21st Panzer Division in Caen Intel

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21st Panzer Division in Caen Intel

#1

Post by Duncan_M » 11 May 2021, 16:59

I'm currently reading Decision in Normandy by D'Este.

In it, while setting up the British landings in Normandy, he related how SHAEF, 21 Army Group, and British Second Army all knew that the 21st Panzer Division had moved from Renne and then again from Falaise and had forces massed around Caen. But D'Este also states that Crocker in I Corps and subordinate division and brigade commanders were unaware and only knew about the older intel report that placed them 10-30 miles south, so not immediately expected.

Was this the result of a simple breakdown in communication where Second Army HQ failed to disseminate that critical intel? Or is there another explanation?

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Re: 21st Panzer Division in Caen Intel

#2

Post by Alanmccoubrey » 11 May 2021, 19:37

If the Intelligence came from Enigma then it was not allowed to go below Army level.
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Re: 21st Panzer Division in Caen Intel

#3

Post by Richard Anderson » 11 May 2021, 20:04

Duncan_M wrote:
11 May 2021, 16:59
I'm currently reading Decision in Normandy by D'Este.

In it, while setting up the British landings in Normandy, he related how SHAEF, 21 Army Group, and British Second Army all knew that the 21st Panzer Division had moved from Renne and then again from Falaise and had forces massed around Caen. But D'Este also states that Crocker in I Corps and subordinate division and brigade commanders were unaware and only knew about the older intel report that placed them 10-30 miles south, so not immediately expected.

Was this the result of a simple breakdown in communication where Second Army HQ failed to disseminate that critical intel? Or is there another explanation?
It is simply unclear how "unaware" the assault divisions really were on 6 June. For example, d'Este remarks that the 3 British Infantry Division location information as found in Scarfe's Assault Division was derived from the 14 May Intel Sum appended to the division operations order. However, that is just what is in the division file (I just checked). The first divisional Intel Sum No. 1 remarks to its encounters with Panzergrenadier Regiment 192 on D-Day, but doesn't really say they were surprised it was there. In essence, we simply don't know what the I Corps and 3 Division staffs had internalized from the revised SHAEF estimate of 3 June. I suspect the same is true of the 2 CAN and 3 CID reports of 23 May.

The same is also true for the story of the presence of the 352. Inf-Div on the beaches. We know that SHAEF, the armies, and the corps were aware of the change, but it is less clear how well that late-arriving information was taken in by the assault divisions. I suspect that d'Este read more into what he found in the files than what was really there.
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Re: 21st Panzer Division in Caen Intel

#4

Post by Richard Anderson » 11 May 2021, 20:05

Alanmccoubrey wrote:
11 May 2021, 19:37
If the Intelligence came from Enigma then it was not allowed to go below Army level.
The intel was allowed below army, but the source was disguised.
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Re: 21st Panzer Division in Caen Intel

#5

Post by Sheldrake » 11 May 2021, 20:40

I don't think Carlo D'Este has been entirely fair.

It is one thing for the G2 staff at Army Group HQ to identify that the 21st Panzer Division was in the Falaise Area, and even draw a goose egg on a map. Identifying the locations of its constituent units in enough detail to include them in tactical plans ay divisional or corps level was a different matter.

Ultra played no part in locating the 21st Panzer Division. According to Ultra in the West by Ralph Bennett, the move of 21st Panzer division to Rennes was known in March - but not the subsequent move to the Falaise area - though it could be inferred from the move of other formations to Rennes.

CAB 44 /243, the British classified history - Section D, chapter II: operation "Overlord", "D" day 1944 June 6; book I, the enemy; has a summary of the intelligence reports.

It quotes GSI 231 AG Neptune Reviews Nos 13-17 of May June.

There were lots of other movements based on reports of rail moves of particular train consists that indicated armour. The inclusion of particular types of rail wagons indicated Panther tanks or Tiger tanks. The source was obviously the resistance in SNCF. This is how the allies could work out that X Panzer Division was in a certain area.

