Underground Warfare 1914-1918

by Simon Jones

  Russian saps between Serre and the Redan prepared for the 13 November 1916 attack. From NA WO153/905.

  The battle began at 5.45am on 13 November in darkness and dripping fog. Opposite Serre, 252 Company had opened John, Mark, Excema and Grey tunnels at midnight and Lewis guns were positioned outside the exits, but the attack again failed. There was no role for the tunnels and they reclosed the exits. For the attack on Beaumont Hamel, by 2nd and 51st Divisions, 252 Company had loaded the ends of Russian saps with charges designed to blow communication trenches at zero. They had driven new saps from the sunken lane, which had been incorporated into the British line after 1 July. This had significantly narrowed no man’s land facing the village and North Street and South Street, running from the sunken lane, served to further reduce it. First Avenue (formerly Sap 6) was directed at the salient south of Beaumont Hamel which contained Y Ravine. Mary was on the far south of the divisional front and its end was in the 63rd Division area.

  They opened these in the last week of October, but on 7 November both entrances to First Avenue tunnel were smashed in and completely lost, entombing eighteen men who were all rescued. Two days later it was again smashed in by shellfire, trapping two infantrymen who were not released until the following day.

  On 13 November a 1,000lb bore charge in the end of Cat tunnel was blown to create a communication trench on the extreme left of 5th Brigade (2nd Division). The 5th Brigade took the German front line, but the attack to the north at the Quadrilateral failed and the trench was not completed. The tunnel was temporarily closed, but was eventually connected to the German front line on Redan Ridge, although the work was much hampered by snipers until darkness. North Street tunnel was opened up 25 minutes after zero and the tunnel was reported to have been very useful. In the 51st Division, the ends of South Street, First Avenue and Mary were extended by Pioneers assembled in the tunnels the remaining 50yds to the German lines, partly with tubes of explosives and partly by digging. This was not to be carried out until the captured German lines were consolidated and in the case of South Street this was not done until the afternoon of the second day of the attack.63

  For the Hamel attack by 63rd Division 252 Company started work on 17 October on four tunnels in front of Hamel, dug for the 3 September attack by 174 Company. On 27th they loaded No.2 tunnel with a small mine charge of 600lbs ammonal, which was to be blown against a German salient. Trower reported that it made a very good crater into the German lines. The remaining three were opened and used as communication trenches and one was used additionally as a battalion headquarters.64 The Brigade Major of 188 Brigade recalled that one of the tunnels was blocked or caved in and was cleared by sappers detailed to open it after the leading infantry had moved forward, but he was still distrustful of it:

  Russian saps dug at Thiepval up to 27 September 1916. Of ten saps dug for 1 July, saps 3, 8 and 10 (Peterhead) have been extended. The use of parallels linking the saps reflects siege warfare practice and the methods tried by the French in 1915. From NA WO153/905.

  I believe the tunnel served its purpose in saving casualties amongst runners, reserves hurrying up etc. I was advised to use it myself during a forward recce but having inspected the entrance decided on the open route across the top.65

  Harvey claimed in 1929 that one of the lessons of the Battle of the Somme was that ‘Russian saps have solved the difficulty of crossing No Man’s Land.’66 This, however, was clearly not borne out by the experience of the Somme or of subsequent battles. GHQ reported on the value of the tunnels in the attack, giving recommendations as to their construction and reporting that their utility was greatest when the attack was temporarily held up:

  The real use of these galleries is brought out when the infantry attack progresses very slowly. On the 13th November on that portion of the front at which the attack was successful, the advance was so rapid as to render these galleries unnecessary except in the case of the two tunnels, which were on the flank of the successful attack.

  The reservations expressed by the Brigade Major of 188 Brigade were also addressed:

  The infantry still appear to have a great prejudice against going down a tunnel and will only use it under strong provocation, but the utility of such tunnels has been proved and where they are prepared this disinclination on the part of the infantry should be overcome by preliminary explanation.67

  A 5th Army letter, probably drafted by Preedy, in response to a request for more information by the 1st Army, denied that such a prejudice existed.68 It had not been conceived on 1 July 1916 that men could use the tunnels to emerge one at a time from easily observed tunnel entrances, although plans for troops to emerge from tunnels behind enemy defences were put forward after the war by fiction writers. The practical difficulties, evidently understood more clearly during the war, prevented this method from being attempted.69 The report by GHQ on Russian saps, however, led to the most important uses of subways, as they came to be called, for the offensives at Arras and Vimy Ridge in April 1917 to assist passage to and from the front line and also to mass troops safely and secretly for the attack.

  Chapter 10

  Underground Accommodation and Communications

  In 1917 the Russian sap evolved into the infantry subway when the use of underground galleries to get men across no man’s land gave way to the use of tunnels to allow safe movement up to the front line. This chapter will examine the use of tunnels for communication and of deep dugouts for accommodation. Underground accommodation became a major feature of trench warfare from 1915 when the Germans in particular began to excavate deep and extensive dugouts.

  German dugouts as developed during 1915 with cover increased to 5m and double bunks for eight men, shown in relation to the fire and support trenches. From Seesselberg, Der Stellungskrieg.

