Tuesday, April 30, 2013

New article on ULTRA in the Med

A very interesting article regarding the effects of ULTRA intelligence against the Italian Navy’s supply convoys is available from the Naval War College Review.

The article is ‘The Other Ultra: Signal Intelligence and the Battle to Supply Rommel's Attack toward Suez’ by Vincent P. O'Hara and Enrico Cernuschi. The authors are critical of the view that codebreaking allowed the Brits to sink Rommel’s supplies and stopped the Axis advance towards Egypt.
According to the authors: ‘This article examines the impact of intelligence in the war against Axis shipping in the two months leading up to the battle of Alam el Halfa, which concluded on 2 September 1942. It demonstrates that Ultra information was not always accurate or timely and that Hinsley overstates Ultra ’s impact by crediting it with sinkings that had nothing to do with either signals intelligence (SIGINT) or traffic to Africa. It also casts light on the role of the Italian navy’s intelligence service, the Servizio Informazioni Segreto (SIS). The SIS provided intelligence that often offset the timely and relevant Ultra SIGINT that Britain did possess. Its code breakers enabled Supermarina, the operational headquarters, located in Rome, of the Regia Marina, the Italian navy, to read, often in less than an hour, intercepted low-grade radio encryptions from British aircraft, and, more slowly, first-class ciphers from warships and land bases. Supermarina’s communications and command system disseminated information in near real time, thereby amplifying the operational value of its SIGINT. This is a fact that the British were unaware of at the time and that has remained virtually unknown since.

Monday, April 29, 2013

Biographies of famous codebreakers

Well it’s true that you can find anything online if you search for it! Site janeckovokrypto has  pictures and short biographies of countless WWII codebreakers (Americans, British, German, Polish etc). Interesting site.

Saturday, April 27, 2013

Decoding Prime Minister Chamberlain’s messages

In the 1930’s Hitler’s foreign policy was focused on dismantling the Treaty of Versailles that was keeping Germany militarily weak.

First compulsory military service was reintroduced in 1935, then the Rhineland was remilitarized in 1936 and finally the Sudeten territories of Czechoslovakia were annexed by the Reich in 1938.
In the diplomatic field the Germans were able to outmaneuver their British and French adversaries mainly thanks to two factors.

One was a disinformation campaign that convinced Western leaders of the Luftwaffe’s destructive power. 
The other was their success in acquiring secret intelligence. The Forschungsamt, Goering’s personal intelligence agency, was able to decode French diplomatic communications (probably physically compromised) and eavesdrop on telephone conversations of politicians and diplomats (especially Czech president Benes and his ambassador in London Masaryk!). Thus Hitler was always one step ahead of his rivals.

In addition to these successes ‘European Axis Signal Intelligence in World War II’ volumes 1 and 7 reveal another very interesting case. Apparently during the negotiations regarding the fate of the Sudetenland German codebreakers were able to solve Prime Minister Chamberlain’s messages to London. EASI vol1, p21 says that ‘Hitler once delayed a conference with Chamberlain for several hours in order to get such decodes’.
The source for this information is listed as IF-132 Das Forschungsamt des Luftfahrtminsteriums  - Hq USFET Weekly Intelligence summary # 12, 4 Oct. 1945’.

Unfortunately page 5 of that document repeats the same story without giving more details.

A clue regarding the cipher system used is available from the TICOM report DF-241 ‘The Forschungsamt - Part IV’, p40

Of the numerous examples which might be adduced, the following may serve as an example: The additive number used by Great Britain, which ran to 40,000 elements and served for the encipherment of the 5-digit code and was replaced at definite intervals of time, offered as a rule adequate assurance of security. But if in periods of greatly increased diplomatic activity with telegraphic traffic many times the usual volume the additive is not replaced correspondingly sooner, especially since increased security is desirable in such periods, then this is a sign of deficient control’.

Thus it is possible that the German codebreakers were able to solve the British Foreign Office cipher in the 1930’s.