Detailed dispositions of the troops manning coastal defences were helped by the German policy of fortifying coastal defences. Not only did these show up on air photographs, but resistards among the construction workers could report what they had seen.

Para 24 says that the move of 21st Panzer Division from Rennes to Calvados had been noticed from troop movements by road and rail, including moves for tracked and wheeled carriers from 27th April. "On 7 May a large concentration of armoured vehicles was reported in the Foret de Cinglais between the Orne and Falaise which indicated that the 21st Panzer Division's tanks were east of the Orne. Whatever might be the detailed dispositions of the division it now lay but a short distance from the Neptune Beaches."

Para 26 discusses the problem presented by the 21st Panzer Division. The allies knew it had a different structure to the other SS and Army panzer divisions, but they did not know in what way. (They had not idea that it was special because it had been cobbled together from scrap French AFVs) Allied intelligence speculation was that the division had a panzer brigade which implied more than a single tank regiment - although the wagon counts of its rail moves gave no sign of it having more than two tank battalions.

The first cut of the Allied Fire plan was made in April with the final version dated 19th May and signed off around 23 May. Few if any of 21st Panzer Division unit positions was in the D Day fire plan. The units arrived too late to be spotted by allied intelligence.

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Re: 21st Panzer Division in Caen Intel

#6

Post by Richard Anderson » 11 May 2021, 21:19

Sheldrake wrote:
11 May 2021, 20:40
I don't think Carlo D'Este has been entirely fair.

It is one thing for the G2 staff at Army Group HQ to identify that the 21st Panzer Division was in the Falaise Area, and even draw a goose egg on a map. Identifying the locations of its constituent units in enough detail to include them in tactical plans ay divisional or corps level was a different matter.
Yep.
Ultra played no part in locating the 21st Panzer Division. According to Ultra in the West by Ralph Bennett, the move of 21st Panzer division to Rennes was known in March - but not the subsequent move to the Falaise area - though it could be inferred from the move of other formations to Rennes.
Not entirely true. Special Intelligence correctly identified the locations of all but one of the German units - 2. FJD. At least according to HW 11/8, G.C.&C.S. Air and Military History Volume VIII, The Western Front, 1944-1945 - I, p. 86.
CAB 44 /243, the British classified history - Section D, chapter II: operation "Overlord", "D" day 1944 June 6; book I, the enemy; has a summary of the intelligence reports.

It quotes GSI 231 AG Neptune Reviews Nos 13-17 of May June.

There were lots of other movements based on reports of rail moves of particular train consists that indicated armour. The inclusion of particular types of rail wagons indicated Panther tanks or Tiger tanks. The source was obviously the resistance in SNCF. This is how the allies could work out that X Panzer Division was in a certain area.
That led to the principal error WRT 21. Panzer, which was its strength and tank types. Based on the use of heavy train carriages it was assumed they had Panthers and possibly Tigers, and it wasn't until November that a captured pro forma dated 23 July enabled them to deduce what the intercepted tank state reports were actually reporting. Nevertheless, by 10 June enough other information had been collected from decrypts and other sources that a tentative analysis of the pro forma was made. It assessed the division with 88 Mark IV, 29 Mark V, 11 38(t) (which it called "Czech 38-ton tanks!), 8 "Jaguar" tanks (later deduced to be command tanks), and 30 7.5cm AT guns. Overall, it was correct, albeit it was probably counting only operational tanks and assumed the actual Panzer IV(k) were Panthers. Op.cit. pp. 92-93.
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Re: 21st Panzer Division in Caen Intel

#7

Post by Michael Kenny » 11 May 2021, 22:33

Richard Anderson wrote:
11 May 2021, 21:19
wasn't until November that a captured pro forma dated 23 July enabled them to deduce what the intercepted tank state reports were actually reporting.
If you read The Canadian War Diaries you can watch this type of confusion play-out in real time.

