The preparations for the offensive were conducted with the greatest possible secrecy, and in order to secure the maximum surprise effect it was arranged for the attack to be delivered without any preliminary bombardment or even registration of batteries, the road into the enemy's defences being cleared instead by a vast number of tanks. The attack was delivered by the IV (Woollcombe) III (Pulteney) and VII (Snow) Corps, on a six-mile front, between Hermies and Gonnelieu, a subsidiary operation being conducted north of Bullecourt by the VI Corps (Haldane). The 56th Division was thus outside the actual area of advance, but was to co-operate on the opening day by means of the feint attack, for which it had already made preparations, and its further action was to depend on the success gained in the main operation. The left flank of the area of advance was intersected by the Canal du Nord, running between Bourlon and Mœuvres. The frontage in this region was taken up by the 36th (Ulster) Division, which adjoined the right flank of the 56th and was the left of the whole attack. The 36th was to attack with two brigades east of the Canal and one brigade west, the Division moving northwards along the Hindenburg system towards Mœuvres. The rôle of the 56th Division was to depend on the degree of success attained by the 36th. If the latter's attack succeeded in forcing the retirement of the enemy west of the Canal, this area would be occupied by the brigade of the 36th Division which was on the west bank; if, however, this success was not achieved the 56th Division was to attack over the open with tanks, the 169th Brigade advancing on a front between Mœuvres and Tadpole Copse, and the 167th forming a defensive flank from the Copse to our present front line. The enormous success which attended the initial stages of the Cambrai battle needs no elaboration here. At 6.30 a.m. on 30th November the dead silence was suddenly broken by the roar of a very great concentration of batteries of all calibres up to 15-inch, and preceded by 380 tanks the assaulting divisions swept over the first and second systems of the Hindenburg line. With the exception of a check due to the destruction of the Canal de l'Escaut Bridge at Masnières, and of another at Flesquières (where a most gallant resistance to the 51st Division was put up by a single German officer, who continued to serve his gun after all the team were killed and succeeded in knocking out several tanks), the success of the day was considerable. The villages of Havrincourt, Graincourt, Ribecourt, Marcoing and La Vacquerie were added to the British territory, and it was obvious that the surprise effect had been complete. On the left the 36th Division established itself north of the Cambrai Road, astride the Hindenburg line, and the 169th Brigade swung its right flank northward to conform to its neighbours' movements.