The official history ‘British Intelligence in the Second World War’ - vol2, p642 says that:


1. Main Cypher Books

Despite an extensive attack in 1938 and 1939, the Germans failed to break the long subtractor system used to re-cypher the Foreign Office's basic cypher books. Against similar tables that were in force from November 1940 to January 1941 they had some limited success, but not enough to enable them to reconstruct the book before both the basic book and the tables were again changed. There is no evidence of later success, and according to German testimony after the war the main Foreign Office systems were never broken’.

However in the notes it also says:

The discovery after the war in the archives of the German Ministry of Foreign Affairs of  a 90-page volume of British diplomatic signals for the immediately pre-war period led to a  Foreign Office enquiry in 1968. This established that a number of the signals had been dispatched en clair. It also noted that there was reliable evidence that the Italians had obtained temporary possession of the cyphers of the Rome Embassy in 1935, and had photographed them, and that they had had fairly regular access to the cyphers at the Mission to the Holy See during the war, so that they might have read all telegrams to Rome up to the outbreak of war and telegrams to and from the Mission to the Holy See from the outbreak of war to the autumn of 1943. After the war the cryptanalysts of the German Foreign Ministry asserted that they obtained no information about British cyphers from the Italians’.

The British statements may have been accurate about the work of the decryption department of the German Foreign Ministry but they do not mention the Forschungsamt effort… 

Wednesday, April 24, 2013

The German bombe and the M-209 cipher machine

Back in April 2012 I uploaded TICOM report DF-114 ‘German Cryptanalytic device for solution of M-209 traffic’.

This report is a translation of a German document retrieved in 1947. It describes a cryptanalytic device used by German codebreakers against the US M-209 cipher machine.
The only other reference in TICOM documents is in I-149 ‘Report by Uffz. Karrenberg and Colleagues on Allied Cipher Machines’ which says:

A cryptanalytic party, numbering about 20 men, under Wm. ENGELHARDT also worked with Senior Signals Recce Commander Oberst KOPP. The ENGELHARDT party worked on British and U.S. systems, using, among other things, an electrically driven apparatus constructed by themselves. (This was a heavy, black-painted metal box, measuring approximately 50 x 50 X 40 cm, composed of two parts of about equal size. In front of the machine was a keyboard, like a teleprinter. The machine was fitted in the upper part with a set of indicating lamps; when a key was depressed, a letter was illuminated above, as on the German cypher machine). The construction and function of this apparatus, and the systems with which it dealt, are unknown to us. It is alleged that complete solutions (not breaks-in) were achieved by mean of this machine.’

Thankfully an article in a German magazine had an interview with one of the persons who designed and used it during the war:
So when I posted that report I expected that people would be interested in the fact that the Germans had their own bombe. I also thought that someone would be able to explain the operating principle of the machine but again this hasn’t happened. What’s up with that?

Wednesday, April 17, 2013

The secret messages of Marshall Tito and General Mihailović

The Kingdom of Yugoslavia was one of the states that were created when the old Austro-Hungarian empire collapsed at the end of WWI. The country covered a large area in the Balkans but was politically unstable since it was made up of a diverse group of peoples (Serbs, Croats, Slovenes, Montenegrins).

Yugoslavia was part of the Little Entente organized by France. Although its foreign policy was pro-Allied it did not declare war on Germany in 1939. The defeat of France in 1940 caught the Yugoslav leaders by surprise and forced them to adopt a pro Axis policy. This change however was opposed by a group of military officers and in March 1941 a coup replaced the regent Prince Paul with General Dušan Simović. This maneuver (thought to be organized by the British) infuriated Hitler and he ordered that the country was to be destroyed as a political entity. In April Yugoslav troops were quickly overrun by German forces and a period of occupation and internal strife began.
During the occupation the old antagonisms between ethnicities (Serbs vs Croats) and political movements (Right vs Left) resurfaced and led to a multisided civil war. The Chetniks of General Mihailović fought the Communist Partisans of Marshall Tito and both attacked the collaborationist government of Milan Nedic, the German and Italian occupation troops and the Croat forces of Ante Pavelić.

