The Australian Victories in France in 1918

by Sir John Monash

For the present battle it was accordingly arranged that the barrage should open on a line which was dead straight for the whole 7,000 yards of our front, and the Infantry tape lines,[14] which were to mark the alignment of the Infantry at the moment of launching the assault, were to be laid exactly 200 yards in rear of this Artillery "start line." The barrage was to advance, in exactly parallel lines, 100 yards at a time, at equal rates along the whole frontage. These rates were 100 yards every 3 minutes, for the first 24 minutes, and thereafter 100 yards every 4 minutes, until the conclusion of the time-table at 143 minutes after Zero. By such a simple plan every one of the 432 field guns engaged was given a task of uniform character.

Great as was the care necessary to conceal all Artillery preparations, it required still greater thought and consideration to keep entirely secret the presence behind the battle front of some 160 Tanks, and particularly to conceal their approach march into the battle. To both combatants, the arrival of a Tank, or anything that could be mistaken on an air photograph for a Tank, had for long been regarded as a sure indication of coming trouble. And, therefore, imputing to the enemy the same keenness to detect, in good time, the presence of Tanks, and the same nervousness which we had been accustomed to feel when prisoners' tales of the coming into the war of enormous hordes of German monsters had been crystallized by the reports of some excited observer into a definite suspicion that the fateful hour had arrived, I considered it wise to repeat on a much elaborated scale all the precautions of secrecy first employed for this purpose at Hamel.

It is quite easy to detect from an air photograph the broad, corrugated track made by a Tank, if the ground be soft and muddy enough to record such an impression. Consequently, Tanks were forbidden to move across ploughed fields or marshy land, and were confined to hard surface. They moved only in small bodies, and only at night, and were carefully stabled, during the daylight, in the midst of village ruins, or under the deep shade of woods and thickets. Thus, by daily stages, and by cautious bounds, each Tank or group of Tanks ultimately reached its appointed assembly ground, from which it was to make its last leap into the thick of the battle, where it would arrive precisely at Zero hour.

But that last leap was just the whole difficulty. For the Tank is a noisy brute, and it was just as imperative to make him inaudible as to make him invisible. By a fortunate chance, the noise and buzz made by the powerful petrol engines of a Tank are so similar to those of the engines of a large-sized bombing plane, as for example of the Handley-Page type, especially if the latter be flying at a comparatively low altitude, that from a little distance off it is quite impossible to distinguish the one sound from the other.

It was therefore possible to adopt the conjurer's trick of directing the special attention of the observer to those things which do not particularly matter, in order to distract his attention from other things which really do matter very much. In other words, a flight of high-power bombing planes was kept flying backwards and forwards over the battle front during the whole of that very hour, just before dawn, during which our 160 Tanks were loudly and fussily buzzing their way forward, along carefully reconnoitred routes, marked by special black and white tapes, across that last mile of country which brought them up level with the infantry at the precise moment when the great battle was ushered in by the belching forth of a volcano of Artillery fire.

The subterfuge succeeded to perfection, as was obvious to observers and confirmed by the subsequent narratives of prisoners. The German trench garrisons and trench observers were fully occupied in listening to the hum of the bombing planes, in watching their threatened visitation for their customary "egg" dropping performances, in engaging them with rifle fire, and in holding themselves in readiness to duck for cover should they come too near. They never suspected for a moment that this was merely a new stratagem of "noise camouflage," and that the real danger was stalking steadily and relentlessly towards them over the whole front, upon the surface of the ground, instead of in the air.

But the trick would not have succeeded so well, or would perhaps have failed altogether, if the employment of those planes had been confined to the morning of the battle. Such an unusual demonstration might have aroused vague suspicions sufficient to justify a "stand to arms" and a preparedness for some further activity on our part. And what we had most to fear was the danger of "giving the show away" in the last ten minutes. For it would have taken much less than that time for nervous German trench sentries, by the firing of signal rockets, to bring down upon our front line trenches, crowded as they were with expectant fighters, a murderous fire from the German Artillery.

Consequently the puzzled enemy was treated to the spectacle of an early morning promenade by these same bombing planes on every morning, for an hour before dawn, during several mornings preceding the actual battle day. Doubtless the first morning's exhibition of such apparently aimless air activity in the darkness really startled him. After two or three repetitions, it merely earned his contempt. By the time the actual date arrived he treated it as negligible. All prisoners interrogated subsequently agreed that neither the presence nor the noisy approach of so mighty a phalanx of Tanks had been in the least suspected up to the very moment when they plunged into view out of the darkness, just as day was breaking.