5th Division was moved south to join in the Somme Offensive and was engaged in the Attacks on High Wood (20 July – 1 August). During these actions the RE were engaged in building positions round Longueval and sections were attached to the infantry for each advance, in which they acted as riflemen as well as sappers. The division then continued in the September battles, in all of which the company suffered casualties, at Guillemont (3–6 September), Flers–Courcelette (18–22 September) and at Morval (25–26 September).