Mines on the first day of the Somme
The 19 mines on the first day of the Somme comprised a series of underground explosive charges, secretly planted by British tunnelling units beneath the German front lines on the Western Front during the First World War, ready to be detonated in the morning of Saturday 1 July 1916, the first day of the Battle of the Somme. The joint explosion of these mines ranks among the largest artificial non-nuclear explosions.
The tunnelling companies of the Royal Engineers were to make two major contributions to the opening attack of the Battle of the Somme: Firstly, by preparing a number of large and small mines; and secondly, by preparing a series of shallow Russian saps from the British front line into no man's land, which would be opened at and allow the infantry to attack the German positions from a comparatively short distance.
The 19 mines consisted of eight large and eleven small charges deep in the chalky ground which were "overcharged" to throw up high lips for screening and to give advantage to the attackers when they captured the resulting craters. The mines can be grouped into the large mine at Beaumont-Hamel, the charges near La Boisselle, the three large Triple Tambour mines opposite Fricourt, the Bulgar Point and Kasino Point mines, and the nine small charges placed further south. The small charges were to remove local German positions like machine gun posts and were laid from the ends of comparatively shallow tunnels.
Brigadier Sir James Edmonds wrote in 1932 about the mines prepared for the first day of the Somme that "Lack of manpower prevented more being undertaken" and in 2007 Sir Martin Gilbert wrote that although fewer mines than planned had been completed, "... it was a formidable enterprise". When they were fired on 1 July 1916, the Lochnagar and Hawthorn Ridge mines were the largest ever detonated and the sound of the blast was considered the loudest man-made noise in history. Reports suggested that the sound was heard in London and beyond. The mine detonations on the first day of the Somme were surpassed on 7 June 1917 by the mines fired at the start of the Battle of Messines.
Background
1914
French and German military operations began on the Somme in September 1914. After the German advance towards Albert had been brought to a halt at La Boisselle and attempts to resume offensive warfare in October had not been successful, both sides reduced their attacks to local operations or raids and began to fortify their remaining positions with underground works. On 18 December, the French captured La Boisselle's village cemetery at the west end of a German salient and established an advanced post only from the German front line. By 24 December, the French forced the Germans back from the cemetery and the western area of La Boisselle but their advance was stopped a short distance forward at L'îlot de La Boisselle, in front of German trenches protected by barbed wire. Once the location of a farm and a small number of buildings, L'îlot became known as Granathof to the Germans and later as Glory Hole to the British. On Christmas Day 1914, French engineers sank a first mine shaft at La Boisselle. Local but heavy fighting underground also took place in the winter of 1914 and spring of 1915 at Fricourt, Bois Français and Carnoy.1915
From January 1915 to the start of the Battle of the Somme in July 1916, L'îlot de La Boisselle was the scene of fierce underground fighting. Having started mining at La Boisselle shortly after the French, the Bavarian Engineer Regiment 1 continued digging eight galleries towards L'îlot. On 5 January, French sappers were heard digging near a gallery and a camouflet was quickly placed in the gallery and blown, collapsing the French digging and two German galleries in the vicinity. A charge was blown on 12 January, which killed more than forty French soldiers. On the night of three more German mines were sprung close to L'îlot. On the night of a German sapper at La Boisselle inadvertently broke into French gallery, which was found to have been charged with explosives; a group of volunteers took racking minutes to dismantle the charge and cut the firing cables. Between April 1915 and January 1916 alone, sixty-one mines were sprung around L'îlot, some with of explosives.In summer 1915, the French mine workings in the La Boisselle area were taken over by the Royal Engineers as the British moved into the Somme front. Great secrecy was maintained to prevent the discovery of the mines as no continuous front line trench ran through L'îlot de La Boisselle, which was defended by posts near the mine shafts. G. F. Fowke moved the 174th and 183rd Tunnelling Companies into the area, but at first the British did not have enough miners to take over the large number of French shafts; the problem was temporarily solved when the French agreed to leave their engineers at work for several weeks. On 24 July, 174th Tunnelling Company established headquarters at Bray, taking over some 66 shafts at Carnoy, Fricourt, Maricourt and La Boisselle. No man's land just south-west of La Boisselle was very narrow, at one point about wide, and had become pockmarked by many chalk craters. The Germans had also dug defensive transverse tunnels about long, parallel to the front line. To provide the men needed for significant counter-mining operations against the Germans, the British formed the 178th and 179th Tunnelling Companies in August, followed by the 185th and 252nd Tunnelling Companies in October. The 181st Tunnelling Company was also present on the Somme.
