They had not very long to work together, yet it was essential that the infantry should have confidence in the trench-spanning and wire-cutting power of the Tanks. Infantry units were therefore invited by the Tank Corps to build their own defences and entanglements, the Tanks guaranteeing to cross the trenches and chew up the wire of their best efforts. Some very formidable and ingenious defences were made. The Tanks, however, everywhere carried out their guarantee, to the great edification of the infantry. The following table gives briefly the allocation of Tanks and infantry to the various objectives: ALLOCATION OF FIGHTING TANKS _1st Brigade Battalions._ _Tanks (No.)_ _3rd Corps Divisions._ D (4) 42 On Right: 51st. E (5) 42 51st and 62nd. G (7) 42 On Left: 62nd. _Objectives_: Havrincourt, Flesquières. Of each battalion: thirty-six Tanks for 1st, 12 (plus survivors) for 2nd Objective. _Exploitation towards_ Fontaine, Bourlon Wood, the Bapaume-Cambrai Road, Bourlon Village and Graincourt. Bridges over Canal du Nord. _2nd Brigade Battalions._ _Tanks (No.)_ _4th Corps Divisions._ B (2) 42 on Right. 6th. H (8) 42 on Left. 6th. _Objectives_: Beaucamp, Villers, Plouich Road. _Exploitation towards_ Marcoing, Preny Chapel, and Nine Wood. _3rd Brigade Battalions._ _Tanks (No.)_ _4th Corps Divisions._ C (3) 42 12th. F (6) 42 ” I (9) 42 20th. A[44] (1) 42 ” _Objective_: La Vacquerie. _Exploitation towards_ Crèvecœur, Masnières, and Marcoing. The part to be played by the artillery was carefully worked out. There was to be no preliminary bombardment, but as soon as the attack was launched the heavy guns were to begin counter-battery work and were to shrapnel the bridges along the Canal. At the same time a jumping barrage of smoke shells and H.E. was to cover the advance of the Tanks and infantry. The secrecy of the attack made it impossible for any registering shots to be fired, and the ranges could be worked out in theory only. Several squadrons of the R.A.F. were to co-operate, flying low; their especial work being to bomb enemy Headquarters. The cavalry were also billed to co-operate. Special wire-pulling Tanks fitted with grapnels were employed to clear convenient broad lanes through the wire for them, and their needs were throughout carefully considered. For one reason and another, however, the cavalry did not, after all, find it possible to take much part in the fighting. The preparations for the battle were of the thorough and laborious kind always requisite for a “full-dress” attack.