KRI Nanggala (402), a diesel-electric attack sub, has gone missing following a torpedo drill north of Bali.


Torpedo Drill sounds like another HTP (high test peroxide) accident. HTP is part of the propellent mix for torpedo's

Thinking Kursk.

Okie


No chance, after abortive trials by the Royal Navy for sub propulsion in the 1950's, that technology was rejected in the West, not sure if the USN had tried it with propulsion for subs or torpedoes, they too never used it as far as I'm aware, likely rejected throughout NATO too, when this sub was built in West Germany.
Only the Russians that we know of, went with it with, as you say, tragic results for the men of the Kursk.

In any case, this former USN Submariner has done an in depth look at this accident, he's very well informed, put on line before that oil slick, it also covers the sub itself and of the likely causes of the accident, torpedo explosion isn't mentioned.
https://www.youtube.com/watch?v=vujd4b60eXA
 
N965UW
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Re: Indonesian Navy Submarine Missing

Fri Apr 23, 2021 10:50 pm

The 72-hour window for finding the crew before the sub's oxygen supply runs out has closed. Unfortunately it seems efforts will be shifting from rescue to recovery.
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cjg225
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Re: Indonesian Navy Submarine Missing

Sat Apr 24, 2021 1:10 am

If the torpedo drill involved firing one, I wonder if could have been a circle-runner? Or a case of a failure of the outer (or inner) door causing uncontrolled flooding of the torpedo room?

If the sub had been the object at that 50-100m depth, they surely would've been able to get down to that depth easily by now or get a clear picture with side-scan sonar. Watch that object be an uncharted or forgotten wreck from World War II or something.
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cskok8
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Re: Indonesian Navy Submarine Missing

Sat Apr 24, 2021 2:45 am

cjg225 wrote:
If the torpedo drill involved firing one, I wonder if could have been a circle-runner? Or a case of a failure of the outer (or inner) door causing uncontrolled flooding of the torpedo room?

If the sub had been the object at that 50-100m depth, they surely would've been able to get down to that depth easily by now or get a clear picture with side-scan sonar. Watch that object be an uncharted or forgotten wreck from World War II or something.


Firing a torpedo involves opening the submarine's interior to the outside water pressure. Many things could go wrong with the outer or inner doors other than the torpedo itself
 
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cjg225
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Re: Indonesian Navy Submarine Missing

Sat Apr 24, 2021 3:20 am

cskok8 wrote:
Firing a torpedo involves opening the submarine's interior to the outside water pressure. Many things could go wrong with the outer or inner doors other than the torpedo itself

I didn't say that the torpedo would cause problems with the doors. I said simply a "failure" of the inner or outer doors, which at the (im)proper time would lead to flooding of the torpedo room. Could be for any number of reasons, such as an inexperienced crewmember making a fatal error.
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astuteman
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Re: Indonesian Navy Submarine Missing

Sat Apr 24, 2021 6:03 am

cskok8 wrote:
cjg225 wrote:
If the torpedo drill involved firing one, I wonder if could have been a circle-runner? Or a case of a failure of the outer (or inner) door causing uncontrolled flooding of the torpedo room?

If the sub had been the object at that 50-100m depth, they surely would've been able to get down to that depth easily by now or get a clear picture with side-scan sonar. Watch that object be an uncharted or forgotten wreck from World War II or something.


Firing a torpedo involves opening the submarine's interior to the outside water pressure. Many things could go wrong with the outer or inner doors other than the torpedo itself


A list of what you think these "many things" are would be interesting.....
The reality is that the safety interlocks that exist between the inner and outer doors make this probably the most unlikely cause.
They are a first level safety system with multiple redundancy and 10^-7 safety or better.

Also for reference, firing a torpedo dos not involve opening the submarine's interior to the outside water pressure

Much more likely causes would be:-

Crew error
Some type of system failure
A battery fire.

The "circle runner" torpedo is believed to have been a possible cause in the past

https://en.wikipedia.org/wiki/USS_Scorpion_(SSN-589)

Torpedo control technology has moved on since then...

Rgds
 
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flyingturtle
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Re: Indonesian Navy Submarine Missing

Sat Apr 24, 2021 10:59 am

The sub and debris has been found, well below the survivable depth.

https://www.bbc.com/news/world-asia-56871694
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astuteman
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Re: Indonesian Navy Submarine Missing

Sat Apr 24, 2021 11:53 am

flyingturtle wrote:
The sub and debris has been found, well below the survivable depth.

https://www.bbc.com/news/world-asia-56871694


A sad end, and decidedly not a nice way to go....
Rest in Peace to the crew, and condolences to their family.

