Underground Warfare 1914-1918
Page 10
This will prove the biggest mine yet exploded. If advantage is taken of the dust! (Bricks, mortar & G.’s) by sending forward attacking party the same time the button is pressed. Not waiting for air to clear it should give ample cover for attacking party. Wiser to get a few men hit with falling bricks or G’s than to get a larger number hit by Machine Guns.5
Rough plan of the Hill 60 mines blown by the British on 17 April 1915. From Military Mining, 1922.
Full surprise was achieved with the mines, which were blown at ten-second intervals, with the artillery only opening fire on the detonation of the first pair. The troops were warned to take cover from the debris, which was thrown 200–300ft high and scattered over 250yds, although a man who looked over the parapet to see the explosions was killed. Those Germans who survived the mines were overwhelmed by the attackers, who took the craters in minutes, and the actual assault cost the British just seven casualties, although the Germans brought very heavy fire onto the captured positions.6
It was realized that Hill 60 alone would be difficult to hold, as the Germans were still in possession of the Caterpillar on the opposite side of the railway cutting. Two days after the capture, Norton Griffiths visited Major William Johnston VC, commanding 172 Tunnelling Company, which had just taken over the Hill 60 sector. Norton Griffiths was constantly looking for opportunities for his Moles and recommended that General Glubb should now attack the Caterpillar:
It is important for the Chief Engineer to know that some 450 feet from the position we now hold there is another Hill which is strongly fortified. It would be easy to mine this from the position we now hold running the Mole along the side of this Hill & then run under them. A good blow & happy results could be obtained here. Johnston keen on this & no time should be lost to get busy at once.7
Norton Griffiths was also becoming aware of the larger potential of mining and the danger of using it merely to deal with positions which were a local annoyance. An officer on Glubb’s staff later described the problem of attempting to hold Hill 60 in isolation:
Probably, as events turned out, it would have been wiser to have raided the defences and retired as originally proposed, forcing the enemy to keep a large garrison on the hill exposed to fire if he wished to retain it. For Hill 60 when recaptured would form a small but pronounced salient, exposed to attack on both sides: officers who knew the ground were of [the] opinion that it could not be held unless the Caterpillar also was taken. (Col. James Edmonds, Staff Officer to Engineer in Chief, GHQ)8
Indeed, the Germans retook Hill 60 using chlorine gas just nineteen days later on 5 May and held it for almost two years.
The mine blows of 17 April apparently came as a surprise to the Germans9 and the difficulty of pushing forward tunnels at Hill 60 led to an attempt by the Experimental Company of the Prussian Guard Pioneers to use an electric tunnelling machine, without success (see Chapter 8). In early October the company was ordered to the sector on either side of the Menin Road to take over mine workings there, including at Hooge. The company took over the Divisional Mining unit and addressed the technical problem of sinking mines in this area, which led to successful blows in June 1916.
On 14 March the Bavarians fired two mines at St Eloi, south of Ypres, capturing the village, trenches including a mine shaft and a 30ft high heap of earth called the Mound by the British and the Lehmhugel by the Germans. After severe fighting the British retook the village, but the Mound remained in German hands.10
British mining was carried out by a Field Company, which ran out two galleries and was relieved on 25 March by 172 Tunnelling Company. Both sides frequently blew small charges against one another and then, exactly a month after taking the Mound, the Germans again fired a mine, creating a very large crater 70ft in diameter. It did not, however, damage a 172 Company shaft sunk from the cellar of a ruined house 50ft away.11 The regular Sapper OC of 172 Company, Johnston VC, disliked mining and obtained a posting in early May, leaving in command a Territorial Captain in the Monmouthshire Regiment, William Clay Hepburn. Hepburn was an experienced mining engineer and colliery agent and the first non-regular Sapper to command a Tunnelling Company.12 Norton Griffiths worked to persuade GHQ that mining engineers should be allowed to command Tunnelling Companies and by the autumn of 1915 this became accepted.
