damagelethality of depth charges

[rtrapasso]

ORIGINAL: herwin

You're asking for classified information.

hmmm - not sure if you are implying that such data exists, or not... [:D]

Anyway - subs, despite the immense stresses that they are built to withstand, are amazingly delicate. Some years ago (5 or 6, iirc) i went through various sources and tried to find all subs that had been involved in "bumping" incidents - generally US subs and Russian subs grazing each other while underwater, generally at pretty low relative speeds.

IIRC - every one of these subs either never sailed again, or was retired very soon.

i am not sure about some of the more recent collisions - where the one sub hit the seamount while traveling at high speed, etc.

[herwin]

ORIGINAL: rtrapasso

ORIGINAL: herwin

You're asking for classified information.

hmmm - not sure if you are implying that such data exists, or not... [:D]

Anyway - subs, despite the immense stresses that they are built to withstand, are amazingly delicate. Some years ago (5 or 6, iirc) i went through various sources and tried to find all subs that had been involved in "bumping" incidents - generally US subs and Russian subs grazing each other while underwater, generally at pretty low relative speeds.

IIRC - every one of these subs either never sailed again, or was retired very soon.

i am not sure about some of the more recent collisions - where the one sub hit the seamount while traveling at high speed, etc.

"Crazy Ivan!"

The Soviet and American submariners played grab ass throughout the Cold War. Not much of that ever got reported.

Modern nuclear boats of all navies are built to be quiet. That makes them vulnerable to shock.

[DuckofTindalos]

I'd prefer to have a modern AIP diesel-electric to a nuc boat. They're stealthier.

[rtrapasso]

"Crazy Ivan!"

The Soviet and American submariners played grab ass throughout the Cold War. Not much of that ever got reported.

Yeah, it was kinda tricky finding all that stuff and trying to put it together.

[herwin]

ORIGINAL: Terminus

I'd prefer to have a modern AIP diesel-electric to a nuc boat. They're stealthier.

And slower. YMMV.

[herwin]

ORIGINAL: rtrapasso

"Crazy Ivan!"

The Soviet and American submariners played grab ass throughout the Cold War. Not much of that ever got reported.

Yeah, it was kinda tricky finding all that stuff and trying to put it together.

It's awfully easy to get it wrong.

Google "harry erwin" "submarine combat system"

[rtrapasso]

It's awfully easy to get it wrong.

In this case, i found a list of collisions that the Soviets had accused the USN of provoking. Some of them were bogus, however, many did prove to be true and i traced down the semi-official reports quoted in Jane's, and USNI books and publications. They would quote official USN statements.

Of course, there *may* have been many more that took place that we never heard about...

[DuckofTindalos]

ORIGINAL: herwin

ORIGINAL: Terminus

I'd prefer to have a modern AIP diesel-electric to a nuc boat. They're stealthier.

And slower. YMMV.

And shorter-ranged... and smaller... I know, but still...

[ChezDaJez]

Modern nuclear boats of all navies are built to be quiet. That makes them vulnerable to shock.

Actually, just the opposite, Herwin. Because most things in US subs are sound-isolated from the hull, they are better able to absorb shock. Think of the sound isolators as being giant shock absorbers. Doesn't mean they are invulnerable, just a little more resistant.

However, shock can be a major mission kill component. You don't have to hard kill a sub to make him ineffective. You just have to deliver a big enough shock to uncage his gyros. Without gyros, the boat loses all navigational and targeting ability. A SSBN is expecially vulnerable to this. Once the gyros have been uncaged, it takes some time to realign them and the new position is likely to have some induced error... at least until the boat can come close enough to the surface to obtain a sat fix. If the gyros have been damaged, its pretty much game over as the boat will have no attitude information when submerged.