The article says the sub was 40 years old ..... built just after I started work.........

Rgds
 
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casinterest
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Re: Indonesian Navy Submarine Missing

Sat Apr 24, 2021 12:47 pm

astuteman wrote:
flyingturtle wrote:
The sub and debris has been found, well below the survivable depth.

https://www.bbc.com/news/world-asia-56871694


A sad end, and decidedly not a nice way to go....
Rest in Peace to the crew, and condolences to their family.

The article says the sub was 40 years old ..... built just after I started work.........

Rgds



A Terrible tragedy., My Condolences to the their families, friends and colleagues. I wonder if their will be a salvage attempt or if they will leave it to rest.
Twenty years from now you will be more disappointed by the things you didn't do than by the ones you did..So throw off the bowlines. Sail away from the safe harbor. Catch the trade winds in your sails. Explore. Dream. Discover.--Mark Twain
 
T4thH
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Re: Indonesian Navy Submarine Missing

Sat Apr 24, 2021 3:02 pm

The only good thing is, when you get too deep; the submarine will just implode, this is so fast over, the crew will not even have had time to recognize the implosion itself. So one second all alive, next second, all gone.

RIP.
 
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cjg225
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Re: Indonesian Navy Submarine Missing

Sat Apr 24, 2021 8:24 pm

astuteman wrote:
A list of what you think these "many things" are would be interesting.....
The reality is that the safety interlocks that exist between the inner and outer doors make this probably the most unlikely cause.
They are a first level safety system with multiple redundancy and 10^-7 safety or better.

Also for reference, firing a torpedo dos not involve opening the submarine's interior to the outside water pressure

Much more likely causes would be:-

Crew error
Some type of system failure
A battery fire.

The "circle runner" torpedo is believed to have been a possible cause in the past

https://en.wikipedia.org/wiki/USS_Scorpion_(SSN-589)

Torpedo control technology has moved on since then...

Rgds


By any chance is "astute" in your s/n have anything to do with something related to the Royal Navy....?

We don't know how modernized the sub is, so we could be talking some older technology.

T4thH wrote:
The only good thing is, when you get too deep; the submarine will just implode, this is so fast over, the crew will not even have had time to recognize the implosion itself. So one second all alive, next second, all gone.

RIP.

On the flip side, depending on how long the descent is, you'll know it's coming, and that has to be a pretty awful final few moments of thought.
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ThePointblank
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Re: Indonesian Navy Submarine Missing

Sat Apr 24, 2021 8:41 pm

cjg225 wrote:
astuteman wrote:
A list of what you think these "many things" are would be interesting.....
The reality is that the safety interlocks that exist between the inner and outer doors make this probably the most unlikely cause.
They are a first level safety system with multiple redundancy and 10^-7 safety or better.

Also for reference, firing a torpedo dos not involve opening the submarine's interior to the outside water pressure

Much more likely causes would be:-

Crew error
Some type of system failure
A battery fire.

The "circle runner" torpedo is believed to have been a possible cause in the past

https://en.wikipedia.org/wiki/USS_Scorpion_(SSN-589)

Torpedo control technology has moved on since then...

Rgds


By any chance is "astute" in your s/n have anything to do with something related to the Royal Navy....?

We don't know how modernized the sub is, so we could be talking some older technology.

T4thH wrote:
The only good thing is, when you get too deep; the submarine will just implode, this is so fast over, the crew will not even have had time to recognize the implosion itself. So one second all alive, next second, all gone.

RIP.

On the flip side, depending on how long the descent is, you'll know it's coming, and that has to be a pretty awful final few moments of thought.


The reports I've seen is that the sub last entered a major refit back in 2012 in South Korea, which was reported to be fairly comprehensive, with most of the sub's superstructure, sensors, combat system, and propulsion replaced.
 
N965UW
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Re: Indonesian Navy Submarine Missing

Sat Apr 24, 2021 11:01 pm

T4thH wrote:
The only good thing is, when you get too deep; the submarine will just implode, this is so fast over, the crew will not even have had time to recognize the implosion itself. So one second all alive, next second, all gone.

RIP.


If the crew were alive at the time crush depth was reached, I'd agree.

From https://en.wikipedia.org/wiki/KRI_Nanggala_(402):

After the finding of debris from Nanggala, Yudo Margono stated that the submarine may have cracked instead of exploded, as an explosion would have been detected by sonar.


