 The troops were preceded by a rolling barrage, edging forward in lifts of every four minutes, permitting the infantry to keep up while negotiating the mud.On the left flank, the 8th Canadian Infantry Brigade captured Wolf Copse and secured its objective line but was ultimately forced to drop a defensive flank back to link up with the 63rd (Royal Naval) Division, the flanking division of the Fifth Army.In the centre, the 9th Canadian Infantry Brigade found the German barbed wire to be well cut by the preliminary artillery bombardment and within an hour captured the Bellevue pillboxes.