All sides took to heart the motto ‘the enemy of my enemy is my friend’. This meant that at times some resistance group would make a deal with the occupation authorities and agree to leave them alone so both could attack another group. The results of this widespread conflict were mass destruction of property and loss of lives as each group attacked the villages that supported their enemies.
During the period 1941-44 the Germans mounted major operations against the resistance movements but they could not destroy them. In their war against the Chetniks and the Partisans however they took advantage of signals intelligence. The resistance groups used codes that could not withstand a serious cryptanalytic attack and their cipher clerks made many mistakes that facilitated solution. By reading the traffic of Tito and Mihailović the Germans could build up the OOB of their organizations, identify important personalities and anticipate enemy operations.

At the same time the British also used cryptanalysis in order to monitor the internal Yugoslav situation and decide which resistance group they should give supplies to. Their ability to decode the Enigma cipher machine meant that they could use German military messages to see if the information coming from the Chetniks and the Partisans was corroborated by official German reports. They also read Chetnik and Partisan messages including the clandestine traffic between Moscow and Tito (this program was called ISCOT).

Tuesday, April 16, 2013


Time for some new reports:

CSDIC/CMF/Y36 - First detailed interrogation report on one German army intercept PW (Reudelsdorff) - 1945
I-23 ‘Interrogation of Major Ernst Hertzer, German Army Signals Intelligence Service (KONA 1)’ - 1945

I-103 'Second Interrogation of Reg.Rat Hermann Scherschmidt of Pers Z S Auswaertiges Amt, on Turkish and Bulgarian systems’ - 1945

Monday, April 15, 2013

WWII Myths – Crimea evacuation 1944

Books relying on Soviet sources claim that in the fighting in the Crimea in 1944 most of the Axis troops were killed or captured with only a handful escaping.

For example ‘When Titans clashed: how the Red Army stopped Hitler’ by Glantz and House says in page 191 ‘Somewhat less than 40,000 men of Seventeenth Army's original force of 150,000 made it out of the Crimea.
‘World at Arms: A Global History of World War II’ by Gerhard L. Weinberg says in page 671 ‘By mid-May the 120,000 men formally organized as the 17th German Army had been crushed. Only a small proportion was evacuated, there was no long siege as in 1941-42. The Soviet victory was one of the most complete, if least known, of the war.

These statements are not correct. The Germans and Rumanians were able to evacuate 121.000 men by sea and 24.500 by air.
Rumanian website worldwar2.ro has a detailed overview of the naval operations:

The Romanian Royal Navy named the evacuation of Crimea Operation "60,000", because the number of Romanian troops still found in the peninsula was around 62,000 – 65,000 in April 1944. This operation was executed in two phases: the first one between 12 April and 5 May and, the most dramatic, between 6 and 13 May.

In total during the first phase of the operation, between 14 and 27 April 1944, 73,058 people left Crimea by sea:

  • 20,779 Romanians, of which 2,296 wounded
  • 28,394 Germans, din care 4.995 wounded
  • 723 Slovaks
  • 15,055 Russian volunteers
  • 2,559 POWs
  • 3,748 civilians
Of these about 1,5% died during the crossing. One German tanker and one lighter, representing 8% of the tonnage engaged in the operation, were sunk (about 3,000 tons) and several Romanian transport ships were damaged. One Romanian destroyer and two armed transport pontoons, as well as two German submarine hunters were damaged. On the other side the losses were also important. 12 VVS aircraft were shot down, one submarine and one motor torpedo boat were sunk. Another submarine was seriouslt damaged.


In this second phase of the evacuation, 47,825 de men were transported by sea to Constanta: 15,078 Romanians, 28,992 Germans and 3.755 Soviets (volunteers, POWs and civilians).About 10,000 men were lost during the crossing , of which some 4,000 were Romanians.

In total, between 14 April – 13 May 1944, 120,853 men and 22,548 tone of cargo were evacuated by sea from Crimea:

  • 36.557 Romanians, of which 4,262 wounded
  • 58,486 Germans, of which 12,027 wounded
  • 723 Slovaks
  • 15,391 Soviet volunteers
  • 2.581 POWs
  • 7.115 civilians
The Romanian Royal Navy received congratulations from the grand admiral Karl Dönitz, the commander of the Kriegsmarine, and from vice admiral Helmuth Brinkmann, commander of the German forces in the Black Sea, for the way it operated during the evacuation.

