About 2 miles east of Ypres, along the Menin Road, lies the village of Hooge. Between 1914 and 1917, this was the scene of fierce fighting. Hooge was obliterated as the village passed from Allied hands to the Germans, then back again. In May 1915, the British retook Hooge and set about mining the German trenches. It took just over five weeks for the 175th Tunnelling Company Royal Engineers to dig a 190-foot tunnel under no-man’s-land to two concrete pillboxes. The charge of 3,500lb of ammonal was placed in a chamber above the gallery which had 6 inches of water in it. German mining in the area had been halted because of the water problem. This was one of the first occasions that ammonal used. Ammonal was a commercial explosive adopted by the Royal Engineers because of the shortage of conventional military high explosives which were needed for artillery shells. The mine, largest of the war thus far, was fired at 7.00 pm on 19 July 1915. The lip of the resulting crater was 15 feet above ground level, while the crater was 120 feet across and 20 feet deep. The crater was immediately occupied by two companies of the 4th Middlesex. The troops had awaited the detonation in saps that had been dug into no-man’s-land in preparation; ten men were killed by falling debris when the mine exploded because they were too close. Several hundred German troops died in the explosion. The Germans counter-attacked but were fought off by bombing parties from the 4th Middlesex and the 1st Gordon Highlanders. Unfortunately, they ran out of grenades and lacked artillery support because they were too far forward, so two-thirds of the trenches that had been captured from the German 126th Regiment were taken back by them.
The Germans initiated mining operations on the Western Front when, on 20 December 1914, they exploded ten mines under British positions at Givenchy. In early 1915, they blew numerous mines, large and small, under the Allied lines. Some of the smallest contained no more than 100lb of explosive. The BEF had no specialist mining unit within the Royal Engineers at the start of the war. It was evident that such a unit was urgently needed. In the meantime, the Royal Engineers did the best they could with the personnel available. Prior to the creation of the tunnelling companies, the Royal Engineer siege companies attached to individual regiments performed most of the mining tasks but there were not enough of them to carry out all the mining operations that were needed. Not only mining but counter-mining work became increasingly important to operations on the Western Front. Digging counter-mines was the only effective way of dealing with German attempts to put mines under Allied trenches.
Eight tunnelling companies were formed in February 1915 from men with civilian mining experience and especially clay-kickers who knew about tunnelling in clay. Another twelve companies were formed later in the year with another added in 1916. In addition to these companies, the Canadian Army formed one in France in December 1915; another two were formed in Canada and arrived in March 1916. A New Zealand tunnelling company arrived in France in March 1916 and three Australian tunnelling companies arrived in May of the same year. By June of that year, the BEF had twenty-five companies and an additional seven from overseas, all actively engaged in mining operations. These operations involved approximately 25,000 men.
Mining operations were a major aspect of the fighting on the Western Front throughout the war. While mines in siege warfare had a long history, the scale of the mining operations carried out on the Western Front was unprecedented. Indeed, mining became a quite distinct form of warfare in itself in which, whenever the two sides met face to face, it was always underground. The fighting under such circumstances was very close and savage. This occurred because each side dug counter-mines and listening parties eavesdropped on the enemy. Counter-mining inevitably led to break-ins on enemy mine shafts, either deliberately or accidentally, although when the break-in was deliberate, the attackers were not usually the miners but infantry brought down the gallery for the job. Battles underground were especially vicious affairs in which pistols, maces, daggers and spades were the principal tools but sometimes even poison gas was pumped in. Miners always tried to work quietly to minimize the risk of detection; sometimes it was necessary for them to remain still and silent for long periods. Mining was not only physically demanding but it was high-risk work. Apart from detection by the enemy there was always the risk of collapses. If a mine was discovered, it was often blown by the men who had dug it in the hope of destroying the counter-mine at the same time. Then it could become a race to see who fired their mine first. The subterranean war on the Western Front was initially fought almost independently of what occurred above ground in the trenches. For the most part, the first the men in the trenches knew of a mine, friendly or hostile, was when it exploded. This had a detrimental effect on nerves since everyone feared being buried alive.
In every major offensive operation on the Western Front, several mines were detonated and it was not unusual for some of these to be big mines. They were also fired in many small-scale operations to straighten out the line, capture a strongpoint, dislodge snipers or destroy machine-gun positions. In every instance, companies of friendly troops were tasked with capturing the resulting crater. The race for the crater rim was as crucial as blowing the mine in the first place. This race could not begin until time had been allowed for the debris to fall back to earth, which could take 20–30 seconds, although troops did not always wait that long because getting to the crater before the enemy was paramount. The rim was usually far higher than ground level so that whoever held it dominated the surrounding area by means of snipers, machine-guns and, of course, observation posts. Trenches were dug along the rim and dugouts could be built into the side of the crater. The crater bottom tended to fill with water, forming greasy, stagnant, gas-contaminated pools.
British tunnellers became very good at mining and counter-mining, so much so that they established a dominance over their German counterparts during the first half of 1916, a dominance which they maintained throughout the rest of the war, especially after Messines in 1917. There were a large number of mine craters in the British-held part of the line around Loos in early 1916, most of them from mines blown by the Germans under the ground captured by the British in the battle the previous September and October. In the Hohenzollern sector, so called because of the German Hohenzollern Redoubt which the British had failed to capture in the fighting at Loos, there were nine craters from mines blown by the Germans when they recaptured some of the ground they had lost. Most of these craters were then taken by the British in the fighting of 2 March 1916, following the blowing of three more mines of 8,000lb, 10,055lb and 7,000lb, running north–south along the German front line.
Many of the early British mining operations were relatively small scale, partly through lack of time to dig the galleries and partly through lack of explosives. Some of them were merely to dig underground listening posts intended to detect German miners but even those that were offensive, rather than passive, often were dug too hastily. This was entirely due to lack of organization and no defined tactical scheme for such operations. The idea developed that quickly dug small mines, blown all along German positions in random locations opposite the British line, would keep the Germans wrong-footed. However, the lack of coordination of mining with operations above ground merely squandered resources and achieved very little. Ye t sections of the front line at Givenchy and Hill 60, the Bluff and St Eloi in the Ypres salient became the scenes of almost continuous mining and counter-mining. At St Eloi, the British fired thirteen mines and twenty-nine camouflets in 1915, while over the same period the Germans blew twenty mines and two camouflets. A camouflet was a small charge set to blow up the gallery of a hostile mining operation. At the end of March 1916, as part of an operation to capture the small German salient at St Eloi, the BEF fired six mines under the German positions which ranged in size from a mere 600lb of ammonal to 31,000lb, completely wrecking the German trenches. There then followed intense fighting to take and hold possession of the craters which continued for the next three weeks. In the end, the Germans occupied four of them.
By the time of the opening of the Somme in July 1916, the BEF was actively mining in twenty-eight sections of the British-held front line, between Hooge in the north and Mametz in the south. The most active sections were between Givenchy and Arras, which made the First and Third Armies the most active of the four British armies in France at that time.
