On 12th September attacks by the 56th Division on the south and the Guards on the north reduced the neck of the horseshoe, or pocket, to about 500 yards, but could not close it. The situation within the horseshoe was undefined, and the exact positions of the Quadrilateral and other trenches were not known, owing to the bad flying weather. Even our own positions were in doubt, as almost every vestige of roads, railways and even villages had disappeared under the continuous bombardments.
On night 11/12th September the 71st Infantry Brigade (Brig.-Gen. J. F. Edwards) relieved part of the Guards Division and the 16th Infantry Brigade (Brig.-Gen. W. L. Osborn), part of the 56th Division, with orders on the 13th September to straighten the line by capturing the Quadrilateral. The 71st Infantry Brigade attacked with the Foresters north of the railway and 9th Suffolk Regiment south of the railway, while the 8th Bedford Regiment, who were close to the Quadrilateral on the north-east of the Leuze Wood, co-operated by bombing up the trench towards it. The artillery co-operation was weak, observation being difficult, and though the troops advanced with the greatest gallantry the northern attack could only make 500 yards, and the southern attack of the 71st Infantry Brigade still less, while casualties from the enemy artillery and machine-gun fire were very large.
A second attack at 6 p.m. the same day succeeded in bringing our line to about 250 yards from the Strong Point, and in getting touch on the right with the 16th Infantry Brigade.
Preparations were now made to include the Quadrilateral in the general attack of the 15th September instead of making it a subsidiary operation--a situation which recurred two years later almost to a day in the attack on Holnon Village, and which had similar results.
The British objective for the 15th September was Gueudecourt-Flers-Lesbœufs-Morval -- the XIV Corps (Guards and 6th Division) to capture the two latter. It was the first occasion on which tanks were employed, and as far as the Division was concerned was a failure, for of the three allotted to the 6th Division two broke down before starting, and the third, moving off in accordance with orders long before the infantry, had its periscope shot off, its peep-holes blinded, was riddled by armour-piercing bullets, and had to come back without achieving anything. This again found a parallel in the attack on the Quadrilateral, near St. Quentin, on 18th September 1918, when the tanks were ineffective.
To facilitate the movement of the tanks a gap of about 200 yards had been left in the creeping barrage. This gap unfortunately coincided with the strongest point of the Quadrilateral. The barrage, moreover, had passed over the German trenches by the time the infantry advanced; the latter had, consequently, to attack up the glacis-like slopes without any artillery support except the bombardment. This, owing to the enemy's trenches not having been accurately located, was ineffective.
The 16th Infantry Brigade attacked on a battalion front--one company of the Bedfords bombing up the trench from Leuze Wood, and the remainder over the open to the north against the south-west face. The Buffs and York and Lancasters supported the attack, but in spite of the greatest gallantry could not take the Strong Point.
The 1st Leicesters and the Norfolks, passing through the entrenched Foresters and Suffolks, attacked the Quadrilateral from the north-west with equal drive, but they too failed. Some ground, however, was made, and by 10 a.m. the 16th Infantry Brigade on the south, and the 71st Infantry Brigade on the north, were digging in close to the enemy's wire and trenches.
During the day constant reports arrived that the Guards had gained their objectives, and that tanks and cheering men were moving through Lesbœufs. It was not until the following morning that this report was proved to be incorrect, and that it was Flers which had been captured. In the meantime it appeared to the Divisional G.O.C. (General Ross) that the prospect of a break-through on a large scale was prejudiced solely by the repulse of the 6th Division. He therefore ordered a night attack on the flanks of the Quadrilateral to be executed by two battalions of the 18th Infantry Brigade (Brig.-Gen. R. J. Bridgford). These battalions, the 2nd Durham Light Infantry and the 11th Essex, moved round after dark and attacked; the former from the north, the latter from the south-east to the left of the 16th Infantry Brigade. The 11th Essex lost direction, while the 2nd D.L.I. bombed down a trench only to find that it did not lead into the Strong Point. Except on the 6th Divisional front and at High Wood, which was captured during the night, the whole line had advanced, and it was a bitter blow to the Division to think that their sacrifices had been in vain.
On the night of the 16/17th September the 18th Infantry Brigade relieved the sorely-tried 71st Infantry Brigade, and fresh preparations were made for an attack, on the 18th, of the Quadrilateral, which had been strongly reinforced by the enemy through the sunken road.