Virtually the whole of the summer of 1918, 11 DLI served purely in its primary Pioneer role as specialised labour for the 20th Light Division. The battalion left Frevillers on 2 May 1918 and proceeded via Canada Camp at Chateau de la Haie to the unusually named Ratata Camp at Carency. The battalion HQ remained there for the next five months supporting the 20th Light Division in the Lens-Avion sector.
Essentially the daily routine was filled either with trench work (most of the time) or providing support for gas attacks. For example on 23 May, three Companies were employed pushing gas cylinders to the front line and bringing back the empties along rail tracks. Four days later, the Germans retaliated with a gas attack on 11 DLI at night – bearing in mind that they would be out working on trenches at the time. Two of the casualties among nine officers affected who had survived the ravages of the retreat during March: Lt A Philip and Captain Percy Vickerman Kemp. Kemp died in hospital at Etaples on 31 May 1918. There were 122 casualties among the other ranks, several of whom also died. This pointless tit for tat continued for the rest of the summer – 19 men being badly gassed on 3 July.
There was some to and fro among the officers. During July 2nd Lt HJE Whitfield left to join the Royal Air Force, Captain WFE Badcock transferred to 6 DLI, and Lt GR Burnett and Captain JG Taylor took their places. In August it was all change at the top when Lt Colonel Boulton was replaced by Lt Col TH Carlisle as commanding officer. Carlisle remained for the rest of the deployment. Incongruous though it may seem, on 31 July the battalion held a Transport Horse Show. Otherwise it was the tedious round of trench work, gas attacks and sporadic shelling, with a slow attrition on the health and strength of the men. Some forty or so of the miners were attached to 185th Tunnelling Company at the end of August in charge of 2nd Lt WH Charnley.