Underground Warfare 1914-1918

by Simon Jones

  The British attack on St Eloi, 27 March 1916, with British mines numbered 1–6. From Edmonds, Military Operations, France and Belgium, 1916.

  Autumn [1915] arrived and with it came the inevitable rain. Mud was the order of the day. Even in billets at Dickebusch one could not get away from it. Rubber hip boots became standard dress. One’s clothing became saturated with moisture. ‘D1’ heading progressed steadily. It was deep. The blue clay was clean. It was hard. It was dry. It was a place of escape. (Lieutenant F.J. Mulqueen, 172 Tunnelling Company)12

  The Germans, however, had an extensive defensive system and were aggressively mining at the intermediate levels. Mulqueen was in the D1 gallery when the Germans blew a camouflet:

  It is true strange noises were heard there, but that was no cause to worry. Rather the surroundings were a pleasant place in which to listen to them. And then the shock came. It was possibly 3.00 AM. Five of us were in the heading. The gallery heaved first to one side and then to the other. It shuddered. It regained its equilibrium. It shuddered again. It was intact. We picked ourselves up.

  A mine had been fired close by. But where? As we neared the top of the shaft we could feel the earth shake under the impact of heavy bombardment. The noise too became deafening.

  He discovered that the Germans had blown against the F heading on the far east of the position:

  Bewildered members of the infantry working party were standing at the shafthead not knowing quite what to do. They were put to work on the blower. Almost immediately the Corporal arrived with a canary. Together we went below. A sapper followed and was stationed at the foot of the shaft.

  As we approached the face we heard shouting and knew that at least one man was alive. The forward part of the gallery was badly smashed. The mine had been fired from the right and [the gallery] assumed the form of an “X”. There was insufficient oxygen in the air to burn a candle. We were forced to fall back on our flashlights. The canary was O.K. and for the moment at least there was no fear of gas.

  It was the practice in this heading to move the sandbags from the face to the shaft on a small rubber-wheeled truck. The first obstacle encountered was the truck. It was jammed in a lower section of the “X” and had evidently kept the timbers from completely crushing the man who was pushing it. He was wedged on its far side between the splintered timbers, but could talk to us. Further down the heading the shouting continued and then came a most reassuring instruction. “For God’s sake shut your bloody mouth”. Unfortunately the instructions were not followed.

  The Corporal left to get a rope, a jack and some assistance. I surveyed the situation. Care would be necessary. If we pulled the truck out and any of the timbers, the whole gallery might collapse and bury the men who were forward. The man at the truck was cool. He reported there were in all four men in the heading.

  The Corporal returned. The rope was tied to the truck and it was pulled gently and slowly out without bringing down any dirt. The man on the far side helped considerably by giving directions and he was released little the worse for wear. But the following step was not so simple. The next two men were badly squeezed between the timbers. The jack was brought into action. It was difficult to get a good bearing for it. Gradually the splintered timbers were removed. Two hours passed. Our flashlights started to give out. Fortunately the air improved. One man was released. Then the other. The fourth was at the face. The mine had been fired behind him and he was not badly jammed. The man who had done all the shouting was not badly hurt. All four were sent back to headquarters for medical observation and rest.13

  The men in F gallery had a lucky escape. Mulqueen concluded that the Germans had blown prematurely because the noise of the truck had caused them to misjudge the distance. On 2 November, Norton Griffiths reported that Mulqueen was working well at 60ft and proposed that they sink twenty or thirty shafts into the blue clay, about 50–70yds apart, from St Eloi east to the Bluff. On 9 November General Fanshawe, commanding 5th Corps, informed General Plumer that with the assistance of the mines being prepared they might capture the trenches around the Mound. He gave Plumer the option of carrying out the attack when the mines were ready, but put forward the view that it would be better to preserve the mines for a larger attack.14 In November, apprehension was felt for the St Eloi sector after the Germans blew at the Bluff and Fanshawe ordered 172 Company to construct a continuous line of shallow galleries.15 Norton Griffiths, however, was convinced that local commanders, including at Corps level, were not using mining on a large enough scale. On 7 December he reported that 172 Company had three deep shafts at St Eloi, but that their work was held up because instead they had to improve the shallow defensive galleries: ‘the usual 5th Corps attitude’. He continued to press his scheme and encouraged Syme, now commanding in place of Hepburn who had been sent home sick, to put forward a proposal for six more shafts between St Eloi and the Bluff.16 The shaft at F, where the Germans had blown the camouflet, was constructed of timber only, and on 8 February failed under the pressure of wet sand. They enlarged the shaft to take a steel caisson, but the ground behind the timber became so unstable that both the shaft and the dugout housing it began to cave in and the deep gallery had to be abandoned.17