https://heritage.canadiana.ca/view/ooci ... 12?r=0&s=4

https://heritage.canadiana.ca/view/ooci ... 23?r=0&s=4

https://heritage.canadiana.ca/view/ooci ... 28?r=0&s=4

https://heritage.canadiana.ca/view/ooci ... 32?r=0&s=4

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Re: 21st Panzer Division in Caen Intel

#8

Post by Sheldrake » 11 May 2021, 22:53

Richard Anderson wrote:
11 May 2021, 21:19
There were lots of other movements based on reports of rail moves of particular train consists that indicated armour. The inclusion of particular types of rail wagons indicated Panther tanks or Tiger tanks. The source was obviously the resistance in SNCF. This is how the allies could work out that X Panzer Division was in a certain area.
That led to the principal error WRT 21. Panzer, which was its strength and tank types. Based on the use of heavy train carriages it was assumed they had Panthers and possibly Tigers, and it wasn't until November that a captured pro forma dated 23 July enabled them to deduce what the intercepted tank state reports were actually reporting. Nevertheless, by 10 June enough other information had been collected from decrypts and other sources that a tentative analysis of the pro forma was made. It assessed the division with 88 Mark IV, 29 Mark V, 11 38(t) (which it called "Czech 38-ton tanks!), 8 "Jaguar" tanks (later deduced to be command tanks), and 30 7.5cm AT guns. Overall, it was correct, albeit it was probably counting only operational tanks and assumed the actual Panzer IV(k) were Panthers. Op.cit. pp. 92-93.
The principle problem re 21st Panzer Division was not how many and what sort of tanks it had but where were its units? 3rd Division was well prepared to repel tanks - as evidenced by their performance on D Day. My book contains a much more gloomy contemporary prognosis - German tanks laying back 200 yards from deep minefields.

IN retrospect, the big surprise was that so much of 21st Panzer Divisions infantry anti tank guns and artillery were north of Caen. This ended any possibility of the Allies capturing Caen on D Day.

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Re: 21st Panzer Division in Caen Intel

#9

Post by Richard Anderson » 12 May 2021, 01:02

Sheldrake wrote:
11 May 2021, 22:53
The principle problem re 21st Panzer Division was not how many and what sort of tanks it had but where were its units? 3rd Division was well prepared to repel tanks - as evidenced by their performance on D Day. My book contains a much more gloomy contemporary prognosis - German tanks laying back 200 yards from deep minefields.
Yes, but a "problem" is not necessarily the same as an "error". The SHAEF estimate had placed the 21. Panzer in striking distance of the beaches, with its principal strength, its tanks, properly located.
IN retrospect, the big surprise was that so much of 21st Panzer Divisions infantry anti tank guns and artillery were north of Caen. This ended any possibility of the Allies capturing Caen on D Day.
Well, did it? The battalion lying between JUNO and SWORD was a nuisance and a bit of a surprise, but it did not accomplish that much and certainly did not end the possibility of capturing Caen on D-Day...that was probably just a bridge too far.
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Re: 21st Panzer Division in Caen Intel

#10

Post by Alanmccoubrey » 12 May 2021, 13:58

Richard Anderson wrote:
11 May 2021, 20:05
Alanmccoubrey wrote:
11 May 2021, 19:37
If the Intelligence came from Enigma then it was not allowed to go below Army level.
The intel was allowed below army, but the source was disguised.
No it wasn't allowed below Army level in any form because the intelligence was of such a nature that it couldn't have come from any other source and so no disguise would fool the Germans if they in their turn discovered it, that is part of the reason that the entire thing remained secret for as long as it did.
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Re: 21st Panzer Division in Caen Intel

