Work had started on all parts of the 3rd Corps front by 8 August, on average 130m from the German lines. The French plan was to advance the front line an average of 80m and create a new trench, scheduled to be established on about 18 August. This line, designated in siege parlance the ‘parallèle de départ’, was to be the starting point of the Russian saps, which were then advanced to the sunken road. Six hundred men were to work day and night on the saps. It was anticipated that the work would attract the attention of the Germans, who would bombard and possibly also raid it. Hache asked that the heavy artillery of the 10th Army be available for counter-battery work to reduce the artillery fire on the sapping, which it was anticipated might be costly. The sappers were to be protected by covering troops with grenades against German raiders.³