The French were also very active with mining and counter-mining. French miners dug some of the longest galleries of any army. They tended to favour small charges, partly because they needed less time to set up than larger charges, but a lot of small charges in the same area tended to make the ground more difficult for the infantry to cross without doing significant damage the German line. When the British took over some of the sectors previously held by the French, they found numerous galleries of unfinished mining operations, some of which the British proceeded to complete. The Germans undermined all the French and British trenches with a very large number of shallow galleries which meant British tunnelling operations had to start further back behind the line and the miners had to dig to a greater depth to ensure that their galleries passed undetected beneath the German works. The absence of cooperation between the infantry and the tunnellers led to uncompleted British galleries being abandoned because newly arrived battalions chose to dig new trenches in fresh ground, sometimes over German mines which were subsequently blown. To make matters worse, miners began to encounter mine gas and carbon monoxide, which led to accidents. These in turn led to the formation of mine rescue teams which worked in the same way as rescue teams in civilian collieries. Poison gas sometimes seeped into the galleries from above.
With the growing number of tunnelling companies and the BEF taking more frontage from the French, it became clear in late 1915 that a proper organizational framework to coordinate and manage mining operations needed to be established. Hitherto, all mining operations had been controlled by Armies without any overall control by GHQ. In December 1915, such an organization was set up, headed by an Inspector of Mines who reported to the General Staff. Henceforth, tactics, listening and rescue became systemized with properly formulated training schemes to enable the miners in each army to follow standardized procedures. The first mining school was set up by the First Army in June 1916 and soon afterwards the Second and Third Armies set up their own schools.
One of the remarkable successes in mining operations was the development of effective listening techniques which were aided by the invention of the geophone, designed to detect sound pulses in the ground. Using several of these instruments, each at a different location, listeners were able to pinpoint individual miners by triangulation, although this was not achievable until the end of 1917; the instrument nevertheless proved invaluable long before that level of skill was achieved. Neither the French nor the Germans were any better equipped for any aspect of mining than the British at the start of the war, although the British and the French could at least share expertise and experience as they gained more knowledge. The French tended to dig narrower galleries than the British, who were less than enthusiastic about taking them over when they acquired new sections of the line as the BEF grew in size during 1915. The Germans were active miners up to the Battle of Messines in June 1917 when the BEF detonated nineteen big mines and effectively annihilated the German mining force. All mines had to be dug by hand using hand tools to avoid making undue amounts of noise, although the British did have the advantage of the clay-kickers who could dig tunnels much faster in clay than men working with hand tools.
At the beginning of March 1916, the BEF took over 20 miles of the front formerly occupied by the French Tenth Army, running from Loos in the north to Ransart in the south. This included the ridge known as Vimy Ridge that ran southeast from Souchez for 9 miles. The region had been fought over by the French since September in three major battles, the Battles of Artois, and while the French had made some territorial gains, Vimy Ridge had remained in German hands. This dominant position allowed the Germans to observe whatever the French and, subsequently, the British were doing, pick targets and shell them. The problem for the British when they took over this section of the line was compounded by the poor state of the trenches previously occupied by the French. By this time, the defences consisted of three lines of trenches connected by communication trenches, part of a process of evolution that had begun following the Battle of Loos the previous September, whereby defence in depth became the standard. The Germans had initiated the process as a counter to a break-in by assault troops. Hitherto, a single line of defences could be penetrated by attacking troops and if follow-up forces were fed into the penetration, break-in could be converted into breakthrough, allowing the attacker to get into the open country behind the defensive line. By developing a defence in depth, a break-in could be contained by a second line of defences that mirrored those which the attackers had just broken through.
One reason why penetration had not become breakthrough at Loos was a problem with command and control of a fluid battle, not one of poor generalship or lack of fighting spirit. The truth was that there was no reliable means by which a commander could maintain control of a battle in 1915 nor, for that matter, in 1916. This was not a matter of inadequacy on the part of individual generals but rather a practical problem. Information that reached commanders was already many hours old whereas battlefield decisions needed to be taken straight away to respond appropriately to the situation on the ground. However, artillery timetables in particular did not allow for changes to the plan once the battle had started. There was no simple or reliable means by which the artillery fire could be redirected. Nor, indeed, was there a quick means by which reinforcements could be directed to the right place at the right time. These were problems of command and control which were very much on the minds of commanders and had to be resolved if the deadlock on the Western Front was to be broken.
The principal means by which commanders were kept informed about the progress of a battle were telephone and runner. Alternatively, pigeons or dogs could carry messages and there was visual signalling with rockets and flags. None was ideal. By the time runners reached the intended recipient – provided they managed to survive and many didn’t – the battle had moved on and the information they carried was out of date. Pigeons and dogs ran much the same risks as runners. Visual signals were often useless in the smoke of battle and while rockets were visible at night, the correct colours of the day had to be used. The telephone overcame the delay problem but, even when lines were buried the regulation 6 feet below ground, an instruction which dated from April 1916, the lines were still vulnerable to shellfire. Six feet of earth was supposed to be enough to prevent a 5.9-inch shell from damaging the line but repeated shelling reduced the depth of earth and made the line vulnerable. Breaks had to be found and repaired, a Sisyphean task. As part of the many preparations for the Somme offensive in July 1916, an unprecedented amount of line laying was carried out. In all, 7,000 miles of cable were laid for this one offensive alone. This was but a fraction of the total distance of telephone line that was set up for the coming battle. Another 43,000 miles of line was set up between poles, well behind the front, as well as the countless miles that were simply laid on the surface.
In the past, generals had commanded from the front but armies were too big and spread over too large an area for that to be a realistic way to control the flow of battle by the time of the First World War. Indeed, no one individual man could control a battle because of the many different elements involved. Staffs were needed to gather and process information. Generals and staff officers knew that the only sure of way of finding out what was happening was to go and look for themselves. Many did and many died in the front line as a result – sniped, shelled or killed by any of the many ways a man could die on the Western Front. Fifty-eight British generals were killed in action or died of wounds on the Western Front. Most were brigade commanders but a significant number were divisional commanders. In all, ten divisional commanders became fatal casualties, three of them at Loos. A further 117 British generals were wounded on the Western Front, eight of whom were gassed, while another four became prisoners of war.
While new methods of command and control were developed, and as new fighting tactics were devised from experience, the defensive lines became ever more complex. By 1917, German defences along the Hindenburg Line were up to 15 miles deep, with three defensive lines, each one a formidable obstacle. This was a far cry from the single and discontinuous trench line protected by a few strands of barbed wire of 1914.
In early 1916, neither the British nor the French had developed defences in depth. Some defensive lines, in fact, were little better than those dug in 1914. Those in front of Vimy Ridge were in dire need of improvement as far as the British were concerned. In March, the ground was a quagmire of deep mud. There were no continuous trenches, merely a collection of shell holes and craters hastily joined up. By May, the ground was bone hard but the conditions were otherwise atrocious, with few of the usual trenches of any kind and, according to the Official History:
all were undrained and utterly unsanitary. Dead bodies, months old, still lay unburied, and a vast amount of débris and rubbish covered the whole area. The wire, where any existed, was ‘thin and weak’, or ‘in bad condition’; the positions for machine guns were ‘very poor’. The dug-outs, except those some distance from the front, were ‘small, damp and bad’.
