Trench tactics: how was war fought in the WW1 trenches?

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It was a bloodbath. Thompson recounted: “It was like pie meat for the Germans, near everyone was getting [trapped] in the barbed wire... They were just cutting us like cutting hay. The fire was rapid, continuous, machine-gun fire and shrapnel bursting. You wonder who’s going to be shot next – and I was shot next.”

Although Thompson managed to crawl back into the trench and reach safety, many of his companions weren’t so lucky. For the next two years, the Allies failed to gain control of that one, small hill.

Why was there so much trench warfare during WW1?

Millions of men perished in trench warfare, but it was one of the defining strategies of World War I – particularly on the Western Front. However, this strategy was nothing new: armies had been holing down in the earth for centuries, to avoid having soldiers exposed.

But World War I saw the strategy explode. There were several reasons for this: before the war had broken out, military technology had vastly improved: the machine gun had been unveiled in 1884, and artillery had been consistently upgraded since the late 19th century. As well as facing deadly weapons, in 1914 more soldiers were on the battlefield than ever before – meaning more men needed protection.

To avoid being massacred where they stood, in September 1914, both sides began to dig trenches that they could hunker down in and defend, and subterranean corridors soon stretched from northern France all the way to the Swiss Alps.

Although we typically have visions of trench warfare where each side unleashed a storm of heavy artillery on the enemy before sending wave after wave of men charging through no-man’s land – a hellish stretch of territory between the two trenches, tangled in barbed wire and pockmarked by craters – this is often an overgeneralisation.

For a start, in many instances no-man’s land was typically abandoned farmland, with hardly anything in it – including shell holes, at least in the early days of the war. At the beginning of the conflict, both sides were comparatively light on artillery, and simply couldn’t enact the kind of damage that we associate with trench warfare today.

However, as the war ground on, trenches grew into mighty military installations designed with defence in mind. Often working under the cover of darkness, soldiers would dig several parallel lines of trenches, radiating back from the front line and connected by a network of communications trenches. And they could be truly labyrinthine: some German systems built in 1918 stretched out over 14 miles.

What weapons were used during WW1 trench warfare?

The trenches were protected by machine-gun emplacements sheathed in barbed wire, or housed in concrete shelters called pillboxes. They also offered protection to soldiers during artillery attacks via deep dugouts, where troops could shelter and wait for the shelling to stop.

But conventional weapons weren’t the only threat soldiers faced. As the war progressed, armies turned to chemical warfare to try and gas the enemy into submission. The first major deployment of poison gas was in 1915, during the second battle of Ypres, when yellow-green clouds smelling of “pineapple and pepper” floated towards the Allied trenches. This was chlorine gas, released by the Germans, and caused thousands of soldiers to hack and cough – leaving scores with breathing problems.

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Within the space of a few months, the Allies and the Central Powers had both added poison gas to their arsenal, commonly pumping noxious gas cocktails into artillery shells. While one of the deadliest was the colourless phosgene gas – being several times more potent than chlorine gas – the ‘King of Battle Gases’ was mustard gas. If a soldier inhaled it directly, it would attack their lungs and throat as well as their eyes, nose and mouth, potentially leading to blindness or even death. Even if they were wearing a gas mask, mustard gas was still a hazard: it seeped through their uniforms and caused pus-filled blisters to break out all over their bodies.

With this explosion in weaponry, millions of soldiers were wounded or killed on the battlefield. Stretcher-bearers combed the battlefield after the fighting had stopped, and wounded men were transported several miles away to casualty clearing stations – often set up in tents – or makeshift field hospitals in abandoned buildings.

As well as physical wounds, many soldiers developed a condition called ‘shell-shock’, with symptoms ranging from headaches and tremors to partial paralysis. It was often viewed with suspicion, with some doctors believing patients with shell-shock were malingering – making up their symptoms to avoid the front lines. Treatment varied from giving patients a hot meal and a warm bed away from the fighting, to offering talking therapies or administering electric shocks.

How did the WW1 stalemate in the trenches end?

After four years of fighting, in 1918 the war finally came to a close. The Allies had learned bloody lessons at the battle of Somme, which inspired groundbreaking new tactics that were published in training manuals. Changing the rulebook resulted in key breakthroughs in 1917, such as the battle of Messines – the first completely successful British battle of the war on the whole of the Western Front.

These new tactics were combined with new technologies – like tanks, which offered vital protection against machine guns – and became the bedrock of the ‘all-arms warfare’ of 1918. The stalemate was over: in just over 100 days, the Allies finally smashed their way through the German trenches.

This article was first published in the July 2023 issue of BBC History Revealed