Inside the WWI Trenches: Warfare, Survival, and the Soldiers' Experience

The dreadful birthplace of a new form of war

What is Trench Warfare?

No phrase is associated as closely with World War I, especially the Western Front, as "trench warfare." The impenetrable line of defenses dug into the ground, crossing much of Europe from the Swiss border to the North Sea, became the symbol of the war: dreary waiting in mud-filled, disease-riddled pits; disastrous human wave attacks across no man's land into barbed wire and enemy machine gun fire; and the technological race to break the deadlock that was draining the blood of all belligerent nations. This article, dedicated to the British and Commonwealth, French, American and German soldiers who fought and died on the Western Front, will shed light on WWI trenches: why and how they came to be, what it was like to live and fight in them, and what it really was that finally ended the stalemate.

Origins of Trench Warfare in WWI

The use of trenches on a battlefield predated the Great War by centuries. Trenches were dug by armies besieging a castle or a walled city to allow the attackers to move closer while being safe from defensive cannonfire. Even before the era of gunpowder, the Byzantines used trenches against the Persians at the Battle of Dara in 530 A.D., and an entire battle between Muslim Arabs and the pagan Quraysh tribe in 627 A.D. Is known as the Battle of the Trench after the defensive works constructed by Muhammad.

In the modern era, the use of the trenches got a new lease on life thanks to their effective defense against artillery. Some historians state the one of the first pioneers of modern trench warfare were the native Māori of New Zealand, who made good use of earthen fortifications and trenches against the superior firepower of British cannons and muskets in the mid-19th century. The sieges of Vicksburg and Petersburg during the American Civil War saw the construction of massive trench systems (over 30 miles <48 km> of trenches dug at the latter) and a style of fighting that presaged World War I, including the use of the Gatling gun, which was a precursor of machine guns. The Civil War also saw the first use to wire obstacles, another future World War I staple, when Union General Ambrose Burnside had telegraph wire strung between tree stumps to slow down a Confederate attack during the Battle of Fort Sanders. The Crimean War, the Paraguayan War, the Second Anglo-Boer War in South Africa, and the Russo-Japanese War of 1904-05 all saw the use of large trench systems.

What Made Trench Warfare Necessary?

Advancements in engineering, metallurgy and chemistry, however, led to the development of heavy artillery, which lobbed shells in a high arc and had enough range to bombard the battlefield from a safe distance. If both sides positioned their heavy artillery close enough to hit enemy infantry and cavalry but still at a safe distance form enemy artillery, soldiers actually standing on the field of battle became helpless victims without the ability to strike back. And yet you still needed soldiers on that field, since they had to stop the German army from marching up to your artillery and destroying it.

Modern trenches were a solution to this problem. Built narrow and relatively deep, soldiers staying inside the trench were safe from the shrapnel and blast wave of most shell impacts, and could only be killed by a direct hit, while they themselves could still shoot at any enemies approaching them.

When Germany attacked into France and Belgium in the fall of 1914, they expected to capture Paris and destroy French and British forces in 40 days. After the invasion was held up at the First Battle of Marne, both sides started to dig in. Once a trench was established, machine guns and accurate, powerful, long-range rifles made it seemingly easy to hold it against a frontal attack. As we will later see, however, the real problem of trench warfare was not taking an enemy trench; it was taking and keeping it.

The best way of defeating an enemy trench is to simply go around it, since trenches don't move; and this was what both sides started doing. Of course, each attempt to flank the trenches ran headway into the enemy's flanking attempt, forcing both sides to dig some more trenches. The next attempt to outflank these new trenches led to another meeting and more digging, and so on. In about one month, this process, now called "the Race to the Sea," led to the two sides digging a continuous trench system from the border of neutral Switzerland in the south to the North Sea, where it ran into the water some 15 miles (24 km) from the same Dunkirk (Dunkerque in French) that would witness the miraculous British evacuation in World War II. (Read our earlier article) With no more ground to execute flanking attempts on, the frontline froze and the belligerent sides set about figuring out how to break through the enemy's trenches.

Construction of WWI Trenches

So, what did a trench look like? A typical fire trench, the one closest to the enemy, was about 3-6 ft (1-2 m) wide and at least 8 feet (2.5 m) deep so that soldiers in trenches could stand up straight and still be protected. Since you can't shoot your rifle if the edge is 8 feet up, there was a fire step you could stand on and an elbow rest just below the crest. The reinforced outer side (facing the enemy) was called the parapet. A similar reinforcement, called a parados, was often but not always built on the ground behind the trench. The purpose of the parados was to offer additional protection against shells and bombs that might hit the ground behind the trench, so shrapnel wouldn't hit soldiers in the back or neck.