In addition to which, the parapets were not bulletproof. When the British took over, they spent a week digging and building frantically, always under the gaze of the Germans on the Ridge above them. Apart from the parlous trenches, the French had left the British an extensive network of underground galleries, incomplete and not very suitable for future mining operations. Moreover, the Germans were also actively mining, their galleries going deeper and further than those left by the French. The sensible decision would have been to withdraw to the old French line of a year earlier but this was not an option so the British had to make the best of it. The British chose to take the mining fight to the Germans and, over the next three months, ten BEF tunnelling companies and five French companies were engaged in mining operations here. The British fired four mines on 3 May 1916 and another five on the 15th. The detonating of so many mines played on the minds of the Germans manning the Vimy Ridge trenches. The 163rd Regiment reported that:
These continual mine explosions in the end got on the nerves of the men. The posts in the front trenches and the garrisons of the dug-outs were always in danger of being buried alive. Even in the quietest night there was the dreadful feeling that in the next moment one might die a horrible and cruel death. One stood in the front line defenceless and powerless against these fearful mine explosions. Against all the other fighting methods there was some protection – against this kind of warfare, valour was of no avail, not even the greatest foresight. Running back, retirement, were useless: like lightning from the clear heavens, like the sudden occurrence of some catastrophe of nature, these mine explosions took place.
And the 86th Reserve Regiment stated that:
Our companies had suffered heavy losses through the British mine explosions. It was accepted that other large parts of our trench system were undermined and might fly into the air at any moment, and that some counter-measures must be devised. We could not fight the enemy any longer with his own weapons, for he was superior to us in men and material.
The Germans lost the battle of the mines but dominated the British above ground by constantly shelling and mortaring the mine craters held by them. Eventually, the Germans were left with no choice but to mount a major assault to capture the craters and the mine shafts, which they did on 21 May. The British were forced back, losing over 2,000 men in the fighting. Whether the constant mining in the region and, indeed, elsewhere, proved to be productive or counter-productive is open to question. Certainly, as far as the Germans on Vimy Ridge were concerned, the mining forced them into mounting an attack above ground so that the British lost men, material and ground to no real purpose.
Considering the importance placed on mining by the British, it is hardly surprising that mines should play a significant role in the opening of the Somme offensive on 1 July 1916. Here the ground was chalk rather than clay or earth in which it was easier to tunnel but to avoid making unnecessary noise push-picks were used. When the tunnellers got close to the German line, they used carpenters’ augers to bore holes in the chalk into which vinegar was poured to soften the chalk, making its removal much easier. Eleven small mines and eight big mines were prepared in the weeks preceding 1 July. These were distributed along the front line from Beaumont Hamel in the north, where one of the large mines was set, to Mametz in the south, where two large mines and nine small ones were distributed along a relatively short frontage. Three large mines of 9,000lb, 15,000lb and 25,000lb were set under a German salient, the Tambour, opposite Fricourt, by the 178th Tunnelling Company. Two large mines and two smaller ones were also prepared at La Boisselle. Had more manpower been available, many more mines would have been dug along the entire frontage of the Fourth Army. The Tambour area had been a very active mining area when it had been held by the French and subsequently; there were already eight large craters. All but one of the British mines were fired at 7.28 am on 1 July.
The galleries for the two mines at La Boisselle had been dug with infinite care to avoid making any noise whatsoever. The area had been mined many times since 1915 when the French held this part of the line. There were many galleries dug by both sides and craters. The British tunnellers worked in bare feet while the floor of the gallery was covered with sandbags to muffle sound. Each piece of chalk was carefully prised out of the chalk face with a bayonet held in one hand, the other hand catching the piece of chalk or flint before it hit the floor. Working in this way, the men of the 179th Tunnelling Company managed to advance about 18 inches every 24 hours in tunnels that were only 4.5 feet by 2.5 feet. A charge of 60,000lb of ammonal was place in a chamber under the Schwaben Höhe Redoubt, while a charge of 40,600lb was placed under Y Sap at the end of a tunnel 1,030 feet long, the longest dug in chalk during the war. When the Lochnager mine under the Schwaben Höhe Redoubt was fired, the German strongpoint was obliterated, leaving a massive crater 70 feet deep and 270 feet across. The lip of the crater was 15 feet high. Second Lieutenant Cecil Lewis RFC, who was flying an SE5a above the battlefield when the mines were fired, estimated that the debris rose to nearly 5,000 feet. The detonation not only destroyed the redoubt but collapsed dugouts in nearby trenches.
The 10th Lincolns, the battalion assigned to attack opposite the mines, waited 5 minutes before leaving their trenches, a fatal error of judgement. The Germans were ready for them and cut them down in an intense artillery barrage and with enfilading machine-gun fire. Moreover, the Germans had discovered the Y Sap mine and, not surprisingly, evacuated the garrison above the mine before it was detonated. However, these mines were not merely intended to kill the German garrisons. The principle aim was for the lips of the craters to obscure the view to the flanks and thereby prevent the Germans enfilading the attacking infantry. In this, the British were not entirely successful.
All but one of the mines along the frontage held by the Fourth Army were fired 2 minutes before the infantry were due to climb out of their trenches – go over the top. The mine under the Hawthorn Redoubt at Beaumont Hamel, containing 40,000lb of ammonal, was detonated 10 minutes before zero. The early firing of this mine was a serious error of judgement by the Inspector of Mines, GHQ and Lieutenant General Hunter-Weston, GOC of VIII Corps which faced the Germans on this section of the front line. It represented a compromise between all parties but it was the worst of all possibilities rather than the most logical choice. Hunter-Weston had wanted to detonate the mine 4 hours before zero to allow time for the British to take the rim and hold it. The action would be over and German alarm would have subsided long before 7.30 am. However, the plan was vetoed by the Inspector of Mines on the grounds that, in all likelihood, the Germans would take possession of the crater, not the British, because the Germans were better at doing this than the British. Nevertheless, firing the mine 10 minutes before zero not only alerted the Germans but the artillery fire plan had to be altered to lift the barrage from the Hawthorn 10 minutes before everywhere else to avoid shelling the attackers, which gave the advantage to the German defenders unaffected by the mine. According to the account by the 119th Reserve Regiment which held the German line at the Hawthorn:
a terrific explosion … completely drowned the thunder of the artillery. A great cloud of smoke rose up from the trenches of No. 9 Company, followed by a tremendous shower of stones, which seemed to fall from the sky over all our position. More than three sections of No. 9 Company, were blown into the air, and the neighbouring dug-outs were broken in and blocked. The ground all round was white with the debris of chalk as if it had been snowing, and a gigantic crater … [130 feet in diameter and 58 feet deep] gaped … This explosion was a signal … and everyone got ready and stood on the lower steps of the dug-outs, rifles in hand, waiting for the bombardment to lift.
Clearly, the British infantry stood little chance of getting across no-man’s-land unscathed. Almost as soon as the mine was fired, two platoons of 2nd Royal Fusiliers, with four machine-guns and four Stokes mortars, ran for the near lip of the crater which they reached, but the Germans reached the far lip first and brought the Royal Fusiliers under intense fire. Not only did they suffer but so did the attacking infantry a few minutes later when they climbed out of their trenches. The far lip gave the Germans a better field of fire than had they remained in their trenches. Ironically, the explosion of the Hawthorn Redoubt mine is probably one of the best known, certainly the most recognized, due to the fact that it was filmed from a mile behind the British lines. Tons of earth and chalk rushing upwards is still an awesome sight.
