On 8th March 1915, three sites were chosen for tunnels near Hill 60. These were named M1, M2 and M3. 2 from trench 40 and the other from Trench 38, 50 yards from the German front line. 171 Tunneling Company, RE began the digging. 5m down to start through a mix of sand and clay finding the body of a French Soldier almost immediately. Lifting it out, it fell apart. The gruesome task of the tunnelers was to dig up the French Bodies whom had died here a few months previous and rebury them in quick time, before any tunneling could begin. The shaft was then sunk and the tunneling started. day and night the digging continued, the unstable, waterlogged clay and sand being held back with wooden shuttering which leaked constantly. Survival relied on primitive bellows being pumped continuously. Two men at a time, a candle the only light, but with the lack of oxygen the flame dwindled constantly. Silence was also a must!
The Germans counter-mined and on 16th March, the British could hear them digging and the race was on. This was a new horrific development in warfare where small explosions were detonated to collapse each others tunnels, burying men alive and if their tunnels did meet underground then hand to hand fighting would ensue, there would only be one victor!
By 15th April, the British explosives were in place. Between 500lbs and 2700lbs of explosives were used in each chamber, packed with sandbags to force the explosion forward. At 1900 hours, Saturday 17th April, they were blown. The German trenched above were shattered and the 150 or so men within them killed or buried alive. The hilltop was blown apart! Instantly the 1st Queens Own (Royal West Kent Regiment) and the 2nd Kings own Scottish Borderers swept up the hill meeting trivial resistance from the few surviving Germans and the dug in. The Germans retaliated with instant shell fire and counter-attacked the following morning (Sunday) but were beaten off. The British reinforced with Motorcycle machine Gun Units and a much heavier attack at 0700 hours was also repulsed. The struggle continued for days, both sides throwing fresh Troops at each other with heavier and heavier artillery fire. Finally on 21st April, the fighting eased and the Germans were forced to recognise that the position was lost. More than 5000 dead littered the demolished hill top. Hill 60 was retaken by the Germans following a series of gas attacks from 1 to 5 May. At dawn on 7 May, the British tried to retake the Hill and attacked with two companies of infantry and attached bombers using hand grenades, all of whom were killed or captured. Mining continued in to 1916, these were maintained and then detonated on 7 June 1917, 450 tonnes (450 t) of explosives, were detonated under the German lines. The blasts created one of the largest explosions in history, reportedly heard in London and Dublin, demolishing a large part of the hill and killing approximately 10,000 German soldiers.