The sides of the trench were usually reinforced with sandbags, wire mesh or wooden frames to make them more resistant against artillery strikes. The floor was often covered with wooden duckboards to protect soldiers' feet against water gathering at the bottom; these boards were later elevated and placed atop a wooden frame to allow drainage. Some trenches had corrugated metal roofs for additional defense against shrapnel.

Firing out of a trench was risky, since you'd need to pop your head above the parapet to aim, which would make you a target for enemy snipers. The loophole was a solution, either just a gap in the parapet, or a purpose-made metal ring, which could be covered up with a metal plate. By pushing the plate aside, you could look out and aim through the hole. Of course, snipers on both sides quickly learned to aim for the loopholes and shoot when they opened, and the Germans even had special armor-piercing rifle rounds to go through even a closed plate. The best protection against snipers was to first raise a cap or helmet as distraction, open the loophole while standing to the side, and wait a bit to see if there's a reaction.

Another way to defeat snipers was to observe the no man's ground via trench periscopes, and to use periscope rifles which were designed to be lifted up above the shooter's head and fired (with less accuracy) without exposing oneself.

Trenches never ran straight. An enemy jumping into a trench and pouring gunfire down it could kill a lot of men, and so could the shrapnel and blast wave of a grenade tossed inside. To avoid such hazards, trenches were constructed with frequent traverses, zigzagging turns that prevented hot lead from flying down the entire length of the trench.

Some 70 to 100 yards (65 to 90 m) behind such a firing trench ran a second, parallel support or travel trench, which troops from the firing trench could retreat to during enemy shelling. The support trench also had dugouts in the side for additional protection. British dugouts were usually 8 to 16 ft (2.5 to 5 m) deep; the Germans were much better at trench construction and made superior concrete dugouts which were at least 12 ft (4 m) deep, had up to three levels, a ventilation system, concrete staircases, and were essentially bomb-proof (though they could still be buried by rubble).

The reserve trench was a third line, located a further 100 to 300 ft (90 to 270 m) to the rear. If the firing trench was captured by the enemy, this was where reserve troops would amass for a counterattack. The three trenches were connected through communication trenches that ran perpendicular to them and allowed troops to move from trench to trench without exposing themselves.

Additional trenches could also be built temporarily. Assembly trenches were built near the front in preparation of an attack. Once the first wave went over the top from the firing trench, subsequent waves of soldiers could quickly jump out of the assembly trenches and follow them. Saps were unmanned, often dead-end trenches dug towards the no man's land. These could be used as jump-off points for a small-scale raid, or connect the firing trench to a secret listening post close to the enemy's trenches, where sappers would be listening with stethoscopes for enemy movement.

Behind each such multi-line trench system usually lay at least two more (though not quite prepared), which the defenders could withdraw into should the entire first trench system be lost. German lines also included lines of redoubts, standalone fortifications behind the trenches. These could fire at attackers trying to move to the second trench line, and since they were not connected to the trenches or each other, capturing a single redoubt did not give access to the rest.

Where Were the WWI Trenches Located?

Local geography influenced how trenches could be built and used. In France, the limestone layer below the soil was suitable for tunneling, and this section of the front saw numerous attempts to tunnel over to enemy positions and blow them up from behind with explosives. Some of these attempts, such as the famous Lochnagar Mine near the village of La Boisselle, are still prominently visible today.

In most of Belgium, the water table is only about a yard below the surface, so any trenches dug would have been quickly flooded. The soldiers compensated for this by building upwards, erecting parapets above ground level, but often skipping the parados in the back.

In the Alps along the Italian front, trench warfare extended deep into the high mountains and vertical cliffs. This not only necessitated digging into hard rock, but also led to trench building in the high mountains – the highest-altitude trench in history was located just below the peak of the Ortler, 12,630 ft (3850 m) above sea level. The caves and glaciers in the mountain ranges allowed for massive underground defenses, and Austro-Hungarian troops even carved an entire "City of Ice," with 7.4 miles (12 km) of tunnels with chapels, stores and sanatoriums, into the Marmolada Glacier in the Dolomites.

The Eastern Front was far too huge for a single continuous trench system, but individual areas of frequent fighting did see the digging of localized trenches. The trenches of the Middle East theater always had exposed flanks where the desert began, since you couldn't extend the trenches into the sand. The same deserts, of course, also made flanking attempts very difficult.

