The attack on the 18th was in conjunction with the 6th Division. The task of the 56th Division was to capture the trench on the north of the sunken road to Combles, and the south-west face of Bouleaux Wood, to a point beyond Beef Trench, and from there through the wood to Middle Copse, where touch would be obtained with the 6th Division, who were making another effort to clear the Quadrilateral. The attacking brigades of the latter division declined the aid of Tanks on this occasion.
The weather was appalling. The state of the ground was rather worse than what is so frequently called a quagmire—troops could not get along.
The 167th Brigade had lost heavily, and was not in sufficient strength to attack, so the London Scottish were attached to that brigade. But the battalion was unable to reach the assaulting line.
Zero hour was 5.50 a.m., and on the right the 169th Brigade, with the Queen’s Westminster Rifles and the London Rifle Brigade attacking, failed to cross the fatal sunken road, which was not surprising,
as the mud by itself was an almost perfect obstacle from the German point of view. While on the left the London Scottish failure to reach the assembly trench caused the attack to be abandoned.
But the 6th Division was successful, and the Quadrilateral, which gave such strong support to the enemy troops holding Bouleaux Wood, was captured. The news was received by everyone with a sigh of relief.
Of the fighting as a whole on the 15th September and subsequent days Sir Douglas Haig reported:
“The advance met with immediate success on almost the whole of the front attacked. At 8.40 a.m. our Tanks were seen entering Flers, followed by a large number of troops. Fighting continued in Flers for some time, but by 10 a.m. our troops had reached the north of the village, and by midday had occupied the enemy’s trenches for some distance beyond. On our right our line was advanced to within assaulting distance of the strong line of defence running before Morval, Les Bœufs, and Gueudecourt, and on our left High Wood was at last carried after many hours of very severe fighting, reflecting great credit on the attacking battalions. Our success made it possible to carry out during the afternoon that part of the plan which provided for the capture of Martinpuich and Courcelette, and by the end of the day both these villages were in our hands. On the 18th September the work of this day was completed by the capture of the Quadrilateral, an enemy stronghold which had hitherto blocked our progress towards Morval.
The result of the fighting on the 15th September and the following days was a gain more considerable than any which had attended our arms in the course of a single operation since the commencement of the offensive. In the course of one day’s fighting we had
broken through two of the enemy’s main defensive systems, and had advanced on a front of over six miles to an average depth of a mile. In the course of this advance we had taken three villages, each powerfully organised for prolonged resistance.... The total number of prisoners taken by us in these operations amounted to over 4,000, including 127 officers.”