On 17 February the French carried out attacks preceded by mine explosions on the ridges of Éparges and Vauquois. These ridges, providing important observation east and west of Verdun, were to become major centres of underground warfare. The Éparges ridge, 320m in height, allowed the Germans observation across the Woëvre plain towards Verdun. The French Company 14/15, under Captain JeanLouis-Laurent Gunther, began sapping and mining up the northern and western slopes in mid-November 1914. On 7 February there were signs that the Germans had taken underground countermeasures against the westernmost mines driven from four saps and, so as not to lose four months of work, it was decided to blow these and for the infantry to assault the western part of the ridge on 17 February. The four mines were blown at 1400 but, unlike other mining attacks, this was not the signal for the infantry assault, but for the start of an hour-long artillery preparation, following the methodical procedure of a siege, whereby the artillery and mines together gradually broke down the defences and the artillery bombardment would prevent the Germans from occupying the mine craters. However, it ran the danger of losing the shock value of the mines. The infantry waited at the foot of the slopes at the entrances of the saps until the mines were blown, at which point they entered the saps to be ready to rush the craters as soon as the bombardment lifted at 1500.³² An infantry officer of one of the assaulting columns described the agony of waiting to attack and the moment that the mines were blown:

Everything is empty. I can feel or express nothing but this. All that normally makes up the world, the flow of sensations, thoughts and memories which carry each second of time, nothing is left of them, nothing. No consciousness penetrates the suspense; neither anguish, nor the vague desire of what may occur. All is insignificant, it no longer exists: the world is empty.

And it is at first, against our crouching bodies, a heavy shudder of the ground. We are upright when the monstrous, white fumes, specked with fluttering black things, rise up at the edge of the plateau behind the lines near the horizon. They do not shoot up but expand into immense plumes, which separate one from another, more and more, until forming these four smoking monsters, motionless and riddled with dark projectiles. Now the mines thunder, heavily, gruesomely, like vapours. The noise ebbs, rolls over our shoulders; and at once, on the other side, in every valley, on the whole plain and also the sky, the guns release the breaking floodgates of tumult.

‘Forward! Single file; behind me.’

We climb up towards the entrance to the communication trench without seeing it, buffeted by the tremendous uproar, staggered, crushed, dogged and furious.

‘Forward! Quick!’ The sky splits, cracks and crumbles. The hammered ground gasps for breath. We no longer see anything but a reddish-brown dust which flames or bleeds, and sometimes, through this sooty black and stinking cloud, a fresh stream of adorable sun, a tatter of dying sun.

‘Forward! Follow me… Forward… Follow me…’ (Second Lieutenant Maurice Genevoix, 2nd Battalion 106th Infantry Regiment)³³

Genevoix’s battalion moved up the four saps, from the ends of which the mines had been laid, and at 1500 the artillery lengthened its range and infantry and engineers left the saps to capture the craters. The mines and the bombardment were effective in breaking down the defences and the French took and held the western part of the ridge. There unfolded on Éparges a ferocious underground warfare which lasted until the autumn of 1917.³⁴

As predicted by some military engineers before the war, mining was indeed reverted to as a means of overcoming field fortifications. When taken up it was carried on as part of an established methodology of siege warfare, a series of well-described procedures tested over centuries. Both the Germans and French used mining to bite off parts of their opponent’s defensive systems. Mining, however, required yet more men and trench warfare already drew in large numbers of engineers to maintain and supply defences.

But for a lack of manpower, French and German, and to a lesser extent British, military engineers regarded mining as being well within their technical ability. During 1915 the use of mining would rapidly escalate and in the process many of the practices of siege warfare would be modified or cast off. Ultimately it was the British, starting with the least technical skill, who were to most fully embrace mining.