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:

Introduction

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

Conclusion

A great review is available at amazon.co.uk 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 opponent 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.

The unscrupulous Italian official and the code of colonel Fellers

One of the most damaging compromises of Allied communications security, during WWII, was the case of Colonel Bonner Fellers, US military attaché in Cairo during 1940-2. Fellers sent back to Washington detailed reports concerning the conflict in North Africa and in them he mentioned morale, the transfer of British forces, evaluation of equipment and tactics, location of specific units and often gave accurate statistical data on the number of British tanks and planes by type and working order. In some cases his messages betrayed upcoming operations.

Fellers used the Military Intelligence Code No11, together with substitution tables. The Italian codebreakers had a unit called Sezione Prelevamento (Extraction Section). This unit entered embassies and consulates and copied cipher material. In 1941 they were able to enter the US embassy in Rome and they copied the MI Code No11. A copy was sent to their German Allies, specifically the German High Command's deciphering department – OKW/Chi. The Germans got a copy of the substitution tables from their Hungarian allies and from December 1941 they were able to solve messages. Once the substitution tables changed they could solve the new ones since they had the codebook and they could take advantage of the standardized form of the reports. Messages were solved till 29 June 1942 and they provided Rommel with so much valuable information that he referred to Fellers as his ‘good source’.

The British realized that a US code was being read by the Germans when they, in turn, decoded German messages containing information that could only have come from the US officials in Egypt. The Americans however were not easily convinced that their representative’s codes had been ‘broken’ and it took them months before they changed Colonel Fellers code.

The Germans didn’t know that the Brits had solved messages enciphered on their Enigma machine and thus had different ideas about who betrayed their codebreaking success. Wilhelm Flicke, who worked in the intercept department of OKW/Chi wrote in TICOM report DF-116-Z about this case:

During the war there was stationed at the Vatican a diplomatic representative of the U.S.A. who stood in radio communications with Washington like any other ambassador or minister. In a radiogram sent to Washington in June 1942, enciphered by means of a diplomatic code book, one could read of a conversation which representative of the Vatican had had with an Italian of high position. During this conversation the Italian had mentioned that the Germans could read the most important cryptographic system of the American Military Attaché. The American representative had learned this at the Vatican through a Vatican official and was therefore warning the American War Department against any further use of this cryptographic system.

 

 

Weisser (a cryptanalyst of OKW/Chi) also said that it was the Italians who betrayed the German success in his report TICOM I-201:

 

Did the Germans have a reason to mistrust their Italian allies?

It seems that the answer is yes. On July 24 1942 Leland B. Harrison, US ambassador to Switzerland, sent a telegram to assistant secretary Gardiner Howland Shaw (who was in charge of the State Departments cipher unit) warning him that an Italian official had met with Harold Tittmann (US representative to the Vatican) and had told him that the US diplomatic code used by the embassy in Egypt was compromised.

 

 

The Germans clearly solved this message and thus attributed the end of the Fellers telegrams to Italian treachery. However looking at the dates it’s clear that this was not true. Fellers changed his cryptosystem in June 1942, while this telegram was sent in July.

The British Typex cipher machine

In 1926, the British Government set up an Inter-Departmental Cypher Committee to investigate the possibility of replacing the book systems then used by the armed forces, the Foreign Office, the Colonial Office and the India Office with a cipher machine. It was understood that a cipher machine would be inherently more secure than the codebook system and much faster to use in encoding and decoding messages. Despite spending a considerable amount of money and evaluating various models by 1933 the committee had failed to find a suitable machine. Yet the need for such a device continued to exist and the Royal Air Force decided to independently fund such a project. The person in charge of their programme was Wing Commander Lywood, a member of their Signals Division. Lywood decided to focus on modifying an existing cipher machine and the one chosen was the commercially successful Enigma. Two more rotor positions were added in the scrambler unit and the machine was modified so that it could automatically print the enciphered text. This was done so these machines could be used in the DTN-Defence Teleprinter Network.

