Is FIDO (air-dropped homing torpedo) modelled in game or any mod ?

[bookworm_020]

Bold is in both Stock and GWX versions of the game.

[XanderF]

Originally Posted by Puster Bill

I haven't read anything in the literature suggesting that the Germans knew about FIDO, even though they *SHOULD* have known, or at least suspected.

At the point in the war where the Allies started using FIDO (mid-year 1943), Nazi Germany had substantially larger issues to worry about. And given only 264 attacks with it during the entire war compared to the literally TENS of thousands of depth charges deployed, and thousands of 'squid' and 'hedgehog' deploys....I mean, there were more sorties from Germany's Me-262 jet aircraft, and we all know how big a difference THAT (failed to) make.

[ReM]

Originally Posted by XanderF

At the point in the war where the Allies started using FIDO (mid-year 1943), Nazi Germany had substantially larger issues to worry about. And given only 264 attacks with it during the entire war compared to the literally TENS of thousands of depth charges deployed, and thousands of 'squid' and 'hedgehog' deploys....I mean, there were more sorties from Germany's Me-262 jet aircraft, and we all know how big a difference THAT (failed to) make.

Besides that it was doctrine to only use FIDO's in deep water away from shallows or a coastline in order to avoid a dud falling into German hands. They -literally- never knew what hit them.

[Jimbuna]

Besides that it was doctrine to only use FIDO's in deep water away from shallows or a coastline in order to avoid a dud falling into German hands. They -literally- never knew what hit them.

That is precisely the fundamental point here There are no known records that indicate the Germans knew of the existence of Fido!!

How long did it take them to begin realising that most convoy reports still amounted to wild goose chases because the convoy changed course after it was discovered.....or that their enigma code had been compromised ? :hmm:

[Mush Martin]

Originally Posted by jimbuna

That is precisely the fundamental point here There are no known records that indicate the Germans knew of the existence of Fido!!

How long did it take them to begin realising that most convoy reports still amounted to wild goose chases because the convoy changed course after it was discovered.....or that their enigma code had been compromised ? :hmm:

even more interesting is the fact that the allies started distributing CAT
gear almost three months before Zaunkonig 1's went operational. within
three weeks of the first attack almost all atlantic escort forces were so
equipped.
( I know CAT gear is the wrong one but you know what I mean.)

[Jimbuna]

Zaunkonig (Wren)

The first model T IV (G7es) Falke (Falcon) was introduced in early 1942. It had a contact pistol and a maximum range of 7,500 meters at 20 knots. The relatively slow speed and lack of a magnetic pistol made it in service for a brief period only when it was succeeded by the next generation.
The next generation was designated T Vb (G7es), Zaunkonig (Wren). The allies referred to them as “Gnat”. Based on the T III model, it had a combination of magnetic and contact pistol and a maximum range of 5,750 meters at 24.5 knots. However the Zaunkonig was prone to premature detonation, and since the launching U-boat had to dive deep; and unable to positively confirm the success, many times premature explosions were misconstrued as a hit – leading to somewhat exaggerated claims of its effectiveness. It was not until spring of 1944 that Donitz began to suspect the Zaunkonig was not as effective as he had hoped for.
The allies had a great deal of intelligence about the Zaunkonig – even before it had entered service. Thus as soon as they had confirmation that an acoustic torpedo was being used, they introduced the Foxer, an anti-acoustic torpedo device. This noise maker was towed behind warships to decoy the acoustic sensors of the torpedo. While designed to lure the acoustic torpedo away, it made such a loud noise that it broadcasted the convoy’s location for miles away, attracting U-boats which would have otherwise not have heard the convoy. In addition, it also interfered with the escort’s sensors and sonar, making it of dubious value in its role.
Realizing what was happening, the Germans introduced the second generation of acoustic torpedoes which were more accurately tuned to a ship’s propeller noise. The T XI (G7es) Zaunkonig II also had an improved range and sensitivity, enabling targets moving at 9 knots to be tracked. The Zaunkonig II could also be launched from up to depths of 50 meters (164 feet), compared to 15 meters (49 feet) for Zaunkonig I. As these later versions of acoustic torpedoes were deployed, the allies continued to improve the Foxer.


Range/Speed: 5,750m at 24.5kt
Warhead: 274kg

CAT (counter Acoustic Torpedo) Canadian version

http://en.wikipedia.org/wiki/Foxer

[Puster Bill]

Originally Posted by jimbuna

That is precisely the fundamental point here There are no known records that indicate the Germans knew of the existence of Fido!!

