Underground Warfare 1914-1918

by Simon Jones

  The two large mines were heavily overcharged and were designed to throw debris over the adjacent German positions, as well as create lips 15ft high. At the moment of detonation, the dust thrown up by these mines would screen the village from observation and prevent mutual support. The lips would then serve the same purpose, provided the British reached them first.

  The Division attacking La Boisselle was the 34th, while to the north the 8th attacked Ovillers. The mines were blown two minutes before zero hour rather than the ten-minute delay of the Hawthorn mine. The initial operation orders issued on 21 June by 34th Division indicated that both La Boisselle mines were to be blown at zero hour. These were subsequently amended so that the Lochnagar mine was to be blown at two minutes before zero and the Y Sap mine at zero, then that both should be blown at two minutes before.22 The timing of the mines was not only concerned with the danger of falling debris, but also with the requirement by 34th Division that the first waves of attackers should rise to the attack no more than 200yds from the German front line, to obtain maximum benefit from the British barrage before it lifted to the next target.

  The Y Sap Mine crater. This overcharged mine at La Boisselle threw up high lips supposed to prevent enfilade fire. This drawing appears in The Work of the Royal Engineers in the European War, 1914–19, Military Mining, 1922, wrongly captioned as the Hawthorn Crater.

  Hance, however, believed that the Y Sap mine should have been blown before the attack and an attempt be made to narrow the very wide no man’s land north of La Boisselle, which was up to 650yds wide. This attack, by 34th and 8th Divisions, was across the wide marshy expanse of Mash Valley towards the village of Ovillers. He thought that destroying the Y Sap would enable the British to advance their front line prior to the attack. He was convinced that the attacking infantry would never get across no man’s land:

  No doubt it was hoped that the barrage then coming down would enable them to do this, but I never had any faith in it. For hours, if not days, before zero I could have blown up the Y sap any time I liked, and I, accordingly, saw the Corps Commander, asking for permission to do so. Sir William Pulteney, whilst agreeing that the destruction of the Y sap would save life locally, was of opinion that the explosion of such a great mine would have warned the Germans for five miles North and South that the attack was imminent, and caused every German machine gunner for 10 miles to be on the qui vive. In my humble opinion they would be in any case, and what if the mine had been blown two days before? However, having put forward my view, and having been overruled by the Corps Commander, with all his infinitely wider knowledge of the issues at stake, and the possibilities of success on the Front involved, I could only abide by his decision, but, personally, I have never ceased to regret it. (Captain Henry M. Hance, OC 179 Tunnelling Company)23

  In fact the Germans knew that the Y Sap was undermined and were forced to evacuate the position: nevertheless, their whole front line north of La Boisselle still effectively enfiladed the British advance.

  The infantry attacking at the Y Sap mine were led by the 20th and 23rd Northumberland Fusiliers. The mine dealt only with the sap projecting into no man’s land: the German front line to their front right, running parallel to the Albert to Bapaume road and backed by the defended village, was untouched by it. They were also subject to fire from the village of Ovillers to their left. Immediately they left their trenches, machine-gun fire came from both these positions and the two leading battalions were almost annihilated before they reached the German front line.24 The 8th Division suffered equally badly, although Hance claimed that his mine created a screen from fire from the north:

  Such loss as was incurred by fire from this point was suffered before the mine was fired. Thereafter the infantry were able to approach his trenches on the south of the crater protected from fire by the lips formed.25

  The 34th Division did not attack across the crater field of the Glory Hole owing to the impassable nature of the terrain, comprising wholly of craters filled with barbed wire and steel stakes. There was a great danger, however, from flanking fire from the village against the infantry attacking either side.

  Battalions were to attack either side of the vast Lochnagar mine. Harvey described the impact of the mine on the Germans:

  We reckoned we closed in 9 deep dug-outs, each with an officer and 35 men – for prisoners were taken from the next dug-out, they were all marched out and the officer said there were 9 other dug-outs with the same numbers of inhabitants as his, i.e. 9 x 1 officer and 35 men – 9 officers and 315 men.26

  He claimed that as a result of the mine, ‘our troops went over with few casualties.’ This was true only of the 102nd Brigade on the left, the 21st Northumberland Fusiliers followed by the 22nd, who succeeded in overrunning the trenches of the Schwaben Höhe. They then continued across the next two lines of trenches before being halted by the failure of the 101st Brigade to the right of the mine.27 The task of this Brigade was more difficult. They had to advance up Sausage Valley, where the German line was drawn back so that they were overlooked on both sides by German trenches. No man’s land was up to 500yds wide and so, on the morning of 1 July, the attacking battalions assembled in no man’s land ready to advance. On the right of the crater, however, the 10th Lincolns were ordered to assemble further back to avoid debris from the mine, evacuating a small salient called the Nose. This caused them to begin their attack some way behind the 15th Royal Scots on their right. When the plan of 101st Brigade was presented to the battalion commanders on about 27 June, the commander of 15th Royal Scots, Lieutenant Colonel A.G.B Urmston, argued strongly that the two battalions should advance in line, otherwise the German fire would be concentrated on each battalion in turn. He offered to change places with the Lincolns and take the risk of his battalion being hit by debris, which he believed was preferable to the damage caused by German machine guns firing from the village of La Boisselle to their left and Sausage Valley in front. The Brigade commander, however, told him that the plan could not be changed.