While the mines detonated at the opening of the Somme may not have achieved what was intended, British mine warfare went on unabated. The greatest success occurred in June 1917 at Messines Ridge when nineteen large mines were detonated prior to an assault on the Ridge. There is no doubt that this was the most ambitious and the most intensive mining operation of the war. While mining had been carried out in the area since 1915, the galleries had been dug at a depth of 15 feet; the galleries of the mines blown in 1917, on the other hand, were 60–90 feet below the surface and had taken eighteen months to construct. Some had been started as early as August 1915. It was for the work on these mines that the clay-kickers were employed to deal with the blue clay of the area. The galleries were started 300–400 yards behind the British line and extended for up 720 yards under the Ridge so that the explosive chambers were 80–120 feet below the German trenches. One of the biggest problems was disposal of the spoil which had to be concealed from German reconnaissance aircraft. To this end, it was hidden in ‘distant woods or buried under sandbag parapets’. The Germans never suspected the British were mining under the Ridge. The operation was far from easy as the diggers had to deal with treacherous slurry, a water-saturated mixture of clay and sand which lay between two seams of clay. The whole process of mining at Messines, from surveying and geological analysis of the strata to the employment of silent air pumps, was carried out much more scientifically than any previous mining operation on the Western Front.
In all, twenty-four mines were prepared, but three were not fired and one had been abandoned in August 1916 when the Germans discovered it and blew a camouflet that demolished a great length of the gallery. The usual night-time shelling of the German trenches ceased half an hour before dawn. In the meantime, the assault divisions had assembled and fixed bayonets silently. When the shelling stopped, the quiet was ‘so marked that from the front line nightingales could be heard singing in the distant woods’. Then, at 3.10 am, the British detonated the mines, not quite simultaneously; from first to last, the detonations were spread over 19 seconds. The eruptions of fire, smoke and debris were volcanic. According to one eyewitness, the explosions ‘stood like great pillars towering into the sky’. It was a spectacle in which
roses with carmine petals, or as enormous mushrooms … rose up slowly and majestically out of the ground and then split into pieces with a mighty roar, sending up multi-coloured columns of flame mixed with a mass of earth and splinters high into the sky.
Tremors from the explosions could be felt in London. The report compiled by the German 204th Division, which was holding the line near Hill 60, described how
the ground trembled as in a natural earthquake, heavy concrete shelters rocked, a hurricane of hot air from the explosions swept back for many kilometres, dropping fragments of wood, iron and earth; and gigantic black clouds of smoke and dust spread over the country. The effect on the troops was overpowering and crushing.
The timing of the explosions was especially cruel for the Germans as they were in the middle of a relief, so that both the relieving troops and those being relieved were caught in the blasts. Although the exact number of German casualties is uncertain, in the region of 10,000 died. Most of the trench line was obliterated. When the British, New Zealand and Australian troops crossed no-man’s-land, they met no opposition and took their objectives with hardly a casualty. Those Germans who had survived the mines now surrendered meekly, such was the shock of what had happened. Elsewhere along the front, the Germans were completely demoralized by the scale of the explosions and by the fact that they were not simultaneous which created the fear there were yet more to come.
Not all the mines fired on 7 June detonated. Two failed to explode. The British lost their locations and the mines remained undetected when the war ended. Thirty-seven years later, on 17 July 1955, one of them finally exploded when it was struck by lightning. Fortunately, the only casualty was a cow. The other mine is still where it was laid in 1916 and no one is certain of its precise location. This is the mine abandoned by the British after its discovery by the Germans. The Battle of Messines Ridge, a success of limited scale because the objectives were limited in scope and was well planned and executed, was a preliminary operation to the Third Battle of Ypres which went awry almost from the outset and descended into a bloody slugging match of attrition.
The effects of the mines undoubtedly were a significant factor in the British success at Messines. However, several other factors, arguably of greater importance than the mines, lay at the root of the success; these related to the changing tactical approach to major offensive operations on the Western Front that had been going on for the past eighteen months. Indeed, rather than tactics remaining fixed and unchanging, they were constantly changing and evolving. However, the conclusions drawn from successes, when they came, were not always the right ones and tactical errors were inevitable. Trench warfare had two distinct but intimately related elements, namely small-unit combat, that is, fighting at the section, platoon and company levels; and large-scale combat at divisional, corps and army levels. The tactics of hand grenade and rifle grenade warfare were the tactics of small units. As the platoon was transformed from a rifle-and-bayonet unit to an all-arms one, so the principals of cooperative interaction between the different weapon groups within the platoon reinforced the small unit as a fighting entity, capable of engaging a range of targets which, prior to 1915, were outside the scope of the infantry. These were the means by which infantry engaged and overwhelmed similarly equipped and organized enemies. These were the building blocks from which the tactics of big offensives were formed.
Tactical change was driven by the conflict between firepower and mobility, principally the firepower of artillery and the mobility of infantry. While the firepower of artillery had contributed to the stalemate of 1915, it was not the cause of the protracted mutual siege that began in the autumn of 1914. Indeed, immobility in late 1914 had been a consequence of many factors, including exhaustion of the armies, the unwillingness of France and Britain to concede a foot of territory to the Germans under any circumstances, and lack of weapons and ammunition to continue fighting. The entrenching of the armies in 1914 was intended to be no more than a pause in offensive operations which would resume in the spring of 1915. The trenches were not continuous. They lacked strength in both form and structure. The line of defences lacked depth. Indeed, the Western Front was a discontinuous line of poorly made entrenchments with a few strands of barbed wire stretched out in no-man’s-land. The puzzle, then, is why this weak defensive line could not be penetrated.
At the start of 1915, the French mounted several unsuccessful offensive operations in the Artois and Champagne, while, at the beginning of March, the BEF launched an offensive at Neuve Chapelle. The significance of Neuve Chapelle was not that it failed but that it very nearly succeeded. The problem for the BEF was converting the break-in into a breakthrough. The German defensive line consisted of only one trench line and lacked support and reserve lines, although it did include several strongpoints 1,000 yards behind the trench line. There was some wire in no-man’s-land. After an intense bombardment by 354 British guns lasting only 35 minutes, targetting the trenches, four divisions of 40,000 men from the First Army attacked along a 3,280-yard front. The artillery was supported by eighty-five Royal Flying Corps aircraft which acted as aerial spotters. This was not an innovation as aerial spotting of this kind had been tried during the Balkan Wars a few years earlier. The field guns successfully destroyed the wire but the howitzers, which were supposed to destroy the trenches and the strongpoints, failed to do any significant damage.
Taken by surprise, the Germans were overrun and, in a matter of a few hours, the British had advanced beyond the German line of strongpoints. A rigid timetable and an inflexible plan, made worse by poor communications between the advancing troops and First Army HQ, all contributed to poor control of the battle and prevented the near breakthough from being developed further. After the success of the first few hours, the advantage had been lost by the afternoon. German troops were quick to counter-attack and, within two days, the status quo had more or less been restored, the Germans having lost very little ground.