Depending on the translation, I take this to mean there's a possibility the sub could've flooded at a relatively shallow depth, and by the time it reached crush depth the pressure inside the hull was equalized, and hence there was no "crush."

Purely speculation here, but chances are something went catastrophically wrong well before reaching crush depth, and there were no crew remaining to blow the tanks or otherwise prevent sinking, or even perceive the descent to such depth.

May all aboard rest in peace, and their family and friends find comfort.
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T4thH
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Re: Indonesian Navy Submarine Missing

Sat Apr 24, 2021 11:59 pm

N965UW wrote:
T4thH wrote:
The only good thing is, when you get too deep; the submarine will just implode, this is so fast over, the crew will not even have had time to recognize the implosion itself. So one second all alive, next second, all gone.

RIP.


If the crew were alive at the time crush depth was reached, I'd agree.

From https://en.wikipedia.org/wiki/KRI_Nanggala_(402):

After the finding of debris from Nanggala, Yudo Margono stated that the submarine may have cracked instead of exploded, as an explosion would have been detected by sonar.


Depending on the translation, I take this to mean there's a possibility the sub could've flooded at a relatively shallow depth, and by the time it reached crush depth the pressure inside the hull was equalized, and hence there was no "crush."

Purely speculation here, but chances are something went catastrophically wrong well before reaching crush depth, and there were no crew remaining to blow the tanks or otherwise prevent sinking, or even perceive the descent to such depth.

May all aboard rest in peace, and their family and friends find comfort.

Of the parts found, two have been identified as parts from inside of the submarine. One was a part of the bridge/conning tower (an oiltank for the periscope) and the hull of a torpedo, so from the torpedo room in the front. Or to say it on another way, the front and middle part have most likely imploded, else, these parts would not have found.

There is not much water needed, that a submarine is doomed. It is said, for a submarine in U209 family size, a thumnail big hole for 1 min in 100 m depth is enough and the sub will be doomed. If there was a leakage, it was most likely, that the chambers were not filled, when it reached the crash depth.
"crack" is a nice word, but this is not, what happens, when it fails in crash depth. They completely implodes, so only small parts were left or the hull collapses on the whole lenght or as example, the whole tail section, when the hull fails, is pushed through the whole sub till to the front torpedo room.
In crash depth, they always fail suddenly, complete and all is over in parts of a second. For this, I would not use the word "crack", the term "implode" fits best.
 
astuteman
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Re: Indonesian Navy Submarine Missing

Sun Apr 25, 2021 6:17 am

cjg225 wrote:
By any chance is "astute" in your s/n have anything to do with something related to the Royal Navy....?


It might have ... :)


cjg225 wrote:
We don't know how modernized the sub is, so we could be talking some older technology.

T4thH wrote:
The only good thing is, when you get too deep; the submarine will just implode, this is so fast over, the crew will not even have had time to recognize the implosion itself. So one second all alive, next second, all gone.

RIP.

On the flip side, depending on how long the descent is, you'll know it's coming, and that has to be a pretty awful final few moments of thought.



By definition a 40 year old sub is an old design, but the type 209 is very well known design, with 61 being built and operated by 13 navies (those numbers may not sound big, but 61 of one design of submarine is a HUGE number .....)

https://en.wikipedia.org/wiki/Type_209_submarine

Comprehensive bow cap interlocks were introduced (in the UK certainly) after the Thetis disaster in 1939

https://en.wikipedia.org/wiki/HMS_Thetis_%28N25%29

I'm not saying its impossible, but tube flooding is in my mind less likely than a battery fire, or a hull valve failure, or a control system failure, or an operator error.
Horrible way to go, whatever - especially if the hull was flooding and pressure equalising at the same time.

A crush is pretty quick, the cause of death ironically being scalded to death by adiabatic heating, rather than drowning, as you might think

https://en.wikipedia.org/wiki/Adiabatic_process

Rgds
 
ltbewr
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Re: Indonesian Navy Submarine Missing

Sun Apr 25, 2021 9:15 am

One has to wonder, that if like with pressurized aircraft, there is a finite limit of cycles of compression/decompression for submarines, even if extensively rebuilt. As some have noted, only a small crack can doom a sub. Like with aircraft, you could have a small stress crack develop that over time wasn't seen in maintenance and gives way suddenly. This sub was 40 some years old and one cannot ignore that potential cause of this loss of crew.
 
