Lost Indonesian Submarine

[Steelyeyes]

1. The cause of the sinking?
2. Curious to know if that is possible.
3. The sub has broken into 3 parts so relatively less bulky to lift

If they're going to spend money it should be to replace their 40 year old junkers with more modern and trustworthy equipment.

 

[Bob DBF]

As far as the Lomboc Strait goes, during WWII it was used as a transit, both surface and submerged for US submarines. The knowledge of the underwater currents there increased as the war progressed, but it was used regardless. This was that boat's backyard, the knowledge of currents in the area has increased considerably, and the boat and crew operated in the area, I would doubt that this was a factor.

My guess would be a casualty the was not addressed quickly enough, possibly exerbated by the number of riders onboard. Also an issue with this type of submarine is that the pressure hull is one compartment. If there is any casualty, it cannot be contained by closing watertight doors, isolating the problem. Fire/smoke, flooding, and so on, will effect everyone immediately making recovery fast or impossible.

 

[Akimbo]

Also an issue with this type of submarine is that the pressure hull is one compartment.

Initially, that shocked me until it dawned on me that flooding a compartment (except possibly an escape lock) would send any boat to the bottom, which is crush depth in most cases.

Do you (or anyone else) remember a failure of an internal torpedo hatch? Those always struck me as a weak point for mechanical and/or operator error since they are not pressure seating. I can't imagine that WWI era boats had reliable interlocks. The only non-pressure seating penetration I can think of that might be larger than a torpedo tube is the main induction valve on diesel boats — OK, they are pressure seating but mechanically held open. If I remember correctly, the failed main induction on the Squalus was 36".

I don't recall any external hatches on decompression chamber medical/utility locks but there was a bell mating clamp failure due to operator error. For other readers, submarine and diving system hatches are pressure seating except those mentioned. This means that the pressure forces them closed instead of trying to blow them open against mechanical locking mechanisms. Non-pressure seating systems also have a greater risk of the seal blowing out.

 

[Bob DBF]

Initially, that shocked me until it dawned on me that flooding a compartment (except possibly an escape lock) would send any boat to the bottom, which is crush depth in most cases.

There is flooding and Flooding. It's a matter of how fast the leak can be stopped, and how fast the water can be pumped out. I was in a flooding submarine, and I'm still here, so it isn't an automatic trip to the bottom.

The reason I brought up the large number of riders on a small boat, is that if you are on your way to close a hull valve to stop the flooding and you have to get people out of the way to access the valve, you lose time. Time is not your friend in a casualty. Not only does more water come into the boat, but it has more time to affect other systems like shorting out electrical.

Another issue with diesel electric submarines is a battery explosion and fire. If it happened while snorkeling, the bubble could be lost and never recovered. The USS Cochino sank off Norway, the story of how the crew was saved is worth reading.

There all manner of casualties that could happen. As I was told, "it takes a crew to run a submarine, but only one man to sink it."

Do you (or anyone else) remember a failure of an internal torpedo hatch? Those always struck me as a weak point for mechanical and/or operator error since they are not pressure seating. I can't imagine that WWI era boats had reliable interlocks.

Not offhand. The torpedo tubes on Nuc subs, when I was in were basicly, if not, the same tubes used on WWII and used the same interlocks, so I'm figuring it was an exceptionally good system. I have read about fleet boat disconnecting them to deal with a torpedo stuck partway out of the tube. Of course fleet boats could get the tubes above the water level.

 

[Dan]

There is flooding and Flooding. It's a matter of how fast the leak can be stopped, and how fast the water can be pumped out. I was in a flooding submarine, and I'm still here, so it isn't an automatic trip to the bottom.

The reason I brought up the large number of riders on a small boat, is that if you are on your way to close a hull valve to stop the flooding and you have to get people out of the way to access the valve, you lose time. Time is not your friend in a casualty. Not only does more water come into the boat, but it has more time to affect other systems like shorting out electrical.

Another issue with diesel electric submarines is a battery explosion and fire. If it happened while snorkeling, the bubble could be lost and never recovered. The USS Cochino sank off Norway, the story of how the crew was saved is worth reading.

There all manner of casualties that could happen. As I was told, "it takes a crew to run a submarine, but only one man to sink it."