Sir John French, blamed the failure at Neuve Chapelle on the severe shortage of high-explosive shells. This shortage not only afflicted British artillery at Neuve Chapelle but the whole of the BEF during the first six or seven months of 1915, and became a national scandal when it was made public. The Shell Scandal brought down the Liberal government and led to the creation of the Ministry of Munitions in June 1915, which took over all aspects of munitions production in Britain. The shortage of shells had undoubtedly been a significant hindrance at Neuve Chapelle as the guns had been restricted to 200–400 rounds apiece, a paltry figure when later bombardments lasted for days and weeks of sustained firing. The problem highlighted the importance of artillery in deciding the outcome of battles on the Western Front. Without enough guns and without enough shells, no army could attack and expect to win. Moreover, and just as important, no army could properly defend itself or, in this case, deal effectively with counter-attacks. The intensity – although not by later standards – and the brevity of the preliminary bombardment at Neuve Chapelle wrong-footed the Germans, however, who had already come to expect a longer bombardment to precede an infantry assault. Without question the short, heavy bombardment of the trenches and line of strongpoints had been a major factor in the initial success but the fixed barrages on a strict timetable had been unhelpful. However, at that time, there was no means by which the schedule could be amended once the fire plan had been set in motion.
Despite the shortage of shells, the bombardment neutralized the Germans, thereby allowing the British infantry to seize their objectives. However, because the howitzers failed to destroy the German defences, which allowed German infantry firepower to recover from the initial shock, the British drew the conclusion that more intense and longer bombardments were necessary to secure success. The conclusion that neutralization of enemy firepower rather than destruction of his defences was the key to success was not apparent to anybody at that time. Neuve Chapelle led to an expansion of the artillery so that it became the dominant force on the battlefields of the Western Front. It was evident from French and German experience earlier in 1915 that a preliminary bombardment was essential to success. The question was whether it should be short and intense, or carried out over several days, choices that tended to made according to the number and calibre of guns available. After Neuve Chapelle, a doctrine of destruction of the enemy was adopted by the British in the belief that, not only was complete destruction possible, but the inevitable loss of surprise that came with long intense bombardments did not matter as there would be no enemy left to be surprised.
At the Battle of Festubert in May of the same year, the British adopted a policy of destruction with a bombardment that went on for two days. The loss of surprise cost the British 24,000 casualties, although the failure at Festubert was attributed to insufficient destruction of the German defences. When the British launched an offensive at Loos in September, the barrage lasted for four days but its effects were diminished by the fact that the gun density was only one every 30 yards of front engaged, whereas at Neuve Chapelle it had been one gun for every 5.5 yards. This compromise had been necessary because of the shortage of ammunition which did not allow a heavier bombardment. The ideal level of destruction of the enemy defences was not achieved. The bombardment at the start of the Somme offensive, nine months later, lasted a week and included a hitherto unprecedented number of heavy guns, as well as trench mortars. The number of guns per yard during the preliminary bombardment on the Somme was approximately twice that at Loos, while the frontage was twice as long, 25,000 yards compared with 11,200 yards. Unlike at Loos, there was no shortage of ammunition. The prolonged bombardment and the greater gun density on the Somme was intended to obliterate the wire and German resistance, and especially to destroy German machine-guns, before the infantry assault on 1 July.
At Messines, in June 1917, the preliminary bombardment lasted seventeen days as the doctrine of destruction reached its zenith. The mines fired at Messines were in accordance with this doctrine. The gun density was such that, yard for yard, there were twice as many field guns at Messines than for the preliminary bombardment on the Somme and three times as many heavy guns. On the Somme, there was one field gun for every 21 yards and one heavy for every 57 yards, whereas at Messines, there was one field gun every 10 yards and one heavy every 20 yards. Between 3 June and 10 June, the guns fired 3,258,000 rounds, nearly twice the quantity fired during the first eight days of the Somme (1,732,873 rounds). The mortars at Messines fired 800,000 rounds.
At the same time that the number of guns and quantities of ammunition were increasing in order to bring about the realization of the ideal of complete destruction of the enemy, the manner in which the bombardments were conducted and the targets engaged by the guns went through a series of fundamental changes. Such changes were driven by a need to overcome the enemy and his trench systems. The nature of defence also changed. The concept of defence in depth was created after Neuve Chapelle so that by the time of Loos, the Germans had more than one line of trenches. Had not the nature of defence changed, the search for ever greater firepower to destroy the enemy’s defences would have lacked impetus. At the same time, the increases in firepower and the increases in defensive depth drove a change in infantry tactics. By the beginning of 1916, the power of artillery was such that infantry were at its mercy, while the firepower of the infantry in defence had also increased so that attackers stood little chance if they were caught in the open, especially en masse. The purpose of the attackers’ artillery was to destroy the defenders, to enable the infantry to take their objectives. To complicate matters, the enemy artillery attempted to destroy the attacking infantry and the attackers’ artillery. While counter-battery fire had been employed before the Russo-Japanese War, it now came into its own. This was not merely a question of shooting first since weight of fire and accuracy were crucial. Accuracy was not simply making sure that the shells landed where they were intended, but it was imperative to know the location of the enemy batteries. Thus, aerial photography and mapping became essential to gunnery. Then there was the question of how the infantry should work with the artillery. This was the nature of the struggle which attackers and defenders both faced in 1915–17.
While the French and the British both concluded from the battles of 1915 that the way forward was to increase the firepower of their artillery and lengthen the preliminary bombardment phase of an offensive, the Germans took a somewhat different lesson from these battles. On the one hand, the growing power of artillery seemed to offer the German Army a way to defeat France, which ultimately led to the epic struggle at Verdun that began at the end of February 1916 and continued for ten months; while on the other, the Germans realized that a single line of trenches was not sufficient to prevent a determined Allied assault from breaking through, sweeping all before them. The solution to this problem was to build a second line of defence, similar to the first, which would contain any break-in and prevent a breakthrough. By the time the British launched their offensive at Loos in September 1915, the Germans were in the process of building this second line. And by the time of the Somme offensive in the summer of 1916, the Germans had developed their defence in depth to include a third line. When in 1917, they built the Hindenburg Line, the defensive zone was up to 15 miles deep and included five lines.
To make matters more difficult, the Germans stopped manning their front-line trenches in strength, but withdrew the bulk of their troops to what was, in effect, the second line, with only about a quarter of the infantry being located in the first two trench lines immediately facing no-man’s-land. Thus, at the start of the Somme in 1916 the German trenches closest to no-man’s-land were held very thinly and, once the preliminary bombardment started, the troops in them sheltered in deep bomb-proof dugouts, leaving very few troops to man the trenches. By 1917, the German front line was no more than a series of outposts, thinly held, located hundreds of yards in front of the main line of defence. At the same time, the development of strongpoints with all round defence began to replace linear defensive lines of continuous trenches, a process of change that led to the construction of the Hindenburg Line. Here, the defensive lines were more in the nature of zones than linear trench lines of the sort commonly employed in 1915. In conjunction with the dissolving of rigid lines of defence, the Germans adopted an elastic defence in which the immediate counter-attack to retake any ground lost played a major role.