  Hance reported the impact of the Lochnagar mine:

  The mine was fired at -2 minutes on Z day, and was wholly successful. An enormous crater was formed, extending considerably behind the enemy trench, which, with its occupants and machine guns etc, was entirely destroyed for a considerable length, as well as all his dug-outs for a considerable distance beyond the actual crater being entirely closed, and large portions of his trench being buried. There can be no doubt that the mine generally caused him considerable loss, and by the violence of the shock to his garrison, and the shelter afforded by the lips of the crater itself, enabled our attacking infantry to reach his trenches here, and to pass over them in the first assault, with comparatively light loss. Such loss as was incurred must have been caused by fire from his flank.28

  Devastating as it was, the effects of the mine were, as ever, very local and dealt only with the left shoulder of the Schwaben Höhe position. It also possibly hindered the attackers by disrupting the rapid advance that was vital to stay behind the barrage. The 10th Lincolns were to advance at 7.30 like the other battalions but, because of having to withdraw from the mine danger area, they had further to advance. Within two minutes of zero, before they had crossed their own front line, machine-gun fire raked them and the 10th Suffolks following. Colonel Urmston witnessed the leading companies going forward:

  I could see the blowing up of the mine in front of 10th Lincolns had no effect whatsoever on the German defenders, but utterly ruined our advance, and also re-acted by leaving right flank of 102nd Brigade ‘in the air’ as well.29

  La Boisselle was only captured by the British on 4 July. The attack failed on 1 July because the artillery preparation had been inadequate to deal with the fire that the Germans could bring on the attacking troops from this very powerful position. The failure to capture the village of La Boisselle early in the attack meant that fire from this position had a very bad effect on troops both north and south of the village. The two mines eliminated only a
very small part of this fire.

  The Germans held the village of Fricourt with, to the east, the mining sector of the Tambour, worked by 178 Tunnelling Company, and to the south Bois Français, worked by 174. The British 18th Division held this front in the autumn and winter of 1915. Its commander was impressed by the skill and bravery of the tunnellers, but sceptical of the real value of the mining activity. He wrote to his wife in early September after the first two weeks in the trenches:

  The most awkward and nasty job has undoubtedly been the German underground mining. The Berkshires, Queens and Buffs have each had one or more mines blown up in front of their trenches, and the Buffs had one platoon with about 15 casualties from the explosion. They behaved wonderfully well and when I went to see the company concerned that evening (1st Sept) they were all as cheerful as possible, in spite of the fact that in front of the Buffs two craters were formed which blew up over 50 yards of their front parapets.

  The ‘craters’ are 30 feet deep & some parts of their sides are perpendicular. The bottoms, in this weather, are a jumble of soft mud and destroyed wire entanglements. They form a row of formidable obstacles between our own and the German parapets (which are in places only 15 to 25 yards apart). We also have blown up three mines from a depth of 50 feet below the surface, but I honestly do not see how either we or the Germans have bettered our situations after months of mining effort!!

  The Germans of course started first. We inherited the situation from the French who had allowed the Germans to get the upper hand, or rather lower-hand of them: and we are consequently, from a mining point of view, somewhat handicapped. Digging down shafts 50 feet deep and running horizontal ‘galleries’ for 100 to 300 feet from them is no light labour, and I grudge the useless but inevitable work. It’s very exciting for the miners underground who are often only 10 feet apart – when the question arises which shall blow 100,000 tons of earth first into the air? On the face of it the amusement seems senseless, but those concerned (500 men one way or another, here) are very keen indeed on their job – so are the R.E. officers of the mining companies. (Major General F.I. Maxse)30

  At the beginning of October Norton Griffiths advocated the use of poison gas to deal with the Bois Français sector (referring to the head of the British gas warfare troops Colonel C.H. Foulkes):

  Apparently the real bad position is Bois Francais - & the best remedy … some of ‘Foulkes Cough mixture’ in small doses just to push the Gs back & blow in their shafts – taken once at night time – a Divisional dose.31

  The proposal was not taken up. On 21 December the Germans fired two camouflets within ten minutes of each other at the Tambour. Captain Wellesley, commanding 178 Company, expected the blows and had arranged for the infantry to evacuate the front line. His miners were still working below and those at the face were buried alive while two rescuers were killed by mine gas when they mistakenly took off their breathing apparatus. Immediately after their first mine the Germans heard another explosion and observed a column of flame shoot from the surface, which they assumed was caused by their camouflet detonating a British charge. Altogether 19 were killed and 22 injured and it was probably the worst loss of life suffered by a British tunnelling company in a single incident. Thirty yards of the British front line collapsed and a new line was dug immediately behind it. As retaliation, Wellesley blew two camouflets the following day, using the explosive used for shot blasting, ‘blastine’, perhaps because it was immediately available, which produced far more carbon monoxide than ammonal. The Germans suffered one pioneer gassed or crushed and commented on the great quantities of gas which flooded their system, although Wellesley could not know this at the time. On 26th Wellesley held a conference with the senior staff officer of the 18th Division and Major Danford, who had commanded 174 Company but was now a staff officer for mining with 3rd Army. They decided on a more radical policy, which Danford had already introduced at La Boisselle in October:

