The front assigned to each attacking division was only two kilometres wide, the troops being formed into two storm columns of one regiment each. The third regiment was kept as sector reserves, to develop initial successes.
The storm-troops, led by large numbers of non-commissioned officers, advanced in waves, shoulder-to-shoulder, preceded by a rolling barrage some 300 yards ahead of the first line. This barrage afterwards moved forward at the rate of about 200 yards every five minutes.
The waves advanced resolutely, protected first by the rolling barrage, then by the accompanying artillery and Minenwerfer. Wherever the resistance was too strong, a halt was made, allowing the neighbouring waves to outflank the obstacle on either side, and crush it.
The Germans straightway threw the greatest possible mass of infantry into the Allies' defences.
Amid clouds of gas, smoke and fog, the British in the advanced positions were surrounded and overwhelmed, often before they had realized what was happening.
Nearly all their machine-guns, posted to sweep the first zone, were put out of action.
The First Day (March 21).
The first day of the attack, General Byng's Army from Fontaine-les-Croisilles to Demicourt, withstood the shock steadily, the Germans penetrating the first lines only.
In the centre, before St. Quentin, and to the south, in front of Moy and La Fère, General Gough's Army, overwhelmed by numbers, and notwithstanding the courage of the men, was broken early in the attack.