In addition to these numbers 21.457 men were evacuated by the Luftwaffe and 3.056 by the Rumanian AF. [Source: ‘Eagle in Flames: The Fall of the Luftwaffe’, p201]
How do we know that the aforementioned statistics are correct? During this period the codebreakers of Bletchley Park were able to follow the military operations in the Crimea by reading messages enciphered on the Enigma machine. The official history ‘British Intelligence in the Second World War’, volume 3 part 1 page 41 says: ‘The evacuation was covered in great detail by Sigint. It was carried out by the Navy and the GAF, the decrypts showing that 121.000 men were taken off by sea and 21.500 by air.

Friday, April 12, 2013

Victory through airpower

When the United States entered WWII in 1941 there were many discussions regarding the correct strategy that the US leadership should follow. Books and articles appeared that promoted whatever the author believed was the correct response, from a larger airforce at the expense of Army and Navy to a Germany first strategy.

One of these books was ‘Victory through airpower’ by aviation pioneer Alexander de Seversky.
Seversky was born in Georgia that was then part of the Russian Empire. His father was one of the first Russian aviators and he taught him how to operate the aircraft. In WWI he became a naval aviator but was seriously wounded in a mission and his leg had to be amputated. Despite this he continued to fly and became the leading naval ace of the war.

With the collapse of the Tsarist regime and the communist revolution Seversky left Russia and immigrated to the US where he continued to work on aviation projects and in the 1920’s he founded the Seversky Aero Corporation which later became Republic Aviation. In 1928 he became a major in the Army Air Corps Reserve.

Seversky was a passionate advocate of airpower and strategic bombing. His book came out in 1942 and became a hit with the public. One of the persons who read it and was impressed by the reasoning was the legendary animator Walt Disney. He was such a supporter of Seversky’s ideas that he financed an animated film based on the book and had Seversky narrate parts of it.

The main point of the book was that aviation and long range bombers would allow the US to destroy the Axis production centers without the need for costly ground campaigns.

I found the movie to be both entertaining and thought provoking. You can download it or view it on archive.org.

Tuesday, April 9, 2013

The American SS Sturmbannführers

A very interesting WWII espionage mystery is mentioned in the book ‘The German Penetration of SOE: France 1941-1944, p155. The source of this story was Ernst Vogt, an interpreter at the Sicherheitsdienst HQ in Paris.

According to Vogt in late 1944 - early ’45 Allied agents were parachuted into Germany as a result of a ‘radio-game’. It seems the organization sending the agents had not realized that their network was under German control. Vogt says that it was probably ‘an American espionage service in London’ (OSS?).

One day three agents were parachuted and immediately taken into custody. These men spoke perfect German and they claimed that they were SS Sturmbannführers and should be released.

Vogt’s superior was Hans Josef Kieffer, commandant at the SD HQ at 84 Avenue Foch in Paris. Kieffer was also SS Sturmbannführer. When the men produced their id cards Kieffer showed them his and pointed out that they were different. This did not faze the captured men. They responded that ‘yours is out of date. All SD identity cards are renewable three-monthly now.’

In order to solve this mystery Kieffer sent Vogt to Berlin to report to his superior Horst Kopkow. When Kopkow saw the identity cards he said: ‘it had been intended to call in the existing ones and to issue new ones in this form’ ‘but none in this form had been issued yet’.

So there you have it! A genuine mystery. Who were these men? Who did they work for? and how did they manage to find out about the new SS id scheme?

Sunday, April 7, 2013

Speer and the one factory shift story

Several sources (books, magazines, sites) mention that the Germans could have produced more armaments in WWII if they had forced their workers to work more than one shift per day. The belief that the Germans underutilized their workforce is supposedly based on a statement by Albert Speer.

The actual statement is the following from ‘Inside the Third Reich’, p304:
Of all the urgent questions that weighed upon me during my early weeks in office, solution of the labor problem was the most pressing. Late one evening in the middle of March, i inspected one of the leading Berlin armaments plants, Rheinmetall-Borsig, and found its workshops filled with valuable machinery, but unused. There were not enough workers to man a second shift. Similar conditions prevailed in other factories.

The reason for the manpower shortage was that there was also demand from the armed forces. The same person could not be at the front and in the factory.
The Germans tried to solve this problem by using forced and slave labor.