Hepburn placed Lieutenant Hickling in charge at St Eloi and by early July he and Second Lieutenant Gard’ner had charged two large mines of 1,400 and 1,500lbs and a series of smaller charges. The explosive was ammonal, a commercial blasting explosive safer and more powerful than gunpowder, which was to become the standard British mining explosive. Both of the two large charges were just short of the German front line and when blown would damage the parapets and bury the Germans with debris. Hepburn recalled forty-five years afterwards that he had gone to General Glubb, Chief Engineer of the 2nd Army, to ask for artillery support, but was told that there was insufficient ammunition for an attack and that he would have to blow the mines without an accompanying attempt to seize the craters. They blew the charges on 10 July: Hickling fired the right-hand charges and Gard’ner the left, which he described in a letter two days later:
William Clay Hepburn, the first professional mining engineer to command a Tunnelling Company. From Just a Small One, a magazine produced by 172 Tunnelling Company, Christmas 1915. (RE Museum)
We have just fired some very successful mines. We had two main mines and four smaller ones. The net result of it was to destroy an obnoxious ‘snipers’ house’, blow up a section of trench and swamp a lot more of it with earth, and utterly wreck a lot of German attempts at mining. Altogether we fired off about 4,000lb. of explosive. The Germans were scared to death and ran as if the Devil was behind them, so that our machine-guns were able to get in a lot of useful work. We did not attempt to take the trench, though it could have been done without difficulty – the trouble would have been to hold it afterwards.
The sight was magnificent. With our main charges the explosion was terrific. The earth heaved up like a big pimple, broke with a tremendous flame bursting through, and then the earth shot up in the air for 200 feet like an enormous fountain. In one instance one of our smaller charges exploded a counter-charge in a German gallery which we knew to be alongside of us. We knew we had to take prompt action, and were putting forth every effort to get our main charges completed and ready for firing. The débris was scattered over a tremendous area, and we had to crouch behind parapets to protect ourselves. As the craters were about 100 yards away, you may imagine what it was like in the German trenches. The earth rocked like a ship at sea, and it is reported that one man was actually sick!
The men in our trenches were in great glee, all up on the firing-step of the parapet and blazing away at the panic-stricken enemy.
All the authorities are highly delighted, and the Commander of the 2nd Army Corps sent H. [Hickling] and myself a special telegram of congratulations, so we may yet figure as ‘mentioned in dispatches’. (2Lt Walter Gard’ner, 172 Tunnelling Company).13
With superiority in ammunition, the Germans were able to retake their abandoned front line and the Mound.14 At this stage the tunnels were at about 30ft and into the loam, but Hepburn and Hickling were keen to go deeper.15
There was undoubtedly frustration amongst the Tunnellers that the BEF was unable to make better use of their growing ability to place mines under the Germans. After another blow on 24 July, Gard’ner expressed disappointment that the Army did not have the capability to occupy even temporarily the craters that they were blowing in the vicinity of the German lines:
It would have been advantageous if the infantry could have occupied this crater. As it was, being close to the enemy line, it was occupied by the Germans, who found it a very useful starting point for further mining operations. They were driving piles, &c., without any attempt at avoiding noise, and could be heard most distinctly. Later on, after the system of raiding developed, a party would no doubt have been detailed to rush the crater and destroy the enemy w
orks. (2Lt Walter Gard’ner)16
At Hooge, however, on 19 July, the British succeeded in blowing and occupying a large crater. The 175 Company managed to sink a shaft about 35ft through green sand to blue clay and ran a tunnel 190ft and charged it with 4,900lbs, mainly ammonal.17 The British seized the crater after the blow; there was no preliminary bombardment, owing no doubt to lack of shells, but this gave the British complete surprise, and the Germans had not suspected mining in the area, having abandoned their own attempts owing to the extreme difficulties caused by water.18 The British were able to consolidate the crater and captured trenches. Eleven days later, however, in an operation with parallels to their recapture of Hill 60 using chlorine gas, the Germans retook Hooge with flame throwers in their first use against British troops.