  Operations at the Bluff, for which 172 Company was also responsible, affected those at St Eloi. On 21 January the Germans blew several large mines, which caused work on the shallow mines at St Eloi to be stopped in order to complete the deep scheme as soon as possible.18 Then, on 14 February, the Germans succeeded in capturing the Bluff from the British, also taking prisoner an officer and a number of miners and attached personnel from 172 Company. On 18th Syme was ordered to have two deep offensive mines each from shafts D and H ready by 10 March. He was also to lay defensive charges in the trenches and shafts in case the Germans should attack at St Eloi as they had at the Bluff.19 Norton Griffith learned from Syme that the loss of the Bluff meant that the operation using the mines was now a priority, and also the reason why it was urgent:

  …the St Eloi effort was to be rushed with a view to blowing the deep series in three weeks. It is feared that the 50 [sic] or so miners taken prisoners will be forced to give this deep level scheme away hence the hurry. The intention is to attack after blowing & occupy enemy position round about the Mound.20

  The mines were therefore used in a smaller operation than originally intended because of the danger that the Germans would discover the presence of the deep mines. They were used not simply, as stated in the British Official History, because of General Plumer’s desire to retaliate for the loss of the Bluff, but because of the real danger of the advantage of the deep mines being lost. Plumer ordered that the operation take place as soon as the mines were ready under the Mound and the German front line. Initially set for 10 March, the attack date was put back several times as the miners were hindered by the presence of the Germans as they neared their front line. Mulqueen was posted to command another company on 24 January, after which the St Eloi mines were in the charge of Lieutenant James Douglas:

  Work progressed rapidly and we were nearly half way across before we had our first set back. Enemy noises were reported from the central drive, and listening patrols were able to prove the existence of a German gallery almost immediately overhead, along which footsteps could be followed at various time intervals as far back as our front-line trenches. Lack of active mining noises suggested that a mine had been already laid. It was therefore decided to stop work here and push ahead with the remaining four galleries as fast as possible. (Lieutenant James A. Douglas, 172 Tunnelling Company)21

  The delays with the mines put back the date of the attack and on 24 February Plumer revised it to 15 March. Ultimately six mines were to be used in the operation, of which four from the two deep shafts would be the largest. The first of the mines (H1 or mine No.5) reached its objective on 24 February. Charging with 12,000lbs of ammonal and tamping took another twelve days and it looked unlikely that they would meet the revised date. On 3 March Norton Griffiths compla
ined to the Inspector of Mines that he was concerned that the charging was being carried out too soon, given the danger of the Germans discovering the mines:

  Capt Hill told me the 15th was the date fixed for St. Eloi but they now thought the end of the month instead. Then why charge mine heads so close to front line? Please Sir!22

  On 4th the mine under the Mound reached its objective (D1 or No.3) and charging began, to be completed by 15th. On 18th charging was complete for No.4 (H4). On 25th the four large mines (Nos 2–5) were being tamped:

  Cases were carried up at night, lowered down the shafts and then carried along and stacked by picked men during the day shift. I was personally responsible for laying, priming and subsequently testing the 60 detonators, each of which was inserted into a guncotton primer and then in a waterproof bag of 25lb of Ammonal.23

