Sunday, November 12, 2017

British Tank Production and the War Economy, 1934-1945

All the major powers of WWII used tanks and especially in North Africa and in Europe they played an important role in the actual combat operations. Some of these tanks like the German Tiger were famous for their combat record, while others like the Soviet T-34 and American M4 Sherman were produced in huge numbers.

However both during the war and afterwards British tanks were criticized for being inferior. The design and combat performance of British WWII tanks is a subject that has received attention by historians and several authors like Correlli Barnett, David Fletcher and Peter Beale are critical of British tanks.

The new book ‘British Tank Production and the War Economy, 1934-1945’ by Benjamin Coombs covers the administrative and production history of the British tank program in WWII and its greatest strength is that it tries to explain why certain decisions were made and what effects they had regarding production numbers, tank quality and combat performance.

The book has the following chapters:


1. Government and Industry during Disarmament and Rearmament

2. Government and Industry during Wartime

3. General Staff Requirements and Industrial Capabilities

4. The Tank Workforce and Industrial Output

5. Overcoming Production Problems and Delays

6. Influence of North America upon the British Tank Industry


A great review is available at by user ‘VinceReeves’ so I’ll repeat it here:

‘This is a long-needed objective view of British tank production during World War II that finally manages to eschew the hysteria and nonsense that generally attends this subject. Coombs chronicles the evolution of tank design, and the shifting priorities of production with authority and objectivity, and demonstrates how much misunderstanding has attended the controversies over real and perceived quality issues and inefficient tank production. 

Basically, British tank production underwent three stages during the war; an early stage in which tank production was downgraded in favour of more vital air defence work, a second stage in which quality was sacrificed to boost quantity production to rectify numerical deficiencies, and finally a mature third stage in which quality was emphasised, and British tanks became more effective and reliable.

Coombs makes sense of what appear to be irrational decisions to continue the manufacture of obsolete tanks long after they were required - more often than not this was undertaken to keep production facilities and skilled labour within the tank programme so that they would be available when newer tanks were ready for introduction.’

If you are interested in military history and you want to learn more about the British tank program then this book is a valuable resource.

For me the value of the book is that it helps explain German victories in N.Africa in 1941-42. The Germans benefited by fighting against an enemy whose tanks constantly broke down. In the period 1943-45 the British tanks became more reliable because a determined effort was made to thoroughly check and fix flaws and a high priority was assigned to spare parts production.

Thursday, November 9, 2017

Waiting for the Carlson-Goldsberry report...

I have one more essay that I’m going to upload and it covers, in some detail, the compromise of State Department communications in WWII.

Ideally I would like to get a copy of the Carlson-Goldsberry report from the NSA’s FOIA office but if that doesn’t happen soon I’ll just go ahead and post it anyway. If I need to update it I’ll do so in 2018.

Let’s hope I get lucky and the file is released soon.

Thursday, November 2, 2017

The code of mr Seymour Parker Gilbert - Agent General for Reparations to Germany

After the Allied victory in WWI, the leaders of the US, UK and France imposed harsh peace terms on the defeated Germans. Germany (and the other defeated Central Powers) had to make reparations to the Allied countries.

The problem was that the payments that the German government was supposed to make were so great that they would bankrupt the country. Due to German unwillingness and inability to service the payments the Allies resorted to military measures such as the occupation in 1923 of the Ruhr industrial area.

In order to defuse the situation and find a realistic solution to the reparations problem the Dawes Plan was implemented. Allied troops would leave the Ruhr area and the German government would resume payments, after receiving a US loan that would revitalize the German economy.

In Germany the Allied representative responsible for monitoring the German compliance with the Dawes plan was mr Seymour Parker Gilbert and his official title was Agent General for Reparations by the Allied Reparations Commission.

It seems that the German government closely monitored Gilbert’s communications and was able to solve some of his encrypted traffic to New York (Federal Reserve bank), Paris and Rome.

Documents of the German Foreign Ministry’s decryption department Pers Z, captured at the end of WWII, show that his messages were solved by the German codebreakers:

Source: TICOM report DF-15 ‘Reports of Group A’ (US National archives - RG 457)

Additional information: Gilbert’s 1927 report.

Monday, October 30, 2017

WWII documentary

Interesting newfound footage from WWII. Hitler’s mental and physical deterioration can be clearly seen in this documentary.

Friday, October 27, 2017

The reconstructed Slidex card

At Crypto museum I saw that they’ve uploaded some Slidex cards from 1944. I had a quick look to see if I could locate the one solved by the German codebreakers and found in the report E-Bericht FNASt 9 (US National archives - RG 457 - Entry 9032 - box 22 ‘German deciphering reports’).

