In March 1917 General Anley was appointed Administrative Commander Heavy Branch Machine-Gun Corps with his headquarters in London, Brigadier-General W. Glasgow taking over the command of the Training Centre at Wool. In May he was succeeded by Major-General Sir John Capper, K.C.B., and the Tank Committee under his chairmanship was formed to systematise and strengthen co-operation between the Army and the Ministry of Munitions. On the 1st of this month, Colonel Elles was gazetted Brigadier-General Commanding the Heavy Branch in France.
The experiences gained during the battle of Arras, in April 1917, resulted in proposals being put forward for the expansion of the Heavy Branch from nine to eighteen battalions, nine to be equipped with heavy, and a similar number with medium machines.[20] These proposals mark an important stage in the development of the Heavy Branch and they were destined to be the subject of many discussions.
On June 28, the above expansion was authorised, and the personnel for new units was assembled at the Training Centre at Wool. A month later, however, the call for manpower became so urgent that the expansion of the Heavy Branch had to be suspended. It was on the 28th of this month that the Heavy Branch became known as the Tank Corps.
During the following months, August and September, the question of the Tank Corps expansion was held in abeyance. On October 6 it was once again revived, and a revised establishment for the contemplated expansion to eighteen battalions was submitted. The outstanding feature of these establishments was the abolition of Battalion Workshops and the substitution of Brigade Workshops in their place. This resulted in a considerable economy of man-power, and was rendered possible by the higher training of the tank crews; each tank with its crew thus tended to become a self-contained unit.
On November 27 these establishments received official approval, and exactly one week later, on December 4, arising out of the overwhelming success gained by tanks at the battle of Cambrai (November 20), two new organisations were put forward, the first known as the Lower, and the second as the Higher Establishments. The Lower Establishments were eventually decided upon, and they consisted in a revised edition of the former establishments with various additions, which the experiences gained at the battle of Cambrai had shown to be necessary. These establishments, though made out, were never approved, and the German offensive in March 1918 found the Tank Corps still organised on the lines agreed upon in October.
In April, on account of the pressing needs for infantry reinforcements, the Tank Corps expansion was temporarily suspended, two of the three remaining battalions in England being reduced to cadre units, and the third converted into an Armoured Car Battalion. In July and August the astonishing successes gained by tanks on various sectors of the Western Front once again brought forward the need of increasing the British tank battalions, and the suspension was removed, the two remaining battalions of the expansion of October 1917 proceeding to France in September 1918.
In January 1918, from the experience gained by now in the time necessary to carry through a reorganisation, proposals were put forward for 1919. These were eventually discussed at the Inter-Allied Tank Committee, an assembly of representatives of the various allied Tank Corps, which first met at Versailles in April. The German spring offensive, however, absorbed so much attention that it was not possible at the time to do more than work out, as a basis, the number of tanks required for a decisive tank attack the following year. As the position of the Allies in France stabilised the question first discussed at Versailles was in July retaken up, with the result that an expansion to thirty-four battalions was decided on and completely new establishments called for. In order to bring this work more closely under the War Office it was also decided, at about this time, to dissolve the Tank Directorate, first created in May 1917, and to replace it by a new sub-branch of the Directorate of Staff Duties. This change took place on August 1, when a new branch known as S.D.7 was added to the Directorate of Staff Duties at the War Office to deal with the administration of tanks generally, and the 1919 tank programme in particular.
At the same time the Tank Committee was abolished, its place being taken by the Tank Board, which was constituted as follows:
Major-General the Right Honourable J. E. B. Seely, C.B., C.M.G., D.S.O., M.P., President (Deputy Minister of Munitions).
Sir Eustace Tennyson D’Eyncourt, K.C.B., Vice-President (Director of Naval Construction).
Admiral Sir Reginald Bacon, K.C.B., K.C.V.O., D.S.O. (Controller Munitions Inventions).
Major-General Sir William Furse, K.C.B., D.S.O. (Master General of Ordnance, representing the Army Council).
Major-General E. D. Swinton, C.B., D.S.O.
Major-General H. J. Elles, C.B., D.S.O. (Commanding Tank Corps, France).
Lieutenant-Colonel Sir Albert Stern, K.B.E., C.M.G. (Commissioner Mechanical Warfare, Overseas and Allies Department).
Colonel J. F. C. Fuller, D.S.O. (D.D.S.D. Tanks: representing General Staff, War Office).
Mr. J. B. Maclean (Controller of Mechanical Warfare).
Sir Percival Perry (Inspector of Mechanical Traction).
Captain A. Earle, Secretary.
The constitution of the Board is interesting as it enabled expert naval, military, and industrial knowledge to be concentrated on the one subject—the application of naval tactics to land warfare. The work accomplished by this Board was considerable, it was carried out in a high co-operative spirit and with great good-fellowship, and it would, undoubtedly, have proved a factor of no small importance in the complete destruction of the German armies in 1919, which was practically fore-ordained by a tank programme of some 6,000 machines, had the war continued.