  There were four central mines, two laid from the shaft D and two from H. The largest (D1), beneath the Mound, contained 31,000lbs of ammonal (Crater 2 on illustration, p100). The other three mines were charged with between 12,000 and 15,000lbs (Craters 2–5). In addition, two smaller mines were laid on the flanks, Plumer having ordered on 24 February that the mine (designated ‘I’ or No.1) on the far west was to be fired with the others. On 10 March, however, the Germans blew a camouflet in this gallery, 330ft from the shaft, killing three men and collapsing the last 20ft. On 24th the Germans were heard so close that 172 Company blew a 100lb camouflet from a borehole 50ft from the face, which badly damaged their own gallery for 20ft. It was impossible to work through the section of damaged tunnel in time for the attack and so a small charge of just 1,800lbs had to be laid 240ft from the shaft, even though this was about 150ft short of the German front line. At a late stage, a shallow 38ft-deep gallery was run out on the opposite flank from the failed deep shaft F. After 200ft, and still 100ft from the German line, this gallery came close to the German defensive gallery and was halted and charged with 600lbs to form mine No.6.24 Thus the two flanking mines (Nos 1 and 6), owing to German defensive mining, were both small charges laid short of the German front line. On 26 March the tamping was completed and GHQ notified 5th Corps that the attack was to take place the next morning at 4.15am.

  The mines were expected to give the attackers, 9th Brigade of the 3rd Division, a great advantage of surprise and shock, but they also complicated the operation. The report of the Hohenzollern attack of 3 March was not yet available, but General Haldane, commanding the 3rd Division, had realized after the loss of the Hooge crater in July 1915, eleven days after his troops had captured it, the difficulty of holding craters. He knew that because the troops would be very heavily bombarded by mortars and howitzers, the craters themselves could not be held.25 As a preliminary study, Haldane and Brigadier General Douglas Smith, commanding the 9th Brigade, went on 4 March to the active mining area at Bray-sur-Somme ‘to assist them in the solution of their problem of occupying ground gained by an explosion of mines’.26 Before the operation, however, Douglas Smith was promoted and his place taken by Lieutenant Colonel H.C. Potter, who had not previously commanded a brigade. The plan was devised by Haldane and the detailed orders drawn up by Potter. Potter issued his preliminary order on 18 March, instructing that parts of the front line should be strutted to prevent them collapsing when the mines were blown, and that parts would need to be evacuated. No advance would be possible for 30 seconds after the explosion of the mines, owing to falling debris. The attackers therefore assembled lying on the ground behind their front line. On 12 March the 2nd Army Controller of Mines, Colonel A.G. Stevenson, had produced a map showing the location and likely size of the craters and the extent to which debris would fall. He estimated that large lumps of clay would fall 500ft from the largest mine and that the danger area might be 700ft.

  Potter issued the Operation Orders on 24th. These were not as detailed or careful as those for the Hohenzollern operation. However, a practice area of trenches was marked out and troops were instructed to rehearse every detail of the attack on this ground.

  The six mines were to be fired simultaneously and watches were to be synchronized to time given by the Brigade Signal office. Two battalions were to attack, the 2nd Royal Fusiliers from the east and the 1st Northumberland Fusiliers from the west. Owing to the four mines blowing in the centre of the position Haldane, with the approval of Plumer, ordered that the two units were to advance on either side and converge in the German third line trenches, about 600ft beyond the craters. There was to be no preliminary bombardment and the attack was to rely on the shock and surprise caused by the mines. The signal for the firing of the mines was to be the first salvo of heavy shells. The two battalions would then assault 30 seconds after the explosion of the mines to achieve the optimum balance between avoiding the falling debris and gaining maximum advantage from the initial chaos caused by the blows. The orders also emphasized the need to defend the captured trenches against German counterattack: ‘Consolidation on both lines must be commenced at once and continued with unceasing energy.’27

  Occupation of the craters themselves was regarded as impossible, as so much German fire would be poured into them, and the line to be captured and defended was to be in front of them.