Terminus, you are correct. A modern diesel boat tends to be much quieter than a nuc when submerged though with the advances being made in sound quieting, nucs are pretty much "in the grass" also. The diesel is perfectly suited to shallow areas such as the Baltic, the Med and the Sea of Japan whereas the nuc is much better suited to the open ocean. A diesel sub is a much more difficult beast to locate in shallow water than a nuc in the deep ocean.

rtrapasso: In my ASW years, I was privvy to many of the reports concerning collisions with USSR subs and our own subs and ships. Some of them made for great reading, others were in the "OMG, what were they thinking/" category. The two best public ones IMO were the collisions between the USS Voge and an Echo II SSGN in the Med and the Kitty Hawk and a Victor SSN in the Sea of Japan.

The Echo II was trying to cut the towed array cable on the Voge and was running with just part of the sail awash when she cut astern of the Voge. Unfortunately, the Sov sub miscalculated and rammed the stern of the Voge who lost her prop. The Sov sub immediately surfaced and deep gashes on her hull was visible. The sub claimed the Voge cut across her bow but the entire sequence was filmed from the Voge and it was obvious what had happened.

The Victor had the misfortune of trying to surface in front of the Kitty Hawk in the Sea of Japan and got run over by the carrier. The sub was actually relatively undamaged from the actual collision with the exception of some major dents. The real damage occurred when the sub rolled 360 degrees as a result of the collision and the carrier's wake. Most of the sub crew was injured and the reactor automatically scrammed. It was damaged enough where the boat spent quite a bit of time in the yards for recoring.

One other Soviet sub incident I personally witnessed was with a Juliett SSG near the Straits of Gibraltar in 1980. We had intell that a Juliett was operating in the Alboran Basin and may attempt to transit the straits. We were flying a night FLIR/ESM mission investigating all surface contacts in the area. As the Soviet diesels tended to operate on the surface at night, we were covert (no lights, radar, radio, etc). About 2 hours into the mission, we detected 2 sweeps of a Snoop Slab radar on our ESM equipment and immediately began a run in down the line of bearing. We were at 300 feet and identified the sub about 5 miles ahead on the FLIR (infrared). We we were coming up the stern so our mission commander decided to do a simulated attack. We opened the bomb bay doors (they were empty) and deployed a SSQ-47 (active sonar)sonobuoy from the belly just as we marked on top the sub.

The sub was taken completely by surprise (he would have been dead if we had been at war) and attempted a crash dive. As we came back around, we could see the bow of the sub go under very fast but the stern lifted clear of the water and we could see the two 5-bladed props spinning in the air. The boat hung at about a 60 degree down angle for several minutes before finally sliding under. I can only imagine the pandemonium that must have occurred on that boat! Given that the water is only about 300 feet deep there, I always wondered whether he struck bottom or not. This whole sequence was caught on film also. I wish I had a copy of it.

We did end up pounding his butt until we ran out of active buoys. BTW, the first SSQ-47 we put on top of him didn't yield contact for several minutes as the sub was within the buoy's cone of silence (<100yards). Plus it didn't help that only half of the sub was underwater!!!

These were my favorite type flights.. the ones where you found a sub that nobody knew about or ones where the sub hadn't been actively prosecuted in awhile. When we were "flapping" (round-the-clock ASW ops), it could actually become boring tracking the Soviet SSBNs as they normally transitted at a set course and speed and seldom deviated from it. Those were the times I tell my Sensor 2 to take over while I grabbed some shut eye. The SSNs however were a little less obliging and would often pull a course change just to keep me awake!

Chez

[Speedysteve]

Chez,
&nbsp;
Not related to WiTP I know but related to your comments. Not sure if yiou have any thoughts on this. If not apologies.
&nbsp;
I remember the good old days of Harpoon. The Akula class - I hated them. How were they rated as far as you know?

[rtrapasso]

ORIGINAL: ChezDaJez

Modern nuclear boats of all navies are built to be quiet. That makes them vulnerable to shock.

Actually, just the opposite, Herwin. Because most things in US subs are sound-isolated from the hull, they are better able to absorb shock. Think of the sound isolators as being giant shock absorbers. Doesn't mean they are invulnerable, just a little more resistant.