Thursday, April 4, 2013

Recurring problems of Soviet tank design

In my piece on the T-34 tank I said that postwar Soviet tanks (T-55, T-62, T-72, T-64, T-80) were built on the same principles as the T-34 with unfortunate consequences for the countries that had to use them in combat.

Soviet tanks have performed poorly in WWII, Korea, in the Middle East wars between the Israelis and Arabs and in Gulf War I, in the sense that they have suffered disproportionate losses against tanks that were comparable to them in general characteristics.

It is fascinating to see that the same problems are mentioned in US and Israeli reports separated by decades and referring to different vehicles. From the T-34 in the 1940’s to the T-62 in the Yom Kippur war the same limitations are noted!

Hull size

The T-34 had a huge problem with internal space due to several factors:
1). a large engine that took up roughly half of internal volume

2). its Christie suspension
3). the sloped armor on the sides and back of the vehicle

Postwar tanks did not have these faults but they also suffered from limited internal space since it was a design choice to limit the weight and size of these vehicles.
The result was that all the Soviet tanks were smaller and lighter than their Western contemporaries like the Centurion, M-48 and M-60. This supposedly gave them an advantage in mobility and presented a smaller target at long distances.

However there was a price to pay:
1). The smaller hull affected the performance of the crew and led to fatigue. For example an Israeli evaluation says: ‘As regard to human engineering the best were the Patton tanks (M60/48), then the Centurion and way behind the T-62/55 tanks. The meaning is that the crews of the Patton and Centurion tanks could fight longer periods of time without being exhausted relative to the crews in the T-62/55 tanks.’ [Source: ‘M60 Vs T-62: Cold War Combatants 1956-92’, p39]

2). Compared to Western tanks a smaller number of rounds could be carried. For example the T-34/76 carried 77 rounds but the T-34/85 carried only 56 and 16 of these had to be stored in the turret. In comparison the Pz IV had 87 rounds and the Panther 82.
The Centurion, M-48 and M-60 had about 60 rounds compared to about 40 in the T-55, T-62, T-72. The ability to carry more ammo meant that tanks did not have to leave the battle in order to resupply often. This was noted by the Israelis:

The amount of gun rounds inside the Patton (M60A1, M60, M48) and the Centurion tanks is remarkably higher (about 60 rounds in each) than in the T-62 and T-55 tanks (less than 40 rounds). The meaning is that on average the T-62 and T-55 tanks should leave their active fight and firing positions for refilling of gun ammunition [more often] than the other tanks, which means that on average the percentage of effective tanks in each moment is smaller in T-62 and T-55 units than in the units of the other tank types.’ [Source: ‘M60 Vs T-62: Cold War Combatants 1956-92’, p38]

3). By having ammo and fuel in a small space any penetration of the tank usually led to catastrophic loss of the vehicle and death of the crew. As Zaloga puts it in ‘T-34-85 vs M26 Pershing: Korea 1950’, p23:

Armor data provides only part of the picture of a tank's protection. Other factors in assessing the vulnerability of a tank include the internal arrangement of fuel and ammunition. The T-34-85 is a clear example of the trade-off between the benefits and drawbacks of steeply angled protective armor. Although the T-34's sloped sides reduced the likelihood of the tank being penetrated by enemy projectiles, it also led to a decrease in internal hull volume. In the event that the T-34 was penetrated, the projectile was far more likely to produce catastrophic damage among the fuel and ammunition stored in such a small space. The side sponsors of the T-34's fighting compartment in particular contained fuel cells that if penetrated could lead to fire and the destruction of the tank.

The same problem was identified by the Israelis after the Yom Kippur war. According to ‘M60 Vs T-62: Cold War Combatants 1956-92’, p39:
‘Survivability: The silhouette of the T-62 and T-55 tanks is smaller than [that] of the other tanks and the same is true with the silhouette of their turret. One of the most [sic] disadvantages of T-62/55 tanks is their small internal volume. The meaning is that all the internal systems are too close and when one system is hit after penetration, in most cases another system or systems are also damaged or getting out of action. Because of the small internal volume there is in the T-55 tank a fuel tank combined with gun ammunition stowage in the right front corner of the hull (I am not sure if it is the same in the T-62 tank)[it is]. The meaning is absolute destruction and explosion of the tank in case of a penetration. Analysis based up tests and war analysis showed that the improved Centurion and M60A1 were more or less on the same level survivability. Next came the M48 and Tiran 4/5 and finally the Sherman.