They still should have known, and I suspect that by 1944, they may have suspected. They developed the Torpedowarn und AnzeigeGerat (TAG) specifically to warn against torpedos.

Now, at that point they weren't massing attacks against convoys, nor were they likely to do so in the near future, so 'blue on blue' incidents, even with their own acoustic torpedos, would have been a rare occurance.

However, given the fact that something like 2/3rds to 3/4ths of all FIDO attacks failed, I can see a sonar operator mentioning that after a crash dive, he heard a torpedo in the water that had to have been dropped by the aircraft. A non-homing torpedo is useless against a submerged submarine, so by logical extension it must be a homing torpedo.

There is no record that they knew, but then why bother to develop the TAG and issue gramophone records to train the crews on how to distinguish torpedo noises?

It's kind of like the Ardennes Offensive and Ultra: There is no record that the Germans KNEW we had cracked the Wehrmacht/Luftwaffe Enigma, yet they still kept almost complete radio silence about the upcoming offensive, not transmitting any of the orders by radio or landline, only using couriers. You don't take those kind of precautions, which are inconvenient, without some suspicions.

[ReM]

[quote=jimbuna]

How long did it take them to begin realising that most convoy reports still amounted to wild goose chases because the convoy changed course after it was discovered.....or that their enigma code had been compromised ? :hmm:

According to Clay Blair they suspected it at least a couple of times: Donitz ordered a special commision to investigate if Enigma had been broken on several occasions. Each time they reassured BDU that all was well....(there was also some politics involved in the whole Enigma system that left this as the only possible answer).

The combination of being able to read Enigma and the DF-ing (HuffDuff) of the heavy chatter needed by U-Boats to coordinate their Wolfpack attacks gave the Allies distinct advantages. A lot of this was so top-secret that some archives have only been opened during the 1990's, some 50 years after events took place.

[Jimbuna]

[quote=ReM]

Originally Posted by jimbuna

According to Clay Blair they suspected it at least a couple of times: Donitz ordered a special commision to investigate if Enigma had been broken on several occasions. Each time they reassured BDU that all was well....(there was also some politics involved in the whole Enigma system that left this as the only possible answer).

The combination of being able to read Enigma and the DF-ing (HuffDuff) of the heavy chatter needed by U-Boats to coordinate their Wolfpack attacks gave the Allies distinct advantages. A lot of this was so top-secret that some archives have only been opened during the 1990's, some 50 years after events took place.

Agreed

[Mush Martin]

[quote=ReM]

Originally Posted by jimbuna

According to Clay Blair they suspected it at least a couple of times: Donitz ordered a special commision to investigate if Enigma had been broken on several occasions. Each time they reassured BDU that all was well....(there was also some politics involved in the whole Enigma system that left this as the only possible answer).

The combination of being able to read Enigma and the DF-ing (HuffDuff) of the heavy chatter needed by U-Boats to coordinate their Wolfpack attacks gave the Allies distinct advantages. A lot of this was so top-secret that some archives have only been opened during the 1990's, some 50 years after events took place.

there were more than a few occasions where Operational intelligence was
acted on and left BDU wondering about his signal security, on all occasions
he was advised that it was theoretically impossible for enigma to be
broken as it would take weeks or months per message to decode, and therefore any intelligence the british would glean from it would be out of
date.

the conclusions drawn by the german command were helped by the
fact that their signals people were unwilling to believe in the fallability
of their system while simultanously the gestapo were convinced that
the british spy system was about a hundred times more efficient than
it actually was.

the OIC dictated after the first few near giveaways that any "special
intelligence" could only be acted on if there were another possible explanation for it other than decrypt, such as DF or air reconnasaince
or coastwatcher. that misdirection of responsibiltiy campaign was a
great contributer to the germans keeping enigma in place thus
protecting a compromised source for the brits.

enigma was a broken weapon but it was never clearly realized
by the OKM, Bdu or the Bdienst it was just suspected regularly.
M

[Puster Bill]

Originally Posted by ReM

The combination of being able to read Enigma and the DF-ing (HuffDuff) of the heavy chatter needed by U-Boats to coordinate their Wolfpack attacks gave the Allies distinct advantages. A lot of this was so top-secret that some archives have only been opened during the 1990's, some 50 years after events took place.

