252nd Tunnelling Company

Plan of the H3 mine placed beneath the Hawthorn Ridge Redoubt

The explosion of the H3 mine under Hawthorn Ridge Redoubt I, 1 July 1916 (Photo by Ernest Brooks)

The crater left by the mine fired beneath Hawthorn Ridge Redoubt (IWM Q 1527, November 1916); note shadow of photographer, left foreground

The fields around Beaumont-Hamel after the Battle of the Somme.

In the Somme sector of the Western Front, local but very fierce underground fighting had taken place in the winter of 1914 and spring of 1915 at La Boisselle, Fricourt, Bois Français and Carnoy. Fowke moved the 174th and 183rd Tunnelling Companies there to relieve the French engineers, but the British did not have enough miners to take over the large number of French shafts and the French agreed to leave their engineers at work for several weeks. To provide the tunnellers needed, the British formed the 178th and 179th Tunnelling Companies in August 1915, followed by the 185th and 252nd Tunnelling Companies in October.[7] The 181st Tunnelling Company was also present on the Somme.[4] The tunnelling companies were to make two major contributions to the Allied preparations for the Battle of the Somme (1 July – 18 November 1916) by placing 19 large and small mines beneath the German positions along the front line and by preparing a series of shallow Russian saps from the British front line into no man's land, which would be opened at zero hour and allow the infantry to attack the German positions from a comparatively short distance.[8]

From October 1915 until April 1919 252nd Tunnelling Company served under Third Army.[5][9] After its formation, the company was employed in the Hebuterne-Beaumont-Hamel sector of the battlefield, where it helped prepare the opening of the battle on 1 July 1916 and continued operations throughout the fight.[1] In the north of the battlefield, the unit dug a large mine, code named H3, at Hawthorn Ridge Redoubt[1] and prepared twelve Russian saps[10] facing Serre.[1] Digging the saps required a large force of labour, and by April 1916 the unit had 1,900 infantry attached.[10] Near the Hawthorn Ridge Redoubt at Beaumont-Hamel, 252nd Tunnelling Company excavated three tunnels under no man's land: The first was a 2-by-5-foot (0.61 m × 1.52 m) tunnel dug overnight to link to the now famous Sunken Lane (shown in the film The Battle of the Somme, released in August 1916) with the old British front line, and through which British units moved into position before the attack. In the early hours of 1 July, the 1st Battalion Lancashire Fusiliers would use this tunnel to move up into the "Sunken Lane", the starting position for their attack on Beaumont-Hamel.[11] The two other tunnels were Russian saps, dug to within 30 yards (27 m) of the German front line, ready to be opened at 2:00 a.m. on 1 July, as emplacements for batteries of Stokes mortars.[12] They were called First Avenue and Mary, named after the communications trenches leading into them.[13]

The large H3 mine, located north of First Avenue and Mary, was placed by 252nd Tunnelling Company beneath Hawthorn Ridge Redoubt, the German stronghold on the ridge. Work on H3 began in spring 1916.[13] The tunnellers under the command of Captain Rex Trower[8] dug a gallery for about 1,000 yards (910 m) from the British lines about 57 feet (17 m) underground beneath the German position on the crest of the ridge.[14] By the end of May, the mine gallery had been driven 900 feet (270 m), despite considerable trouble caused by the hard chalk and the number of flints in the face. To preserve silence, the face was softened by the application of water.[13] In June the gallery was finished and charged with 40,000 pounds (18,000 kg) of Ammonal.[15]

The VIII Corps commander, Lieutenant-General Aylmer Hunter-Weston, wanted the Hawthorn Ridge mine to be sprung four hours before zero hour, so that the crater could be captured and consolidated and the alarm on the German side would have died down.[lower-alpha 1] On 15 June 1916, the Fourth Army headquarters ruled that all mines on 1 July should be blown no earlier than eight minutes before zero but an unsatisfactory compromise was reached with Hunter-Weston to blow the Hawthorn Ridge mine ten minutes before zero hour.[14]