This problem became worse and worse as tank gun calibers grew and more powerful ammo was carried. Zaloga says in ‘M1 Abrams Vs T-72 Ural’, p27 that the T-55 carried 220kg of propellant, the T-62 310kg and the T-72 440 kg.

The result:

Turret size

The T-34/76 had a very cramped turret. An evaluation by US personnel noted:

The main weakness is that it is very tight. The Americans couldn't understand how our tankers could fit inside during a winter, when they wear sheepskin jackets

Postwar Soviet tanks had a new hemispherical turret design. This had excellent ballistic protection due to the sloped design but it was very cramped and it seriously affected crew performance and gun depression.

Reload rates
The cramped interior of Soviet tanks limited the speed with which the crew could operate the gun.

The T-34 had a low reload rate of about 4 rounds per minute versus 2-3 times that in German and Western tanks. The same problem was noted in postwar Soviet tanks of the T-55 and T-62 type.

The Soviets tried to solve this problem by installing an autoloader in the T-64, T-72 and T-80 tanks.  This equipment however has a bad reputation due to many cases of malfunction when it was first introduced.

Gun depression
Soviet tanks from the T-34 onwards had poor gun depression which meant they could not fight in hull down position. Western tanks used this tactic with success especially in the Golan front during the Yom Kippur war. From various Osprey books I collected the following statistics:

            Gun elevation
up (+)
down (-)
T-34/76 L-11
T-34/76 F-34
Pz III 50mm
Pz IV KwK 40
Sherman M3
Sherman M1

An Israeli report noted: ‘The T-62 and T-55 tanks have [limited] depression of their gun, up to about -6 to -7 degrees, whereas all the others have gun depression of about -10 degrees. The meaning is that in many cases the T-62 and the T-55 tanks, while in firing position (behind a fold or a small hill) did not have enough depression and so had to expose themselves more and be more vulnerable to the other side.’ [Source: ‘M60 Vs T-62: Cold War Combatants 1956-92’, p38]

Gun performance
Soviet tank guns of WWII developed lower pressure than Western ones with the result that their accuracy and penetration at long ranges suffered. Did the same problem affect postwar vehicles?

The Israelis found the gun of the T-62 to be quite powerful. However a US test of its accuracy showed that after 1km its ability to hit targets was limited. The M-60’s 105mm was significantly more accurate at long ranges. [Source: ‘M60 Vs T-62: Cold War Combatants 1956-92’, p50-52]

The T-34 had poor stability over rough terrain due to its Christie suspension.  Postwar Soviet tanks had torsion bar suspension but the ride continued to be uncomfortable and tiring for the crew.

The dogma of quantity over quality
Why did all the Soviet tanks suffer from the same limitations? The answer is that the Soviet military doctrine emphasized the importance of numbers and the inevitability of heavy casualties. If you expect your tanks to be destroyed quickly then it doesn’t make sense to build expensive ones lavishly equipped with armor and with an emphasis on crew comfort. Instead their goal was to keep weight and size down so they could out produce the West.

The factories of the Eastern bloc churned out thousands of tanks during the cold war and certainly had a big numerical advantage against the West. They also succeeded in building vehicles that were well armed and armored for their time. However their emphasis on production numbers meant that soft flaws (cramped interior, poor gun depression etc) limited their performance in the battlefield.
Western tanks were built on different lines and although they usually had comparable weapons and armor ‘on paper’ in the field of battle they outperformed their Eastern counterparts.

Sources:  various Osprey books including T-34-85 vs M26 Pershing: Korea 1950, Centurion Vs T-55: Yom Kippur War 1973,  M60 Vs T-62: Cold War Combatants 1956-92’, ‘M1 Abrams vs T-72 Ural: Operation Desert Storm 1991’, T-34 Aberdeen evaluation, WWII Myths - T-34 Best Tank of the war