However, shock can be a major mission kill component. You don't have to hard kill a sub to make him ineffective. You just have to deliver a big enough shock to uncage his gyros. Without gyros, the boat loses all navigational and targeting ability. A SSBN is expecially vulnerable to this. Once the gyros have been uncaged, it takes some time to realign them and the new position is likely to have some induced error... at least until the boat can come close enough to the surface to obtain a sat fix. If the gyros have been damaged, its pretty much game over as the boat will have no attitude information when submerged.

Terminus, you are correct. A modern diesel boat tends to be much quieter than a nuc when submerged though with the advances being made in sound quieting, nucs are pretty much "in the grass" also. The diesel is perfectly suited to shallow areas such as the Baltic, the Med and the Sea of Japan whereas the nuc is much better suited to the open ocean. A diesel sub is a much more difficult beast to locate in shallow water than a nuc in the deep ocean.

rtrapasso: In my ASW years, I was privvy to many of the reports concerning collisions with USSR subs and our own subs and ships. Some of them made for great reading, others were in the "OMG, what were they thinking/" category. The two best public ones IMO were the collisions between the USS Voge and an Echo II SSGN in the Med and the Kitty Hawk and a Victor SSN in the Sea of Japan.

The Echo II was trying to cut the towed array cable on the Voge and was running with just part of the sail awash when she cut astern of the Voge. Unfortunately, the Sov sub miscalculated and rammed the stern of the Voge who lost her prop. The Sov sub immediately surfaced and deep gashes on her hull was visible. The sub claimed the Voge cut across her bow but the entire sequence was filmed from the Voge and it was obvious what had happened.

The Victor had the misfortune of trying to surface in front of the Kitty Hawk in the Sea of Japan and got run over by the carrier. The sub was actually relatively undamaged from the actual collision with the exception of some major dents. The real damage occurred when the sub rolled 360 degrees as a result of the collision and the carrier's wake. Most of the sub crew was injured and the reactor automatically scrammed. It was damaged enough where the boat spent quite a bit of time in the yards for recoring.

One other Soviet sub incident I personally witnessed was with a Juliett SSG near the Straits of Gibraltar in 1980. We had intell that a Juliett was operating in the Alboran Basin and may attempt to transit the straits. We were flying a night FLIR/ESM mission investigating all surface contacts in the area. As the Soviet diesels tended to operate on the surface at night, we were covert (no lights, radar, radio, etc). About 2 hours into the mission, we detected 2 sweeps of a Snoop Slab radar on our ESM equipment and immediately began a run in down the line of bearing. We were at 300 feet and identified the sub about 5 miles ahead on the FLIR (infrared). We we were coming up the stern so our mission commander decided to do a simulated attack. We opened the bomb bay doors (they were empty) and deployed a SSQ-47 (active sonar)sonobuoy from the belly just as we marked on top the sub.

The sub was taken completely by surprise (he would have been dead if we had been at war) and attempted a crash dive. As we came back around, we could see the bow of the sub go under very fast but the stern lifted clear of the water and we could see the two 5-bladed props spinning in the air. The boat hung at about a 60 degree down angle for several minutes before finally sliding under. I can only imagine the pandemonium that must have occurred on that boat! Given that the water is only about 300 feet deep there, I always wondered whether he struck bottom or not. This whole sequence was caught on film also. I wish I had a copy of it.

We did end up pounding his butt until we ran out of active buoys. BTW, the first SSQ-47 we put on top of him didn't yield contact for several minutes as the sub was within the buoy's cone of silence (<100yards). Plus it didn't help that only half of the sub was underwater!!!