The new machine was called Typex (originally RAF Enigma with TypeX attachments). The first experimental model was delivered to the Air Ministry in 1934 and after a period of testing 30 more Mark I Typex machines were produced in 1937. The new model Typex Mark II, demonstrated in 1938, was equipped with two printers for printing the plaintext and ciphertext version of each message. It was this model that was built in large numbers and the first contract for 350 machines was signed in 1938. Typex production was slow during the war with 500 machines built by June 1940, 2,300 by the end of 1942, 4,078 by December 1943 and 5,016 by May 1944. By the summer of 1945 about 11.000 (8.200 Mk II and 3.000 Mk VI) had been built (1).

German 80mm Photophone - Carl Zeiss Lichtsprechgerät

One interesting communications device used by the German Armed forces during WWII was the photophone. This was a device that used light waves to transmit speech over long distances.

The photophone models built by the Germans were constructed by the well known Carl Zeiss company. One of these, the 80mm model, was captured by Allied forces in North Africa and it was evaluated by scientific personnel.

The report they produced is called ‘The 80mm German Photophone’ and can be found at the US National Archives and Records Administration.

The file can be downloaded from my Scribd and Google docs accounts.

 

Additional information on the photophone is available from site fieldgear.org and wehrmacht-awards.

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.’

The British War Office Cypher

At the start of WWII and for most of the conflict the standard crypto system used by the British for high level messages was the codebook enciphered with subtractor tables. Both the Foreign Office and the military services relied on these Cyphers for their most important traffic.

The codebook was basically a dictionary that assigned a 4-figure group to each word. For example the word ‘division’ would have the code 5538, ‘attack’ 2090, ‘artillery’ 0231 etc etc. So the cipher clerk would first use the codebook in order to find the code groups corresponding to the words of the message and then he would have to use the subtractor tables in order to encipher them. This means that each codegroup would be subtracted from the key groups (of the subtractor table) without carrying over the numbers.

The War Office Cypher was the Army’s universal high-grade codebook (4-figure) and carried traffic between Whitehall, Commands, Armies, Corps and, later, divisions. There were different sets of enciphering tables for each geographic area (Home Forces, Middle East, etc). The Germans captured two copies of the WOC in 1940. One during the Norway campaign and the other near Dunkirk. The compromise of the code allowed them to focus only on stripping the cipher sequence. This was achieved by taking advantage of ‘depths’ (messages enciphered with the same numeric sequence).

According to TICOM report I-51 ‘Interrogation Report on Ufrz. Herzfeld, Heintz Worfgang and Translation  of a Paper He Wrote on the British War Office Code’, p16-17 (available from site TICOM Archive), in 1941 the German Army’s signal intelligence agency OKH/Inspectorate 7/VI evaluated intercepted British traffic from the Middle East, identified the use of the WOC and from the summer of 1941 was able to solve messages. First back traffic was solved from the Cyrenaica offensive of General Wavell and then messages from Rommel’s offensive in early 1941. In the period September ‘41-January ‘42 current traffic could be read.

 

This information can be confirmed in part from the War Diary of Inspectorate 7/VI. Unfortunately the reports of Referat 2-England are not available for the period June-September ’41 but from October they show that WOC was read by the department. The report of October ’41 says that WOC traffic in the period November 1940 to March 1941 was enciphered with the same subtractor tables but from April ’41 a new subtractor book was used for each month:

In November-December ’41 the addresses from the solved messages (identifying specific units) were issued in confidential reports:

During 1941 the WOC decodes provided intelligence mainly on the order of battle and movement of British units in the M.E. Theatre. It seems that some of the decoded messages contained strength returns as an Enigma message decoded by Bletchley Park in October ’41 gave a summary of the increase in British ground strength in Egypt and the tank strength estimate was so accurate that the War Office was ‘very concerned’.

