text: Tanks Forty tanks of the 1st Brigade were to be used in the attack on the Third Army front, eight with XVIII Corps and sixteen each in VII Corps and VI Corps. When the blue line had been reached, four of the VII Corps tanks were to join VI Corps for its attack on the brown line. The black line (first objective) was not to be attacked by tanks, which were to begin the drive to the front line at zero hour and rendezvous with infantry at the black line two hours later. The tanks were reserved for the most difficult objectives beyond the black line in groups of up to ten vehicles. Four tanks were to attack Neuville Vitasse, four against Telegraph Hill, four against The Harp and another four against Tilloy lez Mofflaines and two were to drive down the slope from Roclincourt west of Bois de la Maison Blanche. Once the blue line had fallen, the tanks still running were to drive to rally points.
  Battle
  First phase
  The preliminary bombardment of Vimy Ridge started on 20 March; and the bombardment of the rest of the sector on 4 April. Limited to a front of only , the bombardment used 2,689,000 shells, over a million more than had been used on the Somme. German casualties were not heavy but the men became exhausted by the endless task of keeping open dug-out entrances and demoralised by the absence of rations caused by the difficulties of preparing and moving hot food under bombardment. Some went without food altogether for two or three consecutive days. By the eve of battle, the front-line trenches had ceased to exist and their barbed wire defences were blown to pieces. The official history of the 2nd Bavarian Reserve Regiment describes the front line as "consisting no longer of trenches but of advanced nests of men scattered about". The 262nd Reserve Regiment history writes that its trench system was "lost in a crater field". To add to the misery, for the last ten hours of bombardment, gas shells were added.