A witness to the detonation of the Hawthorn Ridge mine was British cinematographer Geoffrey Malins who was filming the 29th Division attack. He had his camera set up about 0.5-mile (0.80 km) away, trained on the ridge and waiting for the explosion at 7:20 a.m.:

The ground where I stood gave a mighty convulsion. It rocked and swayed. I gripped hold of my tripod to steady myself. Then for all the world like a gigantic sponge, the earth rose high in the air to the height of hundreds of feet. Higher and higher it rose, and with a horrible grinding roar the earth settles back upon itself, leaving in its place a mountain of smoke.

— Geoffrey Malins[17]

The mine completely destroyed the Hawthorn Redoubt, garrisoned by the Reserve Infantry Regiment 119. The unit's regimental recorded that

... there was a terrific explosion which for the moment completely drowned out the thunder of the artillery. A great cloud of smoke rose up from the trenches of No 9 Company, followed by a tremendous shower of stones.... The ground all round was white with the débris of chalk as if it had been snowing and a gigantic crater, over fifty yards in diameter and some sixty feet deep gaped like an open wound in the side of the hill.

— Reserve Infantry Regiment 119 historian[12]

Many Germans were entombed in a large dugout, all four entrances of which were blocked, but they were rescued later in the day. Others were crushed or blown to pieces. Despite the shock and disorientation caused by the detonation of the mine, German troops immediately occupied the rear of lip of the crater. The Germans also immediately brought down a heavy artillery barrage onto the British trenches. The 2nd Royal Fusiliers, crossing no man's land to occupy the crater, came under heavy German rifle and machine-gun fire from either flank and the rear lip. A few of 2nd Royal Fusiliers managed to reach the closest lip of the crater and held on until noon when they were forced out by a German counter-attack. The failure to take the Redoubt had a serious effect on the VIII Corps' operations north of the River Ancre.[18]

After the detonation of the H3 mine at Hawthorn Ridge Redoubt on 1 July, 252nd Tunnelling Company on 4 July began work on a second mine, loaded with 14,000 kilograms (30,000 lb) of ammonal, which was placed beneath the crater of the first explosion. This new mine was fired to signal Zero Hour at the start of the Battle of the Ancre on 13 November 1916,[19] when a successful British attack took the village of Beaumont-Hamel. The crater visible on Hawthorn Ridge is therefore actually a double crater, lined today with trees and thick undergrowth, but not filled with water. The site affords good views of the location of the German positions.[20]

Map of chalk areas in northern France

In early 1918 half of 252nd Tunnelling Company, arriving from Beaumont-Hamel, was attached to 172nd Tunnelling Company at Vimy.[21]

Vimy was an area of busy underground activity for much of the war. Between October 1915 and April 1917 an estimated 150 French, British and German charges were fired in the 7 kilometres (4.3 mi)-long Vimy sector of the Western Front.[21] The British gallery network beneath Vimy Ridge eventually grew to a length of 12 kilometres (7.5 mi).[21] Other units active around Vimy, particularly in preparation for the Battle of Vimy Ridge (9-12 April 1917) were 172nd, 175th, 176th, 182nd and 185th Tunnelling Companies.[21]

In the German attack of March 1918, the 252nd Tunnelling Company was engaged in defensive mining operations and facing the attack near Boursies.[1]

Once the front had stabilised after the German offensive, British engineers began digging stronger defences. 252nd Tunnelling Company instructed the field companies of 42nd (East Lancashire) Divisional Engineers in digging deep dugouts.[22] In August the Allied Hundred Days Offensive began. During the pursuit after the Second Battle of Bapaume, 42nd (EL) Divisional RE had one field company on front-line work, with Captain Dean's section of 252nd Tunnelling Co attached to search dugouts and roads for booby-traps and mines, clear broken bridges wit explosives, and it also reconnoitred village wells that had been damaged by the retreating Germans.[23]