The tactics employed by the infantry went through a similar process of change. While the infantry tactics of the assault employed in the early battles of 1915 tended to be based on pre-war tactics, so that infantry engaged infantry and artillery provided support, this was soon found to be costly and ineffective. Nevertheless, the notion of attacking in lines or waves persisted well into 1916, largely because of the relationship between the infantry and artillery, whereby the artillery timetable dictated how the infantry attacked. The growing dominance of artillery placed restraints on the infantry because of the nature of artillery barrages. The barrage was intended to support the infantry by preventing the enemy from engaging the assault troops as they approached. However, it forced a rigid timetable on the infantry and took no account of obstacles that might have to be overcome which slowed the advance. Equally, the assault troops had to contend with enemy fire and as his firepower increased so the likelihood of their crossing no-man’s-land unscathed to engage the enemy on his territory diminished. Thus, while linear tactics favoured reasonable coordination between the attackers’ artillery and their assault troops, it also favoured the enemy as linear waves presented unmissable targets, especially when the enemy was able to enfilade the attacking waves. Far from being a straightforward problem that might offer a straightforward solution, a quite different approach to infantry assaults was required.
The idea of doing away with rigid linear tactics and adopting a more flexible approach was considered as early as May 1915, when Captain André Laffargue devised tactics of infiltration which avoided the massed frontal assault. These were derived from his own experience and were a variation on the wave theme. No one took much notice of his theories. At much the same time, and quite independently, Major Wilhelm Rohr, who commanded the German Army’s Assault Detachment, also devised tactics of infiltration. The purpose of the Detachment was to develop new tactics for offensive operations. Rohr and his unit tried the new tactics against the French in the Vogues before using them at Verdun. Rohr and the Assault Detachment, renamed Assault Battalion Rohr in April 1916, were the first Stormtroopers.
The artillery barrage, as distinct from the bombardment that preceded an infantry assault, was intended to help the assault by preventing the enemy infantry from bringing their weapons to bear on the attackers. Counter-battery fire, on the other hand, was purely a duel between the guns, a duel which the Germans increasingly lost from about 1917 because the Allies, and the British in particular, could bring a heavier weight of fire to bear. It was clear from early 1916 that artillery had become the dominant force on the battlefield, and battles were won or lost according to how the artillery was used, or, at least, the casualty level was decided on how well the artillery could deal with the enemy. Indeed, when the Australians attacked Pozières during the Somme campaign and did so without a preliminary bombardment, they suffered very high casualties and failed to take their objectives because of German firepower, both from infantry in the trenches and from artillery. The protective barrage in support of an assault was not an alternative to a preliminary bombardment, of course. The problem was how to hit the enemy trenches while the infantry advanced without causing friendly casualties in the process.
The first barrages were no more than lines of bombardment across the width of the battlefield, targeting the front-line trenches. After a fixed time interval, it moved on a somewhat arbitrary distance to lay down another line of shelling beyond the advancing infantry but not necessarily on the next line of trenches. The straight barrage was of very limited help to the infantry who were often left behind by the advancing barrage. The next development was the lifting barrage, first used by the French in early 1915 in the battles in the Artois and Champagne. The barrage still advanced in the same way as the straight barrage but it hit trenches each time it lifted to the next target. By now, the infantry were accompanied by Forward Observation Officers whose job it was to direct the artillery to improve its shooting. In both cases, the artillery employed indirect fire and one of the problems this highlighted was the difficulty of accurately locating the targets due to a lack of reliable maps. Shooting by the map with accuracy was more of an aspiration than an achievable goal before the middle of 1916. Unfortunately for the infantry, the lifting barrage was no easier to follow than the straight barrage. The added disadvantage was the necessity for the guns to fire registration rounds beforehand to ensure that they had the range of the target. In registering the guns, the enemy was, of course, alerted to the targets that were about to be hit and, indeed, to the fact that an offensive was likely in the near future. Suspicions were increased if a lot of guns were firing registration shots. They were easy to identity because of their apparent randomness, although they bracketed what was clearly a target. It was because of this easy identification of registrations that trench mortars hid theirs during an artillery bombardment.
Although the preliminary bombardment also gave away the fact that an offensive was starting, prior registration of the guns was insignificant to overall lack of surprise. Any bombardment that lasted more than a few hours gave the enemy time to move his infantry and his guns. By 1917, greater effort was made to conceal registration shots so that the targets were less likely to be identified by the enemy. With this in mind, every effort was made to conceal the location of gun batteries to avoid counter-battery fire. They were sited on reverse slopes and some batteries remained inactive so that they remained hidden until the moment they opened fire for the offensive.
In 1916, the so-called piled-up barrage was introduced to satisfy the infantry’s need for a barrage that focused on the trace of the enemy trenches. Whereas the earlier barrages moved forward in lines parallel with the gun line and passed over the enemy trenches in the same straight line irrespective of the trace of those trenches, the piled-up barrage concentrated or piled up as it hit the enemy trenches, until the rest of the barrage had caught up, thereby concentrating the fire on the trenches. This ensured that the entire trace was hit simultaneously, which had not been possible with straight-line barrages. Both the straight and lifting barrages had allowed the enemy in those parts of the trench that were ahead of the advancing barrage line to enfilade the infantry to their left or right. The piled-up barrage overcame this problem. However, to be effective, the full extent of the enemy disposition needed to be identified beforehand. Trench raiding and patrolling helped in this respect but there was no foolproof way to locate all the enemy’s trenches or to determine the strength with which he held the various sections. There was also the disadvantage that the attacking infantry had to assault the trenches simultaneously, irrespective of the location of the trenches. In practical terms, this meant that those troops which had the furthest to go to hit the enemy trench allocated to them had to leave their own trenches before those troops which had a short distance to cover. This made them vulnerable to enemy fire.
The creeping barrage was a solution to the problems posed by the piled-up barrage. Now, instead of the barrage moving forward parallel with the gun line, it was parallel with the enemy trench line. For the first time, it was possible for the assaulting infantry to hit the enemy trenches immediately after the barrage had passed over these trenches. To achieve this, the infantry still had to leave their trenches according to their distance from the enemy so that they all hit the enemy, irrespective of the trace of his trenches, at the same time. Unlike with the piled-up barrage, the infantry did not have to wait until the entire enemy line was under the barrage before leaving their trenches, although in practice they had left their trenches before then, but had to slow their advance or speed it up according to the distance between them and their targets. Good planning and execution were necessary with every type of barrage. And in every instance, the infantry had to advance as close to the exploding shells as they could safely get. Hence, rehearsals on ground that replicated the enemy line were carried out before the offensive, although this was not done with live shells.
Until about the middle of 1916, the infantry assault was a linear operation in that it consisted of lines, or waves, of men with specified time intervals between each line, each of which was straight irrespective of the trace of the enemy trenches. The first day of the Battle of the Somme has been made infamous by the fact that the British troops approached the German trenches in straight-line waves. While the idea of infiltrating groups of men was considered, the plan was not taken up. It has passed into folk lore that the reason for this was the lack of faith of the generals in the troops of the New Armies to execute anything but simple manoeuvres on the battlefield, with infiltration and group tactics being considered too sophisticated for their abilities. However, not only is this view of the relationship between British generals and the New Armies quite unfounded, but the reason for using linear wave tactics had nothing to do with any supposed lack of ability on the part of the citizen soldier of Britain’s New Armies. The linear nature of artillery tactics at that time precluded an alternative to linear infantry tactics. To have attempted to employ non-linear infantry tactics would have required a highly complex artillery plan. Moreover, there was a real fear among the planners of the Somme offensive that localizing concentrations of artillery firepower, which nonlinear infantry tactics would require, could lead to sections of the German trenches, and machine-guns in particular, being missed by the barrage. One advantage of the linear barrage was that the whole of the hostile territory was eventually swept by fire so that everything was subjected to shelling before the infantry reached the trenches. To this end, there was one 18-pounder for every 25–30 yards and one howitzer or heavy gun for every 65 yards.