No Man's Land

The infamous no man's land was the stretch of ground between the front trenches of opposing armies. Along the Western Front, the strip was usually 100 to 300 yards (90 to 270 m) wide, though it shrank down to a mere 30 yards (27 m) at the Vimy Ridge. In one location at Gallipoli in Turkey, the trenches were a mere 16 yards (15 m) apart, allowing Australian, New Zealand and Turkish soldiers to lob hand grenades into the enemy's trench at any moment without warning. The no man's land was typically broken and pockmarked by artillery shell craters, which could fill with water to make them even more daunting obstacles.

Barbed wire obstacles were added by both sides to slow down enemy assaults. Rather than pulled taut, such obstacles were often loose like concertina wire, to better trap people trying to cross. Wiring parties went out nightly to repair and expand their own obstacles and remove enemy wire. Screw pickets, invented by the Germans but also adopted by the Entente powers, were metal augers which could hold the wire. They could be twisted into the ground without having to hammer away at a stake, which tended to attract enemy fire even at night. To their chagrin, the British found that the Germans used thicker wires, which British cutters, designed for thinner British wire, couldn't cut. A quick alternative during an assault was for one soldier to throw himself on the wires and hopefully push them to the ground, allowing others to cross. Intensive artillery bombardment also had a chance to cut up wires, but was an unreliable and expensive method.

Life in the Trenches

Since popping up above the parapet was a deadly risk, soldiers spent most of their day with quiet amusements like gambling or reading trench magazines (often written and printed by the soldiers themselves) which were full of poetry, short stories, songs, cartoons and jokes.

The "stand-to" was a daily activity each dawn (and sometime in the evening), when the firing trench was occupied in force in expectation of an attack. At other times, the trench was only occupied by a light force, and the bulk of the unit would be further back to avoid mass casualties in the first minutes of an enemy shelling and assault.

Nights were not only the time for sleeping, but also a flurry of activity. This was when wiring parties went out, scouts departed to spy on the enemy trenches, and fresh troops and supplies were moved up. It was also the time for small-scale trench raids which targeted a small part of the enemy positions and concentrated on capturing prisoners and documents. Such raids were also considered a moral booster, as soldiers participating in them proved less demoralized by the daily tedium of the trench.

Disease and vermin were a fact of trench life. Trench fever, spread by body lice; gas gangrene, caused by bacteria from manure-fertilized soil getting into a wound, various intestinal parasitic worms; and the infamous trench foot, caused by extended exposure to water gathering in the trenches, caused great misery and a steady death toll and often long-term health effects.

The millions of rats were another problem. Beside spreading disease, they also prevented rest by crawling over sleeping soldiers' bodies and faces, or by making a noise in no man's land that people mistook for the sounds of an upcoming attack. Cats and dogs were often kept to hunt the vermin down, and hunting rats with bayonets (to save bullets) became a popular pastime. Attempts to kill the pests with toxic gases were abandoned once those chemicals started taking a toll on the soldiers. Civilian ratcatchers were sometimes brought in to deal with the problem. Some soldiers also took individual rats as pets, but most veterans generally considered rats one of the worst experiences during the war. It's been suggested that the extremely negative view of rats in western culture today is directly attributable to soldiers' experiences in the Great War.

Units were frequently shuffled out of the trenches to help them deal with the stress. A typical British soldier spent 15% of his time in the firing trench, 10% in the support trench, 30% in the reserve trench, 20% at rest away from the trenches, 25% on other activities like leave, travel or a hospital stay.

Join us on our World War I Tour to see the remnants of the trenches on the former battlefields and learn more about the daily struggle soldiers had to go through during the trench warfare.

The Tactics of Trench Warfare

The biggest question about trench warfare is this: why were trenches so effective? What made them so hard to take? Popular history often holds that it was a matter of defensive technology (machine guns and barbed wire) outpacing offensive technology, and the stalemate ended when the latter caught up. Popular perception also puts the blame on incompetent generals who failed to see the futility of frontal assaults. This is rather unfair; while the war had its share of bad commanders, there were also plenty of highly competent ones who recognized the trench problem early in the war, they just didn't yet have the tools to overcome it.

