By 29 November the German 2nd Army had eighteen divisions around Cambrai. After the defensive fighting of the divisions had to prepare hurriedly for the counter-offensive of 30 November, which was the first offensive against the British since the Second Battle of Ypres in April 1915. Similar methods to those used by the British to obtain surprise were used, artillery ranging was minimal, a one-hour bombardment before the attack was planned, with a rolling bombardment moving at a rate of in five minutes to precede the infantry, while the British in Bourlon Wood were to be neutralised by a gas and high-explosive bombardment. Built-up areas were to be bombarded by howitzers and by-passed by the foremost infantry and then attacked from all sides by following troops. Troops moving beyond by-passed British positions in the , were to overcome centres of resistance by infiltration and envelopment, with , light and field artillery accompanying the infantry for the first time, each battery having a platoon of pioneers and a light machine-gun crew; communication was to be assisted by the use of colour-coded light signals.