[2] Following consultations between the Engineer-in-Chief of the BEF, Brigadier George Fowke, and the mining specialist John Norton-Griffiths, the War Office formally approved the tunnelling company scheme on 19 February 1915.

[3] To make the tunnels safer and quicker to deploy, the British Army enlisted experienced coal miners, many outside their nominal recruitment policy.

These companies each comprised 5 officers and 269 sappers; they were aided by additional infantrymen who were temporarily attached to the tunnellers as required, which almost doubled their numbers.

[2] The success of the first tunnelling companies formed under Norton-Griffiths' command led to mining being made a separate branch of the Engineer-in-Chief's office under Major-General S.R.

[7][8] Sapper William Hackett was posthumously awarded the Victoria Cross for losing his life in an attempt to help fellow miners when a tunnel collapsed at Shaftesbury Avenue Mine at Givenchy-lès-la-Bassée on 26 June 1916.

Hackett helped three men to safety but refused to leave until the last man, Thomas Collins, 22, of the Swansea Pals (= 14th Battalion, Welsh Regiment), was saved.

On 27 June he wrote: “Abandoned all hope of getting those two chaps out this morning & stopped all rescue work for the condition of the shaft was so bad to endanger the lives of the men working there...That chap Hackett died a hero for he would not leave his injured comrade.”[9] In Givenchy-lès-la-Bassée, the Tunnellers Memorial commemorates the action on 26 June 1916 for which Hackett was awarded the Victoria Cross.