#11

Post by Richard Anderson » 12 May 2021, 18:08

Alanmccoubrey wrote:
12 May 2021, 13:58
Richard Anderson wrote:
11 May 2021, 20:05
Alanmccoubrey wrote:
11 May 2021, 19:37
If the Intelligence came from Enigma then it was not allowed to go below Army level.
The intel was allowed below army, but the source was disguised.
No it wasn't allowed below Army level in any form because the intelligence was of such a nature that it couldn't have come from any other source and so no disguise would fool the Germans if they in their turn discovered it, that is part of the reason that the entire thing remained secret for as long as it did.
Sorry, but no that is incorrect. ULTRA information was fused with other sources in the field by qualified officers and became part of the INTELSUMs disseminated through the G-2 system. At all times though, care was taken to mask the original source of the information, typically by attributing it to special agents. If the information was of a nature that it was judged its origin could not be masked, then it was withheld from anyone other than authorized ULTRA recipients. Seventh US Army had a particularly interesting time doing this, because the G-2 officers and commander of VI US Corps had been ULTRA recipients during SHINGLE, when they operated as a semi-independent corps task force.

See, James Leslie Gilbert & John Patrick Finnegan, U.S. Army Signals Intelligence in World War II: A Documentary History, especially pp. 135-138, 150-151, and 192-195. Note that the armies had their own signals intercept, decrypt, and analysis capability for lower grade signals traffic, which followed similar means of security WRT dissemination, see pp. 196-205.
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Re: 21st Panzer Division in Caen Intel

#12

Post by Sheldrake » 12 May 2021, 21:07

Richard Anderson wrote:
12 May 2021, 01:02
Sheldrake wrote:
11 May 2021, 22:53
The principle problem re 21st Panzer Division was not how many and what sort of tanks it had but where were its units? 3rd Division was well prepared to repel tanks - as evidenced by their performance on D Day. My book contains a much more gloomy contemporary prognosis - German tanks laying back 200 yards from deep minefields.
Yes, but a "problem" is not necessarily the same as an "error". The SHAEF estimate had placed the 21. Panzer in striking distance of the beaches, with its principal strength, its tanks, properly located.
IN retrospect, the big surprise was that so much of 21st Panzer Divisions infantry anti tank guns and artillery were north of Caen. This ended any possibility of the Allies capturing Caen on D Day.
Well, did it? The battalion lying between JUNO and SWORD was a nuisance and a bit of a surprise, but it did not accomplish that much and certainly did not end the possibility of capturing Caen on D-Day...that was probably just a bridge too far.
Up to a point Lord Copper...

It is true that the dash for Caen never really got going, being replaced by a dismounted infantry advance. So the German defence of Lebiesy ridge wasn't tested until 7th June.

The 3 Div plan assumed that there would be a dash for Caen after breaking through the coastal defences. The 6th Airborne Division's recce regiment was also supposed to be dashing for the Caen Falaise road east of the river Orne. These plans were based on the flawed intelligence that assumed that the opposition was purely the 716th Infantry Division's units.
Had they been aware that 716th Infantry Division had been reinforced with two panzer grenadier battalions, 21st Panzer Divisions anti tank battalion and a slice of the divisional artillery was already North of Caen that plan would have been abandoned never going to work. So all the fuss about Rennie's or KP smith's lethargy is irrelevant.

While the Panzer Grenadier battalion seems to have done little, the anti tank regiment and artillery units were sufficiently heavily engaged for Feuchtinger to regard them as destroyed. Perhaps not in a single action but a series of engagements that slowed the British and Canadian advance.

In some ways the D Day advance sets the pattern for many of the British operations. Optimistic plans based on blastign known enemy positions that become stuck on previously unforeseen enemy.