The ultimate source of the problem was artillery. For most of gunpowder history, artillery in a field battle meant field guns; light, relatively mobile cannons that fired shots at a low arc and had a relatively short range. Deployed alongside a large number of infantry and a small amount of cavalry, field guns could support both, but could themselves be destroyed or captured by the enemy. This started changing in the second half of the 19th century, when advances in engineering, metallurgy and chemistry led to more powerful guns: heavy artillery, which fired high arcing shells and had the range to hit enemy troops from a safe distance at which infantry, cavalry or field artillery could not shoot back. Your infantry was exposed to a weapon they could not neutralize, but you still needed to have that infantry on the battlefield to prevent the enemy from simply marching up to your own heavy artillery and taking it.

A narrow and deep trench was the obvious answer, since the vast majority of shells would miss it, while you could still use machine guns and powerful rifles to shoot down the enemy trying to approach your own guns while slowed down by barbed wire.

So how do you take an enemy trench, and why is it so hard? If you simply go over the top of your own trench and rush across, you'll be cut down by enemy fire. The solution, it would seem, is to shell the enemy trench with your heavy artillery to destroy defenses and kill the men, and then rush across and occupy the remains of the trench.

This was tried early in the war and didn't work. While bombardment was great at killing some of the defenders and destroying some of the defenses, most of the men simply retreated into the support trench, waited out the bombardment in a dugout, then returned to the firing trench before the attacker could cross no man’s land.

The next step was the invention of the rolling or creeping barrage. Your artillery would simultaneously hit along a line close to and parallel with your own trench. The next salvo would hit in a line a bit closer to the enemy, the third a bit even closer, and so on until the final salvo struck the enemy trench itself. Your own soldiers could walk behind the barrage (a practice called “leaning on the barrage,” arriving at the enemy firing trench just as the last salvo strikes. This was actually a workable way to get your soldiers across, and they would get to the enemy immediately after the first line of defenders was suppressed, not giving them time to man their positions again. Once the attacker was at the lip of the trench, he was in a great position: he could shoot down into the trench, throw grenades, or enjoy an advantage with close combat weapons like bayonets, clubs or shovels with sharpened edges.

Contrarily to what you might see in many historical films, this initial advance on the enemy front line was usually successful, and the attack only failed later. Once the attackers secured a part of the enemy trench, they suddenly found themselves in a tight spot. Any ammunition and heavy weapons like field guns had to be slowly and painfully hauled across the no man's land, which your own rolling barrage had just turned into a labyrinth of steep, slippery shell craters. Meanwhile, the defenders could safely and quickly bring up reinforcements and supplies into their reserve trench, which, in turn, could be easily reached from the nearest train station. Once there were enough defenders in place, they launched a counterattack which almost always killed or drove out the attackers stranded in the firing trench, reinstating the status quo. And this was the main problem: capturing a small part of the enemy trench system was surprisingly easy; holding it was impossible, because you were separated from the rest of your forces, while the defenders were still connected to theirs. The Germans in particular become noted for their prompt and fierce counterattacks after an Entente assault.

How Not to Defeat a Trench System

One way to break this stalemate that was tried and didn’t work was to only ever defend. This didn’t work because the defenders usually took casualties comparable to the attackers. If you never try to actually attack and break through the enemy trench lines, you resign yourself to a bloody war of attrition until one side just runs out of people. However, you would have similarly ghastly losses even if you won, which was politically unacceptable for the leaders of the war's belligerent nations.

If you can't afford to win by attrition, you can turn to technological miracles to gain the upper hand. Aircraft first saw military service in reconnaissance, identifying troop buildups and acting as artillery spotters. It wasn't a big leap of logic to try and turn the artillery spotters in the air into a sort of artillery by putting bombs on them. The problem was that aviation was still in its infancy, and the weak engines of the time did not allow for anything even resembling a useful bomb load.

The tank was a similar attempt to break the stalemate with a new kind of vehicle. It was a British invention, famously supported by Winston Churchill, the First Lord of the Admiralty (the political head of the Royal Navy) at the time. The idea was to create a vehicle that could cross the cratered surface of no man's land thanks to its tracks, withstand enemy fire thanks to its armor, suppress and destroy enemy infantry and fortifications with its machine guns and cannons, and act as a mobile shield for the infantry following closely behind.

Popular history often claims that it was the tank that ended trench warfare in World War I, but this is not true. The first use of tanks on the battlefield was on September 15, 1915, during the Battle of the Somme. Of the 49 tanks sent to the battle, only one-third actually managed to cross no man's land without getting stuck, breaking down or being taken out. Only three were still in operation on the second day. While the idea of the tank was quickly picked up by other nations, and the tank eventually became a major force to reckon with on the battlefield, the tank technology of the Great War was just far too immature and too riddled with teething problems to solve the trench problem.