I didn’t expect to find anything so imagine my surprise when I saw that the Air Support Signals Unit card No. 1 (from 1944) had the same code values:

I’ve added this card in The Slidex code.

Tuesday, October 24, 2017

Signals intelligence and codebreaking operations during the Greek-Italian War of 1940-41

At the start of WWII the Kingdom of Greece, ruled by Ioannis Metaxas  (head of the 4th of August Regime) followed a neutral foreign policy and tried to avoid taking part in the conflict. However constant Italian harassment and provocations (such as the sinking of the cruiser Elli) and the transfer of Italian army units to Albania made it clear that war could not be avoided for long.

In October 1940 Italian forces invaded Greece, in the area of Epirus, and the Greek-Italian war started. The Greek forces were able to contain the assault and the Greek counterattack forced the Italians back into Albanian territory. After the defeat of a major Italian offensive in spring 1941 the front stabilized inside Albania.

At the time Britain was overextended with obligations in Europe, Middle East and Asia. However the British armed forces made a small contribution with an RAF expeditionary corps. When more British forces started to arrive in March 1941, their involvement gave Germany an excuse to become involved in the conflict.

German forces invaded Greece in April 1941 and made rapid progress due to the fact that almost the entire Greek Army was fighting in the Epirus area. The remaining units and the small British forces transferred to Greece in March-April 1941 were unable to stop them. 

Then in May 1941 the Germans were also able to defeat the Greek and British forces that had retreated to the strategic island of Crete.

What role did signals intelligence and codebreaking play during that short conflict? Let’s have a look at the limited information available:

The Italian effort

Italy had two codebreaking departments, one under Army and the other under Navy control.

The Italian army’s intelligence agency SIM (Servizio Informazioni Militari) had a cryptanalytic department that attacked foreign crypto-systems. This section was headed by General Vittorio Gamba and was located in Rome. Personnel strength was roughly 50 people (half cryptanalysts-half linguists and clerks).

The naval intelligence agency SIS (Servizio informazioni Speciali della Royal Marina) was divided into 4 branches. Branch B (Beta) was tasked with signals intelligence. It was subdivided into cryptanalysis, interception and direction finding, security and clandestine radio intercepts. The cryptanalytic department was located in Rome and headed by Commander Mario De Monte.

It is not clear if the Italians had success with Greek Army or Air force codes and ciphers. However in the Archivio dell' Ufficio Storico della Marina Militare there are decoded Greek Navy messages.

Regarding the Greek Air force communications, it seems that the cipher system used was simple transposition (1). Considering the limited security of this system it is reasonable to assume that it was solved by the Italian codebreakers.

The Greek effort

At this time there is almost no information available on the Greek Army’s cryptologic and cryptanalytic effort during WWII. A report from 1938 (2) mentions the Greek Army codebooks: small unit code 1937, large unit code 1937, small unit code 1938, mobilization code 1937, cryptographic lexicon 1935.

Regarding cryptanalysis it seems that the Greek Army Signal Corps may have been able to exploit Italian communications (3). According to an article on Greek military intelligence this information comes from British liaison signal officers:

In addition, according to British liaison signals officers, Greek Signals Corps managed to decipher some Italian traffic during the November/December battles in Albania. On 6 December, a British lieutenant-colonel informed his superiors: “Herewith a batch of Italian traffic intercepted by the Greek General Staff. Also, one copy of cipher ‘O.M.’ for internal use of the Italian Army in Albania.” On 8 December, the reply confirmed Greek success: “Many thanks to Greeks for citrario O.M. Tell them I do not remember having seen it but I am very grateful for it and for any further documents of this nature which may be of assistance in reading Italian codes in Albania which I am afraid are not readable.” We could imagine that Greek Signals Corps may have deciphered key traffic during October, prior to the invasion. Unfortunately, at the Army History Service no files of Greek signals operations can be found. Perhaps some material might be held at the Military Archives Service but we must bear in mind that the 1941 German invasion and the 1941-1944 occupation caused the destruction of many files of sensitive army archives. As to Metaxas, he did not make any reference to signals intelligence in his diary’.

The German effort

The German Army’s signal intelligence agency solved Greek Army and Air force ciphers. According to the TICOM report I-170 in spring 1941 Greek AF single transposition messages were solved and translated (4):

My first employment was on the breaking and translating of Greek Air Force messages in Spring 1941. The unit was in BUCHAREST at that time and later it was at BANJA KOSTENIC in Bulgaria. C.O. was Hptm. SCHMIDT, head of the cryptography and translation department from then until Autumn 1944 was Prof. Alfred KNESCHKE, a Professor of Mathematics from Saxony.