The British tunnelling companies dramatically increased the scale of mining operations by extending and deepening the system, first to and ultimately. In August, the French and Germans had been working at a depth of ; the size of their charges had reached. The underground war continued with offensive mining to destroy the opponents' strong points and defensive mining to destroy tunnels, which were long. In addition to their offensive and defensive works, the Royal Engineers also dug deep wells to supply the troops with drinking water. In October, the 179th Tunnelling Company began to sink a series of deep shafts in an attempt to forestall German miners who were approaching beneath the British front line. At W Shaft they went down from to and began to drive two counter-mine tunnels towards the Germans. From the right-hand gallery the sounds of German digging grew steadily louder. On 19 November, 179th Tunnelling Company's commander, Captain Henry Hance, estimated that the Germans were 15 yards away and ordered the mine chamber to be loaded with of explosive. This was completed by midnight from 20–21 November. At 1.30 am on 22 November, the Germans blew their charge, filling the remaining British tunnels with carbon monoxide. Both the right and left tunnels were collapsed, and it was later found that the German blow had detonated the British charge. The wrecked tunnels were gradually re-opened, but about thirty bodies still lie in the tunnels beneath La Boisselle.
Prelude
As part of the Allied preparations for the Battle of the Somme, the British intensified their underground operations in several selected front line sectors. This was particularly the case of the many Russian saps prepared in the various sectors from February 1916. The Royal Engineer mining units involved in preparing the battle were the 174th, 178th, 179th, 181st, 183rd, 185th and 252nd Tunnelling companies.VII Corps
In the northern-most sector of the British front line, which was allocated to VII Corps in front of Gommecourt, no mines were prepared by the Royal Engineers for the offensive on 1 July. The British Army would use the neighbouring villages of Hebuterne and Foncquevillers as bases for the assault on Gommecourt, resulting in a severe defeat for the attacking force.VIII Corps
In the British front sector allocated to VIII Corps at Beaumont-Hamel, 252nd Tunnelling Company dug a large mine, code named H3, at Hawthorn Ridge Redoubt. and prepared twelve Russian saps facing Serre. Near the Hawthorn Ridge Redoubt, three tunnels were excavated under no man's land: The first was a tunnel dug overnight to link to the now famous Sunken Lane 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. The two other tunnels were Russian saps, dug to within of the German front line, ready to be opened at on 1 July, as emplacements for batteries of Stokes mortars. They were called First Avenue and Mary, named after the communications trenches leading into them.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. The tunnellers under the command of Captain Rex Trower dug a gallery for about from the British lines about underground beneath the German position on the crest of the ridge. By the end of May, the mine gallery had been driven, 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. In June the gallery was finished and charged with of ammonal. The VIII Corps commander, Lieutenant-General Aylmer Hunter-Weston, wanted the 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. On 15 June, the Fourth Army headquarters ruled that all mines should be blown no earlier than eight minutes before zero but an unsatisfactory compromise was reached with Hunter-Weston to blow the Hawthorn Ridge Redoubt mine ten minutes before zero hour.
X Corps
In the British front sector allocated to X Corps at Thiepval, no mines were prepared by the Royal Engineers for the offensive on 1 July, although they dug a series of Russian saps into no man's land, ready to be opened at and allow the British infantry to attack the German positions from a comparatively short distance. Russian saps in front of Thiepval were the task of 179th Tunnelling Company, which also prepared such saps further south at Ovillers and La Boisselle. In the X Corps front section allocated to the 36th Division, ten Russian saps were run from the British lines into no-man's land north-east of Thiepval Wood. Each of the ten tunnels housed two mortars.III Corps
In the British front sector allocated to III Corps at La Boisselle, four mines were prepared: Two charges were planted at L'îlot at the end of galleries dug from Inch Street Trench by the 179th Tunnelling Company, intended to wreck German tunnels and create crater lips to block enfilade fire along no man's land. As the Germans in La Boisselle had fortified the cellars of ruined houses, and cratered ground made a direct infantry assault on the village impossible, two further mines, known as Y Sap and Lochnagar after the trenches from which they were dug, were laid on the north-east and the south-east of La Boisselle to assist the attack on either side of the German salient in the village – .The 185th Tunnelling Company started work on the Lochnagar mine on 11 November 1915 and handed the tunnels over to 179th Tunnelling Company in March 1916. A month before the handover, 18 men of the 185th Tunnelling Company were killed on 4 February when the Germans detonated a camouflet near the British three-level mine system, starting from Inch Street, La Boisselle, the deepest level being just above the water table at around. The Lochnagar mine consisted of two chambers with a shared access tunnel. The shaft was sunk in the communication trench called Lochnagar Street. After the Black Watch had arrived at La Boissselle at the end