  The aim was to accommodate men in or close to the front line so that a large number were available, protected from bombardment, to repel attacks by the enemy infantry. The German policy was to defend the front line at all costs and to accommodate as many troops as possible in the front line in underground bunkers. The French discovered these excavated in chalk at Vimy Ridge when they captured Carency, Ablain-Saint-Nazaire and Neuville-Saint-Vaast in May and June 1915 and studied them carefully. When Capitaine Thobie examined them he concluded that they completely prevented a surprise attack on the trenches:

  Thanks to this security, it was enough to leave sentries in the trench, and the majority of the men rested in the shell proof dugouts. Access to these German shelters was by either a staircase gallery or a shaft. They were very comfortable, measured ten metres in length, two metres in width and 1.80 metres height. They were cased with jointed beams of eight centimetres thickness and covered by five to six metres of earth. This type of dugout with these dimensions was not at that time unique and the form and the dimensions adopted by our enemies depended much on the configuration of the ground and the nature of the subsoil.1

  Plan view of the same type of 1915 vintage dugout as on p214 and as described by Capitaine Thobie. From Thobie, La Prise de Carency.

  South of Arras, the German officer Ernst Jünger lived from the winter of 1915 until the summer of 1916 in a deep dugout at Monchy-au-Bois and described being able to pass at a depth of 6m underground from one flank of the position to the other, with a 60m gallery from his platoon headquarters to his company commander’s dugout:2

  What strongholds we used to have, with galleries as long and comfortable as a Dickens’ novel, whence left and right there opened out living-rooms and sleeping-rooms and ammunition-chambers and exits and entrances and cross-communications, and where one could traverse one’s whole front like a mole without once coming to the surface. At Monchy, besides a comfortable dugout for quiet times, where a wide shaft directed the light of day straight on to my writing table, I was master of an underground dwelling approached by forty steps hewn in the solid chalk, so that even the heaviest shells at this depth made no more than a pleasant rumble when we sat there over inte
rminable games of cards. In one wall I had had a bed hewn out, immense as the box-beds of Westphalian cottages, where, protected from the slightest noise and encased in stout oaken boards, I slept in a casket of soft dry chalk. At its head hung an electric light so that I could read in comfort till I was sleepy. The walls were adorned with pictures in colour from Jugend, and the whole was shut off from the outer world by a dark-red curtain with rod and rings; it was displayed to visitors, with a running commentary of jest, as the last word in luxurious depravity. In those days, secured by wire fifty metres wide, one could venture to sleep in pyjamas, and the automatic that lay to hand beside the ash-tray was only used when it was desired to break the monotony by going on patrol. Those were splendid days.3

  The chalk quarry beneath Monchy-au-Bois used for the defence of the village, discovered according to Jünger via the well (shown right) by a company cook of the 73rd Hanoverian Fusiliers. The dotted line shows an access gallery dug to a communication trench. From Seesselberg, Der Stellungskrieg.

  The Germans also made use of natural or man-made underground quarries and catacombs, which were particularly prevalent in chalk areas. Jünger described how such an excavation beneath Monchy-au-Bois was discovered in 1915:

  There was a quarry out of which in times of peace limestone had been got for building, and this was an important part of the defences. It had been discovered only by chance. A company cook, whose bucket had fallen into a well of spring water, went down after it and discovered a hole that seemed to connect with a large cave. The matter was looked into, and a second entrance was broken through into a bomb-proof refuge that held a considerable body of men.4

  Monchy-au-Bois was immediately behind the German front line and the catacombs were used for accommodation as well as safe movement to and from the front line. A German inventory produced in 1918 listed over 600 such underground spaces in northern France.5

  During the offensives of September 1915, the Allies used prolonged bombardments to destroy the German defences prior to infantry attacks. The German 6th Corps lost positions to the British at Loos and the French at Souchez and afterwards issued instructions addressing the need to increase the size of dugouts:

  The moral effect of almost three days of the most intense preparatory bombardment is naturally very great. The strain on the infantry under such conditions is quite terrific. In order to render officers and men capable of a supreme effort and to preserve their fighting energy through the exhaustive strain of days of continuous battle it is necessary to provide in the most careful and farseeing manner for the bodily comfort of the troops. It is also important that the men should not be accommodated in the dugouts in small parties of three or four, but in two or more groups under responsible leaders. This will enhance the prospects of a successful resistance.6

  The French and British also managed to surprise the Germans before they could leave the shelter of their dugouts by using artillery fire which moved forward over the German positions and behind which, in theory, the attacking infantry advanced protected from German fire. The British adopted the French term ‘barrage’, meaning ‘barrier’, for this type of bombardment, which in 1915–16 was in the form of a ‘lifting barrage’, jumping from one line of trenches to the next. During 1916–17 the technique was refined into the ‘creeping barrage’, in which every part of the German defences was shelled. The shelling could not completely destroy the deep dugouts, but served to prevent the Germans from leaving their cover to fire on the advancing infantry. Success depended on the attackers staying as close as possible behind the moving wall of shells so that they arrived in the German trenches before the Germans could emerge from their dugouts. German 6th Corps instructions to address the danger of defenders being trapped in their dugouts included the posting of good lookouts, an efficient system of alarm bells and proper exits. The most important point was the speed with which the infantry left the safety of the dugouts to man the trench once the enemy barrage had lifted from their position:

  Above all… every group commander and individual man must know that the success or failure of the defence depends entirely on the timely manning of the parapet. All must be made to understand that the moment the enemy enters our trenches he begins bombing the dugouts. The great point, therefore, is not to lose a second but, even if the alarm is not given in time, to hurry to the firing line the moment the artillery fire lengthens.7

  The German Second Army, holding the Somme front, reacted to the lessons of the September battles by continuing to build stronger deep dugouts:

  On the whole, mined dugouts about three metres below the surface have proved satisfactory. The losses from the intense bombardment were comparatively slight. The entrances to the dugouts were often destroyed or blocked. The frames of these must, therefore, be well braced and specially strong. Steep slopes above the entrances must be avoided. Very heavy shells (28 centimetre) penetrated into these dugouts.8

  The Germans also used underground accommodation to shelter and conceal troops before their attack at Verdun on 21 February 1916. The French were aware of these excavations but took them to be defensive structures. Known as Stollen, or tunnels, the underground barracks, 30–45ft deep, had steps leading up to the communication or assault trenches and were constructed to house the first-line reserves rather than the initial waves. The 2nd Company of the 30th Pioneers built ten such dugouts accommodating 500 men in the second line in the forest position at Ville. Those in the woods of Consenvoye, less than 12,000yds from the French front line, had accommodation for 12,000 men.9 The dangers of underground shelters where large numbers of men were confined in potentially highly dangerous conditions were shown by two incidents during the fighting at Verdun in 1916, when ammunition explosions killed 650 Germans in Fort Douaumont on 8 May and more than 500 French in the Tavannes railway tunnel, used for accommodation and communication, on 4 September.10

  The German policy of deeper dugouts was highly successful in repelling the central and northern parts of the Franco-British attack on the Somme of 1 July 1916, where their use contributed to the spectacular British casualties of 57,000. However, the commander of the British 4th Army, General Rawlinson, had anticipated the German tactic. When he was required by General Haig to capture not only the German front line, but also all of the defence lines behind, he extended the duration of the British bombardment so that the German positions could still be destroyed. He proposed this extension in an amended plan which he submitted to Haig on 19 April 1916:

  …bearing in mind the existence of numerous dug-outs and cellars in the enemy’s lines, I do not think that the moral effect of a six-hours’ intense bombardment will be so great as that of one extended over several days. The effect on moral of a long, accurate bombardment, which will pulverize strong points one by one, gradually knock in communication trenches, prevent reliefs being carried out, and systematically beat down the enemy’s defences, will, to my mind, be much greater, especially as with many new gun detachments we cannot expect very accurate shooting in a hurricane bombardment.

  A long bombardment gives the enemy no chance of sleep, food and ammunition are difficult to bring up, and the enemy is kept in a constant state of doubt as to when the infantry assault will take place. His troops in the front line must be relieved every 48 hours, or they will break down under the strain, and it will be our business so to regulate our fire as to inflict heavy losses, even at night, on any relieving detachments he may endeavour to bring forward.11

  The bombardment was to last a week, extended one day owing to bad weather, which prevented the spotting of the fall of the shells. The experience of the defenders was described by a German junior medical officer:

  A few days before the awaited onset of the British offensive on the Somme, I was transferred to an infantry regiment. We had to strengthen the German lines south of Beaumont-Hamel. On June 24, 1916, the British gunners opened up and their fire increased in intensity, combined with fierce gas attacks. For seven days and seven nights the ground shook und
er the constant impact of light and heavy shells, and in between the bombardments gas alarms were sounded, and we could hardly breathe. Our dug-outs crumbled, tumbled on top of us, and our positions were razed to the ground. Again and again we had to dig ourselves and our comrades out of masses of blackened earth and splintered wooden beams. Often we found bodies crushed to pulp, or bunks full of suffocated soldiers. The ‘drum-fire’ never ceased. No food or water reached us. Down below, men became hysterical and their comrades had to knock them out, so as to prevent them from running away and exposing themselves to the deadly shell splinters. Even the rats panicked and sought refuge in our flimsy shelters; they ran up the walls, and we had to kill them with our spades.

  My first-aid post was in a hollow dell, and the sappers had taken the precaution to provide it with two exits. One of these received a direct hit, but we had the other left, and got busy clearing the first one—you never know! On the morning of July 1st the British gunners directed their fire on our rear position and their armies went over the top in solid formations. …they did not expect any body on the other side to have survived the bombardment. But German machine-gunners and infantrymen crawled out of their holes, with inflamed and sunken eyes, their faces blackened by fire and their uniforms splashed with the blood of their wounded comrades. It was a kind of relief to be able to come out, even into air still filled with smoke and the smell of cordite. They started firing furiously, and the British had frightful losses. (Stefan Westmann, Reserve Infantry Regiment 119)12