At one side of the model was a high wooden platform raised on a scaffolding and reached by a ladder, and from this point of vantage this Ypres Salient in little could be overlooked and memorised as from a kite balloon.

For several weeks before the day appointed for the battle, the platform was almost constantly occupied by groups of officers. Indeed, it was seldom unoccupied during daylight from the time it was erected to the eve of the great attack, and round and across the model perpetually wandered little groups of officers and N.C.O.’s with maps and notebooks and orders—discussing, pointing, explaining. Generals personally conducted their immediate subordinates over the mimic battlefield, whilst N.C.O.’s were coached by their Company Commanders.

From a liaison point of view the model was invaluable. Individual Tank Commanders there met the infantry officers with whom they were actually to fight, and would walk and talk over “the ground” together, until they were perfectly clear about their own and each other’s rôles, routes, objectives and time-tables, after which mutual esteem and confidence would be cemented and reinforced at the dinner table.

In this and similar ways a close and cordial entente was established between the Tanks and their partners the infantry, and there were many battlefield incidents that showed vividly how much success depended on this personal liaison and good fellowship.

V

There was to be nothing novel in our general plan of assault.

[34] “The 5th Army attack was to be carried out on well-recognised lines; namely, a lengthy artillery preparation followed by an infantry attack on a large scale and infantry exploitation until resistance became severe, when the advance would be halted and a further organised attack prepared on the same scale. This methodical progression was to be continued until the exhaustion of the German reserves and moral created a situation which would enable a complete break through to be effected.”

Tanks were everywhere to be auxiliary, and were to be employed to deal with strong points and for “mopping up” behind the infantry.

There was, however, one great improvement in the method of using them.

They were to be used in definite “waves.” That is to say, supposing thirty-six Tanks were to be employed on a sector where the Germans had established the usual three lines of defence, twelve Tanks would start at zero and be used to take the first objective. Meanwhile, the second wave would have been advancing, and as soon as the first objective had been taken by the first wave, the second wave would pass through them and on to the second objective. The third party of twelve would advance in the same way—a wave to each objective.