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Re: 21st Panzer Division in Caen Intel

#13

Post by Alanmccoubrey » 15 May 2021, 12:28

Richard Anderson, I think we'll have to agree to disagree on this, especially since you are using a US source for your side of the argument.
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Re: 21st Panzer Division in Caen Intel

#14

Post by Richard Anderson » 15 May 2021, 17:45

Alanmccoubrey wrote:
15 May 2021, 12:28
Richard Anderson, I think we'll have to agree to disagree on this, especially since you are using a US source for your side of the argument.
Okay, but I can't imagine the British method of dissemination was much different. Fundamentally, we're talking the difference between maintaining source security while disseminating intelligence. An intelligence product that is only accessible to a small set of most senior commanders and that is burn before reading is fundamentally useless. BTW, if you look at much of the actual ULTRA product in the series HW5/446 to HW5/576 (the period March-August 1944 related to NEPTUNE), it was actually written couched in terms that implied it was not derived from SIGINT.
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Re: 21st Panzer Division in Caen Intel

#15

Post by EKB » 16 May 2021, 00:32

Alanmccoubrey wrote:
12 May 2021, 13:58
Richard Anderson wrote:
11 May 2021, 20:05
Alanmccoubrey wrote:
11 May 2021, 19:37
If the Intelligence came from Enigma then it was not allowed to go below Army level.
The intel was allowed below army, but the source was disguised.
No it wasn't allowed below Army level in any form because the intelligence was of such a nature that it couldn't have come from any other source and so no disguise would fool the Germans if they in their turn discovered it, that is part of the reason that the entire thing remained secret for as long as it did.

If true, the cause might have been bureaucratic inertia. The author of Kept in the Dark claims that the USAAF had better access to British signals intelligence than RAF commands based in England …

Within the internal stresses and conflicts in Whitehall there was another issue that has become apparent. The policy for handling and disseminating intelligence within and from the Air Ministry was flawed. The flaw related particularly to the provision of signals intelligence to the Home Air Commands. The Air Ministry policy was that signals intelligence for those commands would flow from the Ministry and not from the producers of the data.

That would have been very reasonable, except that the Ministry had no facility for handling the mass of data that came from the various grades of signals intelligence. Also, the Ministry was inadequately aware of the detail of air operations being separately conducted by Fighter Command and Bomber Command. The political powers in Whitehall were closely interested in those operations that were taking place in every sense over their heads. This may well have created pressure for the Air Ministry and a need to be ‘seen to be doing something’.

In contrast, signals intelligence support for overseas air commands flowed directly from Bletchley Park. Those operations were largely ‘out of sight’ for the Whitehall warriors and the archives show that those air commands were able to benefit from that timely intelligence. The same was true for the Army and particularly for the Navy.

The availability and use of signals intelligence – and this includes the high-grade ENIGMA and ULTRA material – within the context of the bombing campaigns has hardly figured in the official histories, except for the History of British Intelligence in the World War 2. That history was written long before public release of any of the evidence and it does not address the politics surrounding the use of that information within Whitehall.
[…]
The Air Intelligence branch was a small fledgling at the start of the war. As the war developed, that Branch grew from an initial staff of 40 people to a Directorate with over 700 people. Somewhat like the MEW, it was difficult to expand rapidly and remain cohesive. The organisational changes were substantial and tended to be responsive to external changes and pressures.

The recruitment of staff with the necessary skills and personalities was an acute problem; most of the new staff had no military background and were given a one-week training course. Chapter 6 provides a detailed description of the development of the Directorate and then looks at particular internal Deputy Directorates and Sections that had functions which directly related to the provision of intelligence for the bombing offensives. The outstanding example of how the task could be done well was within the Scientific Intelligence section.

One of the key problems within Air Sigint was a fundamental policy that resulted in the Home Air Commands being denied valuable operational intelligence. That denial did not happen for the overseas commands, nor for the USAAFs. It became a matter of the utmost importance and was a long-standing legacy from attitudes that came from an earlier time.

Stubbington, John. Kept in the Dark: The Denial to Bomber Command of Vital Enigma and Other Intelligence Information During World War II. Pen & Sword Books. Kindle Edition.

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