Well, I used to be in the Signals Intelligence business (Ex-US Army 05H, Electronic Warfare Signals Intelligence Morse Interceptor), and I can tell you that while HF/DF would have been valuable in an immediate tactical sense, it wouldn't have been of lesser utility for future planning. Allow me to explain..

Direction finding can only tell you, within a certain margin of error, where a target is located at the moment you DF them. At close range, such as with HF/DF sets mounted on ships, this isn't as much of an issue. In a convoy situation, if you have a couple of ships that have DF gear, you can pretty much nail the location of the u-boat transmitting (provided, of course, that you know the relative positions of the two receiving ships with reasonable accuracy!). Even if you only have one ship equipped with HF/DF, you will still get a 'line of bearing' to the target, that you can run down.

At larger distances, say from the US and the UK to the middle of the Atlantic, the irreduceable errors inherent in HF/DF, caused by the action of the ionosphere, make finding a particular boat a matter of chance. At those ranges, a circle of 50 miles would be a very good error, with 75 or more probably the average result. You also run into another problem: HF/DF in a 'strategic' (ie., fixed land stations) sense, even when combined with traffic analysis and radio fingerprinting techniques, has little to no predictive value. In other words, unless you have assets within range to prosecute the contact when you DF them, you don't know if they are going to head North, South, East, West, or stay in that same spot, which makes targeting them with a Hunter/Killer group problematic. It can still be done, but it isn't anywhere near as efficient as cryptanalytical results.

Cryptanalysis has predictive value. If you can successfully read the messages you are intercepting, many if not most of the time you know what that u-boat is going to do in 24 to 48 hours in the future, or more. You know where he is going to be, so you can place assets like planes and Hunter/Killer groups in the area to meet them.
This allows you to free up some escorts from convoy duty to actually kill the u-boats before they come in contact with the convoy. That keeps the merchant losses down (because a boat in contact with a convoy could still get lucky, but a boat sunk before it even gets anywhere near a convoy has no chance). You can't use them effectively though if you don't know where the u-boats are going to be ahead of time, which really is only possible if you can actually read the traffic between BdU and the boats.

[Mush Martin]

Originally Posted by Puster Bill

Well, I used to be in the Signals Intelligence business (Ex-US Army 05H, Electronic Warfare Signals Intelligence Morse Interceptor), and I can tell you that while HF/DF would have been valuable in an immediate tactical sense, it wouldn't have been of lesser utility for future planning. Allow me to explain..

Direction finding can only tell you, within a certain margin of error, where a target is located at the moment you DF them. At close range, such as with HF/DF sets mounted on ships, this isn't as much of an issue. In a convoy situation, if you have a couple of ships that have DF gear, you can pretty much nail the location of the u-boat transmitting (provided, of course, that you know the relative positions of the two receiving ships with reasonable accuracy!). Even if you only have one ship equipped with HF/DF, you will still get a 'line of bearing' to the target, that you can run down.

At larger distances, say from the US and the UK to the middle of the Atlantic, the irreduceable errors inherent in HF/DF, caused by the action of the ionosphere, make finding a particular boat a matter of chance. At those ranges, a circle of 50 miles would be a very good error, with 75 or more probably the average result. You also run into another problem: HF/DF in a 'strategic' (ie., fixed land stations) sense, even when combined with traffic analysis and radio fingerprinting techniques, has little to no predictive value. In other words, unless you have assets within range to prosecute the contact when you DF them, you don't know if they are going to head North, South, East, West, or stay in that same spot, which makes targeting them with a Hunter/Killer group problematic. It can still be done, but it isn't anywhere near as efficient as cryptanalytical results.

Cryptanalysis has predictive value. If you can successfully read the messages you are intercepting, many if not most of the time you know what that u-boat is going to do in 24 to 48 hours in the future, or more. You know where he is going to be, so you can place assets like planes and Hunter/Killer groups in the area to meet them.
This allows you to free up some escorts from convoy duty to actually kill the u-boats before they come in contact with the convoy. That keeps the merchant losses down (because a boat in contact with a convoy could still get lucky, but a boat sunk before it even gets anywhere near a convoy has no chance). You can't use them effectively though if you don't know where the u-boats are going to be ahead of time, which really is only possible if you can actually read the traffic between BdU and the boats.

