Thursday, March 28, 2013

Lies, damned lies, and statistics - The case of the unreliable Panther tank

The Panther is often castigated because it had a low serviceability rate, especially when it was first introduced in 1943. For example:

1). ‘Panther Vs T-34: Ukraine 1943’, p33 says: ‘In contrast no German panzer unit equipped with Panther Ausf D or A model tanks was able to sustain an operation readiness rate above 35 percent for any sustained period in 1943.

2). ‘Panther vs Sherman: Battle of the Bulge 1944’, p10 says: ‘The Panther's operational rate rose from an appalling 16 percent at the end of July 1943 to the merely wretched rate of 37 percent by December 1943.
Hmmm only 35%-37%? That is embarrassingly low.

Or is it?

What was the general serviceability rate for all the German tanks in the East in the same time period? According to ‘Panzertruppen vol2, p110 the German rates peaked in June ’43 at 89% and then collapsed. The average for the second half of 1943 was 44%.
Not much difference between 44% and 35% is there? Did the other German tanks also suffer from mechanical problems or were there other factors at play?

Maybe the low rates were mainly caused by the heavy fighting and lack of maintenance? Just a thought…

Sunday, March 24, 2013

German signals intelligence and the Stalingrad offensive

In the summer of 1942 the German forces in the East managed to surprise the Soviet High Command by attacking in the area of Army Group South. The Germans together with their Rumanian, Hungarian and Italian Allies overwhelmed the Soviet troops and advanced far in the Soviet South towards the oil producing areas of Baku.

However their efforts to clear the western part of the Volga were checked by the Soviet forces defending Stalingrad.

In November ’42 the Soviets, after secretly massing their forces, counterattacked and used their mobile forces against the flanks of the German front that were defended by the German Allied nations. The result was the collapse of the front and the encirclement of the Stalingrad troops.

How were the Soviets able to surprise their enemies? Didn’t German intelligence have any indication that powerful enemy forces were being moved close to the front?

It seems that through signals intelligence the Germans were able to identify major concentrations in the area. However this information was discounted by the analysts of the central evaluation department Fremde Heere Ost (Foreign Armies East) because it did not agree with their preconceived motions.

Let’s take a look at the relevant information.

The signal intelligence service of the Luftwaffe performed well in the Eastern front thanks to the low security of the Soviet AF cryptosystems. According to postwar reports they were also able to identify enemy concentrations faster than their Army counterparts because the aerial units assigned to ground troops could not hold radio silence.

Regarding the Stalingrad battle TICOM report I-41, p2 says: ‘Sigint units were the Cinderella of the GAF until the "STALINGRAD affair". III/LN. Rgt. 4 warned, and warned, that the Russians had assembled 5 Air Armies in the sector. After STALINGRAD, Sigint was held to be the main source of Intelligence.


Army signal intelligence units were also able to detect new Soviet units close to Stalingrad. Alexis Dettmann, chief cryptanalyst at the Army’s cryptanalytic centre in the East HLS Ost (Intercept Control Station East) says in TICOM DF-112, p110:

 ‘3 .In the fall of 1942 the cryptanalytic section was able to determine the setting up of new Armies (62nd, 63rd, 64th, 65th… 69th) to the east of Stalingrad. Although these observations were constantly supplemented and confirmed, people at the highest level could not make up their minds to believe these reports. Only after the 64th army appeared in a sector of the front near Stalingrad was Foreign Armies East permitted to enter the other armies (with question marks!) on the chart of the Red Army and to present this at the discussion of the situation at the Fuhrer's headquarters without expecting to exposed to wild insults.



Are these statements correct or were the Germans exaggerating?

David Thomas in ‘Foreign Armies East and German Military Intelligence in Russia 1941-45’ has tried to evaluate the performance of the FHO by looking at the reports they issued during the war.

