By early November the army had closed up to the Sambre–Oise Canal. The Battle of the Sambre opened on 4 November. Two platoons of 5th/6th RS were given the task of attacking le Donjon two minutes after Zero Hour behind special barrage, and if possible to obtain a crossing over the canal. Finding themselves unable to follow the assigned path through the marsh, the two platoons the half the battalion followed the 1st Dorsets across a floating bridge; le Donjon fell at 10.45. At 13.30 the 5th/6th RS and 1st Dorsets advanced to establish the bridgehead defences: the opposition was so negligible that no barrage was required.