The infantry wave tactic would have been successful had the artillery been able to destroy or neutralize all the enemy machine-guns, some of which were positioned in shell holes in no-man’s-land, as well as between the trench lines, but the artillery had been unable to do this. So long as the waves moved forward according to the timetable in the plan, they could keep up with the barrage. In some areas of the front, the lifts were short enough for a creeping barrage to be created. This was as much a function of the accuracy and precision of the guns as it was a deliberate intention to creep the barrage forwards. But as soon as the leading wave was held up by more resistance than anticipated, such as machine-guns or surviving enemy infantry, the whole assault scheme ran the risk of descending into chaos as each successive wave ran into the back of the preceding wave. For the plan to function smoothly, the timetable had to be followed, which was governed by the artillery lifts and the resistance of the enemy. Had the artillery had the technical sophistication to achieve a precise piled-up barrage rather than an imprecise approximation of one, the effect on the German trenches would have been much more destructive. To achieve a precise piled-up barrage, precise gunnery was needed but, at the time of the Somme, such precision was not technically feasible.
The rise in importance of counter-battery fire meant that more heavy guns were allocated to this role than to infantry support, which hindered the weight of fire in the preliminary bombardment and in the supporting barrages. The Germans discovered in 1915 from their experience on the Eastern Front that surprise and weight of fire were more important to success than bombardments which might last for up to a week. Indeed, contrary to the Allied practice of prolonging bombardments and increasing the weight of fire, the Germans increased their weight of fire but decreased the duration of the bombardment. Whereas the Allies bombarded the Germans on the Somme for a week and the British shelled the Germans at Messines in 1917 for a week, the Germans fired a preliminary bombardment on the French at Verdun for only 10 hours. On 21 March 1918, at the start of the German Michael offensive, the assault was preceded by a bombardment of only 5 hours in which 6,473 guns and 3,532 trench mortars fired millions of shells, including more than 2 million gas shells. German artillery outnumbered British guns by more than 2.5 to 1.
This highlighted the different philosophies of destruction and neutralization. While the Allies had gone down the total destruction road, the Germans had opted for neutralization and had developed their infantry assault tactics accordingly. At the same time, they adapted their defensive policy to reflect the same principals. As the Allies tried ever harder to destroy the German lines before an assault in 1917, so the Germans withdrew the bulk of their infantry and artillery from the forward zones at the start of an Allied offensive, shelled the British trenches when they calculated the assault was about to start, withdrew again and shelled their former positions when the Allies were in possession. Reserves were kept out of artillery range, approximately 5.5 miles to the rear but still within the defence zone. By extending their defence zone the Germans diluted the effect of Allied destruction tactics. They developed island strongpoints each of which was located to take advantage of local topography and road links and sited so that each strongpoint could act cooperatively with its neighbours, thereby creating lethal zones through which attacking infantry would have to pass. And always the Germans used the immediate counter-attack, with ad hoc formations of troops when necessary, to deal with any loss of ground. The notion of linear assault tactics and barrages were made redundant by such defensive measures.
Destruction tactics were applied by the British with ever greater intensity at Vimy Ridge, Messines and Passchendaele. While Vimy and Messines were both limited actions, Third Ypres was a major offensive and, while the limited actions achieved limited successes, Third Ypres became a costly battle of attrition in atrocious conditions which, in terms of its original objectives, was far from a success. At Passchendaele, the tactic of destruction was at last shown to be counter-productive.
The last British offensive of 1917, Cambrai, marked a radical departure from previous artillery and assault tactics. Not only were tactics of neutralization employed by the artillery, but Cambrai saw the first use of massed tank assaults in support of the infantry. The tank had been devised independently by British and French engineers during 1915 and 1916, as a solution to the trench deadlock. British tanks first saw action during the later stages of the Somme battles in September 1916. The French first used theirs in April 1917 during the disastrous Chemin des Dames offensive. Neither debut was a success, however, and their achievements, such as they were, were modest. From the outset, tanks were under-gunned, under-armoured, under-powered and mechanically unreliable, while they were quite unsuited to crossing the shell-cratered landscape of the Western Front as they easily stuck in craters and trenches, tended to throw a track on rough ground and sank in mud. Indeed, their unreliability was the biggest cause of operational losses; more tanks broke down or were ditched than were knocked out by enemy action. At Cambria, 378 tanks started out from the start line on the first day of the offensive and, although some tanks remained in continuous action for 16 hours, no fewer than 114 were lost through mechanical failure and ditching, while sixty-five were knocked out by enemy action.
Cambrai also saw the use of aircraft in an air-support role to suppress the enemy’s ability to fight, an operational innovation pioneered by Lieutenant Colonel J.F.C. Fuller, one of the advocates of tank warfare. Moreover, there was an emphasis on air observation for communicating the fall of shot to the artillery batteries. The artillery did not fire registration shots before the battle so that complete surprise was possible. Instead, gunners used predicted fire for counter-battery work. Although predicted fire had been tried before, it was not until late 1917 that it could be relied upon as an effective means by which to hit enemy batteries. Predicted fire was a science, not an art, which combined the technical skills of several disciplines to ensure that the target was hit precisely. Not least among these was map-making. Without accurate maps, no amount of clever gunnery was ever going to result in the intended target being hit except by chance. To this end, thousands of aerial photographs were taken by reconnaissance aircraft flying over enemy-held territory, in support of which fighter aircraft flew escort patrols to prevent enemy aircraft shooting down the reconnaissance planes. From these photographs, accurate maps were prepared and regularly updated using new photographs by the map-making branch at GHQ.
Fundamental to accurate gunnery was an understanding of the science of ballistics. Aspects of this included the weight of the shell, muzzle velocity and the effect of barrel wear on range and accuracy. Such issues applied specifically, not to the artillery in general or to a battery, but to individual guns. Since 1915, gunners had become aware that the rifling in a barrel was worn down by each shot fired and that, as barrels became worn, so accuracy and range diminished. Indeed, shooting from very worn barrels could result in shells landing unpredictably on friendly troops. By the end of 1917, gunners were able to factor all this into their calculations, for each gun, along with the wind speed and direction as well as the air temperature to ensure that the first shot fired from each gun would have a very high probability of hitting the target. Thus, the need to fire registration shots became redundant and tactical and strategic surprise were once more realistic possibilities. Cambrai was the first opportunity for British gunners to put all this into practice. The object at Cambrai was not to destroy the Germans in a prolonged artillery bombardment, like those of the past, but to prevent the enemy from engaging the British artillery, tanks and infantry. In other words, the object was to neutralize the enemy’s ability to fight. With this in mind, smoke and tear gas rounds were fired in addition to high explosive, while the tanks created corridors through the wire obstacles for the infantry and acted as mobile artillery to deal with pillboxes and strongpoints. There was no preliminary bombardment. When zero hour arrived, a creeping barrage from more than 1,000 guns led the way and the tanks and infantry moved forward, 300 yards behind the barrage.
