Only a very “full dress” attack on so highly organised a system as the Hindenburg Line was likely to be successful, and in order to launch such an attack it was essential that we should already hold the Knoll and Guillemont and Quennemont Farms. We have seen how in the last day or two of the battle of Epehy we assaulted the line again and again, duly captured the sector opposite Bellicourt, but how, two days before the main attack was to be launched, the Knoll and Quennemont were still in the hands of the enemy. This state of affairs caused grave anxiety, as the whole set-piece attack was based on the idea of using this line as a “jumping-off” position. It had been intended that the two American Divisions, which were to fight on this sector, should only be put in when this line had been secured. It was now decided that they must themselves make a final effort to capture the outpost line before the main assault, which was due for dawn on September 29. Therefore, at dawn on the 27th, the 27th American Division, assisted by twelve Tanks of the 4th Battalion, again attacked under cover of a creeping barrage. [93]“The attack met with strong opposition, and the final position reached was the subject of conflicting reports from the troops engaged and from the air observers. Subsequent events showed that small parties of Americans and Tanks had reached the vicinity of their objective, and had very gallantly maintained themselves there; but the line as a whole was not materially advanced by the day’s operations.... The barrage could not now be brought back on this flank owing to the knowledge that parties of American troops, as well as a number of American wounded, would be exposed to our own fire. Also any alteration in the barrage plans, which had already been issued, would inevitably lead to confusion.” Either, therefore, the whole main attack must be delayed, or the American divisions and some of the British troops north of them must start some 1000 yards behind their barrage, and from a very indefinite jumping-off line. The latter course was decided upon. [94]“The artillery start line, as originally planned, was to hold good, and the troops of the 27th American Division would form up for the attack on a line as far forward as possible, and would be assisted by an additional number of Tanks. The strength in Tanks was augmented to such an extent as should easily overwhelm the enemy resistance west of the start line. It was thought that this, with the slow rate of barrage, would enable the Americans to carry out their task.” But there was yet one more difficulty, a serious obstacle of which we were serenely unaware. A British anti-Tank minefield, consisting of rows of buried heavy trench-mortar bombs, each holding 50 lb. of ammonal, had been put down just prior to our loss of the area in March 1918, and of this minefield no information had reached the Tanks.