Leaving Amesbury on 20 July, by 26 July the division was concentrated in the Lumbres area east of Boulogne-sur-Mer. By 30 July the Division was part of III Corps of the First Army, and was billeted in the area between Hazebrouck and Armentières. Training now began in trench warfare, with officers and N.C.O.s being posted to the 8th and 27th Divisions, and bombing (grenades), machine gun and gas mask training for the other troops. The units of the division were rotated though the 8th and 27th Divisions in turn to experience trench warfare first hand between 2 and 17 August. The engineers and pioneers were employed at various tasks behind the lines.