In Britain prior to 1936 the Master General of the Ordnance was the supreme authority responsible for tank design and procurement. Under him the Director of Mechanisation supervised actual design work in conjunction with the Mechanisation Board, which was a committee made up of senior representatives of the "user" arms. By the outbreak of war in 1939, the Master General of the Ordnance had become the Director General of Munitions Production and all designs and procurement responsibilities were transferred from the War Office to the newly-established Ministry of Supply. Overall tank design responsibility then came under the Director-General of Tanks and Transport with, in 1940, a Controller of Mechanisation supervising the Director of Mechanisation, who worked with the Mechanisation Board as before. In May 1940, following British reverses in the French campaign, a new War Cabinet was formed under Winston Churchill, who approved the setting up of a Tank Board to examine faults in the existing design and procurement system and to advise on improvements. They proposed a Director of Armoured Fighting Vehicles (DAFV) to represent the War Office (General Staff) interest, with separate Directors of Design and Production, all under the Director-General of Tanks and Transport, who took the place of the old Director of Mechanisation.
Early in 1941 the Tank Board was reorganised and given executive powers to expedite War Office requirements in matters affecting tanks. Included on the board were the Director-General of Tanks and Transport and the Director of Artillery (for tank gun, anti-tank gun, ammunition, and SP equipment matters), plus DAFV and General Staff representatives. In September 1942 a Chairman, Armoured Fighting Vehicles Division, was appointed, who also became chairman of the Tank Board and was the chief executive responsible for tank design in the Ministry of Supply. The Tank Board was also reconstituted to contain equal representation from the Ministry of Supply and the War Office (who represented the "users"). This general organisation remained in force until the end of the war.
British design authorities
On the design side itself, however, there were several important changes largely due to the vast industrial participation in tank production, which had increased dramatically since the outbreak of the war. Such vehicles as the Churchill and Valentine, for example, were designed mainly by the firms which built them, with only relatively minor help from the Department of Tank Design, the organisation, which, following the 1940 reforms, carried out actual design work under the Director-General of Tanks and Transport. In late 1941 the Department of Tank Design was placed under the Controller General of Research and Development, and as the war progressed the department changed its function from designing proper to co-ordination of design and production facilities. In other words, instead of actually designing a vehicle itself, the Department of Tank Design passed requirements to one of the tank producers and approved (and if necessary improved) the design the producers drew up. The old "drawing board" orders, which had generally resulted in tanks (like the Churchill and Covenanter) with a formidable record of "teething troubles", became a thing of the past. Under the new organisation at least six pilot models were generally built. Similarly, a proper "design parentage" organisation was built up whereby one particular company took full charge of design and production of one particular vehicle and supervised all necessary subcontract work for the vehicle in question. The Churchill (Vauxhall) and Valentine (Vickers) in 1940 set this pattern, subsequently adopted with all later British tanks, and the Department of Tank Design did not itself design a complete tank again until 1944-45, when it was responsible for the Centurion. By 1945 the Department had become very influential indeed and, in the circumstances, left a most creditable wartime record in the face of continually fluctuating War Office (ie “user") requirements, frequent friction between War Office and Ministry of Supply, and a good deal of War Office conservatism.