This mine was started on 18 December 1915 behind the British trench known as G.2 by 250 Tunnelling Company, No.2 section commanded by Captain Haydn Rees, a Welshman from the collieries of south Wales.
By January the shaft was completed at 65 feet and the main drive was begun. From the outset this was a troublesome mine due to the heavy ground and the tunnel being full of water, sand and slime. As a precaution a second shaft was sunk to a depth of 70 feet in hard blue clay and this connected with the first.
In the main drive the clay was causing problems by swelling more rapidly than normal and as a result splintered the mine timbers and these were replaced with heavier props. In March 1916, 1st Canadian Tunnelling Company were attached to 250 TC for instruction with two sections of 250 TC being temporarily transferred to undertake urgent work at The Bluff. In their absence the gallery was driven 500 feet from the shaft and by the end of March half a section from 2nd Canadian Tunnelling Company had joined for instruction.
The progress was slowed due to enemy bombardments and increased trench mortaring, trench mortaring was part of German counter mining tactics used to destroy shaft heads, and on the 29 April the tunnellers had to assist the infantry in repelling a German raid. Progress was further delayed by the tunnellers having to relay the tram track in the tunnel due to the swelling of the clay. At 1,145 feet ‘A’ branch of the gallery was under Peckham Farm and the charge of 87,000 lbs (39,462 kg) of ammonal was chambered and made ready.
‘B’ branch gallery was 370 feet from ‘A’ when a collapse at the face occurred and water and sandy clay flooded into the gallery. The gallery was abandoned and a dam built 120 feet further back across the face. A new gallery was started and after passing the end of ‘B’ it too ran into trouble and was abandoned. ‘C’ gallery, to the right of ‘B’ and at an angle of 45 degrees, was cut in blue clay and driven towards the German reserve line. This gallery also ran into trouble from flooding with hand pumping being unable to keep the water under control and electric pumps introduced. A series of small chambers were created and 20,000 lb (9,071 kg) of explosives were stacked in them. This mine was abandoned when the gallery collapsed after the electric pumps broke down.
In January 1917 when it seemed that all the problems had been overcome the main gallery collapsed cutting off the main charge at ‘A’ gallery. It was not possible to repair the gallery and a new gallery to pick up the leads of the mine in ‘A’ gallery was begun. Steel joists were used, replacing the heavy wooden props, and the gallery was driven 1,000 feet before they considered it safe to break into the old drive. By March 1917 they had connected with the mine in ‘A’ gallery and it was made ready.