Another early success by a Tunnelling Company was achieved by Preedy’s 170 Company at a position known as the Brickstacks, which was dominated by piles of bricks at a former brickworks. Some of the stacks were in British hands, some German. The company sank three shafts, 4ft square, from the front line to a depth of 16ft, and drove tunnels beneath no man’s land in order to check German mining work. At 65ft from the shafts they joined the three tunnels with a transversal. On 13th March Norton Griffiths reported that Preedy’s instructions limited him to defensive work, and that his No.3 drive had 150ft to go before it would reach the German lines. Subsequently, however, he was authorized to drive an attack with two of the tunnels. The soil was a softish sandstone mixed with loam, which was not suitable for clay-kicking and gave off a lot of water. These galleries were 3ft 6in high by 2ft 9in at the bottom and 2ft 6in at the top. As the tunnels grew longer, however, conditions became extremely difficult as water pumps and air blowers proved inadequate. They stopped work 25ft short of the German lines as the risk of detection became serious and Preedy had to give three days notice that he was ready to fire a mine. Permission being given, he continued driving until just short of the German trench: No.2 gallery was 170ft and No.3 158ft. The drive had taken 15 days. They charged No.2, in front of one of the brickstacks, with 1,000lbs gunpowder and No.3 with 650lbs guncotton. When blown on 3 April, No.2 was claimed to have brought down the face of the brickstack, while No.3 destroyed 90ft of trench.19
The first operation by a Tunnelling Company was to accompany the British attack at Aubers Ridge on 9 May to coincide with the Second Battle of Artois. With difficulty, 173 Tunnelling Company and Norton Griffiths’s manager Leeming drove two long tunnels, of 285 and 330ft, beneath the German lines and charged each with 2,000lbs of explosive. They had to abandon four galleries further to the south owing to flooding, but discovered that at Cordonnerie Farm, 15ft beneath the waterlogged running green sand, was stiff blue clay. Leeming was to pioneer the sinking of shafts through the running sands to the clay levels. The clay-kickers could drive tunnels though this layer, although at times they accidentally broke into the sand above. The distinctive blue clay had to be concealed during the digging of the galleries as an indicator of mining activity. The Germans were aware of the blue clay layer but probably lacked the skill to sink a shaft to it and to work through it:
…the British offensive came as a surprise on our front. No special preparations had been noticed, and even the presence of the mines driven under the front trenches of the regiment next to us had not been perceived. Our own efforts at mining up to now had failed owing to the amount of surface water, nevertheless the enemy had dug a gallery through a belt of loam that underlay the thin clay stratum which held the surface water. He thereby prepared a way for his initial success. (History of the Bavarian Reserve Regiment No.17)20
The two mines, 70ft apart, were, like the Hill 60 mines, blown at zero. They assisted the attacking infantry of the 1/13th London Regiment (Kensingtons) in this particular sector, who took the craters, and supporting troops continued beyond the German’s third trench.
The blows by Preedy’s 170 Company at the Brickstacks in early April against the German 14th Westphalian Division caused it immediately to set about forming specialized mining companies. Very probably due to a realisation that the British must have used specialist miners to have driven quickly through difficult ground, miners and reserve officers who were mining engineers or mine surveyors in civil life were found from the infantry and formed into two mining companies. They were placed under the commander of the 3rd Company of the 7th Westphalian Pioneers, which had carried out the first attack against the British on 20 December 1914. The actual construction of tunnels in the Division was placed entirely in the hands of the mining companies, while the charging and blowing of explosives was the responsibility of a ‘Sprengkommando’ under an NCO from the 3rd Company of the 7th Pioneers. The miners set about pushing forward defensive galleries and blowing mines to destroy the British tunnels reaching close to their lines. Two large craters, called Monokel and Brille (monocle and spectacles), were blown, seized and consolidated and then used as the starting points for new attack tunnels, in the manner traditional in siege operations, as they moved from the defensive to the offensive. Soon the German miners neared the British line and were both above and below British galleries. They worked with great care and in silence, using neither drills nor mine trucks. They went without boots in stockinged feet and placed each cut spit of sandy clay into sandbags, which they carried up the incline. In conditions of silent working, there were break-ins in which Rothe, commanding the Sprengkommando, particularly distinguished himself in the ensuing underground fights, and:
…who penetrated into an enemy tunnel and whose personnel settled the matter partly with the pistol, partly by taking prisoners, whereupon the tunnel was speedily charged with explosives and blown. The Iron Cross First Class formed the wages for his courageous act.21
They constructed defensive transversals and placed microphones in the listening galleries to detect the British at work. The inclined mine galleries begun from the front lines did not allow them to descend quickly enough to the required depth and they began to set them back either between the first and second trenches or behind the second trench. They sank beneath and behind the piles of bricks, and quickly reached down 5–6m before reaching a thick water-bearing chalk layer. The removal of this water required electric pumps and a special troop of fitters to pipe away the water into the canal. Eventually it was found that the labour and difficulties of dewatering rendered working below the water table impractical. The German tunnel system at the Brickstacks lay at most 6–7m deep and the water level did not permit going any deeper. According to the regimental historian, miners were frequently cut off by British camouflets, but at that comparatively shallow depth they were able to dig themselves free. The miners adopted their own faster system of timbering, using frames only every 50cm unless the ground was badly shaken by blows. Apart from defensive blows to destroy enemy mining, in principle they only blew if they heard British work with the naked ear. The Germans claimed that their mining companies prevented the British from approaching or blowing under their positions. They also managed to drive a gallery 200m, working knee-deep in water, to the British second trench and blow a charge of 7,500kg beneath a brickstack which they believed to conceal a headquarters dugout.22
