Two companies of the Eleventh Tank Battalion (twenty-four tanks) were placed at the disposal of the Canadian Corps on April 13, 1918. These tanks had officers, drivers, and armament, but no other personnel. A sufficient number of trained Lewis gunners were found from the First, Third, and Fourth Canadian Divisional wings and the Canadian Field Artillery supplied the required number of gunners.
The tanks were then distributed at the critical points in the corps area, namely: Behind the St. Catherine switch at intervals of about 300 yards, facing south—18 tanks. In the gap between the Souchez River and Bois-en-Hache, facing east—three tanks. On the ridge line behind Angres, facing east—three tanks.
It was intended that these tanks should form points of resistance to check any forward flow of hostile forces and so give time to the Canadian infantry to re-form in case they should be forced back. In any event the tanks were to remain in action for twelve hours after coming in contact with the enemy and thus gain the time so essential in a crisis.
The First Canadian Motor Machine-Gun Brigade, now returned from the Amiens Battle, was held as a mobile reserve at one hour's notice. Bridges, railways, roads, and pumping stations were prepared for demolition, to be blown up as a last resort.
Extended almost to the breaking point, in danger of being annihilated by overwhelming attacks, the corps confidently awaited the assault. All ranks of the corps were unanimous in their ardent resolve to hold to the last every inch of the ground intrusted to their keeping.
It was for them a matter of great pride that their front was substantially the only part of the British line which had not budged, and one and all felt that it could not budge so long as they were alive.
Eventually, the First, Third, and Fourth Canadian Divisions were relieved in their sectors by the Fifteenth, Fifty-first, Fifty-second, Twentieth, and Twenty-fourth British Divisions. The relief started on May 1 and was completed on May 7, 1918.
As the relief progressed, the Canadian Corps handed over command of the Avion-Lens-St.-Emile-Hill 70 sectors to the Eighteenth Corps and the balance of the front to the Seventeenth Corps.
The length of front held by the Canadian Corps at the various stages of the German offensive has been given previously, but it is here recalled that from April 10, 1918, until relieved the corps held a line exceeding 29,000 yards in length; the Second Canadian Division, then with the Sixth Corps, was holding 6,000 yards of front, making a total length of 35,000 yards of front held by the four Canadian divisions. The total length of the line held by the British army between the Oise and the sea was approximately 100 miles, therefore the Canadian troops were holding approximately one-fifth of the total front.
Thus, although the Canadian Corps did not, during this period, have to repulse any German attacks on its front, it nevertheless played a part worthy of its strength during that period.