of July 1915, many existing Allied fortifications, originally dug by the French, had been given Scotland-related names. The Lochnagar mine probably had the first deep incline shaft, which sloped to a depth of about – . It was begun behind the British front line and away from the German front line. Starting from the inclined shaft, about below ground, a gallery was driven towards the German lines. For silence, the tunnellers used bayonets with spliced handles and worked barefoot on a floor covered with sandbags. Flints were carefully prised out of the chalk and laid on the floor; if the bayonet was manipulated two-handed, an assistant caught the dislodged material. Spoil was placed in sandbags and passed hand-by-hand, along a row of miners sitting on the floor and stored along the side of the tunnel, later to be used to tamp the charge. When about from the Schwabenhöhe, the tunnel was forked into two branches and the end of each branch was enlarged to form a chamber for the explosives, the chambers being about apart and deep – . When finished, the access tunnel for the Lochnagar mine was and had been excavated at a rate of about per day, until about long, with the galleries beneath the Schwabenhöhe. The mine was loaded with of ammonal, divided in two charges of and. As the chambers were not big enough to hold all the explosive, the tunnels that branched to form the 'Y' were also filled with ammonal. The longer branch was long, the shorter was long. The tunnels did not quite reach the German front line but the blast would dislodge enough material to form a high rim and bury nearby trenches.
The tunnel for the Y Sap mine underneath the German trenches overlooking Mash Valley just north of La Boisselle started in the British front line near where it crossed the D 929 Albert–Bapaume road, but because of German underground defences it could not be dug in a straight line. About were dug into no man's land, before it turned right for about another. About of ammonal was placed in the chamber beneath the Y Sap mine. The Lochnagar and the Y Sap mines were "overcharged" to ensure that large rims were formed from the disturbed ground. Communication tunnels were also dug for use immediately after the first attack but were little used in the end. The mines were laid without interference by German miners but as the explosives were placed, German miners could be heard below Lochnagar and above the Y Sap mine.
XV Corps
In the British front sector allocated to XV Corps at Fricourt, the German positions were extremely strong and the village itself was like a fortress. For this reason, no frontal assault was planned in this area for 1 July as the British infantry would have had to advance across large crater fields. Instead, the tunnellers would place a group of three mines known as Triple Tambour beneath the German Kniewerk stronghold. Local but fierce underground fighting at Fricourt had taken place in the winter of 1914 and spring of 1915, during which the Tambour had been extensively mined. The French had carried out mining operations in the Tambour area when they held this sector of the line and British tunnellers began working there on mines in August 1915. The whole area was a veritable warren of shafts and tunnels which had produced a patchwork of small craters, German trench maps indicating five craters before 1 July 1916. The three Tambour mines were laid by 178th Tunnelling Company. The craters resulting from the explosion of the charges were intended to protect the infantry advance of the 21st Division from German enfilade fire from the village of Fricourt. It was thought the mines could raise a protective "lip" of earth that would obscure the view from the village and the German machine-gun positions but the effort failed. The three Tambour mines were loaded with relatively small charges of, and which were detonated at 7:28 a.m., just before the British infantry advanced; one failed to explode due to damp and is still buried off Fricourt. 178th Tunnelling Company's war diary entry reads "1/7/16 “Z”Day. Mines in G3E, G19A exploded at 7:28 a.m. 2 minutes before Zero. G15b not successful". The site of the mines appears as a small area of cratered ground in the field beyond the Commonwealth War Graves Commission Fricourt New Military Cemetery. The land the craters are on is private property. The two craters on the eastern edge of the craterfield are probably the G3 and G19 mines.In the front sector allocated to XV Corps between Fricourt and Mametz, the Mametz West group of four mines was planted along the German trench lines running east from the heights of Bois Français, located south of Hidden Wood and south-east of Fricourt. The unit in charge was the 174th Tunnelling Company. Underground fighting at Bois Français had already taken place in the winter of 1914 and spring of 1915. Before the summer of 1916, no-man's land south of Bois Français had already witnessed the blowing of at least eight mines, and the area of Kiel and Danube trenches, located some to the east of Bois Français, had also seen extensive underground operations. In October 1915, John Norton-Griffiths had even advocated the use of poison gas to deal with the German resistance in the Bois Français sector, but the proposal was not followed up. As at Fricourt, no frontal assault was planned in this area for 1 July as the British infantry would have had to advance across large crater fields. Instead, the Royal Engineers placed the Mametz West mine group there – three charges at Kiel Trench and one at Danube Trench. The first purpose of these mines was to protect the left of the 7th Division's attack south of Mametz, while the second was to protect the 20th Battalion, Manchester Regiment during their attack on the German lines.