South of the Brickstacks, the quiet working in sandy clay also led to incidents where the opponents broke into one another’s galleries. On 6 September, 173 Company experienced two instances of contact. The first occurred when a heading came up against German timbers, behind which the Germans could be heard talking. They placed a charge and tamped it, leaving a length of armoured hose running through the tamping to the German tunnel. Through this a German-speaking intelligence officer listened for nineteen days, hoping to find some information of value. In the second contact, the floor of the British tunnel suddenly gave way and collapsed into a German gallery. The Germans were lying in wait and opened fire on the British miners. In the darkness, the British managed to place and fire a 25lb charge of blastine. Lt Fred Bell then entered the gallery and used his revolver to clear the Germ
ans out and keep them at bay while a sandbag barricade was built. The British then placed a 200lb charge against it, tamped and blew the charge.23
Some of the mine blows resulted in fierce fights above ground and troops in an active mining area lived in an atmosphere of continual fear and uncertainty, robbed of any security that the trenches and dugouts might have given them. All noises became suspect. As early as June 1915 the Brickstacks sector was a mass of craters along the length of no man’s land for a distance of 1,000yds.24
An attack was carried out on 15 June at Givenchy to support a French attack scheduled but then postponed. The Tunnelling Company, 176, was commanded by a civil engineer on the RE Reserve, Captain Edward Momber. It blew a mine of 3,000lbs of ammonal, plus 30lbs of guncotton, at the Duck’s Bill near the junction of the British 7th and the Canadian Divisions. The artillery had been carrying out a slow bombardment for 48 hours before the attack, which did not come as a surprise to the Germans. The mine was fired at 5.58am, two minutes before the infantry attacked. Some Canadians who had not heeded warnings from 176 Company to leave the danger area were injured by falling debris. The German infantry, however, manned the trench firesteps and were ready to repel the attack at 6am. The British lacked artillery owing to a serious shell shortage and any impact that the blowing of the mine had was lost to German superiority in artillery.25
The British fired several mines on 25 September 1915, either directly as part of the British offensive at Loos or for diversionary attacks on other parts of the front. The most extensive subsidiary attack was at Ypres on the Menin Road, preceded by the firing of two pairs of mines under the German front line, prepared by 175 Company with assistance from the 9th Brigade Mining Company. At the same time as the mine explosion, sappers from a Field Company rushed forward to blow gaps in the German wire and the German trench was taken in the first rush. Further progress could not be made, however, and in the afternoon the Germans forced the British out of their trenches with shelling and grenades. North of the road a mine was blown just before the attack, and although British troops managed to keep possession of it, they also could not retain any German trenches.26 On either side of the La Bassée Canal, where the 2nd Division attacked on the northern flank of the actual British offensive, four mines were fired as part of the attack. Prior to 25 September, however, the extent of mining in this area caused the Germans to modify their defensive tactics. They evacuated their front trench, levelling the parapet so that it offered no cover for attackers, and converted the trench 100yds behind into their main defence. Although the pre-war doctrine of holding the front line in strength was to remain official German practice until late 1916, pulling back from the front line was a simple means of increasing the width of no man’s land and negating the danger of mine galleries that had taken the British many months to construct. The high lips of the craters in no man’s land also left the front lines vulnerable to parties of attackers assembling close by under their cover. In particular, south of the La Bassée Road, the two largest craters, known as Vesuvius and Etna, had lips over 8ft high which concealed the trench lines. Such withdrawal was not an option easily available to the Allies: for the French every piece of ground was liberated territory and in the northern area around La Bassée contained valuable coal mines.27 The British were unaware of the German withdrawal and on 25 September the 2nd Division attack was made against the evacuated front line. Four mines were blown on the 2nd Division: at the Brickstacks 170 Company blew two mines to support the 2nd South Staffords, while to their right 173 Company also blew two (each 1,000lbs of gunpowder) to support the 19th Brigade. These, however, were ordered to be fired at two minutes before zero which, in the words of the official historian, ‘put the enemy thoroughly on the alert.’ The infantry crossing no man’s land (already hampered by their own drifting chlorine gas) were forced to bunch into the gaps between existing and new craters, which served to disorganize the attack and helped the Germans to concentrate their fire. Furthermore, the prior evacuation of their front line by the Germans wholly negated the effect of these mines.28 North of the La Bassée Canal a major diversion was staged commencing at 6.00am, half an hour before the main attack. At Givenchy 176 Company was ordered to blow a mine which they had laid under the German front trench, again at two minutes before zero. Again, owing to the German withdrawal, the attacking infantry found the German front trench empty and, continuing to the support trench, came under heavy fire.29