That was a large part of the OIC experience they had to convince the
admiralty that not only could they use it to review historical situations
for insight as the germans predicted they would be able to do. they
also had to convince them that the submarine tracking room could
forecast future movements of individual uboats and raiders based
on established patterns of normal behaviour and precedented patterns
of deviant behaviour. they were lucky to have Roger winn as there
First attempt analyst an intelligent and insightful man he was indeed
able to well predict a better than average percentage of movements
and patterns and showed an uncanny insight for being able to
pull together unrelated threads into a firm prediction of future
action, more importantly with the precedent and patterns established
So also were his succesors able to also.

the OIC predicted the channel dash two weeks or so prior to it
happening based the decrypts and traffic patterns and movements
of Kriegsmarine units such as destroyers and minesweepers
(each of which used totally different cyphers)
as well as Photo Reconassaince and traffic from OKM.
Sadly "A series of unfortunate events" including two seperate
photo reconnasaince flights in different areas that missed seing
the sortie due to mechanical failure, allowed the german units
to gain an early leadoff and they managed to maintain the
initiative through the voyage where inertia ruled the day
for the coastal and air forces.
M

[Puster Bill]

Originally Posted by Mush Martin

That was a large part of the OIC experience they had to convince the
admiralty that not only could they use it to review historical situations
for insight as the germans predicted they would be able to do. they
also had to convince them that the submarine tracking room could
forecast future movements of individual uboats and raiders based
on established patterns of normal behaviour and precedented patterns
of deviant behaviour. they were lucky to have Roger winn as there
First attempt analyst an intelligent and insightful man he was indeed
able to well predict a better than average percentage of movements
and patterns and showed an uncanny insight for being able to
pull together unrelated threads into a firm prediction of future
action, more importantly with the precedent and patterns established
So also were his succesors able to also.

the OIC predicted the channel dash two weeks or so prior to it
happening based the decrypts and traffic patterns and movements
of Kriegsmarine units such as destroyers and minesweepers
(each of which used totally different cyphers)
as well as Photo Reconassaince and traffic from OKM.
Sadly "A series of unfortunate events" including two seperate
photo reconnasaince flights in different areas that missed seing
the sortie due to mechanical failure, allowed the german units
to gain an early leadoff and they managed to maintain the
initiative through the voyage where inertia ruled the day
for the coastal and air forces.
M

One of the major problems with using non-cryptanalytical signals intelligence is convincing people that it means something.

The sinking of HMS Glorious is a perfect example: Harry Hinsley at BP was able to deduce through traffic analysis and HF/DF that major elements of the Kriegsmarine were going to sortie into the North Sea. He passed the warning on to OIC, who promptly ignored it. Not long after, the carrier HMS Glorious (who's captain, had he survived, should have been courtmartialed for not posting lookouts or have a CAP up in the air) was attacked and sunk by the Scharnhorst and Gneisenau. The OIC realized that had it listened to Hinsley and broadcast a warning, the Glorious might not have had her guard down, and might not have been surprised. It was an expensive lesson.

Still, the intelligence provided by Hinsley wasn't specific. It merely said that major units of the Kriegsmarine could be expected to sortie from the Skagerrak. That kind of intelligence, while useful in a defensive sort of way, has little offensive value: It doesn't tell you the where and when necessary to "get thar firstest with the mostest"

Another major problem is that TA and HF/DF are more susceptable to being 'spoofed'. The Japanese did this with the Kido Butai that attacked Pearl Harbor: They left the radio operators from their ships on shore in Japan to simulate normal traffic while the actual task force maintained radio silence. You can also do what the Allies did before D-Day: set up a communications structure that simulates an entire Army group, when in reality it is just a relative handful of operators. It's hard to do this, though, because the fake radio traffic has to be cohesive and consistent with what one would expect of an actual unit. This was simplified for the Allies, because the idea was that this was an Army group training, so pro-forma practice traffic solely to exercise the operators would be what you expect to see.

It is harder to do that kind of thing on an operational basis (ie., the putative units are supposed to be front line units), as pretty quickly the analysts will discover that what is being said in the traffic is not being done in real life. It's a fool me once, won't get fooled again kind of thing. You can get away with it on an occasional basis, as the US showed before the Battle of Midway: They knew, through decryption of the JN-25 code, that the Japanese were going to attack a target they designated as 'AF'. The analysts at station HYPO in Hawaii thought 'AF' might be Midway (based on the fact that in previous decrypts the 'A' series stood for Hawaiian locations), but Washington disagreed. To resolve the issue, they cabled Midway to send via radio a message that their desalination plant had broken down. A couple of days after this was done, we intercepted a Japanese message stating that 'AF is short of water'. This was a one-shot deal, however. Keeping up a deception that is internally and externally consistent would be extremely difficult.

