In this part of the great series of victories we have to follow the operations of the 2/4th Battalion, and we shall deal with them in the first instance from the opening of the offensive on August 8th until their final disbandment on September 12th. We shall then proceed to follow the unrolling of the battle northwards and the engagement in it successively of the Third and First Armies, with both of which the 1/4th Battalion fought until the Armistice.
The date fixed for the great attack was 8th August, and on that day Rawlinson's Fourth Army, comprising from left to right the III, Australian and Canadian Corps, would combine with Débeney's First French Army in a supreme effort to relieve Amiens from the menace of the Huns. With the details of the battle beyond the 58th Division's area we are not concerned but we must, in order to understand the rôle which the Division was expected to play, offer some brief description of the terrain and its effect on the Australian advance on the right.
The main advance was to be made on the south bank of the Somme by the Canadians and the Australians, while the III Corps, including the 18th and 58th Divisions in line, operating solely on the north bank of the river, would secure the left flank of the attack as far north as Morlancourt. The establishment of this defensive flank entailed the capture of a very strong naturally defended position, the possession of which was vital to the success of the troops south of the Somme.
The Somme, like the Oise, is a winding canalised river running through a marshy valley. Its south bank, though undulating, has no specially marked hill features, but on the north the adjoining land rises to a considerable height on the spur which traverses the narrow wedge between the Somme and the Ancre. This plateau is furrowed by a number of deep gullies running northward from the river, and the sharp hills between these valleys, falling in places by abrupt chalk cliffs to the Somme, form very commanding features from which it would be possible for a determined enemy to play havoc with any attempt to advance south of the river, for they completely dominate the south bank. The most marked of these spurs is the long saddle immediately east of the village of Chipilly. This feature is almost girdled by the Somme (which makes a narrow sweep round the east, south and west sides of it), and projects almost a mile south of the general line of the river. It thus forms a barrier across the ground for which the Australians would be made responsible.
The capture of the Chipilly Ridge was the task allotted to the 58th Division, while the 18th would complete the defensive flank from the north end of the Ridge at Gressaire Wood to Morlancourt.
The line of advance from the British front trenches was full of obstacles. Immediately in front of the line, and on the river bank was the village of Sailly Laurette, the garrison of which, if not immediately overcome, would be able to enfilade the whole advance as the troops crossed No Man's Land. A mile and a half east of Sailly Laurette lay Malard Wood, covering both slopes of one of the declivitous gullies already alluded to; while half-way between the Malard Wood valley and the final objective on the cliff of Chipilly Ridge, lay a second gully, badly enfiladed from Chipilly village and completely overlooked from the Ridge itself. Heavy going all the way, up hill and down dale, through features eminently suited to machine-gun defence, culminating in a breathless scramble up a steep slope to meet an enemy who would probably defend it to the last; a total advance of about two and a half miles; altogether no light task for a single division.
In view of the obvious difficulty of carrying so strong a position by frontal attack alone it was arranged that the Australians should advance ahead of the 58th Division and occupy the high ground near Méricourt south-east of the Ridge, by the time the 58th was due to deliver its final assault. By this means it was hoped to squeeze the enemy off the Ridge in the direction of Bray without making a fight for it, in order to avoid complete envelopment.
Such was the general idea: and we must now return to the 2/4th Battalion which we left in the preceding chapter at Pernois on the morning of 2nd August, in order to trace how the idea worked out.
The 2nd and 3rd August were spent in resting and cleaning, and on Sunday, the 4th, after company commanders had been admitted to the rumour that large operations were imminent, sudden orders to move were received. At 9.30 p.m. that night the Battalion again embussed to La Houssoye on the Amiens-Albert Road, whence it marched to bivouacs in a wood near Bonnay (two miles north of Corbie, on the Ancre). Fortunately the weather was fine and warm, for the only shelter provided was one bell tent per company.