The main German success with WOC came during the period November-December ’41, when they could follow the British operation Crusader. The official history ‘British intelligence in the Second World War’ vol2, p298 says:

‘If under-estimation of the quality of Rommel's equipment was one reason why British confidence was high when the Crusader offensive began, another was the failure to allow for the efficiency of his field intelligence. By August 1941 the Germans were regularly reading the War Office high-grade hand cypher which carried a good deal of Eighth Army's W/T traffic down to division level, and they continued to do so until January 1942. Until then, when their success was progressively reduced by British improvements to the recyphering system, whereas GC and CS's success against the German Army Enigma continued to expand, this cypher provided them with at least as much intelligence about Eighth Army's strengths and order of battle as Eighth Army was obtaining about those of Rommel's forces.’

The British knew that the WOC was in enemy hands and could be exploited but they had no alternative than to keep using it. Security was upgraded in late ’41 and from early ’42 the Germans could not solve messages. The traffic continued to be investigated during 1942 and back traffic was solved but not current messages.

 

This was not the end of the German solution. According to Herzfeld, the WOC used by Home Forces in Britain was solved in 1943. After investigating the intercepted messages in late 1942 it was discovered that the Brits had added code groups in the WOC for the most commonly used phrases.

Based on these findings back traffic of 1942 up to end of January ’43 was read, as can be seen from the War Diary of Inspectorate 7/VI:

 

This would be their last success with the WOC as in 1943 the subtractor tables were replaced by the new stencil cipher which proved to be unbreakable.

Conclusion

Signals intelligence and codebreaking played an important role in WWII. In the first half of the war the German sigint agencies were able to exploit several high level British cryptologic systems.

One of these was the British Army’s War Office Cypher and the decoded messages from the M.E. Theatre in 1941 gave them valuable intelligence, especially during the Crusader offensive.

Sources: ‘Intelligence and strategy: selected essays’, ‘British intelligence in the Second World War’ vol2,  TICOM reports I-51, I-113, IF-107, CSDIC SIR 1704-‘The organization and history of the Cryptologic service within the German Army’, CSDIC/CMF/Y 40-'First Detailed Interrogation Report on Barthel Thomas’, ‘European Axis Signal Intelligence in World War II’ vol1 and 4, , Cryptologia article: ‘Brigadier John Tiltman: One of Britain’s finest cryptologists’, War Diary Inspectorate 7/VI

The British Interdepartmental Cypher

One of the high level British cryptosystems exploited by the Germans in WWII was the Interdepartmental Cypher. This was a 4-figure codebook enciphered with 5-figure subtractor tables.

The ID Cypher was used by the Foreign Office, Colonial, Dominions and India offices and the Services. Also used by the Admiralty for Naval Attaches, Consular Officers and Reporting Officers.

The Germans captured the codebook from the British consulate in Bergen in May 1940 and subsequently ‘broke’ the encipherment. Although their success was mainly based on cryptanalysis, they also received some enciphering tables from the Japanese in 1941.

All the German agencies (OKW/Chi, Forschungsamt, Pers Z plus the cryptanalytic agencies of the German Army, Navy and Airforce) worked on the ID Cypher and they exchanged results. During the period 1940-43 they were able to gain valuable diplomatic and military intelligence by reading the messages.

The Navy’s central cryptanalytic department OKM/SKL IV/III (Oberkommando der Marine/Seekriegsleitung IV/III) was able to decode the British Admiralty’s weekly intelligence summaries sent to naval attaches. In addition messages from the Freetown Area were decoded and provided intelligence on the movement of heavy ships and convoys. Traffic between the Admiralty and Consular Officers and Reporting Officers gave information on convoys and independently routed ships in the Atlantic. From ADM 1/27186 ‘Review of security of naval codes and cyphers 1939-1945’, p75-76

The Luftwaffe’s Chi Stelle read the communications of air attaches in the Near East, Portugal, Sweden and Switzerland. Maximum daily traffic was about 100 messages according to Ferdinand Voegele, the Luftwaffe’s chief cryptanalyst in the West. From TICOM IF-175 Seabourne Report, Vol. XIII. ‘Cryptanalysis within the Luftwaffe SIS’ Part 1, p21

Diplomatic messages were solved by OKW/Chi, the Forschungsamt and Pers Z. Interesting information was received regarding negotiations between Britain and Turkey.

