On Z day the preliminary bombardment was to be the same as on former days, with no increase until zero hour. When the intense fire, or barrage, commenced, there were gaps left in it for the advance of Tanks.
For the XIV Corps there were, taking part in this attack, fifteen Tanks. Nine were allotted to the Guards Division, three to the 6th Division, and three to the 56th Division.
The instructions given to Tanks were that they should start their attack at a time which would enable them to reach the first objective five minutes before the infantry. When they had cleared up the first objective, a proportion of them was to push forward a short way, to prearranged positions, and act as strong points. Departure from this programme to assist any infantry held up by the enemy was left to the discretion of the Tank Commander.
On the second objective Tanks and infantry would advance together and pace was to be regulated to “tank pace,” which was given as from 30 to 50 yards a minute. For the third and fourth objectives there would be no creeping barrage, and Tanks would start in time to reach the objectives before the infantry. In all cases their action was to be arranged so as to crush wire and keep down hostile rifle and machine-gun fire.
Signals between Tank and infantry were arranged for by means of coloured flags—a red flag meaning “out of action,” and a green flag “am on objective.”
The main task of the 56th Division was to clear Bouleaux Wood and form a strong protective flank,
covering all the lines of advance from Combles and the valleys running from the north-east of Combles. The 167th Brigade were ordered to advance as far as the bit of Beef Trench running through Bouleaux Wood, and to Middle Copse on the left of the wood; a flank was also to be formed to the south-east and clear of the wood. The 168th Brigade were to pass through the 167th and carry on the advance by further bounds. The 169th Brigade were to hold the line through Leuze Wood and the left of square 27, and to capture the well-known trench (Loop Trench) to the south-east of the wood which runs into the sunken road to Combles.
One Tank was to advance on the right of Leuze Wood and assist the 169th Brigade to drive the enemy beyond the sunken road; it would then establish itself in the Orchard as a strong point. This Tank was called the Right Tank.
Two Tanks were to work from the north of Leuze Wood along the left of Bouleaux Wood and assist the 167th and 168th Brigades. These were known as the Centre and Left Tanks, and were eventually to proceed to a railway cutting north-east of Bouleaux Wood, which promised to be a point of some difficulty.
The Right Tank, having seen the 169th Brigade safely in its objectives, was to move along the south-east of Bouleaux Wood and take up a position on the cutting in the top end of square 22.