These were my favorite type flights.. the ones where you found a sub that nobody knew about or ones where the sub hadn't been actively prosecuted in awhile. When we were "flapping" (round-the-clock ASW ops), it could actually become boring tracking the Soviet SSBNs as they normally transitted at a set course and speed and seldom deviated from it. Those were the times I tell my Sensor 2 to take over while I grabbed some shut eye. The SSNs however were a little less obliging and would often pull a course change just to keep me awake!

Chez

Great stuff!! Thanks!!! [&o]

[ChezDaJez]

The Akula class - I hated them. How were they rated as far as you know?

I don't remember how they were rated in the game but they should have been rated similar to the early Los Angeles class boats. The Akula is a very capable submarine, especially the Akula II. They are pretty quiet and can generally go deeper than our own as they are more robustly built. They are also pretty maneuverable. They also have the same powertrain as the Sierra and the Oscar though the Oscar has two powertrains. The powertrains are of the same design though.

I think the Akula is one of the best SSNs the Russians have built. Unfortunately, I have been out of the field long enough that newer classes have come along that I don't know anything about. Same with our boats. I know very little about the SSN-21 Seawolf powertrains.

I have never had the pleasure of flying against a Sierra but I do have quite a few hours in contact on the Akula and the Oscar classes. For a large sub, the Oscar is amazingly quiet, somewhere in between a SSBN and a SSN for noise levels.
I also had the opportunity to fly one flight on a Typhoon but she was surface most of the time. Can't believe just how big that boat is! It looks as though you could land on her deck!

BTW, Russian submarines are typed by their powertrains, not their mission. We did this because there were times when SOSUS are some other passive sensor would pick up the signs of a particular powertrain but couldn't resolve it any further. The type designations we used are as follows:
Type 1 Nuc: Hotel, Echo, November
Type 2 Nuc: Charlie, Victor
Type 3 Nuc: Yankee, Delta
Type 4 Nuc: Papa
Type 5 Nuc: Alfa
Type 6 Nuc: Sierra, Oscar, Akula
Type 7 Nuc: Typhoon
Type 8 Nuc: Mike

We did the same with their diesels:
Type 1 Dsl: Foxtrot I, Whiskey, Romeo, Zulu, Golf I, II
Type 2 Dsl: Juliett, Bravo
Type 3 Dsl: Foxtrot III, Tango, Golf III, V
Type 4 Dsl: Kilo

BTW, I have had the opportunity to fly with, or debrief crews from Britain, Germany, Japan, Australia and Canada and I must say I've been impressed with them all. Every one of these countries have very good airborne ASW forces. I've always believed that if a non-nuclear war had come between the Soviets and the Allies, we would have destroyed 90% of the Soviet subs at sea within the first 24 hours. Those that survived wouldn't live much longer.

I got to fly in a Nimrod with 206 Sqdn from Kinloss during a NATO exercise out of Gibraltar. I was very impressed with the Marconi sonar gear. Very comparable to our AQA-7 series and in some ways better. It was a bit disconcerting though to be down at 100 feet, at night, in a 45 degree angle of bank in an airplane that has a wingspan much greater than 100 feet!

I also flew with a German crew in an Atlantique during the same exercise. I had never considered the Atlantique to be a very capable ASW bird prior to my flight but the crew made me eat my thoughts. The were outstanding at shallow water ASW! They are also crazy flyers!!!

The Japanese are also outstanding. They are probably the premier shallow water experts. They seem to be able to sniff out diesel subs that no one else can

I never got to fly with the Aussies or the Canadians. I have debriefed many of their crews though and they are also very good though I think the Canadians made a mistake when they purchased the OL-82 sonar suite for their Auroras. Thats the same system that the S-3A used and the S-3A couldn't find a submarine in a bathtub. Thats probably more a function of the carrier admirals using them for everything but ASW. Still, the system itself has some major deficiencies.

Unfortunately, I think we also took a major step backward with the P-3C Update III sonar suite, the UYS-1. The AQA-7V 10/11 gear installed in previous versions was an outstanding piece of gear. Easy to maintain, simple to operate and a good operator could make it sing. Plus the paper grams provided a contact history that was hard to beat.