The German efforts were assisted by poor British cipher practices. A security investigation in 1942 showed that the tables were overloaded, leading to heavy ‘depths’ and the indicators were not selected correctly.

The German success finally ended on 15 June 1943 when the codebook was changed.

Sources: ‘British intelligence in the Second World War’ vol2, TICOM reports I-12, I-22, I-172, I-119, HW 40/75 ‘Enemy exploitation of Foreign Office codes and cyphers: miscellaneous reports and correspondence’, HW 40/85 ‘Exploitation of British Inter-Departmental cipher’, ADM 1/27186 ‘Review of security of naval codes and cyphers 1939-1945’, ‘European Axis Signal Intelligence in World War II’ vol5, TICOM IF-175 Seabourne Report, Vol. XIII. ‘Cryptanalysis within the Luftwaffe SIS’

RAF strength Med/Middle East - 1941-43

In the period 1941-43 the main theatre of war between British and German military forces was North Africa. There British forces had to fight against the German Africa Corps and the Italian Army.

The RAF strength during this period was the following:

Middle East Command and later Mediterranean Command

 

 North West African Air Forces

RAF - North West African Air Forces
Types		7-May-43		3-Sep-43
Spitfire		686		703
Hurricane		165		181
Kittyhawk				97
Beaufighter		62		144
Wellington		31		207
Marauder		15		16
Boston		40		74
Blenheim		44		63
Hudson		57		43
Baltimore				71
Spitfire recon		15		20
Mosquito recon				4
Total		1,115		1,623

 

Numbers refer to planes operational plus those serviceable within 14 days.

RAF Malta

 

Source: Daily strength reports from AIR 22 - 'Air Ministry: Periodical Returns, Intelligence Summaries and Bulletins'

Some comments:

Numerical strength goes up dramatically during the period 1941-43. From 385 fighters and bombers in May ’41, to 1.202 in May ’42, to 2.926 in May ’43 (including NWAAF).

In terms of quality the picture is not as clear as regards quantity. Even though the Brits have the excellent Spitfire fighter, in the Med they use the outdated Hurricane and the US P-40. Both these planes are inferior to the Bf-109. The Spitfire is finally used from mid 1942 but is only available in large numbers in late ’42.

The bomber force also suffers from mediocre quality. Initially it is made up of the outdated Blenheim and Wellington types. In 1942-43 the US types Boston, Maurauder, Baltimore, Maryland and Hudson are also used.

Standardization does not seem to be an issue with the RAF. In 1941 there are 2 fighter and 4 bomber types in use. In 1942 there are 6 fighter and 9 bomber types. Finally in 1943 there are 5 fighter and 8 bomber types.

Lend Lease plays a vital role in N.Africa, as the American P-40 fighter and the Boston, Maurauder, Baltimore, Maryland and Hudson bombers make up a large part of RAF strength in the theatre (roughly a third of ME Command in 1941-42).

Comparison with Axis strength:

Unfortunately I don’t have similar data for the Italian AF but Luftwaffe strength for Luftflotte 2 and Sud Ost has been posted here.

The RAF had a significant numerical advantage over the German AF, however that does not mean that the Germans were always outnumbered.

Against Malta the Luftwaffe could concentrate a large force of fighters and bombers operating from Sicily. In the first half of 1942 they had between 300-400 combat planes versus less than half as many British planes.

On the other hand in North Africa it was the Brits that had crushing superiority. The strength of Fliegerführer Afrika fluctuated between 200-300 planes versus up to 6 times as many in Middle East Command.

The Germans also faced serious supply problems that forced them to rely mainly on the Bf-109 and Ju-87. Bombers like the Ju-88 could not be permanently based in N.Africa but operated from Italy and Greece and were resupplied in N.African airports. The RAF on the other hand had the benefit of a large number of twin-engined bombers operating from N.African bases.