According to that article, p269: ‘Nevertheless, signals intelligence was the basic source for most FHO estimates of the enemy situation. Unfortunately, when the results of signal reconnaissance consisted of tactical indicators that contradicted the strategic indicators of enemy intentions upon which FHO had already based its assumptions, FHO refused in some instances to modify its existing evaluation to accommodate the results of signal reconnaissance. Stalingrad is the locus classicus. On 11 October, the Leitstelle fur Nachrichtenaufklarung reported a comprehensive regroupment of Soviet forces between the Don and Volga, including the establishment of a new Soviet field headquarters, 'Don Front'. FHO evaluated the insertion of this headquarters, the regrouping of Soviet units in the zone of the Soviet Sixty-Third Army, and the enemy movements in front of Fourth Panzer Army as 'defensive enemy behaviour'. Another signal reconnaissance report submitted to FHO in November confirmed the existence of a large grouping of Soviet forces behind the bridgehead of Serafimovich and provided clear evidence that the Red Army had recognized the weaknesses of, and the boundary between, the Rumanian and Italian armies to the north of Stalingrad. However, this evaluation contradicted the forecast of Soviet intentions and fighting strength submitted by Gehlen in late August, 'Gedanken zur Weiterentwick-lung der Feindlage im Herbst und Winter'; specifically, the fundamental assumption that the Red Army would be unable to mount more than one winter offensive, because of insufficient manpower reserves after the summer campaign season.

So if the Germans had more respect for their signal intelligence departments maybe history would be written differently…

Sources: TICOM reports DF-112 and I-41, Journal of Contemporary History article: ‘Foreign Armies East and German Military Intelligence in Russia 1941-45’

Friday, March 22, 2013

RAF 2nd TAF strength 1944-45

The 2nd Tactical Air Force was a RAF group that supported the Allied troops fighting in Western Europe in the period 1944-45.

Strength returns of 2nd TAF are available from ‘AIR 22-Air Ministry: Periodical Returns, Intelligence Summaries and Bulletins’

2nd Tactical AF
1-Jan-44
1-May-44
1-Sep-44
1-Jan-45
SE Fighters
697
1,017
1,080
1,044
Army Coop
120
112
112
Medium Bombers
319
294
360
396
Sum
1,016
1,431
1,552
1,552

These numbers refer to operational aircraft.

The fighters used were the Spitfire and P-51 Mustang together with the fighter/ground attack plane Typhoon. These planes make up the majority of 2nd TAF strength. At the same time there are a small number of medium bombers of the Mosquito, Mitchell and Boston types. There was also a small number of Auster observation aircraft.

Monday, March 18, 2013

The Mortain counterattack – Effects of ULTRA and airpower

In the final days of July 1944 the Allied forces fighting in Normandy were able to break out and threatened the German forces with annihilation. The German response was an attack near Mortain with the goal of cutting off the Allied forces and restoring the front.

The Mortain counterattack is the victim of two myths. The first one is that Allied fighter bombers single handedly defeated the German attack. I’ve covered this here. The other one is that the defending forces were forewarned thanks to ULTRA intelligence.
For example ‘Why the Allies Won’ by Richard Overy says in page 174

Intelligence on the counter-attack at Mortain was plentiful on the Allied side. The time when it would be launched was revealed through Ultra decrypts. Bradley was able to place forces in strongly fortified areas in front of the German threat. A little after midnight on 7 August the Panzer forces began their attack. One division under cover of darkness and early morning mist covered 10 miles. But when the mist finally cleared at midday, the German armour was subjected to an air attack of exceptional intensity. The German forces made no progress and suffered heavy losses. On that afternoon Bradley began to counter-attack. By the end of the following day, the German Panzer divisions were back where they had started, and faced irresistible pressure on either flank.

Although the solution of German crypto systems provided valuable intelligence to the Allies that does not mean that every operation was betrayed from this source or that Allied units were always aware of the enemy plans.

