On this day the battle of Epehy continued on the front Epehy-Villeret, some 7,000 yards long. In this attack twenty tanks of the 2nd Battalion assisted the IIIrd Corps, Australian Corps, and IXth Corps. On the IIIrd Corps front heavy machine-gun fire was encountered and overcome, many machine guns being destroyed. On that of the IXth progress was slow, and the Australians, meeting with little resistance, captured Ronssoy and Hargicourt.
After two days’ rest the attack was continued on the 21st, nine tanks of the 2nd Battalion operating on the IIIrd Corps front against the Knoll and Guillemont farm. Two of these machines carried forward infantry, but the machine-gun fire was so heavy that it was not possible to drop them. During this day the enemy put up a most determined resistance and there were not sufficient tanks engaged to silence his machine guns. Another two days’ rest followed, and then again was the attack renewed on the IXth Corps front against Fresnoy-le-Petit and the Quadrilateral, nineteen machines of the 13th Battalion attacking with the 1st and 6th Divisions. So heavy was the enemy’s gas barrage on this day that some of the tank crews were forced to wear their respirators for over two hours on end. In spite of the enemy being in great strength eighteen machines assisted the infantry. Thus ended the battle of Epehy and though the advance was not great nearly 12,000 prisoners and 100 guns were added to the “bag.”
Preparations were now set in hand for an extensive attack against the Hindenburg and auxiliary lines of defence, which together formed a zone of entrenchments for the most part very heavily wired and extending over a depth varying from 8,000 to 16,000 yards. This attack entailed another hasty reorganisation of tank battalions, which was completed by September 26, when the battle order of Brigades was as follows:
| 1st Tank Brigade H.Q. Bihucourt | 7th Battalion | Mark IV | Bullecourt. |
| 11th „ | Mark V Star | Barastre. | |
| 12th „ | Mark IV | W. of Ruyaulcourt. | |
| 1st T.S. Coy. | S. of Velu. | ||
| 2nd G.C. Coy. | Bancourt. | ||
| 2nd Tank Brigade H.Q. Gomiecourt | 10th Battalion | Mark V Star | Auchy les Hesdin. |
| 14th „ | Mark V | Winnipeg Camp. | |
| 15th „ | Mark V Star | Hermies. | |
| 2nd T.S. Coy. | Gomiecourt. | ||
| 1st G.C. Coy. | N.W. of Vaux-Vraucourt. | ||
| 3rd Tank Brigade H.Q. Barleux | 5th Battalion | Mark V | E. of Cartigny. |
| 6th „ | Medium A | S. of Tincourt. | |
| 9th „ | Mark V | S. of Tincourt. | |
| 3rd T.S. Coy. | S. of Tincourt. | ||
| 4th Tank Brigade H.Q. Templeux-la-Fosse | 1st Battalion | Mark V | Manancourt. |
| 4th „ | Mark V | S. of Manancourt. | |
| 301st American Battalion | Mark V Star | S. of Manancourt. | |
| 4th T.S. Coy. | S. of Manancourt. | ||
| 5th Tank Brigade H.Q. Bois-de-Buire | 2nd Battalion | Mark V | Suzanne. |
| 3rd „ | Medium A | S. of Roisel. | |
| 8th „ | Mark V | S. of Tincourt. | |
| 13th „ | Mark V | S. of Tincourt. | |
| 16th „ | Mark V Star | S. of Tincourt. | |
| 17th „ | Armoured Cars | Buire. | |
| 5th T.S. Coy. | S. of Tincourt. |
The rapidity with which these changes were made would, a few months back, have bewildered both the Tank Corps Headquarter Staff and the Brigade and Battalion Commanders themselves; now the knack of rapid movement had been mastered, and though great energy had to be exerted during such reorganisations, they were generally accomplished in time and efficiently.
On September 27 the great battle began, comprising the First, Third, and Fourth Armies on a front of sixteen miles. The battlefield was divided into two main sectors, to the north that of the First and Third Armies, between the Sensée river and Gouzeaucourt, with the object of capturing Bourlon hill, and to the south that of the Fourth Army with the capture of the Knoll, Guillemont farm, and Quennemont farm as its objectives.
East of the First Army front line ran the canal Du Nord, a formidable obstacle to tanks in spite of the fact that it was dry, having never been completed. This canal varied from 36 to 50 ft. wide at the bottom, and was 12 ft. deep, and the slopes of its sides were in many places steep. The enemy, evidently suspecting that tanks might attempt to cross it, had at certain places rendered this temporarily impossible, so it was thought, by cutting in its bank a vertical wall 9 ft. deep for several hundreds of yards along the eastern side between Mœuvres and Inchy. In the Maquion-Bourlon sector the enemy had made little anti-tank preparation, probably considering that the canal itself formed a sufficient obstacle. In the Beaucamp sector, however, anti-tank preparations were exceptionally thorough, many anti-tank rifles being placed in position here.
Sixteen tanks of the 7th Battalion, all Mark IV.s, some of which had fought over very nearly the same ground in November 1917, were allotted to co-operate with the Canadian Corps. In spite of the formidable great ditch which lay in front of them, fifteen of these machines crossed the canal Du Nord near Mœuvres, and attacked Bourlon village and the western edge of Bourlon wood. Of these fifteen machines only three were put out of action, one by a mine placed in a road leading through a gap in the canal and two by a battery near Deligny hill.
On the Third Army front Corps were disposed from north to south as follows: XVIIth, VIth, IVth, and Vth Corps.