[4] The Battle of Neuve Chapelle had shown that one breastwork was insufficient to stop an attack and the fortifications opposite the British were quickly augmented.

Each battalion had two machine-guns and these were emplaced at ground level, set to sweep no man's land from flanking positions.

The new communication trenches were arranged so that the support companies could easily block a break-in from the flanks; most of the field artillery of 6–12 four-gun field batteries and several heavy batteries in each division, were on Aubers Ridge 2,500–4,000 yd (1.4–2.3 mi; 2.3–3.7 km) behind the front line, between Lorgies and Gravelin.

[6] A second line of gun positions between La Cliqueterie Farm, Bas Vailly, Le Willy and Gravelin, about 2,500 yd (1.4 mi; 2.3 km) behind the forward battery positions, had been built so that the guns could be moved back temporarily, until enough reinforcements had arrived from Lille and La Bassée to counter-attack and reoccupy the front line.

[8] Trench layout, traffic flows and organisation behind the British front line did not allow for easy movement of reinforcements and casualties.

[10] Three squadrons of the 1st Wing Royal Flying Corps (RFC) were attached to the First Army for defensive patrols for four days before the attack, to deter enemy reconnaissance.

During the attack they were to conduct artillery observation and reconnaissance sorties and bomb German rear areas, railway junctions and bridges further afield.

It is doubted if it had the slightest positive effect on assisting the main French attack 15 mi (24 km) to the south.

[13] In the aftermath of the Aubers Ridge failure, the war correspondent of The Times, Colonel Charles à Court Repington, sent a telegram to his newspaper highlighting the lack of high-explosive shells, using information supplied by Sir John French; The Times headline on 14 May 1915 was: "Need for shells: British attacks checked: Limited supply the cause: A Lesson From France".