  A series of communication trenches were to be dug to link the captured positions to the old front line, to enable them to be reinforced and supplied during the heavy German bombardment, which would follow the attack. On the western flank a trench to the small No.1 crater in no man’s land was to be made by blowing a long pipe charge, which had been forced beneath the surface by a hydraulic Barrett jack. This promised to create a trench at the moment of attack.

  At 4.15am, Syme and Lieutenant Birtles pressed the plungers of the exploders (Douglas was in hospital injured). They did not blow the mines simultaneously, but in sequence: first 2 and 3, (D2 and D1), followed by 4 and 5 (H4 and H1), then 1 (I) and finally 6 (F).

  Harvey described the result:

  On firing the mines a mushroom shaped mound appeared over each charge which rose to a height of 40 to 60 feet and then fell outwards releasing a volume of gas and flame and cloud which rushed skywards to a height of 200 to 300ft. There was an earth shake but no roar of explosion.28

  To witnesses ‘it appeared as if a long village was being lifted through flames into the air’ and two miles away, at Hill 60, the trenches rocked and heaved.29

  The Northumberland Fusiliers attacked through a gap with the group of four mines to their left, and the small mine No.1 to their right. The commanding officer reported that the mine blew at 30 seconds after 4.15 and that his men did not wait the 30 seconds but moved off ‘in quick time’, crossing their own parapet with ladders forty seconds before the German barrage landed on it. The first obstacle was the German wire, which was strong and unaffected by the mine explosions, although it did not stop the advance and they were through it before the German artillery began bombarding no man’s land.

  The CO reported that the mines ‘had a great moral effect upon the enemy’ and that they saw the Germans fleeing their trenches 400yds from the westernmost mine.30

  In the east, however, the Royal Fusiliers’ attack fared badly. The intervals between the blows, which appeared to the commanding officer as three distinct explosions, caused the attackers confusion. Unlike the Northumberlands, the Royal Fusiliers did not have an obvious gap between craters to pass through, facing instead Nos 4 and 5, the two eastern of the large mines, which formed an impassable barrier. When mine No.6 exploded on their front left, they mistook it for mine No.5, which caused them to lose direction:

  My instructions were to wait 30 seconds after the explosion before advancing as I understood that there would be practically only one and that all six mines would be fired simultaneously. The officers and men, however, appear to have [been] too eager [and] apparently moved directly after the first explosion with the result that quite a large number of Y Company were over our parapet when No 5 mine [sic] exploded in front of them. Directly the mines went up an enemy machine gun somewhat ne
ar point 85 opened on the parapet where W, X and Y companies were crossing. The fire from this gun was very accurate and caused a large number of casualties amongst the three companies. (Lieutenant Colonel G.G. Ottley, commanding 4th Battalion, Royal Fusiliers)31

  The Royal Fusiliers were not able to move so swiftly, probably because of the mines directly in front of them, and this delay proved fatal. Whereas the Northumberlands avoided the German fire on their trenches and no man’s land by seconds, the Royal Fusiliers were caught by it. The battalion lost forty per cent of its strength almost immediately from machine-gun fire and a shrapnel barrage in no man’s land:

  I regret to have to confess that my battalion failed to take the objective allotted to it. I knew well before I started that if I was to be successful I should have to take the enemy completely by surprise and was counting on reaching the enemy first line unobserved. That the enemy were very much on the alert and expecting an attack was proved by the quickness with which he opened on my parapet with a M.G. and swept the ground over which my companies had to advance with shrapnel before many men had time to even get over my own parapets. (Lieutenant Colonel G.G. Ottley)32

  The new mine craters had so altered the landscape and removed familiar landmarks that the Royal Fusiliers, attacking before dawn, found it impossible to orientate themselves. Mine No.6, as well as causing confusion, was too small and too far from the German trenches to assist them in their advance. They succeeded in occupying the crater made by mine No.6 and an old crater adjacent, mistaking them for the two large mines 4 and 5.