The UYS-1 basic system was very good but they paired it with a low-res, logarythmic display that basically washed out all the frequency characterisitics that a good operator needs to identify a frequency source. So it eventually became a frequency numbers matching game... pretty useless when you are in an area where ships are producing frequencies similar to the ones you're looking for.

Anyways, now that I've given away all of our secrets, I better go hide. Think I'll answer the knock at the door first...

Chez

[herwin]

Whoa--back 20 years! I agree that flexible mountings for machinery reduce the shock hazard as long as the range of movement allowed for is less than that produced by the pressure wave. If the range of motion exceeds that limit, you get hard contact, just like when you bottom your shocks. Then with the shock front penetrating to the machinery, you can get more motion for a longer time due to the reduced inertia and the flexible mountings. Come to think of it, the gyros were probably the most vulnerable component, although sub crew took pride in being able to fix practically anything.

[Speedysteve]

Thanks for that Chez. Very interesting reading[:)]

[ChezDaJez]

The part of your earlier statement that I disagreed with was the part where you said sound isolation on modern nuclear boats makes them vulnerable to shock damage. The implication I got was that they were more vulnerable to shock damage than were boats without sound isolation. Maybe I read too much into it, if so please accept my regrets.

I do agree that there is a finite limt to just how much shock they can handle before damage is incurred. It probably doesn't provide a great deal of protection but some is better than none.

It's a similar principle to earthquake "proofing" a building by putting it on rollers and shock absorbers as opposed to a building that has none.

Chez

[DuckofTindalos]

Very nice rundown on Russian subs and Allied ASW, Chez. Muchas Gracias!

[herwin]

ORIGINAL: ChezDaJez

The part of your earlier statement that I disagreed with was the part where you said sound isolation on modern nuclear boats makes them vulnerable to shock damage. The implication I got was that they were more vulnerable to shock damage than were boats without sound isolation. Maybe I read too much into it, if so please accept my regrets.

I do agree that there is a finite limt to just how much shock they can handle before damage is incurred. It probably doesn't provide a great deal of protection but some is better than none.

It's a similar principle to earthquake "proofing" a building by putting it on rollers and shock absorbers as opposed to a building that has none.

Chez

Right, what you lose on the straightaways, you gain back on the roundabouts. The flexible mountings work by reducing the energy that gets through, but that also means the mass of the hardware on the mountings is smaller, so if the isolation is overwhelmed, the acceleration is potentially greater. There are innumerable tradeoffs involved.

I was a systems engineer, not someone in the trenches, so a lot of my perspective is--by definition--wrong.

[jeffs]

Just a few comments (back to WW2)
&nbsp;
In May 1943 the Germans lost around 30 subs (In large part because Adm King finally relented and allowed bombers to be used in Iceland to close the ASW gap). On of the U-Boats sunk contained the son of Adm Donitz
&nbsp;
&nbsp;hedgehogs would not have rattles as they were activated by direct hits. It is thought one could kill a sub, 2 or 3 almost certainly would. The USS England killed 6 subs in 2 weeks with hedgehogs.
&nbsp;
Where ASW is poorly (or not as the case might be) in WITP is the effectiveness of allied subs. I think they sunk 25 to 30 IJN subs were sunk by allied subs (one can find out what happened to every IJN sub here...I got half way through and found 15 subs killed by allied subs).
&nbsp;
So giving allied air/DDs an extra advantage, while not optimal, makes up for the lack of sub ASW (only 1 allied sub was sunk by a Japanese sub).

[Nikademus]

According to Clay Blair IIRC...the biggest statisical killer of Uboats were aircraft, particularily ultra long range B-24's

[Sardaukar]

And especially during night with radar and powerful searchlights called "Leigh Lights" or something. And then there was that homing torpedo "Fido" later too. 72 U-boats sunk by Liberators alone, 70 of those by RAF Coastal Command Liberators.