There was no British army mining organisation in 1914, except for a short course for Royal Engineers but after the First Battle of Ypres in 1914, siege warfare and mining began and the British realised that the Field and Siege Companies RE were in too great a demand to provide men for mining.
On 3 December, Lieutenant-General Henry Rawlinson asked for a specialist battalion of sappers and miners and on 28 December the War Office was requested to send 500 clay kickers, civilian specialists in tunnelling through clay.
The British Expeditionary Force (BEF) was ordered to form Brigade Mining Sections with miners and tunnellers already in the army.
In February 1915, it was decided to form eight tunnelling companies from civilians recruited in Britain and transfers from the army.
Another twelve companies were formed later in 1915, one in 1916, a Canadian Tunnelling Company was formed in December 1915, two more arrived in France in March 1916 and a New Zealand and three Australian tunnelling companies arrived in May. Counter-mining by the Tunnelling Companies RE began at St Eloi in the spring of 1915.
Much of the mining in this sector was done by the 177th Tunnelling Company and the 172nd Tunnelling Company.

The Ypres area has a shallow soil layer of loam or sand above waterlogged semi-liquid sand and slurry patches of sand and clay.
Beneath the second layer is a thick seam of blue clay.
The early mining took place above the blue clay which put very heavy pressures of water and wet sand on the underground works.
In August the digging of galleries had begun to be complete by the end of June 1916.
Both sides spent 1915 mining and counter-mining, the British springing 13 mines and 29 camouflets against 20 German mines and 2 camouflets.
In September, Brigadier-General George Fowke the Engineer in Chief, proposed a mining offensive in the blue clay 60–90 ft (18–27 m) underground.
Since the Germans were on the higher ground, galleries could be driven horizontally into the blue clay from shafts about 300–400 ft (91–122 m) back from the front line.
By January 1916, the 172nd Tunnelling Company had sunk shafts into the blue clay and began to dig galleries 80–120 ft (24–37 m) under the German front position.
After the Second Army offensive in the summer of 1916 was postponed, the mining offensive was made even more ambitious with a plan to mine Messines Ridge.
There was no British army mining organisation in 1914, except for a short course for Royal Engineers but after the First Battle of Ypres in 1914, siege warfare and mining began and the British realised that the Field and Siege Companies RE were in too great a demand to provide men for mining. On 3 December, Lieutenant-General Henry Rawlinson asked for a specialist battalion of sappers and miners and on 28 December the War Office was requested to send 500 clay kickers, civilian specialists in tunnelling through clay. The British Expeditionary Force (BEF) was ordered to form Brigade Mining Sections with miners and tunnellers already in the army. In February 1915, it was decided to form eight tunnelling companies from civilians recruited in Britain and transfers from the army. Another twelve companies were formed later in 1915, one in 1916, a Canadian Tunnelling Company was formed in December 1915, two more arrived in France in March 1916 and a New Zealand and three Australian tunnelling companies arrived in May. Counter-mining by the Tunnelling Companies RE began at St Eloi in the spring of 1915. Much of the mining in this sector was done by the 177th Tunnelling Company and the 172nd Tunnelling Company.
The Ypres area has a shallow soil layer of loam or sand above waterlogged semi-liquid sand and slurry patches of sand and clay. Beneath the second layer is a thick seam of blue clay. The early mining took place above the blue clay which put very heavy pressures of water and wet sand on the underground works. In August the digging of galleries had begun to be complete by the end of June 1916. Both sides spent 1915 mining and counter-mining, the British springing 13 mines and 29 camouflets against 20 German mines and 2 camouflets. In September, Brigadier-General George Fowke the Engineer in Chief, proposed a mining offensive in the blue clay 60–90 ft (18–27 m) underground. Since the Germans were on the higher ground, galleries could be driven horizontally into the blue clay from shafts about 300–400 ft (91–122 m) back from the front line. By January 1916, the 172nd Tunnelling Company had sunk shafts into the blue clay and began to dig galleries 80–120 ft (24–37 m) under the German front position. After the Second Army offensive in the summer of 1916 was postponed, the mining offensive was made even more ambitious with a plan to mine Messines Ridge.
Actions of St Eloi Craters