By the end of September Fourth Army had closed up to the Hindenburg Line. 12th Brigade came under the command of IX Corps once more for Fourth Army's assault crossing of the St Quentin Canal on 29 September. The canal defences had largely been destroyed by the heavy guns, which continued firing on the canal banks until the last possible moment as 137th (Staffordshire) Brigade stormed the outpost line and then scrambled across the canal in the morning mist. The objectives were taken by 15.30 and 70th Siege Bty moved forwards to new positions before the end of the day. It crossed over the canal after dawn on 1 October to support 32nd Division's attack on the Beaurevoir Line the following day.