Air reconnaissance observed huge numbers of French guns and troops arriving at Doullens station, which showed that the French offensive would continue. A counter-attack to capture Ecurie, to disrupt the French artillery effort was considered and rejected due to the shortage of troops. Only at Neuville could troops assemble unseen and have good artillery observation. The 15th Division (Major-General Vollbrecht) at Neuville, was reinforced with troops from the 115th Division and attacked at 8:30 p.m. on 22 May; despite a 1st Trench Mortar Battalion bombardment and flame thrower support, the attack was a costly failure. To the south, the defence of the Labyrnthe continued, with frequent attacks to recover the first position in the centre, to relieve the right flank, which had been enveloped on three sides but without which Neuville could not be held. Bavarian Reserve Infantry Brigade 2 managed to assemble troops for a counter-attack towards the Lossow-Arkaden and advanced for about 160 yd (150 m) before being repulsed. French attacks in the opposite direction up to six times each day also failed, except for some ground on the Thélus road on the evening of 11 May. German reinforcements which had just arrived, were rushed forward to block the French advance on Thélus. The British attacked on the night of 15/16 May, south of Neuve Chapelle and by 20 May, had advanced 1.9 mi (3 km) and drawn in German reinforcements, which were able to defeat British attacks from 20–21 May over the Estaires–La Bassée road. The French offensive had severely eroded the 6th Army, which had used up all the fresh units sent from the OHL reserve in France. The 2nd Guard Reserve Division was diverted to VII Corps opposite the British and units worn out by the French supporting attacks beyond Artois were needed, before they had been rested. Only the tired 111th Division, 123rd Division and 8th Bavarian Reserve Division remained in the OHL reserve. Artillery reinforcements increased the firepower of the 6th Army, from 100 heavy howitzers and 74 heavy guns to 209 heavy howitzers and 98 heavy guns by 22 May, with plenty of ammunition. From 9–19 May, the 6th Army had fired 508,000 field artillery and 105,000 heavy shells. On 19 May, Krafft von Delmensingen, the 6th Army Chief of Staff, was replaced by Colonel von Wenge and sent to Italy with the new Alpenkorps. At the Lorette Spur, the 117th Division was sent forward to relieve the 28th Division on 18 May, from the Schlammulde (Muddy Hollow) to Ablain and the south end of Souchez. Most of the trenches had been demolished and those near the river were 2 ft (0.61 m) deep in water.