General Haig had spent most of the afternoon of the 16th May visiting each of the Corps and Divisional Headquarters of the units involved in the offensive. He came to the conclusion that on the left the problem was one of artillery. It seemed impossible for the British artillery to master their adversaries.
Trying to continue to take the Ferme Cour d’Avoué and the Ferme du Bois would be difficult as it was not possible to counter the flanking guns at Lorgies. On the right of the battlefield the situation appeared more positive if the gap between the 2nd and 7th Divisions could be sealed.
I Corps was therefore ordered to close the gap and secure a line running along La Quinque Rue from Festubert to the Ferme Cour d’Avoué. That achieved a defensive left flank would be formed from the captured zone back to the old British front line.
What was not realised was that during the night the Germans had themselves decided to pull back along much of the sector as far as the Ferme du Bois to a new line about a kilometre to the rear.
The Quadrilateral was subjected to a heavy bombardment which destroyed most of its defences. Its garrison of over 400 men was all too happy to run the gauntlet towards the British front line and surrender when it became evident that it would not be possible for them to fall back safely.
In fact a pilot from 16 Squadron RFC had noticed new trenches in the rear of the Ferme Cour d’Avoué but the information was ignored and as the weather closed in the chance of finding out if the new trench ran the entire length of the front was lost.
By 0900 hours most of the German troops in the area of the Rue des Cailloux had been withdrawn. When the 2nd Bn Royal Scots Fusiliers of 21st Brigade advanced against the German front they found few left to oppose them. By 1015 hours the Quadrilateral was in their hands.
The 1st Bn King’s Regiment were on their left attacking from the 6th Brigade sector. Their right managed to link up with the Scots Fusiliers but their left came under very heavy fire from the Ferme Cour d’Avoué and were halted.
The first reports of the general success suggested to General Haig that the Germans were ceding ground and gave orders that the momentum apparently gained had to be continued. The 3rd Canadian Brigade were placed at the disposal of I Corps and the Indian Corps were instructed to take over ground to their right in order to allow 2nd Division to concentrate its efforts.
It was essential Haig told his commanders that a firm base along La Quinque Rue be founded before a large scale advance was attempted. His orders from Sir John French commanding the British Expeditionary Force had also changed.
The objective was no longer the Aubers Ridge but La Bassée and the canal.
A second attack by the 2nd and 7th Divisions was ordered for the early afternoon, but both ran aground without achieving a great deal.
The 2nd Bn Wiltshire regiment managed to get up as far as the North Breastwork but were forced back again by enfilading fire from the new German front line.
The Scots Fusiliers who had already been bombarded once by their own artillery during the morning were subjected to the same treatment in the afternoon and lost a heavy number of casualties for the second time.
The 5th and 6th Brigades of 2nd Division were also supposed to have launched an assault at 1500 hours against the Ferme Cour d’Avoué but postponed the attack until they could be reinforced by the 4th (Guards) Brigade marching up from Le Touret, five kilometres away.
The roads were packed and it was almost dark by the time that the Guards finally managed to reach the Rue des Cailloux. It was too late to do anything other than move some of the units up into the front line, the 2nd Bn Grenadier Guards finding itself alongside the 1st Battalion (20th Bde/7th Div) for the first time since the war had broken out.
On the far right the 2nd Bedfordshire and 1/4th Cameron Highlanders of the 21st Brigade advanced against the South Breastwork which unbeknown to the British formed part of the new German front line.
With little to no preparation the two battalions had advanced across the 400 metres of no man’s land which was heavily interspersed with waterlogged ditches. The Highlanders managed to get into the German lines but the Bedfordshire were held up twice during the course of the afternoon.
The Highlanders had lost all their grenades whilst getting across the ditches and were forced out of their position by counter attacks from the flanks. Between them the two battalions suffered 700 casualties.
After battling throughout the day both sides settled down for a quiet night in the pouring rain.