Not offhand. The torpedo tubes on Nuc subs, when I was in were basicly, if not, the same tubes used on WWII and used the same interlocks, so I'm figuring it was an exceptionally good system. I have read about fleet boat disconnecting them to deal with a torpedo stuck partway out of the tube. Of course fleet boats could get the tubes above the water level.

I guess over loading the crews from the originally designed for 38 crews to the latter 53 crews had made things worse too.

KRI Nanggala (402) - Wikipedia

 

[Bob DBF]

I guess over loading the crews from the originally designed for 38 crews to the latter 53 crews had made things worse too.

KRI Nanggala (402) - Wikipedia

From what I can read from the link is the normal crew of the sub is 34 with a contingent of special forces numbering 16, making a total complement of 50. At the time of the accident there was only 49 of the ships complement, and 4 riders. I walk back my opinion of people in the way, as anyone assigned to the ship would know how to act during drills and casualties. If they have a long term assignment aboard they could possibly have qualified on subs, making them an asset in an emergency.

Having a larger complement only decreases the habilitability on the boat and reduces the time it can be deployed before running out of food. With a costal submarine this is not a big issue, as you are relatively close to base.

From your link.
"The navy subsequently sent a distress call to the International Submarine Escape and Rescue Liaison Office at around 09:37 to report the boat as missing and presumably sunk.[37] The navy stated that it was possible that Nanggala experienced a power outage before falling to a depth of 600–700 m (2,000–2,300 ft)"

There are numerous ways for a power outage to occur, both flooding and battery explosion/fire are two.

 

[Centrals]

Technically, nearly all of the KRI Nanggala could be recovered. Practically, which really means financially, no.

Thank you.
Technically possible is the part that I like to know.
Practically is another issue.

 

[Dan]

From what I can read from the link is the normal crew of the sub is 34 with a contingent of special forces numbering 16, making a total complement of 50. At the time of the accident there was only 49 of the ships complement, and 4 riders. I walk back my opinion of people in the way, as anyone assigned to the ship would know how to act during drills and casualties. If they have a long term assignment aboard they could possibly have qualified on subs, making them an asset in an emergency.

Having a larger complement only decreases the habilitability on the boat and reduces the time it can be deployed before running out of food. With a costal submarine this is not a big issue, as you are relatively close to base.

From your link.
"The navy subsequently sent a distress call to the International Submarine Escape and Rescue Liaison Office at around 09:37 to report the boat as missing and presumably sunk.[37] The navy stated that it was possible that Nanggala experienced a power outage before falling to a depth of 600–700 m (2,000–2,300 ft)"

There are numerous ways for a power outage to occur, both flooding and battery explosion/fire are two.

Or another failure in torpedo firing refit work.

From the same article:
“Indonesian People's Representative Council member and retired major general of the Indonesian Army Tubagus Hasanuddin suspected that the refit, performed by a South Korean firm in 2012, may not have been performed properly. He stated that after the refit, the submarine had failed a torpedo firing test, which resulted in three deaths.”

Why wouldn’t the refit work be done by OEM?

 

[Bob DBF]

Or another failure in torpedo firing refit work.

From the same article:
“Indonesian People's Representative Council member and retired major general of the Indonesian Army Tubagus Hasanuddin suspected that the refit, performed by a South Korean firm in 2012, may not have been performed properly. He stated that after the refit, the submarine had failed a torpedo firing test, which resulted in three deaths.”

Why wouldn’t the refit work be done by OEM?

I'd have to hear about the accident, any manner of things can go bad on a submarine without being the builders fault. A politician posturing is nothing new, I believe they were in contract for three new type 209 variants, so it couldn't have them that upset.

Price would be one reason not to ship it back to Germany, availability and time would be another. Also, DMSE is a large shipbuilder in Korea and has a submarine refitting, upgrading, and building type 209 variants for the Korean Navy. Their first submarine, Jang Bogo, was commissioned back in 1993. They have built ten and refitted, including upgrading some of those.

I was on the SSBN 619 that was built at Mare Island, California but was refitted and upgraded at Portsmouth, New Hampshire. As long as the shipyard has the expertise, it makes no difference which one is used.

 

[Centrals]

ROV should be able to send more close-up detail of the wreck.
850m is nothing for most of them.