FM Lord Alan Brooke's WWII diary shows that after Dunkirk, the ministry gave him the choice for the year's production between 600 2pdr and 200 6pdr; he chose the former.
One might wonder why, or if, it was an either or proposition. For instance, might Brooke's have opted for a mix of 300 x 2pdrs and 100 x 6pdrs if offered?
I did too, Dave, but there was nothing further, just an entry of note. So much for primary sources! There must be a detailed official history of the UK WWII Munitions industry but I don't go there.
The single-volume British "official" history British War Production by Michael Postan in 1952 barely touches on the subject and like much British "official" commentary it contains limited references so it is a near impossible task to track down the background on the decision making without a deep dive into Kew. However, some tentative inferences can be made.
One thing that becomes immediately obvious is that the British decision to produce tank and antitank guns was made quite late. In December 1938, the War Department requirement for 2-pd tank and antitank guns was 0 (zero, nil, nada, zilch), since production of the 489 to that date exceeded peacetime scales for what was effectively a 8 or 9-division army, but by April 1940 the wartime scales for the 36-division army planned for 31 August 1941 were 13,561, but only 1,786 had been produced. In fact, although the gun design began in 1934, the first orders were placed in December 1935, and the first deliveries were made in April 1937, there was no real urgency felt for them, as priority continued to be for the RAF and Antiaircraft Command - aircraft production and the 3.7" AA gun. By the second quarter of 1940 (April-June) production of the 2-pdr was averaging just under 100 guns per month...when
hundreds 509[/edit] were lost in the French debacle. Post Dunkirk, the requirements were expanded to equip 55 divisions by 30 November 1941 and the requirements for 2-pdr tank and AT guns expanded to 20,670...when production in the second half of 1940 was just 1,081, averaging just over 180 per month. At that rate, assuming no losses were incurred it would have taken about 100 months, until about November 1948, before the requirement could be met. While it was realized that production would increase (it did, to an average of 712 per month in 1941, with peak production in November of 1,393), the requirements could only be met if priority was given to quantity of production rather than the quality of the design produced and the 6-pdr simply had to wait (the same bad bargain occurred with tanks).
The result was the first 6-pdr production was accepted in June 1941, when all of 2 were completed, followed by 1 more in July, 4 in August, and 1 in September. Production finally expanded, to 13 in October, 32 in November, and 146 in December, giving a total of 199 in the same year 8,547 2-pdr guns were completed.
The key decisions occurred in 1940 and early 1941. According to Postan (p. 194):
"In August the War Office notified the Ministry of Supply that the number of 6-pounder guns was to be governed by the effect on 2-pounder production, which was poor. This turned out to be the crucial issue in the evolution of the problem. An earlier order for a few pilot models was now increased to fifty in order to get production under way, and in December 1940 the Ministry of Supply, on its own initiative, though in agreement with the War Office, increased the order from fifty to 500. The War Office, however, was still anxious not to prejudice the prospective output of 2-pounders through increased orders for the 6-pounder. It had been informed that the production of 100 complete 6-pounders in the year would entail a loss of 600 2-pounders. The alternative was presented to the Defence Committee (Supply) which discussed it in February 1941 and decided that a diversion of capacity from 2-pounders to 6-pounders could not be afforded and that the urgently necessary acceleration of 6-pounder production must at the outset be solely from new capacity. This was in fact the decision which the Ministry of Supply had itself taken in August 1940 in response to the War Office view that the number of 6-pounder guns was to be governed by the effect on 2-pounder production. The subsequent production of the gun was thus entirely dependent upon new capacity coming into production."
Production of the 6-pdr increased in 1942, reaching 1,517 in May and totaled 17,842...but 2-pdr production increased as well, to 16,830, this after it was long realized the gun had only marginal utility. In the same year, 17-pdr production was 1,203. A comparison of the production for the three types is illuminating:
(prewar/Sep-Dec 1939/1940/1941/1942/1943/1944/January-May 1945)
Edited by Rich, 19 December 2018 - 1422 PM.