170th Tunnelling Company
170th Tunnelling Company was a Royal Engineers unit that conducted offensive and defensive underground warfare on the Western Front during the First World War.
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Overview
The 170th Tunnelling Company was a specialist unit of the British Army's Corps of Royal Engineers formed during the First World War for underground operations on the Western Front. Rather than operating as a commercial brand, it was a military engineering company whose work included mining beneath enemy trenches, counter-mining, tunnel construction, underground demolition, and the creation of protected subterranean facilities. Its activities formed part of the British response to the extensive German mining system that confronted the British Expeditionary Force in France and Belgium from late 1914 onward. The company was created in February 1915, during the rapid expansion of British tunnelling capabilities. The scheme for dedicated tunnelling companies had been formally approved by the War Office on 19 February 1915 following discussions involving Engineer-in-Chief Brigadier George Fowke and mining specialist John Norton-Griffiths. Norton-Griffiths helped organize the first group of companies, numbered 170 through 177, and drew heavily on men with practical experience in coal mining, sewer construction, and clay-kicking. The 170th included civilian sewer workers from Manchester associated with Norton-Griffiths's business, together with former miners transferred from infantry formations including the 8th Battalion of the South Wales Borderers, the 11th Battalion of the Welsh Regiment, and the 8th Battalion of the South Staffordshire Regiment. Its personnel therefore combined military engineering training with specialist underground skills, particularly those developed in the South Wales coalfield and urban sewer networks. Initially attached to the 11th Field Company of the Royal Engineers, the unit was sent almost immediately to Givenchy to counter German underground activity. It was later deployed near Cuinchy and the La Bassée Canal, where British and German miners competed to detect, disrupt, and destroy one another's galleries. The company's most extensively documented operation took place around the Hohenzollern Redoubt during and after the Battle of Loos. Beginning a new mining effort there on 14 December 1915, the company sank shafts and constructed deep galleries through the chalk. Sections of the 180th Tunnelling Company were temporarily attached to assist with the work. By late February 1916, the 170th had driven galleries approximately 49 to 61 metres below ground and brought them close to German front-line positions and existing German workings. Four mines were prepared beneath the German gallery system. On 2 March 1916, the charges were detonated in support of an infantry attack by the 12th Division. The explosions created several large craters, which became contested tactical positions. The company subsequently took part in the destruction of German mine entrances and galleries and continued underground operations during a prolonged period of crater fighting, repeated mine explosions, infantry attacks, and severe winter weather. Its work helped reduce the immediate threat posed by German mining in that sector, although underground warfare continued throughout the area. From May 1916 until the end of the war, the 170th Tunnelling Company served under the Reserve Army, later redesignated the Fifth Army. Its duties during this period continued to involve underground engineering and mine warfare rather than conventional infantry operations. In April 1918, during the German Spring Offensive and the wider fighting around Béthune, members of the company helped combat a major fire. The available historical record emphasizes the unit's operational engineering work and does not identify a separate consumer-facing identity, commercial ownership structure, or postwar successor. The company is remembered as part of the Royal Engineers' specialized tunnelling force and of the broader development of organized military mining during the First World War.
History
The formation of the 170th Tunnelling Company reflected the British Army's urgent need to develop a systematic response to German underground warfare. By January 1915, British commanders on the Western Front had recognized that German mining was being conducted according to planned systems rather than as isolated local efforts. The British Expeditionary Force initially lacked both suitable counter-mining doctrine and specialized underground listening equipment. Field Marshal Sir John French and Secretary of State for War Lord Kitchener therefore supported an investigation into the creation of dedicated British mining units. Brigadier George Fowke, the BEF's Engineer-in-Chief, consulted the mining specialist John Norton-Griffiths, whose experience in civil tunnelling and workforce organization proved important to the new scheme. The War Office formally approved the tunnelling-company system on 19 February 1915. Norton-Griffiths arranged for companies numbered 170 to 177 to be made ready during the same period. These early units were staffed by regular Royal Engineers and by civilian miners and underground workers recruited or transferred for their specialist knowledge. A typical early company had five officers and 269 sappers, with infantry personnel attached when operational conditions required additional manpower. The 170th was assembled from Manchester sewer workers familiar with clay-kicking, as well as experienced miners drawn from military units. A substantial South Welsh mining presence linked the company to the wider recruitment of coalfield workers for Royal Engineers tunnelling units. The unit was initially attached to the 11th Field Company, Royal Engineers, and was dispatched to Givenchy soon after formation. Its first task was to counter German mining in that sector. It was relieved there by the 176th Tunnelling Company in June 1915 and then moved to the Cuinchy area under the 2nd Division. Around Cuinchy and the Brick Stacks position near the La Bassée Canal, it operated alongside other tunnelling companies, including the 173rd and 176th. These operations involved listening for enemy excavation, driving galleries, placing charges, and preventing German miners from reaching British positions. The company's principal recorded campaign was at the Hohenzollern Redoubt near Loos-en-Gohelle. The unit had already participated in the opening of the Battle of Loos, from 25 September to 14 October 1915, when it exploded two mines at the redoubt. After other tunnelling personnel