CANADA HISTORY - War-WWI

Vimy - Preparations

Preparations for the Attack

No particular secret was made of the plan, except as regards the day and hour of attack, and the Canadians were given an unprecedented opportunity to learn their roles. Thoroughness was the keynote of the preparations. In the rear area the German defences were reproduced in full-scale detail from aerial photographs, with tapes to mark trenches and flags to mark strong points, and repeated rehearsals were held. All ranks were well acquainted with the sector on their own side of No Man's Land. Great numbers of detailed maps were provided. Meanwhile the Engineers were extending the roads and light railways so that the necessary stores and ammunition could be moved forward. Complementary increases in telephone and telegraph facilities, water supply and other services were undertaken. Even though this activity was carried on in full view of the enemy, little effort was made to disrupt the preparations.

It was planned to destroy the enemy's defences by a two-week bombardment. With the aid of aerial photographs all essential targets were carefully tabulated and arrangements made to take immediate action upon the correlation of information subsequently obtained from aircraft, balloons, sound rangers, flash spotters and ground observers. It was emphasized that success would depend largely upon close co-operation between artillery and machine-guns and between the Intelligence sections of First Army and Canadian Corps Headquarters. Observed fire would be laid down daily on trenches, dugouts, concrete machine-gun emplacements and other strongpoints, entrances to tunnels, road-junctions, ammunition dumps and light railways to a depth of 4000-5000 yards behind the German front line; it was realized, however, that apart from the foremost lines of defence the total destruction of barbed wire entanglements would be out of the question. By night attention would be switched to the enemy's communications, which would be harassed by incessant shell and machine-gun fire. Unprecedented importance was attached to counterbattery work, the ruling principle being that isolated batteries should be dealt with first, since those that were closely grouped could be more easily and economically neutralized later by high explosive and gas shells. These tasks were to be carried out by 245 pieces of heavy artillery and 618 field guns and howitzers placed at the disposal of the Canadian Corps, assisted by 280 more guns of the flanking British 1st Corps. The resulting density was one heavy gun for every 20 yards of frontage and one field gun for every 10 yards, a considerable increase over the firepower available for the earlier Somme offensive. The Canadian Machine Gun Companies' 280 guns were allotted harassing fire tasks, and trench mortars were to join in the destruction of the foremost German trenches.

The first phase of the bombardment began on 20 March, but only about half the batteries participated in order to conceal as long as possible the great concentration of artillery on such a narrow front. The guns of the Third Army joined in on 2 April for the second and more intensive phase which the Germans called "the week of suffering." Special attention was given to the villages of Thelus, Les Tilleuls and Farbus and the German support troops resting there were driven into the open fields with a consequent loss in sleep and efficiency. Numbers of Germans in the forward trenches went without food for two or three days and were further exhausted by the endless task of trying to keep open the entrances to their deep dugouts. The persistently bad weather impeded the flow of ammunition required to replenish our forward dumps but increased the effect of the shelling, causing the enemy's forward defence system to lose its continuity in places. Nightly raids were conducted during the bombardment, varying in size from a few individuals to the 600 all ranks sent out by the 10th Canadian Infantry Brigade on 31 March. It was learned that the Ridge was defended by five regiments; four of these had been in the line for at least five weeks and many of the rifle companies were greatly reduced in strength. The first and second trenches were manned by a forward battalion of each regiment, a second battalion was either in the third trench or immediately to the rear as close support, while the third battalions were resting in villages five or six miles back and could not reach the battlefield in less than two hours. Thus there would be approximately 5,000 troops to oppose the initial attacks by 15,000 Canadians and a reinforcement of 3,000 to meet the 12,000 Canadian and British troops available to support the first attacks or press forward to the subsequent objectives. The only further German reserves were two divisions 12 to 15 miles distant near Douai. Haig points out in his dispatch that the artillery preparation depended largely upon air reconnaissance. Accordingly, "a period of very heavy air fighting ensued, culminating in the days immediately preceding the attack in a struggle of the utmost intensity for local supremacy in the air." Bad flying weather and superior German aircraft and equipment resulted in the Royal Flying Corps suffering considerable losses; but thanks to its good work some 86 per cent of the enemy's 212 active batteries were located. Starting with the night of 5 April limited bombing was carried out against German airfields and railway installations and, although the weather was far from ideal, these operations were continued on each succeeding night.