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cjg225
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Re: Indonesian Navy Submarine Missing

Sun Apr 25, 2021 3:15 pm

astuteman wrote:
It might have ... :)

Good to know for purposes of this conversation, then. :D

astuteman wrote:
Comprehensive bow cap interlocks were introduced (in the UK certainly) after the Thetis disaster in 1939

https://en.wikipedia.org/wiki/HMS_Thetis_%28N25%29

I'm not saying its impossible, but tube flooding is in my mind less likely than a battery fire, or a hull valve failure, or a control system failure, or an operator error.
Horrible way to go, whatever - especially if the hull was flooding and pressure equalising at the same time.


Well, now I know where Ice Station Zebra got that scene from...

astuteman wrote:
A crush is pretty quick, the cause of death ironically being scalded to death by adiabatic heating, rather than drowning, as you might think

https://en.wikipedia.org/wiki/Adiabatic_process

Rgds

I would've thought it would've been essentially being crushed instead of any other cause. Interesting, though; maybe I'd heard that before but just had forgotten.
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ltbewr
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Re: Indonesian Navy Submarine Missing

Sun Apr 25, 2021 3:25 pm

astuteman wrote:
A crush is pretty quick, the cause of death ironically being scalded to death by adiabatic heating, rather than drowning, as you might think

https://en.wikipedia.org/wiki/Adiabatic_process

Rgds

I would've thought it would've been essentially being crushed instead of any other cause. Interesting, though; maybe I'd heard that before but just had forgotten.[/quote]

Is this related to 'the bends' like when a deep diver go up too quickly, boiling the nitrogen in the blood ?
 
VSMUT
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Re: Indonesian Navy Submarine Missing

Sun Apr 25, 2021 3:36 pm

ltbewr wrote:
Is this related to 'the bends' like when a deep diver go up too quickly, boiling the nitrogen in the blood?


No, that is a different thing. An adiabatic process is more like cumulonimbus clouds rising up through the atmosphere. It is the method used by a diesel engine to combust the fuel-air mixture. Increasing the pressure increases the temperature, decreasing it brings it down.
 
astuteman
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Re: Indonesian Navy Submarine Missing

Sun Apr 25, 2021 3:45 pm

VSMUT wrote:
ltbewr wrote:
Is this related to 'the bends' like when a deep diver go up too quickly, boiling the nitrogen in the blood?


No, that is a different thing. An adiabatic process is more like cumulonimbus clouds rising up through the atmosphere. It is the method used by a diesel engine to combust the fuel-air mixture. Increasing the pressure increases the temperature, decreasing it brings it down.


A little rule of thumb is that every 10m depth adds 1 atmosphere to pressure,
If she crushed at say 1,000ft, or 300m, that would equate to 30 atmospheres. A bit like a diesel engine with a compression ratio of 30:1
Says it all really.
20:1 or so for a diesel is enough to ignite the fuel.....

https://en.wikipedia.org/wiki/Compressi ... el_engines

Diesel engines use higher compression ratios than petrol engines, because the lack of a spark plug means that the compression ratio must increase the temperature of the air in the cylinder sufficiently to ignite the diesel using compression ignition. Compression ratios are often between 14∶1 and 23∶1 for direct injection diesel engines, and between 18∶1 and 23∶1 for indirect injection diesel engines.


I wonder if they'll recover the hull to assess the cause?

Rgds
 
VSMUT
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Re: Indonesian Navy Submarine Missing

Sun Apr 25, 2021 4:00 pm

astuteman wrote:
VSMUT wrote:
ltbewr wrote:
Is this related to 'the bends' like when a deep diver go up too quickly, boiling the nitrogen in the blood?


No, that is a different thing. An adiabatic process is more like cumulonimbus clouds rising up through the atmosphere. It is the method used by a diesel engine to combust the fuel-air mixture. Increasing the pressure increases the temperature, decreasing it brings it down.


A little rule of thumb is that every 10m depth adds 1 atmosphere to pressure,
If she crushed at say 1,000ft, or 300m, that would equate to 30 atmospheres. A bit like a diesel engine with a compression ratio of 30:1
Says it all really.
20:1 or so for a diesel is enough to ignite the fuel.....


Or 27 ft per hPa at sea level. AFAIK, its an exponential curve. The increase will be way higher once you go down a bit.
 