In the case of the Mortain battle it is true that the codebreakers of Bletchley Park were able to decode the German orders. However the information was sent just before the Germans attacked thus leaving no time for redeployment.
The USAF history ‘D-Day 1944 Air Power over the Normandy Beaches and Beyond’ admits:

On the evening of the 6th, orders went out for five Panzer divisions to attack through Mortain (which had already fallen to American troops) ninety minutes later--at 18:30 hours. ULTRA did not send out this message until midnight, but the German attack had itself been delayed in the field until just after midnight. The Allied signals arrived immediately before the German attack, offering the Americans no time whatsoever to make extensive plans or redeployments for the assault.

Similar information is available from the official history ‘British Intelligence in the Second World War’, vol3 part 2, in pages 245-6
Another emergency signal sent out at 20:01 reported that 2nd SS Panzer was to attack Mortain and then St Hilaire. The latter would be bombarded until midnight. The decrypt of JK II's affirmative reply to 2nd SS Panzer's request for support was signalled at 21:40. At 00:11 on 7 August another emergency signal from GC and CS reported JK II's statement that Seventh Army would attack west from the Sourdeval-Mortain area in the evening of 6 August with elements of five Panzer divisions. …...

So the failure of the German attack was not due to the fact that Allied units were expecting them. Instead it was a result of standard military factors (low combat strength due to losses, low morale, lack of supplies, efficient defense by the American units etc)
Sources: ‘British Intelligence in the Second World War’, vol3 part 2, ibiblio.org, ‘The history of Hut 6’, ‘Why the Allies Won’, wikipedia

Friday, March 15, 2013

Update

Time for some new TICOM reports:

I-44 ‘Memorandum on speech encipherment by ORR Huettenhain and SDF Dr Fricke’ - 1945

I-192 ‘Interrogation of Gustav Schade of OKM 4 SKL III and of the Reichspost and ReichsRundfunk’ - 1946

 
I-208 ‘Interrogation report on Kurt Selchow former head of the Pers Z S department of the German Ministry of Foreign Affairs’ - 1947

Available from my Scribd and Google Docs accounts

Wednesday, March 13, 2013

Wartime exploitation of Turkish codes by Axis and Allied powers

The Republic of Turkey remained neutral during most of WWII, while at the same time maintaining close economic relations with Germany. The Turkish leaders were successful in protecting their country’s territorial integrity through constant negotiations with Germany, Britain and the Soviet Union. They finally joined the Allied cause and declared war on the Axis only in February 1945. 

During the war Turkey, as a neutral power, had a major advantage since it could operate embassies in both Allied and Axis nations. This gave Turkish officials the opportunity to get valuable information from both sides. For this reason Turkish diplomatic communications became a target for Axis and Allied cryptanalysts.
The Turks used mainly 4-figure codebooks (INKILAP, ZAFER, SAKARYA, CANKAYA, INONU, ISMET) enciphered with additive sequences.

Turkish systems were attacked by several German agencies. The diplomatic codes were attacked by the Pers Z, Forschungsamt and OKW/Chi. Military systems by the OKL Chi Stelle, the Army’s Inspectorate 7/VI and OKW/Chi.
Italy, Hungary and Finland also read Turkish traffic with significant success throughout the war.

All the Axis powers took advantage of the fact that some of the Turkish codebooks were simply repaginations of previous versions.

Thursday, March 7, 2013

Book review - Air Power at the Battlefront: Allied Close Air Support in Europe 1943-45

Airpower played a major role in WWII. The German victories in the period 1939-41 are linked with the support they received from the Luftwaffe and especially from ground support aircraft like the Ju-87 ‘Stuka’.

The Soviet AF also produced and used huge numbers of the Ilyushin Il-2 ‘Sturmovik’ aircraft.

The USAAF and RAF on the other hand were guided by the doctrine of strategic bombing. For that reason they invested huge resources on heavy bombers but did not produce a specialized ground attack aircraft like the Germans and Soviets. Instead they used in that role their standard fighter aircraft Hurricane, Typhoon, P-40, P-47, P-51.

