The 171st Tunnelling Company was one of the tunnelling companies of the Royal Engineers created by the British Army during World War I. The tunnelling units were occupied in offensive and defensive mining involving the placing and maintaining of mines under enemy lines, as well as other underground work such as the construction of deep dugouts for troop accommodation, the digging of subways, saps (a narrow trench dug to approach enemy trenches), cable trenches and underground chambers for signals and medical services.The Tunnelling Companies RE , access date 25 April 2015
Background
By January 1915 it had become evident to the BEF at the Western Front that the Germans were mining to a planned system. As the British had failed to develop suitable counter-tactics or underground listening devices before the war, field marshals French and Kitchener agreed to investigate the suitability of forming British mining units. 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.
Norton-Griffiths ensured that tunnelling companies numbers 170 to 177 were ready for deployment in mid-February 1915.Watson & Rinaldi, p. 49. In the spring of that year, there was constant underground fighting in the Ypres Salient at Hooge, Hill 60, Railway Wood, Sanctuary Wood, St Eloi and The Bluff which required the deployment of new drafts of tunnellers for several months after the formation of the first eight companies. The lack of suitably experienced men led to some tunnelling companies starting work later than others. The number of units available to the BEF was also restricted by the need to provide effective counter-measures to the German mining activities.Peter Barton/Peter Doyle/Johan Vandewalle, Beneath Flanders Fields - The Tunnellers' War 1914-1918, Staplehurst (Spellmount) (978-1862272378) p. 165. To make the tunnels safer and quicker to deploy, the British Army enlisted experienced coal miners, many outside their nominal recruitment policy. The first nine companies, numbers 170 to 178, were each commanded by a regular Royal Engineers officer. 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. 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. Rice, and the appointment of an 'Inspector of Mines' at the GHQ Saint-Omer office of the Engineer-in-Chief. A second group of tunnelling companies were formed from Welsh miners from the 1st and 3rd Battalions of the Monmouthshire Regiment, who were attached to the 1st Northumberland Field Company of the Royal Engineers, which was a Territorial unit. The formation of twelve new tunnelling companies, between July and October 1915, helped to bring more men into action in other parts of the Western Front.
Most tunnelling companies were formed under Norton-Griffiths' leadership during 1915, and one more was added in 1916. On 10 September 1915, the British government sent an appeal to Canada, South Africa, Australia and New Zealand to raise tunnelling companies in the Dominions of the British Empire. On 17 September, New Zealand became the first Dominion to agree the formation of a tunnelling unit. The New Zealand Tunnelling Company arrived at Plymouth on 3 February 1916 and was deployed to the Western Front in northern France.Anthony Byledbal, "New Zealand Tunnelling Company: Chronology" (online ), access date 5 July 2015 A Canadian unit was formed from men on the battlefield, plus two other companies trained in Canada and then shipped to France. Three Australian tunnelling companies were formed by March 1916, resulting in 30 tunnelling companies of the Royal Engineers being available by the summer of 1916.
Unit history Formation 171st Tunnelling Company was formed between February and March 1915 of a small number of specially enlisted miners, with troops selected from the Monmouthshire Siege Company of Royal Engineers. 171st Tunnelling Company thus included a significant number of miners from South Wales, as did the 184th, 170th, 172nd, 253rd and 254th Tunnelling Company.Ritchie Wood, Miners at War 1914-1919: South Wales Miners in the Tunneling Companies on the Western Front, Wolverhampton Military Studies, Solihull (Helion and Company) 2016, .
From its formation until the end of the war the company served under Second Army in the Ypres Salient.Watson & Rinaldi, p. 20.
Hill 60/Messines
171st Tunnelling Company was first employed in March 1915 in the Hill 60/Bluff areas at Ypres. The Germans held the top of Hill 60 from 16 December 1914 to 17 April 1915, when it was captured briefly by the British 5th Division after the explosion of five mines under the German lines by the Royal Engineers. The early underground war in the area had involved both the 171st and 172nd Tunnelling Company.
In July 1915, 171st Tunnelling Company moved to Ploegsteert and commenced mining operations near St Yves at the southern end of the Messines ridge. The four deep mines at St Yves, charged with a combined load of of ammonal, formed part of the mine galleries that were dug by the British 171st, 175th, 250th, 1st Canadian, 3rd Canadian and 1st Australian Tunnelling companies as part of the prelude to the Battle of Messines (7–14 June 1917), while the British 183rd, 2nd Canadian and 2nd Australian Tunnelling companies built underground shelters in the Second Army area.