However, the inferential nature of Traffic Analysis, outside of cryptanalysis of the actual message contents, means that the spoofing side can keep the charade going for longer. If successful to any degree, it can also make the other side doubt the intelligence derived from traffic analysis/DF, which is a significant benefit.

[Mush Martin]

Originally Posted by Puster Bill

One of the major problems with using non-cryptanalytical signals intelligence is convincing people that it means something.

The sinking of HMS Glorious is a perfect example: Harry Hinsley at BP was able to deduce through traffic analysis and HF/DF that major elements of the Kriegsmarine were going to sortie into the North Sea. He passed the warning on to OIC, who promptly ignored it. Not long after, the carrier HMS Glorious (who's captain, had he survived, should have been courtmartialed for not posting lookouts or have a CAP up in the air) was attacked and sunk by the Scharnhorst and Gneisenau. The OIC realized that had it listened to Hinsley and broadcast a warning, the Glorious might not have had her guard down, and might not have been surprised. It was an expensive lesson.

Still, the intelligence provided by Hinsley wasn't specific. It merely said that major units of the Kriegsmarine could be expected to sortie from the Skagerrak. That kind of intelligence, while useful in a defensive sort of way, has little offensive value: It doesn't tell you the where and when necessary to "get thar firstest with the mostest"

Another major problem is that TA and HF/DF are more susceptable to being 'spoofed'. The Japanese did this with the Kido Butai that attacked Pearl Harbor: They left the radio operators from their ships on shore in Japan to simulate normal traffic while the actual task force maintained radio silence. You can also do what the Allies did before D-Day: set up a communications structure that simulates an entire Army group, when in reality it is just a relative handful of operators. It's hard to do this, though, because the fake radio traffic has to be cohesive and consistent with what one would expect of an actual unit. This was simplified for the Allies, because the idea was that this was an Army group training, so pro-forma practice traffic solely to exercise the operators would be what you expect to see.

It is harder to do that kind of thing on an operational basis (ie., the putative units are supposed to be front line units), as pretty quickly the analysts will discover that what is being said in the traffic is not being done in real life. It's a fool me once, won't get fooled again kind of thing. You can get away with it on an occasional basis, as the US showed before the Battle of Midway: They knew, through decryption of the JN-25 code, that the Japanese were going to attack a target they designated as 'AF'. The analysts at station HYPO in Hawaii thought 'AF' might be Midway (based on the fact that in previous decrypts the 'A' series stood for Hawaiian locations), but Washington disagreed. To resolve the issue, they cabled Midway to send via radio a message that their desalination plant had broken down. A couple of days after this was done, we intercepted a Japanese message stating that 'AF is short of water'. This was a one-shot deal, however. Keeping up a deception that is internally and externally consistent would be extremely difficult.

However, the inferential nature of Traffic Analysis, outside of cryptanalysis of the actual message contents, means that the spoofing side can keep the charade going for longer. If successful to any degree, it can also make the other side doubt the intelligence derived from traffic analysis/DF, which is a significant benefit.

all good but hinsley was at OIC not BP.
M

[Puster Bill]

Originally Posted by Mush Martin

all good but hinsley was at OIC not BP.
M

Err, no:

At Bletchley Park, Hinsley studied the external characteristics of intercepted German messages, a process sometimes termed "traffic analysis": from call signs, frequencies, times of interception, and so forth, he was able to deduce a great deal of information about the structure of the German Navy's communication networks, and even about the structure of the German Navy itself.[3]

From the Wiki article about Harry Hinsley: http://en.wikipedia.org/wiki/Harry_Hinsley

He was the liason between Bletchley Park and the OIC at the Admiralty. Here is a quote, in his own words:
"I was pitchforked into Bletchley Park in October 1939 at the age of 20 and at the beginning of my third year at Cambridge, one of about twenty undergraduates who formed the first of the annual drafts of recruits with GC&CS took direct from the universities for the rest of the war."
F. H. Hinsley, "BP, Admiralty, and Naval Enigma" in "Code Breakers: The inside story of Bletchley Park" by F. H. Hinsley & Alan Stripp.