The Birdcage at Ploegsteert Wood, the Germans called it Ducksbill, was the location of some of the earliest mining with 174 Tunnelling Company blowing two mines beneath the German lines in June 1915. 174 TC was relieved by 171 TC and towards the end of 1915 they began the work of sinking two shafts as part of the deep mine offensive, originally planned for 1916.
Near the northeast corner of the wood at Trench 121 was formed a right angle, and it was immediately behind the elbow that they sank shaft M.I and by early January 1916 they had sunk the shaft to a depth of 84 feet through the stiff blue clay. They then started the drive towards the objective of Le Pelerin. When they had gone some 100 yards, they heard the sound of the Germans working in a gallery above them. Work was suspended for a while and when it resumed they took the precaution of branching to the right and created a protective gallery to prevent the shaft being outflanked. This gallery inclined up to 60 feet below the surface to act as an intermediate level and then as soon as it had gone a few yards a chamber was cut and the objective was soon reached.
A few days after commencing M.I they began to sink a second shaft M.3 also in trench 121 the two shafts were connected by a drive and later they sank a third shaft further back M.4 and this was connected to M.I and M.3. By April 1916 the drive from shaft M.3 had reached its objective.
During the mining operations the 11th Battalion Royal Scots were in the line at Ploegsteert Wood, until the end of May 1916. They occupied the trenches at Le Gheer opposite the ‘Birdcage’. Much of their time was spent on improving the trenches, the Regimental history records that: ’ the men flattered themselves that as a result of their efforts their trenches were the best in France.’ They also assisted the tunnellers and during this time Private David Lamond, DCM, a Falkirk District man from Avonbridge, was killed by a sniper. He is buried in Rifle House cemetery within Ploegsteert Wood. https://www.theypressalient.com/post/david-lamond-d-c-m
The four mines, at the ‘Birdcage’ were left dormant. The British GHQ had decided that German reserves would be closer to the craters and therefore would be in a position to fortify them before the British infantry could get forward. It was decided to keep them charged for possible use in later operations.
After the British attack, Lieutenant B C Hall, 3rd Canadian Tunnelling Company wrote about his inspection of the dormant mines: ‘I then had to go and inspect the other mines which weren’t blown and send a report down as to whether the leads were alright and so on. The leads were alright but the tunnels were hour-glassing (the shaft lining had been fractured and sand was filling the chambers) – all the timbers were broken.’ The British had intended excavating the mine charges and removing the fifty-five tonnes of ammonal explosive after the war but after the German advance of April 1918, the precise location of the charges was lost and they were eventually abandoned.
On the 17 July 1955, the Number 3 Birdcage mine exploded, some thirty-eight years after the charge had been laid. A massive burst of energy from a lightning strike had struck one of the armoured firing leads and blew the charge. It left a huge crater, today filled in and there is a slight depression in the ground to mark the location. No one was harmed. It is a reminder that the detonators are still highly dangerous however, what was surprising was that the ammonal had survived as this was an explosive that was prone to degradation in damp conditions (the tunnels had flooded).
