Battlefield Innovations: 1915–1917

French Trench in Vosges Mountains, 1915

By David Stevenson

Although the Western Front remained static in 1915–17, it would be wrong to assume that tactical procedures failed to adapt to the new conditions, despite the stereotyped view that attacking forces simply went on repeating the same mistakes. On the contrary, we can see an evolution towards better coordinated combined operations. In September 1915 and April 1917 the British and French armies on the Western Front attempted sequenced offensives, a preliminary blow drawing off the German reserves before the main attack came in a different sector.

 At the Chantilly conferences of December 1915 and November 1916 the Allies adopted even more ambitious plans for synchronized offensives in summer 1916 and spring 1917 respectively. The summer 1916 schedule of attacks (Russia’s Brusilov offensive in June 1916; the Anglo-French Somme offensive starting in July; Romania joining the Allies in August; and Italy’s capture of Gorizia in the same month) placed the Central Powers under great pressure, and the Allies agreed to follow it up with still more powerful synchronized attacks in the following spring, until the March 1917 revolution in Russia disrupted this scheme.

In summer 1917 the British planned to combine an inland advance from the Ypres salient with an ambitious amphibious landing on the Flanders coast in order to  capture the ports of Ostend and Zeebrugge (which the Germans were using as destroyer and submarine bases), although this project failed to get beyond the first phase.

At the tactical level, moreover, the Allies were improving their capacity for all-arms operations. They developed more sophisticated air reconnaissance and photography, and began locating enemy artillery by flash-spotting and sound-ranging. First the French and then the British experimented with the "creeping barrage:" a protective curtain of field-gun fire running just ahead of the attacking infantry, which if correctly timed would force the defenders to keep their heads down until the attackers were virtually upon them.

But the Germans (who by and large were on the defensive on the Western Front) meanwhile evolved new counter-techniques of defensive warfare, particularly  after Paul von Hindenburg and Erich Ludendorff took over the German Army High Command (Oberste Heeresleitung—OHL) in August 1916. These techniques included building ever more elaborate trench fortifications, which by 1917 might comprise five successive defensive systems, each consisting of three principal trench lines plus communication trenches and including deep dugouts—or continuous trenches might be abandoned in favour of mutually supporting and camouflaged concrete strongpoints. But in addition, the Germans concentrated fewer troops in the first line (where they were most vulnerable) and held them further back for prompt counter-attacks, while their artillery lay further back still and mostly survived Allied bombardments. These methods worked well against the French Chemin des Dames offensive in April 1917 and against the British Third Ypres offensive during August.

Mine-Destroyed German Trench on Messines Ridge, 1917

More generally, the German army had a strong tradition of systematic and self-critical learning from experience and regular revision of doctrine. Not only was it developing new defensive tactics but it was also developing new offensive ones: particularly the Bruchmüller artillery system and the "stormtroop" (Stosstruppen) tactics for infantry, which will be discussed further in the next section. These methods can be seen developing from the Battle of Verdun in 1916, via the operations in Galicia (July 1917), at Riga (September 1917), and at Caporetto (October 1917). 

The Battle of Cambrai in November 1917 encapsulated the new developments. The initial British attack there used 476 tanks and a surprise artillery bombardment and air strike, before the infantry broke through the German lines. But a German counterattack two weeks later, delivered by specialized assault troops who also achieved surprise, recaptured much of the lost ground. At this stage the two new systems seemed more or less to cancel each other out. 

From: "Joint or All-Arms Warfare on the Western Front, 1918,"  2014 International Forum on War History: Proceedings