took over in October, the 170th returned to the area on 14 December to begin a more ambitious mining operation. The ground presented difficult engineering conditions: a clay layer over chalk made it possible for opposing sides to work at different depths and with varying levels of concealment. The company began by sinking six shafts, while two sections of the 180th Tunnelling Company were attached to sink three more. Work in the clay helped conceal the principal British effort in the chalk below. During the winter, British tunnellers extended deep galleries to a point close to the German front line and beneath shallower German workings. By late February 1916, the galleries were approximately 49 to 61 metres deep and had reached within roughly 9 metres of the German trenches. Four charges were placed. The recorded loads included ammonal, blastine, and a smaller fourth mine. The operation was coordinated with an infantry attack planned by the 12th Division for 2 March. At 5:45 p.m. the mines were fired, producing some of the largest British underground explosions up to that point in the war. The resulting craters were occupied during the infantry advance, and the company also destroyed German entrances discovered in the Triangle Crater. The operation did not end the fighting. German forces retook Triangle Crater on 4 March, and further combat occurred around the crater lips during snow and extreme cold. The 170th eventually entered the German gallery system from a British tunnel and demolished it on 12 March, reducing the likelihood of an immediate German mining attack. German miners then developed new galleries through the clay layer, while both sides continued to detonate mines and launch infantry attacks to consolidate or seize crater positions. British mines were fired repeatedly through March and April, as were German mines, and each explosion altered the local defensive ground. From May 1916 until the Armistice, the company was assigned to the Reserve Army, later known as the Fifth Army. Its work remained part of the broader British underground war, which included offensive mining, counter-mining, tunnel maintenance, and the construction of subways, dugouts, signal chambers, medical facilities, cable trenches, and other protected spaces. In April 1918, during the fighting around Béthune, members of the company helped tackle a large fire. The available sources do not provide a complete postwar administrative history or clearly state the date on which the company ceased to exist. Its wartime record nevertheless illustrates the importance of skilled civilian miners and civil-engineering workers in the British Army's adaptation to industrialized trench warfare.
- 1918
Fire-fighting at Béthune
[1]In April, personnel of the company helped fight a major fire during operations around Béthune.
- 1916
Hohenzollern mine explosions
[1]Four mines were detonated on 2 March in support of a 12th Division attack, creating large craters and disrupting German underground positions.
- 1916
Destruction of German gallery system
[1]On 12 March, the company reached and demolished German galleries from a British tunnel.
- 1916
Transfer to Reserve Army
[1]From May, the company was assigned to the Reserve Army, later redesignated the Fifth Army.
- 1915
Formation of the tunnelling-company system
[1]The War Office approved dedicated British tunnelling companies on 19 February 1915 after German mining made specialized underground warfare necessary.
- 1915
170th Tunnelling Company formed
[1]The company was formed in February and initially attached to the 11th Field Company of the Royal Engineers.
- 1915
Deployment to Givenchy
[1]The newly formed unit was sent to Givenchy to conduct counter-mining against German underground operations.
- 1915
Operations near Cuinchy
[1]After leaving Givenchy, the company operated near Cuinchy and the La Bassée Canal under the 2nd Division.
- 1915
Mines at Hohenzollern Redoubt
[1]The company fired two mines during the opening of the Battle of Loos at the Hohenzollern Redoubt.
- 1915
Renewed Hohenzollern mining operation
[1]On 14 December, the company began a new offensive mining project at Hohenzollern Redoubt and started sinking multiple shafts.
Products and positioning
A specialist British military engineering unit focused on underground warfare, mine operations, and subterranean construction during the First World War.
Military engineering · 1915
Offensive mining
The company excavated deep galleries beneath enemy positions and placed explosive charges intended to destroy trenches, galleries, observation points, and other defensive works. Its best-known offensive mining operation was conducted at the Hohenzollern Redoubt in 1915–1916.
Underground warfare · 1915
Counter-mining
Counter-mining involved detecting German tunnelling, driving interception galleries, destroying enemy entrances, and neutralizing underground systems before they could be used to attack British lines.
Military infrastructure · 1915
Subterranean military construction
Royal Engineers tunnelling companies also constructed and maintained underground shelters, subways, cable routes, signal chambers, medical spaces, and other protected facilities needed in trench warfare.
Marketing campaigns
- 1916Hohenzollern Redoubt crater campaign
France · Western Front
The company constructed deep galleries, planted four mines, and detonated them on 2 March in coordination with a 12th Division infantry attack. It then participated in fighting and engineering work around the resulting craters and German galleries.
Outcome. The company destroyed a German gallery system on 12 March, although crater fighting and reciprocal mining continued through March and April.
- 1915Givenchy counter-mining operations
France · Western Front
Immediately after formation, the company was sent to Givenchy to oppose German mining activity and help protect British defensive positions.
Outcome. The company was relieved by the 176th Tunnelling Company in June 1915.
- 1915Cuinchy and La Bassée Canal operations
France · Western Front
The company worked near Cuinchy and the Brick Stacks position against German underground activity in an area controlled operationally by the 2nd Division.
Outcome. The operation formed part of the continuing British counter-mining effort around the La Bassée Canal.
- 1915Battle of Loos mine attack
France · Western Front
At the opening of the Battle of Loos, the company fired two mines beneath the Hohenzollern Redoubt in support of the British assault.
Outcome. The company later returned to the sector for an extended mining and counter-mining campaign.
Sources2 sources
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