Land Mines were to be a special feature of the action. The explosion of twenty of these containing over a million pounds of ammonal was to be the signal for attack on the morning of June 7.
Some of the mines had been ready for more than a year, and we had constructed nearly five miles of galleries. The Germans too had not been idle.
At the time of our attack we knew that the enemy was driving a gallery leading to our Hill 60 mine. By careful listening we judged that if our offensive were launched on the date arranged the enemy’s counter-mine would just fail to reach us. He was, therefore, allowed to proceed.
Altogether seventy-two Mark IV. Tanks were to be employed, and, the lesson of Arras having been learnt, twelve Mark I. and Mark II. Tanks had been converted into supply machines. Each of these was able to bring up sufficient petrol, ammunition and other stores to replenish five fighting Tanks.
Forty Tanks were to cross the parapet at zero hour and the rest of the Tanks were to be held in reserve.
They were to be distributed as follows:—
To the North: twelve Tanks were to work with the 10th Corps, whose objective was the Oosttaverne line.
In the Centre: sixteen Tanks were attached to the 9th Corps, who were to capture Wytschaete.
To the South: twenty Tanks were to fight with the 2nd Corps, who were to take Messines and a strong point named Fanny’s Farm, the reserves pushing on to capture the Oosttaverne line in the second phase of the attack.
The weather had been fine and hot for nearly three weeks before the battle, and a heavy thunder shower which fell on June 6 hardly laid the dust which had hung for weeks in a hazy curtain over the approach roads.