The Germans were completely surprised and overwhelmed. The assault broke into the German line and penetrated to a depth of 5 miles on a 6-mile front in 10 hours, by which time tank crews and infantry were exhausted. Tanks outran their infantry, despite their slow speed. There were no tank reserves so that by the third day there were, in effect, no tanks in action. The initial success could not be exploited and when the Germans counter-attacked ten days after the start of the battle, the advantage had passed to them. The British lost most of the ground they had taken but more importantly they had been stopped from converting the break-in into breakthrough.
During the Cambrai counter-attack, the Germans applied infiltration techniques and used them again in their spring offensives of 1918. At the same time, they applied more flexible artillery tactics that, like the Allied artillery, now no longer focused on destruction, but on neutralization. The object was not so much suppression of the ability of the enemy’s ability to fight, as destruction of their morale by subjecting them to a sudden and very intense bombardment of short duration, followed by an immediate infantry assault. Such artillery tactics were devised by an artillery commander, Lieutenant Colonel Bruchmüller, who tried them out on the Eastern Front before applying them to the Western Front. The Germans also used predicted fire without registration. The new artillery tactics were combined with infantry tactics which emphasized infiltration, as well as fire and movement, and both were integrated in a strategy which sought to apply a heavyweight punch on a short sector of front to achieve a breakthrough. Such tactics were named after General von Hutier who first applied them at Riga on the Eastern Front in September 1917. Part of this overall attack plan included so-called stormtroop tactics which were aggressively applied in the assault phase by elite units of stormtroopers, leaving more conventional troops to deal with pockets of resistance bypassed by the stormtroopers. This was how the spring offensives of 1918 were mounted.
Stormtroopers did not occupy trenches like ordinary infantry regiments but were moved into those sectors where and when they were required from behind the lines. They were highly trained for a specific purpose and the German high command could see no sense in allowing them to be whittled down by the day-today attrition of trench duty. Unfortunately, the rest of the infantry received more conventional training so that, in effect, there was a two-tier infantry system within the German Army, with the second tier lacking in skill, training and competence compared to the stormtroopers.
By 1918, both the Germans and the Allies had developed new offensive and defensive techniques based on a more flexible response to developing circumstances, which avoided the linear approach to battle that characterized the battles of 1915 and 1916. Moreover, there was a closer integration of all arms, including air power, within the overall strategy. The Allies were beginning to apply a zone principal to defence by the beginning of 1918, but the system was far from complete when the Germans struck on 21 March 1918 in the first of several offensives designed to break through the Allied lines and return to mobile warfare, whereby victory could be achieved. Although trench warfare was not to end for another four or five months, it was no longer of the form that typified the fighting of 1915 and 1916. Static permanent positions had become less useful and temporary positions began to assume greater importance, as the movement of battle lines could now be measured in miles rather than the yards that had typified the battles of the first two years of trench warfare.
The German Michael offensive of March 1918 employed neutralization tactics with infiltration and stormtroop tactics, aided by fog, to punch a hole in the line held the British Fifth Army. The Fifth Army was caught off-guard and lost men, material and ground at an alarming rate, although the Third Army faired better. By the time the Germans lost momentum at the beginning of April, they had driven a salient 40 miles deep into British-held territory. Their failure to produce a decisive breakthrough from this initial success was attributable to several factors, not least among them being the dogged resistance of those troops who were able to fight back. Indeed, where the island defences of the British were occupied by troops determined to resist, the Germans were held up and stopped. Nevertheless, the German failure was logistical, as well as being caused by a severe lack of mobile tactical support from the artillery which could not keep up with the pace of the initial advance. Logistically, the Germans had not planned how to carry ammunition, food and water across the devastated landscape over which the infantry advanced so rapidly. Moreover, for all their tactical fluidity at the start of the offensive, they lacked the mobility to exploit success.
These shortcomings were not solved in the succeeding offensives over the next few months, which became successively more desperate with an inevitable reversion to old-style tactics. This was in part due to the loss of trained stormtroop units who suffered very high casualties during these operations. The British, the French and, increasingly, the Americans, who were now actively involved in combat operations on the Western Front, succeeded in containing the Germans by employing greater tactical flexibility in defence than had been the case in previous years. British and French artillery fired in depth at the German reserves, ammunition supplies and headquarters, rather than on the leading waves of German troops who were engaged by the infantry, machine-guns and mortars. The Stokes mortar, in particular, proved quite capable of inflicting severe casualties on the German infantry.
By the time the Allies went on to the offensive in July 1918, the face of battle on the Western Front had changed completely from what it had been even nine months earlier, let alone during the battles of 1915 and 1916. While trench warfare persisted almost to the end of the war, the mobility of battles in the last few months was a far cry from the slogging matches of the earlier years. The manner in which the Allies employed artillery in defence and attack in 1918 was quite different from the past. The emphasis was on depth, engaging targets well beyond the reach of its infantry, and hitting them hard and simultaneously or in quick succession. Thus, instead of supporting the infantry by directly hitting targets which they were about to engage, the artillery struck targets which prevented the movement of enemy troops and artillery on the battlefield, thereby disrupting his ability to create effective counter-attacks. Areas where infantry might form up for a counter-attack, as well as defensive positions well behind the front line, were hit with sudden and intense predicted fire. Headquarters and gun batteries as well as road and rail links were all hit. Dead ground was targetted by Stokes mortars so that troops sheltering from the artillery were still hit. Air power also played a big role in operations, not only spotting for the artillery, but bombing troops behind the lines.
At Amiens in August 1918, tanks and aircraft worked cooperatively ahead of the infantry to deal with the wire, so that the artillery could focus on more distant targets. Tanks were employed to create gaps in the wire, ahead of the infantry, while aircraft flew ahead of the tanks to locate and engage anti-tank guns by bombing and machine-gunning them before the tanks arrived. Aircraft also flew interdiction sorties to hit roads and railways to disrupt reserves and cause mayhem. Nearly 2,000 Allied aircraft took part in the Amiens offensive as the German Army was severely mauled and forced into headlong retreat. There was no preliminary bombardment before the battle opened on 8 August with an unheralded hurricane bombardment which delivered a weight of fire that in 1917 would have been taken several days. The BEF employed 630 tanks on the first day, although the number of serviceable tanks fell off sharply over succeeding days. Their reliability and, indeed, workability was very poor. Tank crews could not tolerate more than a few hours of continuous action because the conditions inside the machines were too uncomfortable.
All these factors worked together in a new form of warfare, referred to as three-dimensional warfare. This year of the war saw the emergence of what was to become known as deep battle, whereby the artillery fired deep into enemy territory rather than focusing on the front line to be engaged in the infantry assault. These concepts were developed in direct response to the stalemate on the Western Front. They have remained at the heart of modern warfare ever since.
The emergence of these new forms of warfare, along with the ever-widening employment of tanks on the battlefield, led to the development of new types of weapon to, on the one hand, counter the tank, and on the other, provide close artillery support to the infantry who accompanied the tanks. The former led to the development of anti-tank guns, the anti-tank mine (extemporized from artillery shells buried in a hole), while the latter led to the self-propelled gun, an artillery piece on tracks which could keep up with the infantry. Warfare would never be quite the same again.