The Mametz East group consisted of four mines in the Mametz sector, all laid by 183rd Tunnelling Company. Bulgar Point, a heavily wired German strong work facing the 1st Battalion South Staffordshire Regiment's attack south-east of Mametz, was mined with of explosives; a sap further west was loaded with a charge in support of the Gordon Highlanders' attack; and two more mines were laid beneath Austrian Trench, on the extreme right of the 7th Division's sphere of action, on the boundary with the front sector allocated to XIII Corps. In addition to placing the four mines, 183rd Tunnelling Company from February 1916 onwards prepared dozens of Russian saps for the attack, which ran from the British front line to the very edge of the German positions. Small charges could be blown from the end of these tunnels and they could then be used to reinforce the captured positions. Four saps were further equipped with Livens Large Gallery Flame Projectors, ready to cover the German front line with liquid fire. In order to protect them from enemy fire, the flame throwers were hauled into the saps just hours before the battle. Two tunnels which housed such weapons – located at Kiel Trench south-west of Mametz and between Carnoy and Kasino Point – were damaged by German shellfire before the attack. The two remaining were put to use from saps immediately left of the mine crater field at Carnoy. In view of the work required, 183rd Tunnelling Company took a calculated risk by stopping its defensive mining activities between Carnoy and Fricourt, which had so far guaranteed the underground safety of the British trenches in that area. By 1 July, the British tunnel network excavated in this sector extended under no man's land.
XIII Corps
Early underground fighting at Carnoy had taken place in the winter of 1914 and spring of 1915. Mine warfare directly in front of Carnoy, near the Carnoy–Montauban road, was conducted by both sides from May 1916. In this southern-most sector of the British front line, which was allocated to XIII Corps, three mines were laid by 183rd Tunnelling Company. Two were to be fired north of Carnoy at 07.27 hours: a charge under a German salient at Kasino Point and a charge on the extreme left flank, intended to collapse German dug outs and destroy machine-gun nests. The third mine in the Carnoy group also held a charge. As in the Mametz East sector, 183rd Tunnelling Company had to stop its defensive mining activities off Carnoy so the work underground could be finished in time. All deep mining was halted, except at Kasino Point where an inclined gallery was built. As the chalk grew harder, the method of softening involved drilling holes with a carpenter's auger, into which the miners poured vinegar. When it was fired, the mine produced a crater with lips in diameter and deep. The miners reported after the attack that the Kasino Point mine had buried three German dugouts and four sniper's posts, and probably a machine-gun emplacement as well. During tunnelling at Kasino Point, the British broke into a German dugout but were able to cover it up before the breach was noticed. Edmonds wrote in 1932 that this incident occurred during the digging of Russian saps rather than the Kasino Point mine. Middlebrook wrote in 1971 that the Kasino Point Salient was between Mametz, Carnoy and Montauban and the mine planted there was one of seven large mines that were due to be detonated on 1 July.Battle: 1 July 1916
The mines were detonated by the Royal Engineers in the morning of Saturday 1 July, the opening day of the Battle of Albert, the name given by the British to the first two weeks of the Battle of the Somme. The British Third and Fourth armies, together with nine corps of the French Sixth Army, would attack the German 2nd Army in an area stretching from Foucaucourt south of the River Somme northwards beyond the River Ancre, to Serre and Gommecourt, beyond. The objective of the attack was to capture the German first and second positions from Serre south to the D 929 Albert–Bapaume road and the first position from the road south to Foucaucourt.The Hawthorn Ridge mine was detonated at. The explosion was filmed by British cinematographer Geoffrey Malins who had his camera set up about away. A frame from the film became one of the iconic photographs of the first day of the battle. As soon as the mine blew, the British heavy artillery bombardment on the German front line lifted and Stokes mortars began a hurricane bombardment on the front trench. British troops rushed the crater where they were engaged by machine-gun and rifle fire from the far lip and the flanks. Three sections of German infantry of the 9th Company were killed in the mine explosion and platoons were trapped in their Unterstände, from which only two sections escaped. The rest of the company in a Stollen survived but the entrances were blocked and the troops inside were not rescued until after the British attack. Despite the shock and disorientation caused by the detonation of the mine, German troops immediately occupied the rear lip of the crater. The Germans also immediately brought down a heavy artillery barrage onto the British trenches. The 2nd Battalion, 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 British soldiers 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 Hawthorn Ridge Redoubt had a serious effect on the VIII Corps operations north of the River Ancre.
