The second phase of the Cambrai—St. Quentin battle opened on the morning of October 8 on an eighteen miles front—it was entirely successful. Tanks were allotted as follows, eighty-two in all being used:
| 1st Tank Brigade | 12th Battalion | 1 Company to IVth Corps. |
| 1 Company to VIth Corps. | ||
| 1 Company to XVIIth Corps. | ||
| 11th Battalion | To Vth Corps. | |
| 4th Tank Brigade | 1st Battalion | To XIIIth Corps. |
| 301st American Battalion | To IInd American Corps. | |
| 3rd Tank Brigade | 3rd Battalion | To IInd American Corps. |
| 6th Battalion | To IXth Corps. |
The attacks, carried out by the 12th Tank Battalion on the front Niergnies—La Targette, were successful, the infantry universally testifying to the assistance rendered by this battalion. An interesting encounter now took place, the enemy counter-attacking from the direction of Awoingt with four captured British Mark IV tanks, one male and three females. The counter-attack was speedily dealt with, the renegade male being knocked out by a 6-pounder shell fired by one of our own tanks and one female put out of action by a shell fired from a captured German field gun by a tank section commander; the remaining two females fled on the approach of one of our machines of the same sex. So ended the second tank encounter as successfully as the first, which it will be remembered was fought near the village of Cachy on April 24, 1918.
The other actions fought on this day were briefly as follows:
One Company of the 11th Battalion assisted the 32nd Division against Villers-Outreaux, another company operated with the 21st Division and the third company with the 38th. This last company was of great assistance, as the infantry had been held up by a broad belt of wire which they were unable to cross until the tanks crushed down pathways through it.
The 6th Tank Battalion, operating with the IInd American Corps, carried out its programme, one of its machines putting three batteries of field guns out of action in Fraicourt wood; and the 3rd Battalion came into action in the neighbourhood of Serain. This village was very strongly defended, the enemy holding it to cover his withdrawal.
On October 9 the attack continued along the whole front, eight tanks of the 4th Battalion coming into action east of Premont and the 17th Armoured Car Battalion, under orders of the Cavalry Corps, operating around Maurois and Honnechy. Two days later, on the 11th, five tanks of the 5th Battalion operated with the 6th Division north of Riguerval wood; this was the last tank action fought in this battle.
The battle of Cambrai—St. Quentin was at an end. The Hindenburg Line had now to all intents and purposes ceased to exist as an obstacle. It had been broken on a front of nearly thirty miles, on which frontage a penetration of some twenty miles had been effected, and no fewer than 630 guns and 48,000 prisoners captured during the last fourteen days. The effect of this great battle, coupled with the successes of the French in the south and the operations east of Ypres and round Courtrai, fought by the British, French, and Belgians in the north, resulted in the withdrawal of the German forces in the Roubaix, Lille, and Douai area, and with this withdrawal the whole of the British forces in France from north of Menin to Bohain, seven miles north-west of Guise, were faced with field warfare; open country stretched before them, uncut by trench, unhung by wire. The period of exploitation had arrived—that period all our endeavours had been concentrated on attaining during four years of the most desperate and relentless war in history.
Considering the comparative weakness of the British Army, the time of the year, and the nature of the fighting, it had truly been a notable performance on the part of the English and the Dominion infantry, to have fought their way so far. To carry out a rapid pursuit was beyond their endeavours, for the German Army, though beaten, was not yet broken. For cavalry to do so was unthinkable, for the German rearguards possessed many thousands of machine guns, and as long as these weapons existed, pursuit, as cavalry dream it to be, is utterly impossible. One arm alone could have turned the present defeat into a rout—the tank, but few of these remained, for since August 8 no fewer than 819 machines had been handed over to Salvage by the tank battalions, and these battalions themselves had lost in personnel 550 officers and 2,557 other ranks, a small number indeed when compared with the number of actions the Corps had been engaged in, yet a severe loss out of a fighting state of some 1,500 officers and 8,000 other ranks.
Had it been possible at this crisis to put into the field two fresh brigades of medium tanks, that is about 300 machines, the cost of which would be approximately £1,500,000, or one-fifth that of one day’s cost of the war, the greatest war in all history might have closed on or near the field of Waterloo in a decisive victory ending in an unconditional surrender or an irretrievable rout.