The relief was successfully carried out during the night of April 4, 1916. The British of the Sixty-first Brigade, Third British Division, who had been fighting for five days under heavy shell fire, were found to be in a thoroughly exhausted condition. To this badly hammered line the 27th (Winnipeg) and the 31st (Alberta) succeeded.
General Turner had made plans to make the position secure and tenable, but before they could be more than started the German advance checked further operations.
The working of evacuating the British wounded began in the morning, when the German guns were busy. Lieutenant McCaw's company held fast while the bombardment destroyed the greater part of their position and sixty-seven out of the ninety men present were killed or wounded. Captain Meredith of the 27th found that the position he was to occupy had been wiped out and it was only possible to find shelter for a few groups of bombers and his sentries in shell holes and behind improvised refuge barriers. It was necessary to send most of his men back while forty tried to hold a position where 200 were needed.
In the night of April 5-6, 1916, Captain Gwynn of the 29th Battalion took over Meredith's command from the left of the line while Lieutenant O'Brien of the same regiment relieved the 27th Company on the right.
Small parties of Germans during the night of the 5th, dashing through the Canadian artillery fire, had been steadily massing within striking distance on the front, while the battered 27th Battalion was being relieved.
The German artillery preparation began at 3 a. m. on April 6, 1916. Canadian officers around the telephone dugout discovered that the line was cut. The bombardment increased to a tornado of fire. Officers were unable to rejoin their units. To move even was certain death; while shell holes opened everywhere and trenches were shattered. The Sixth Canadian Brigade found that many of its rifle and machine guns had become clogged with mud and were useless. As day broke, the Germans were seen advancing up the Wytschaete road toward Sackville Center. Every Canadian gun was brought to bear, but the mud thrown up by the bombardment had put them out of action, and groups were too isolated to make a counterattack with the bayonet. Lieutenant Browne of the 22d French Canadians turned his Lewis gun on the Germans, but after a few of the enemy were shot down it went out of action. The Germans dashed by toward the craters in the rear, overpowering the small groups holding them. Two or three hundred Germans with machine guns held Craters 2 and 3, to the left of the Canadian position, and in the course of the day working to the left won Craters 4 and 5. The trench between Campbelltown Corner and the old British line became untenable, and while some got back to the original line, others occupied Craters 6 and 7. While here they were presently attacked by the Germans, who, however, gained nothing, being beaten off by Major Doughty of the 31st, who organized the defense. All this took place while the relief of the 27th was being completed, a time when there is always some confusion. Small parties found themselves in danger of being surrounded and retired toward Sackville Center and Fredericton Fort, where Captains Gwynn and Meredith were organizing the defense. The officers determined to hold on though under heavy machine-gun fire, and called on Colonel Snider, the nearest commanding officer, for help. The cover was poor, and many men fell. Lieutenant Jackson went out to discover the precise position of the enemy and returned with one private, eight others having been immediately killed. The Germans' fire on the communication trenches made it impossible for the Canadian command to move up supports, and believing the enemy was only a raiding party, hesitated to bombard for fear that more Canadians than Germans would be killed. Not until 5 o'clock on the 6th did General Kitchen learn that Craters 2 and 3 had been lost, when artillery fire was opened on Crater 2.
The trench mortars in the right-hand trenches were out of action, but some 18-pounders were brought up and turned on the enemy in Crater 2. A bombing and infantry attack from the north and northeast was prepared and the 28th Battalion was ordered to move up behind the center of the position and aid in the assault.
Parties of the 27th and 29th and machine-gun teams of the Fifth Brigade, struggling to reach the rallying point before Crater 1, lost heavily. Only one gun was brought out of action by Sergeant Naylor of the 24th. Parties of the 25th and 26th were never seen again. Lieutenant Browne of the 22d (French-Canadians) and a handful of men marched through the enemy line and after a hand-to-hand fight in an enemy trench reached Fredericton fort with only two men of his section alive.
Captains Meredith and Gwynn, who were defending Fredericton, held on for two hours longer, their men falling fast around them and were then forced to retire.
The Canadians had lost all the new line except a few outpost positions, and the remainder of the struggle was devoted to attempts to regain the lost ground and drive the Germans from the craters.