The Greek Air Force messages were a matter of simple boxes, the text being sent in T/L groups. The indicator took the form of 3 letters which were always in a given position, the first three T/L groups and had to be knocked out before entering the cipher text in the clear box. This was broken by writing out the cipher text in vertical strips of varying depth and sliding them against each other until a few Greek syllables appeared above one another. After the initial break it became clear that a large part of the messages began with the words ‘parakalw', 'anaferw’ and ‘apesteilamen’ and that the width of the box was as a rule between 15 and 22 columns. On the basis of the above, initial words, all messages were tried out on the normal number of columns and nearly everything was read. I had less to do with the actual evaluation, firstly because the two departments were kept separate and secondly because we were kept fully occupied with our own job. In any case the content of the messages was usually of insignificant strategic value, although the continuous check on officer personalities, deliveries of stores and knowledge of airfields combined with D/F bearings indirectly contributed to considerable tactical results'.

Regarding Greek Army ciphers there is some information available from the postwar interrogations of Army cryptanalyst dr Buggisch. According to TICOM report I-58, in early 1941 he investigated a Greek codebook enciphered with a 35 figure repeating additive sequence (5). Progress was made in the solution of the cipher but the campaign ended just as the system was starting to be exploited operationally:

c. Greek - In early 1941, B. solved a 5-letter code with a 7-cyclic recipherment (period of 35). Just getting to operational speed when the campaign ended.

German exploitation of Italian communications

It seems that the codebreakers of the German Army did not only monitor the communications of their enemies but also solved the codes and ciphers of their Italian allies.

The War Diary of Inspectorate 7/VI shows that Italian codes and ciphers were worked on by Referat 4 (6). According to the reports of Referat 4 for early 1941, 5-figure and 3-figure codes were worked on:

The 3-figure Army code was successfully solved and read. A 5-figure Air Force code was also worked on and the encipherment solved. A 5-figure enciphered code used by the higher command in Albania was worked on and code groups recovered.

The reports say that emphasis was put on the analysis of the systems used by the higher echelons of command.

Some interesting statements regarding Italian radio communications are made in ‘War Secrets in the Ether’ - vol 3, p25 written by Wilhelm Flicke (he was in charge of the OKW/Chi’s Lauf intercept station):

‘Mussolini had decided on war in the Balkans. Von Papen's warnings made Hitler averse to any immediate action there, but he was only able to restrain Mussolini to the extent of limiting Italy to war with Greece. In less than two months the Italians, who had the advantage in everything save morale, were badly beaten. The political leaders were terribly surprised and the Chief of General Staff, Marshal Badoglio, and numerous other high officers were relieved of their duties. This did not help matters.

One of the most decisive factors during those weeks was the manner in which the Italians employed radio. The set-up was the same as that used in maneuvers of previous years. They employed open circular traffic; that is, they used one uniform frequency for a group of stations belonging to the same unit (e.g., the stations of three infantry regiments of a division for traffic with one another and with the divisional station) and each station used only one call sign for all its traffic. The call sign was supposed to change daily but was often used for several days; not infrequently a change in call sign was followed by errors which betrayed the change. Traffic was so heavy that the enemy always had a chance to take bearings and fix locations. Frequently messages were sent in clear. Several units of the Italian Eleventh Army distinguished themselves in this respect. Moreover, the Greeks had obtained at least two Italian army cryptographic systems, how I do not know, but it is certain that in the very first days of the campaign they could decipher a large part of the Italian messages. This enabled them to learn promptly most of the dispositions of the Italian command and to take appropriate action. The superiority thus gained was utilized cleverly and a series of military actions took place which heretofore would never have been deemed possible’.


(2). German Foreign Ministry’s Political archive - TICOM collection - file Nr. 3.676 - Griechenland 1940 - Korresp. betr. Neue milit. Schl├╝ssel u. Vernichtung alter.

(3). Journal of Intelligence History: ‘Greek Military Intelligence and the Italian Threat, 1934–1940

(6). Kriegstagebuch Inspectorate 7/VI - German Foreign Ministry’s Political Archive - TICOM collection – files Nr 2.755-2.757

Acknowledgments: I have to thank Enrico Cernuschi for sharing the messages from the Archivio dell' Ufficio Storico della Marina Militare.

Monday, October 23, 2017


In Decoding Prime Minister Chamberlain’s messages I’ve added the following:

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…