T4thH
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Re: Indonesian Navy Submarine Missing

Sun Apr 25, 2021 11:50 pm

I have not seen the news here, that the wreck has been found hours ago. Some additional information. The sub, or to say it correctly the three main parts of the sub have been found in 838 m depth. So three main parts and debris around. A ROV was already down there.
In German: https://www.n-tv.de/panorama/Marine-findet-vermisstes-U-Boot-article22513151.html
 
cpd
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Re: Indonesian Navy Submarine Missing

Sun Apr 25, 2021 11:55 pm

I hope the crew didn't suffer too much - that's a terrible tragedy.

RIP and sincere condolences to the families of the crew and all of there colleagues/friends. :(
 
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Aesma
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Re: Indonesian Navy Submarine Missing

Wed Apr 28, 2021 6:05 pm

I suppose there are tools similar to those used in aviation to estimate the fatigue of metal. Looking up for it you sometimes see quite young submarines being retired, but it might be because the maintenance is too much for countries without big ambitions.

The French Marine Nationale is getting a new sub made from two halves of two different subs, one decommissioned and one half burned : https://edition.cnn.com/2021/04/14/euro ... gfooterold
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frmrCapCadet
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Re: Indonesian Navy Submarine Missing

Wed Apr 28, 2021 6:16 pm

'adiabatic process' sounds perfectly horrible in a collapsing sub, but how long does the collapse itself take? Both processes may be faster than nerves travel to register pain (one could hope).
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Sokes
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Re: Indonesian Navy Submarine Missing

Sun May 02, 2021 5:03 am

ltbewr wrote:
One has to wonder, that if like with pressurized aircraft, there is a finite limit of cycles of compression/decompression for submarines, even if extensively rebuilt. As some have noted, only a small crack can doom a sub. Like with aircraft, you could have a small stress crack develop that over time wasn't seen in maintenance and gives way suddenly. This sub was 40 some years old and one cannot ignore that potential cause of this loss of crew.

That sounds likely.
I also don't understand how to overhaul such a very old sub.
In a plane one has a wing and wingbox worth saving. But in a sub, why not just rebuild the full body?

How many such old subs in the world?
Why can't the world be a little bit more autistic?
 
T4thH
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Re: Indonesian Navy Submarine Missing

Sun May 02, 2021 6:26 am

frmrCapCadet wrote:
'adiabatic process' sounds perfectly horrible in a collapsing sub, but how long does the collapse itself take? Both processes may be faster than nerves travel to register pain (one could hope).

In regular cases, when it just implodes below the crash depth; in parts of a second. So the horrible part is the time, when the crew recognizes, they have lost, they have no chance, to stop the sub on the way down and the part of the second, when everything is over. When it implodes, the crew will be immediately killed by the adiabatic process, smashed by the incoming wall of water, smashed by the incoming wall water against something, smashed by the collapsing hull or all together and everything in a part of a second.
As the sub is broken into three big parts and many debris around, there was an implosion, else it would not have been so totally destroyed.
 
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Aesma
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Re: Indonesian Navy Submarine Missing

Sun May 02, 2021 3:03 pm

Sokes wrote:
ltbewr wrote:
One has to wonder, that if like with pressurized aircraft, there is a finite limit of cycles of compression/decompression for submarines, even if extensively rebuilt. As some have noted, only a small crack can doom a sub. Like with aircraft, you could have a small stress crack develop that over time wasn't seen in maintenance and gives way suddenly. This sub was 40 some years old and one cannot ignore that potential cause of this loss of crew.

That sounds likely.
I also don't understand how to overhaul such a very old sub.
In a plane one has a wing and wingbox worth saving. But in a sub, why not just rebuild the full body?

How many such old subs in the world?


Personally I don't really understand how a sub is even possible, with all the plumbing, all the valves, temperature management, oxygen management... It's basically like a space station, except space (low earth orbit to be precise, it makes a difference) is quite stable, the pressure (lack of) doesn't change, everything is done carefully whereas a sub is made for war so things have to be done in a hurry.
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petertenthije
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Re: Indonesian Navy Submarine Missing

Sun May 02, 2021 3:30 pm

Sokes wrote:
I also don't understand how to overhaul such a very old sub.
In a plane one has a wing and wingbox worth saving. But in a sub, why not just rebuild the full body?

How many such old subs in the world?

Submarines, when maintained properly, can get very old.

The oldest one is the Taiwanese SS-791 Hai Shih. It's a US build Tench-class submarine that was launched in april 25th 1945 as the USS Cutlass. It was refitted a few years ago and is expected to remain in service till 2026.
https://nationalinterest.org/blog/the-b ... ears-19150
https://en.wikipedia.org/wiki/USS_Cutlass_(SS-478)
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