In December 1915, 171st Tunnelling Company began work on the deep mine at Trench 127 at St Yves. The mine consisted of two chambers (Trench 127 Left, Right) with a shared gallery. The name indicates the British lines where the initial shaft was dug, not where the mine was placed under the German positions. The shaft was completed to a depth of within four weeks, however after driving a gallery the Royal Engineers faced a sudden inrush of quicksand and a concrete dam had to be constructed. A new attempt was made, and by April 1916 the Trench 127 mine was ready, with the ammonal charges over away from the initial shaft.
At the end of January 1916, 171st Tunnelling Company began mining operations at La Petite Douve Farm. The farm, located next to the road from Messines to Ploegsteert Wood, was enclosed by a German trench system known as ULNA. Also at this point was a junction on the narrow gauge railway system which ran from the forward areas of Messines to the rear areas around Nieuwkerke. This operation was characterized by setbacks. Difficult geology lead to two mines being abandoned before completion, and after a charge of of ammonal had been put in place beneath the farm, the gallery was discovered by a German counter-mining operation on 24 August 1916. Three days later the German miners blew a heavy charge, which shattered about of the main gallery and killed four men engaged in repairs. This camouflet wrecked the British gallery completely and forced the Royal Engineers to abandon the tunnel, which then quickly flooded.
At the end of February 1916, 171st Tunnelling Company began work on the deep mine at Trench 122 at St Yves. The mine consisted of two chambers (Trench 122 Left, Right) with a shared gallery. The name indicates the British lines where the initial shaft was dug, due west of where the crater is today. The area was dominated by a complex of German trenches and by mid-May first charge of of ammonal was in place at Trench 122 Left. Another shaft (Trench 122 Right) was started part way along the original tunnel and after another , a charge of 40,000 lbs of ammonal was placed by the Royal Engineers beneath the ruins of Factory Farm which sat on the German front line.
In April 1916, 171st Tunnelling Company moved to the Spanbroekmolen/Douve sector facing the Messines ridge. At Spanbroekmolen, 171st Tunnelling Company took over from 3rd Canadian Tunnelling Company and extended the work to the German lines, driving the tunnel forward by in seven months until it was beneath the powerful German position. At the end of June 1916 the charge of of ammonal in 1,820 waterproof tins was complete, the largest yet laid by the British. With the mine complete, the British selected two additional objectives to be attacked near Spanbroekmolen, Rag Point and Hop Point, which were and from the main tunnel. A branch was started and inclined down to depth. By mid-February 1917 the branch had been driven and passed the German lines. At that point, the German counter mining activities damaged of the branch gallery and some of the main tunnel. The British decided to abandon the branch gallery because aggressive counter-mining would alert the Germans to the presence of a deep-mining scheme. On 3 March the Germans blew the main tunnel with a heavy charge laid from their Ewald shaft, leaving it beyond repair and resulting in it being cut off for three months. The British started a new gallery alongside the old main tunnel which after cut into the original workings. Mining was greatly hampered by the influx of gas, several miners being overcome by the fumes, but eventually – and only a few hours before the appointed time of detonation at 3:10 a.m. on 7 June 1917 – the ammonal charge was ready again and secured by of tamping with sandbags and a primer charge of of dynamite. The Spanbroekmolen mine exploded 15 seconds late, killing a number of British soldiers from the 36th (Ulster) Division, some of whom are buried at Lone Tree Cemetery nearby.
While employed at Spanbroekmolen, 171st Tunnelling Company also took over work on the nearby deep mines at Kruisstraat. Work there was begun by 250th Tunnelling Company in December 1915, passed to 182nd Tunnelling Company, then to 3rd Canadian Tunnelling Company and 175th Tunnelling Company, which took charge in April 1916. When the gallery reached it was handed over to 171st Tunnelling Company. At a charge of of ammonal was laid and at the end of a small branch of to the right a second charge of was placed under the German front line. This completed the original plan, but it was decided to extend the mining to a position under the German third line. Despite meeting clay and being inundated with water underground which necessitated the digging of a sump, they managed to complete a gallery stretching almost half a mile from the shaft in just two months, and a further charge of of ammonal was placed. This tunnel was the longest of any of the Messines mines. In February 1917, German countermeasures necessitated some repair to one of the chambers and the opportunity was taken to place a further charge of marking a total of four mines, all of which were ready by 9 May 1917.