On September 29, Lieutenant-Colonel H. J. Elles, D.S.O., who, as we have seen, first came into contact with tanks in January 1916, was appointed Colonel Commanding the Heavy Section in France, and on the same day that his appointment was sanctioned it was decided that 1,000 tanks should be built, and that certain improvements in the existing design of machine should be introduced. At this time the Headquarters of the Heavy Section were located in one small hut in the centre of the square of the village of Beauquesne, and as this village was not considered suitable for a permanent Headquarters, Bermicourt was selected instead—a small village just north of the Hesdin-St.-Pol road. At this village the Headquarters remained until the end of the war, expanding from three Nissen huts to many acres of buildings.
On October 8 a provisional establishment for the Headquarters was approved. It consisted of—a Commander (Colonel), one Brigade Major, one D.A.A. and Q.M.G., one Staff Captain, and one Intelligence Officer. These appointments were filled by the following officers: Colonel H. J. Elles, Captain G. le Q. Martel, Captain T. J. Uzielli, Captain H. J. Tapper, and Captain F. E. Hotblack.
At about this time it was proposed to form the Heavy Section into a Corps, giving it an Administrative Headquarters in England and a Fighting Headquarters in France, and of converting the four companies in France into four battalions, and raising five new battalions in England on the nuclei of the two remaining companies. Though the formation of the tank units into a Corps was not sanctioned at the time the other proposals came into force on October 20, Brigadier-General F. Gore Anley, D.S.O., being appointed Administrative Commander of the Tank Training Centre, Bovington Camp, Wool, in the place of Colonel Swinton, with Lieutenant-Colonel E. B. Mathew-Lannowe as his G.S.O.1. Under this organisation the 9 battalions were eventually to be formed into 3 brigades each of 3 battalions, a battalion consisting of 3 companies, each company of 4 fighting sections and a headquarters section. A fighting section consisted of 5 tanks and the headquarters section of 8. In all the battalion was, therefore, equipped with 72 machines.
On November 18, the day on which the approved establishments were issued, the companies, which had continued in the area of operations, were moved to the area round Bermicourt and, ceasing to exist as companies, became A, B, C, and D Battalions Heavy Branch Machine Gun Corps. They were located at the following villages:
| A Battalion | Humières, Eclimeux, Bermicourt. |
| B „ | Sautrecourt, Pierremont, St. Martin-Eglise. |
| C „ | Erin, Tilly-Capelle. |
| D „ | Blangy. |
These battalions were eventually formed into the 1st and 2nd Tank Brigades: the 1st Brigade, consisting of C and D Battalions, on January 30, 1917, under the command of Colonel C. D’A. B. S. Baker Carr, D.S.O.; and the 2nd Brigade, of A and B Battalions, on February 15, under that of Colonel A. Courage, M.C. Later, on April 27, in view of the expected arrival of two battalions from Wool, approval was given to the formation of the 3rd Brigade Headquarters under the command of Colonel J. Hardress Lloyd, D.S.O.
Meanwhile, in England, the whole question of future production was being strenuously dealt with by Lieutenant-Colonel Stern, who, on November 23, assembled a conference in London at which the future production of tanks was explained as follows:
That at the time of the conference there were 70 Mark I machines in France, and it was hoped to deliver improved types of this tank as follows: 50 Mark II tanks by January; 50 Mark III tanks by February 7; Mark IV tanks at the rate of 20 per week from February 7 to May 31. Further, that Mark V tanks would be available in August and September 1917, and that a new light tank, called Mark VI, would be ready for trial by Christmas 1917.
Unfortunately, on account of the difficulty of production and the constant changes demanded in design, the above programme never materialised, and though Mark II tanks were sent out to France, no Mark IV machines arrived there until after the battle of Arras had been fought and won.
Early in the new year the battalions of the Heavy Branch underwent a further reorganisation: they were slightly reduced in size and the number of their machines was cut down from 72 to 60; each company, theoretically consisting of 20 tanks, was divided into 4 sections of 5 tanks each; for practical purposes, however, it was found that a section could not deal with more than 4 tanks, so the number of tanks was reduced to 48, of which 36 were earmarked as fighting and 12 as training machines.