Eight minutes after the explosion of the Hawthorn Ridge mine, the Lochnagar mine was detonated at, along with the other mines prepared for the First day of the Somme. The explosion of the Lochnagar mine was initiated by Captain James Young of the 179th Tunnelling Company, who pressed the switches and observed that the firing had been successful. The two charges of the Lochnagar mine obliterated of German fortifications, including nine dugouts and the men inside them. Earth was thrown into the air. Most of the 5th Company of Reserve Infantry Regiment 110 and the trenches nearby were destroyed. The Lochnagar mine lay on the sector assaulted by the Grimsby Chums, a Pals battalion. When the main attack began at the Grimsby Chums occupied the crater and began to fortify the eastern lip, which dominated the vicinity and the advance continued to the Grüne Stellung, where it was stopped by the German 4th Company, which then counter-attacked and forced the British back to the crater.
At Bulgar Point, located east of Mametz in the front sector allocated to XV Corps, the German position was completely destroyed by the detonation of the No 12 mine with of ammonal. Four other British mines in the already cratered area between Mametz and Fricourt also exploded successfully.
Though the mines on the British front were to be blown at , the Kasino Point mine was late, because the officer in charge hesitated when he saw that British troops had left their trenches and begun to advance across no man's land. The German machine-gunners at the point opened fire and inflicted many casualties, so the officer detonated the mine which, instead of exploding upwards, sent debris outwards over wide area, causing casualties among at least four British battalions, as well as obliterating several German machine-gun nests. A witness wrote later
but the late detonation surprised and demoralised the Germans, whose fire diminished and the British swept over the German front trenches, making it the most successful mine detonation of 1 July. Looking back at building the Lochnagar mine, Captain Stanley Bullock of 179th Tunnelling Company described the conditions of the work,
While the British mines on the first day of the Somme were an undoubted success for the tunnellers who had built and maintained them, their value for the advancing infantry was questioned:
The blowing of the Lochnagar and Y Sap mines at 7:28 a.m. was witnessed by pilots who were flying over the battlefield to report back on British troop movements. It had been arranged that continuous overlapping patrols would fly throughout the day. 2nd Lieutenant Cecil Lewis' patrol of 3 Squadron was warned against flying too close to La Boisselle, where two mines were due to go up, but would be able to watch from a safe distance. Flying up and down the line in a Morane Parasol, he watched from above Thiepval, almost two miles from La Boisselle, and later described the early morning scene in his book Sagittarius Rising,
Aftermath
Following the attack on 1 July, there were few mines blown during the Battle of the Somme. In the south of the battlefield, the front line moved on from the mine systems. In other areas, where the British had not gained much ground, schemes for new Russian saps were put in place by 3 July and the miners' sapping efforts intensified with the aim of quadrupling the number of Russian saps for future attacks.At High Wood, the 178th Tunnelling Company drove a mine at just depth, long, which they charged with of ammonal. It was blown thirty seconds before Zero Hour on 3 September 1916. After advancing British infantry had failed to capture the crater permanently, 178th Tunnelling Company reopened the gallery, charged it with another of ammonal and blew the mine again on 9 September. This time the crater was successfully held.
In the north of the battlefield, 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 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, 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.
During the Allied preparations for the Battle of Vimy Ridge the mines fired on the first day of the Somme became the object of strategic considerations. In order to assess the consequences of infantry having to advance across cratered ground after a mining attack, officers from the Canadian Corps visited La Boisselle and Fricourt where the mines had been blown. Their reports and the experience of the Canadians at St Eloi in April 1916 – where mines had so altered and damaged the landscape as to render occupation of the mine craters by the infantry all but impossible –, led to the decision to remove offensive mining from the central sector allocated to the Canadian Corps at Vimy Ridge.
William Orpen, an official war artist, saw the Lochnagar mine crater in 1916 while touring the Somme battlefield, collecting subjects for paintings and described a wilderness of chalk dotted with shrapnel. John Masefield also toured the Somme, while preparing The Old Front Line, in which he also described the area around the Lochnagar Crater as dazzlingly white and painful to look at.
The land around the Lochnagar Crater was eventually purchased by an Englishman, Richard Dunning, to ensure its preservation after he read The Old Front Line and was inspired to buy a section of the former front line. The site attracts about a year and there is an annual memorial service on 1 July, to commemorate the detonation of the mine and the British, French and German war dead.