  It was felt that this ‘pin pricking’ policy of frequent camouflets did the German galleries and his transversals very little damage and the best method to adopt to force the Germans back was to ‘Blow large’ all round the front face of the Tambour du Clos.32

  This would result in the destruction of the 40ft-deep system taken over from the French and they would need to push forward vigorously the deep level shafts, some of which were already at 100ft and would go still deeper. Wellesley would explode four large mines, which would destroy parts of the British front line. The British would join the lips of the craters to form the new British front line. On 28 and 30 December Wellesley fired four mines of between 8,000 and 10,000lbs, the shake from which was felt three miles away. German galleries were destroyed by the first pair of blows and the men at the face were crushed to death. The second two mines were less successful, with no casualties recorded and a few slightly crushed mining frames. The German mining diary records that the British were heard in all their working faces until ten minutes before the blow, indicating both the energy of the British counterattack and also the deception tactics employed to prevent the Germans suspecting that a blow was imminent.33

  The German miners at the Tambour, the 104th Pioneers, responded when the British blows destroyed their shallow galleries by developing a new deeper system. They dug six chambers behind the front line 20-30ft down, from which they drove inclined shafts running to 100ft. They linked these with a transversal along the whole of their front line and every 80 to 90ft ran out attack galleries towards the British. This was taken over in April by the Bavarian Pioneers and by June 1916 was a powerful underground complex. The system was provided throughout with electric light, powered by a generating station in Fricourt village. Ventilation was provided by centrifugal fans, two of which were electrical, the remainder hand powered. They placed electrical microphones in all the chambers at the ends of the galleries, which were monitored in a central listening station.34 The British were not able to defeat this powerful system. Wellesley had electrical power for pumping water and hoisting spoil and an Ingersoll Rand compressor, which could be used for ventilation as well as for powering drills. His galleries were deeper than the Germans’ but suffered from water because, it was thought, the water more readily percolated down from surface craters and through shattered ground.

  At the end of April the Germans blew two mines at the north end of the Tambour and used incessant mortar bombardment to destroy two of the British shaft entrances and greatly hinder the work underground. They then raided the British trenches in an unsuccessful attempt to destroy the British shafts.

  A Bavarian mine gallery, Stollen 1a, at Bois Français south-east of Fricourt. In this case a vertical shaft sunk from a mined dugout was used to get to the necessary depth, although inclines were favoured by both sides as haulage of spoil was simplified. The gallery ends in a chamber 36m beneath the crater field in no man’s land. Started 68m from the German front line, very large charges could be blown from the end of the gallery without damage to the shaft. From Lehmann, Das K B Pionier=Regiment.

  For the British offensive on 1 July no attacks were made across the crater fields of the Tambour or Bois Français. The German positions on the surface around Fricourt were extremely strong and the village itself was like a fortress. As with 179 Company at La Boisselle, 178 Company was unable to place mines under the village itself. Instead, 178 placed three mines 90ft beneath the Tambour position, increasing in size from north to south, of 9,000, 15,000 and 25,000lbs. These were to form overlapping craters along the whole position, burying the German front line, collapsing dugouts and blocking enfilade fire against the 21st Division attacking north of the Tambour. The mines were also detonated two minutes before zero, at 7.28am, but the larger mine failed to explode and was found to have become damp.35 The shock effect of the mines may have protected the first two companies of the 10th West Yorkshire Regiment, which attacked immediately to the north of the Tambour, but when the second two crossed no man’s land German machine gunners opened a devastating fi
re. The worst machine-gun fire came from the northern edge of the Tambour and continued in action for most of the morning. The machine gunners had survived the mines and may well have used the lips to gain a better field of fire. The two companies were ‘practically annihilated and lay shot down in their waves’,36 the battalion suffering 710 casualties, the worst of any on 1 July 1916. The failure of the largest and most southerly mine to detonate will have had some impact on the ability of the Germans to defend, and meant that the 7th Division to the south also suffered from enfilade fire.

  Two gaps in the British 7th Division attack were left south of Fricourt owing to the mine craters in no man’s land, at Bois Français and Kiel Trench. A series of 500lb mines were blown in the latter area but the gaps in the attack increased losses to the attacker. Despite the very heavy casualties of the assaulting troops, advances on either side of the village rendered the German hold untenable and they withdrew during the night. Mining cannot be said to have made a major contribution to the fall of Fricourt and its legacy in the form of bands of cratered and impassable no man’s land favoured the defenders.