ASSAULTING A TRENCH LINE

As noted earlier, the failure of the Schlieffen Plan had resulted situation where the Germans were content to remain in control of their 1914 conquests and invite the British and French to shift them. In essence, much of the warfare on the Western Front was essentially a form of siege warfare. The British and French commanders sought a means of breaking through the static defences of the German trenches, hoping that a decisive breach would result in a return to open warfare where cavalry could be used to harry a retreating enemy and force a submission. The major set-piece battles of the Western Front were doomed attempts to achieve this decisive breakthrough. It was not until August 1918 that the British and French reached a state of understanding of the nature of trench warfare and had created a technical proficiency in successfully assaulting a trenchline.

One of the first attempts to assault a trench line was at the battle of Neuve Chappelle in 1915. The British achieved intial success as a result of an intense artillery barrage. However, they were not able to sustain the momentum of their attack and the British High Command did not draw the correct conclusions about the decisive role of artillery in mounting a successful attack on a heavily defended trench line.

The essential problem in defeating German defences was to enable the infantry to close with the German trenches without suffering huge losses. World War I was in essence a war in which set-piece battles were determined by the amount and efficiency of artillery. The Somme had shown the efficacy of an accurate “creeping barrage” in protecting the advancing infantry by forcing the German defenders to remain in their dugouts. The problem came when the artillery barrage moved on from the front line trenches to the German support line trenches. Those German defenders who had survived the initial barrage could then emerge from deep dugouts, man the trenches and pour fire on the advancing infantry. Successfully countering this defensive fire without artillery support was the key to successfully storming trenches.

The solution to this problem was the section rush. One section of a platoon could pour fire on the German defenders to suppress the level of defensive fire while other sections moved forward. These sections would then take a position and continue firing while other sections moved forward leap-frogging other section. The critical factor in this tactic was the use of the Lewis Gun, a portable light machine gun that could maintain a high rate of suppressive fire in support of rifle fire. Grenades fired from rifles were also useful in assaulting trenches. Once sections got within close range, the use of hand-thrown Mills bombs, followed up by bayonet charges, often enabled a trench line to be taken. Later the Germans developed defences in considerable depth, with the use of “pillboxes”, concrete structures containing machine guns. Suppressing fire from a section's rifle fire and light machine guns could enable men from another section to creep close to neutralise pillboxes with grenades through the firing slit or back entrance.

This deceptively simple approach had many implications. Firstly, it was necessary for all soldiers to be familiar not only with a rifle and bayonet, but also with the use of grenades, rifle grenades and Lewis Guns. This required extensive training. Then this leap-frogging section rush had to be practised, not only at a platoon level with its four sections, but also at company and battalion level. This tactic placed a premium on the leadership at the platoon commander and non-commissioned officer level, as these men were the ones who would actually direct the section rush during a battle. Thus the leadership and training necessary for these men, and the trust that a battlefield commander had to have in his junior leadership, would need time to evolve.

Providing the resources to enable this tactic to work (in the form of large numbers of Lewis guns, the ammunition for them, the numbers of grenades) and the repetitive training to enable men to master the weapons and to practise the tactic so that they could perform it efficiently, took a lot of time. Furthermore, the infantry needed to practise with the artillery in order to get the timing of a large scale attack right. Guns, ammunition and grenades had to be acquired. Instructions had to be written in plain English. Training grounds had to be found. Instructors had to be detached from units. Transport needed to be provided. All these demands placed a strain on the administrative capacities of the New Zealand Division.

More recently, historians such as Garry Sheffield, Robin Prior and Robin Neillands have been examining the popular conception of “chateau generals”. These historians argue that commanders such as Field Marshals Sir Julian Byng and Sir Herbert Plumer made strenuous efforts to analyse the emerging nature of trench warfare and find ways to overcome it. Working with Divisional Commanders such as New Zealand's Major General Russell, the Australian John Monash and the Canadian Arthur Currie, these commanders sought ways to break the deadlock through increasingly sophisticated fire artillery plans supporting more innovative infantry techniques and, where possible, employing emerging military technology such as tanks and aircraft. As New Zealand historian Chris Pugsley has expressed it,

“Victory in battle depended on maintaining the balance between the artillery and its ability to ‘direct massive artillery' onto the enemy's position, suppressing enemy artillery fire while providing artillery cover to enable infantry to advance, and the ability of trained infantry who because of their ‘strength, condition, training, morale or state of discipline' had the skills to fight their way forward from bunker to bunker.”

The essential problem was that although these tactics could achieve a break in to the enemy line, they could not achieve a break through . To do so would have required the immediate availability of forces (or a technology) to accomplish such a breakthrough. This was not possible because the break-ins were often on a limited scale, and the problem of battlefield communication meant that commanders could not be certain of success in committing cavalry for the pursuit of a retreating enemy. Tanks were too slow and unreliable. The reality was that any breakthroughs were limited to the pace of infantry and the ability of artillery to support them. Aerial reconnaissance was helpful, but the delay in passing messages to a commander meant that any opportunity for a breakthrough might be lost. The potential for a breakthrough remained, but it was not until late 1918 that the British were able to devise a multifaceted weapons system to finally create a breakthrough.

Such a complex approach could not be achieved overnight, and although thorough training was important, actual battle experience using the new tactics would be required to refine this approach. Pugsley argues that the nature of the military situation prevented any large scale breakthrough in early 1917.

“Limited gains at heavy cost, which historians today believe to be part of Haig's battle of attrition mindset, were the reality of manoeuvring an infantry-based army dependent on fighting their way forward on foot in a geographically restricted area defended by mass armies. Both defender and attacker were able to stockpile and use materiel and technology, but by its nature the ground gave greater advantages to the defender. …

Breaking through trench lines on the Western Front was by necessity a battle of tactical-level, small-scale manoeuvre, but because it was not one of the sweeping breakthroughs this manoeuvre has not been recognised for what it was.”

Whether this was clearly understood at the time is a moot point. It is possible that Haig and his senior generals did understand this, but that British politicians did not. In his book, The Great War Generals on the Western Front, Robin Neillands argues that British senior commanders understood that a significant advantage generally lay with the defenders, and that any effort to defeat the Germans was always going to be costly in terms of men's lives. However, he argues quite convincingly that they did as much as could be expected of any general in the circumstances of the time to come up with ideas to achieve local victories. A decisive breakthrough was never a realistic possibility, despite Haig's optimism. Rawlinson's doctrine of “bite and hold” – effectively seize a small amount of territory, hold it against the inevitable German counter-attacks and then seize some more territory – was the only practical approach.

The New Zealand Division was to become an effective exponent of Rawlinson's “bite and hold” strategy. As the winter thaw began and signs of spring returned, the New Zealand Division was training hard to master this new tactical approach. Its first real test would come in the battle for the Messines Ridge in June 1917.