How did these planes perform in battle? Many history books claim that swarms of Allied fighter-bombers destroyed whole German armored units and paralyzed enemy movements. German generals attributed their defeats to crushing Allied air superiority.

The book ‘Air Power at the Battlefront: Allied Close Air Support in Europe 1943-45’ by Ian Gooderson tries to answer this question by analyzing the information collected  by Operational Research Sections during the war.
The ORS teams included both military and civilian personnel and their goal was to collect information regarding enemy losses and performance of weapons from the battlefield.

Their studies of battles in NW Europe from summer 1944 to the end of the war showed that fighter bomber units overstated their kills by a very wide margin and that heavy bomber attacks caused little damage to German troops due to their wide dispersion.

For example the German attack near Mortain  was supposed to have been defeated mainly through air attacks. Allied pilots claimed over 200 tanks destroyed and the German general Hans Speidel wrote: ‘it was possible for the Allied air forces alone to wreck this Panzer operation with the help of a well coordinated ground to air communications system’. However when the area was examined by No2 ORS and ORS 2nd TAF only 46 tanks and self-propelled guns were found and of these only 9 were considered to have been destroyed by air weapons!

During the Falaise pocket battle the RAF claimed 3.340 soft skinned vehicles and 257 armored ones while the USAAF claimed 2.520 soft and 134 armored vehicles. Yet when No2 ORS examined the area they could only find 133 armored vehicles of which only 33 had been the victim of air attack. The stats were better for unarmored vehicles (cars, trucks, motorcycles) as 325 of 701 were victims of air attack but in both cases there was a chasm between claims and confirmed kills.

Allied fighter bombers were fast and could engage enemy fighters but their speed worked against them in the ground attack role. For those missions a dive bomber would be preferable but neither the USAAF nor the RAF could be convinced to design and use such a plane. Officially the reason given was that such a slow and unmaneuverable plane would not survive in enemy airspace but the real reason was they did not want to spend resources for purely Army missions. 

In the field the fighter bombers had a poor record against armored targets. Their guns were moderately accurate but had a low caliber and could not destroy armored vehicles. Their air to ground rockets had more destructive power but they were hopelessly inaccurate. An average Typhoon pilot, firing all eight rockets in a salvo, had roughly a 4% chance of hitting a target the size of a German tank in trials.  In the field of battle one would expect this percentage to be even lower.

Against unarmored targets (like trucks) however their performance was more than adequate.

The other major problem of fighter bombers was their limited armor. Unlike the Stuka and the Sturmovik they did not have adequate protection against A/A defenses. For this reason the German anti-aircraft defenses protecting important targets (bridges, supply bases etc) were able to extract a heavy toll on them.

Despite these problems the Western Allies fielded large ground attack forces and these were used extensively in NW Europe. Even though they had serious limitations they certainly had an impact in the fighting. Although they were not a big threat for armored vehicles they did force the Germans to move supplies only at night.

Overall this book is an excellent study of the evolution of RAF and USAAF CAS doctrine and it debunks postwar exaggerations of Allied air support.

Note: In page 31 it is stated about the 1944 campaign in NW Europe: ‘During that campaign the Germans had been able to set up an air warning system against air attack based on the interception of support requests from British Army units.’
This is a reference to the German exploitation of the Slidex code system and plaintext traffic.

Monday, March 4, 2013

Report on problems of SOE cipher systems

A very interesting report on the problems of the crypto systems used by SOE has been posted at the arcre website.

Sunday, March 3, 2013

The mysterious Irish codebreakers

A British report investigating the security of US diplomatic codes mentions that the Irish had a codebreaking department and were ‘thoroughly well equipped in the art of code breaking’.

According to another report ‘their head cryptographer is extremely able’.

Who could they be referring to? It seems that the head of the Irish codebreaking department was a mr Richard Hayes.