On 15 February 1916, Ackroyd was promoted to temporary captain. The first half of 1916 saw a stalemate between the allies and the German forces and the time was spent by the British preparing for the Battle of the Somme that began on 1 July. The 18th Division was now part of the Fourth Army (United Kingdom) under Sir Henry Rawlinson. By the end of the first advance, the division had covered 3000 yards on a 2500-yard front and had seized Montauban Ridge on the west end of Montauban village. Six hundred and ninety five prisoners had been taken but the division suffered 3307 casualties.