The third and most infamous technological innovation to overcome trenches were chemical weapons, which could, in theory, simply disable or kill the men in a trench even before the attacker got there. Non-lethal tear gas was first used by the French in August 1914, followed by several types of lethal gasses, first deployed by Germany in April 1915. (Note the dates: they show that military leaders quickly recognized the tactical problem posed by trenches and were already working on solutions in the first year of the war.)

Chlorine was the first lethal gas weapon, and could cause permanent lung damage even to survivors. Phosgene, first used in December 1915, was 18 times more lethal and harder to detect. The most dreaded poison gas of the war, however, was mustard gas. It was less lethal than phosgene, but it stuck to surfaces and lingered, able to cause harm in the affected trenches for a long time after the attack. Additionally, it could also cause intense pain and blindness by simply coming in contact with the skin, the eyes or an open wound, even when the gas wasn't actually breathed in.  It was also heavier than air, which meant it gathered inside the trenches rather than being blown over.

And yet, despite how terrible poison gas was, it just wasn't very effective in the big picture. Soldiers quickly learned to urinate on a rag and tie it in front of their mouth and nose, since urea, a chemical compound found in urine, could neutralize early poison gases. Soon after, gas masks appeared in the trenches in great numbers, providing protection against some, though not all gases. Adamsite, an American invention, was one particular irritant that penetrated masks and forced soldiers to take them off, exposing them to the more lethal compounds.

But even so, just deploying chemical weapons was problematic. Firstly, it was unreliable, and a change in the wind could, and sometimes did, blow the gas back into the attacker's trenches. Secondly, even the more potent chemical weapons of the war were needed in very large quantities to have a meaningful effect; producing them was very expensive; and the gases of the time had a short shelf life and thus needed to be deployed quickly, without a long buildup for a major assault. All in all, experience showed that the same amount of damage could be done to the enemy at a lower cost with ordinary explosive shells.

With technology failing, changing doctrine, the way battles were fought, seemed like an alternative. The British and the French experimented with smaller-scale attacks: once the rush across no man's land and the initial assault succeeded, the attackers did not try to gain more ground. Instead, they stopped and started rapidly fortifying the small patch of the trench system they managed to capture. This method, when repeated with enough perseverance, was somewhat successful in slowly dislodging the Germans, but still involved very high casualties which political leaders, still hoping for a "cheap" victory through technological advancement, found unacceptable until 1918.

The Germans went even farther with infiltration tactics. Stoßtruppen ("stormtroopers") would launch small attacks at the weak points in the enemy trench line. Such an attack was preceded by a hurricane barrage, which concentrated on a much smaller area than usual, but was also much more intense. Stormtroopers, equipped with an unusually large number of automatic weapons, grenades and flamethrowers, would bypass strongly held positions and move ever forward to capture valuable targets in the rear like enemy headquarters, disorient the defenders, and help surround them. Meanwhile, a follow-up force of regular infantry would launch a frontal assault and finish off the confused defenders. (The Germans weren't the only ones to experiment with such tactics, but they are the best-known for it. The French also tried similar attacks, and so did the Russians on the Eastern Front, though the latter mainly because shortages of artillery ammunition forced them to.)

Such infiltration attacks proved very good at overrunning the enemy and sometimes even defeating multiple trench lines, but they failed to solve the fundamental problem: once the attackers took their targets, they were still separated from their supplies and reinforcements by no man's land, and the defenders could still mount a counterattack.

The End of Trench Warfare

So, what did solve the trench problem? In short: the worst-case scenario played out, the very thing commanders were trying to avoid throughout the war. In the end, attrition won. After several years of Entente naval blockade around German sea ports, food and many industrial resources simply ran out. The situation on the German home front became so bad that the government collapsed. A deadly flu epidemic, and the entrance of the United States into the war with a practically limitless source of fresh American troops on the Entente side, simply left German forces without the means to fight. The trench problem could not be solved; it could only run its merciless course until one side was bled dry, if not of blood, then of resources.

In the spring of 1918, after Russia collapsed due to the Bolshevik Revolution and had to sue for peace, Germany launched one final offensive, the Kaiserschlacht ("Emperor's Battle") to win in the West before U.S. troops could join the war. The offensive made some notable headway before it inevitably ran out of steam and segued into the Hundred Days Offensive, the Entente push that ended the war. Tellingly, one of the major problems was that while German stormtroopers made rapid advances early on, supplies and reinforcements could not keep up with them, underlying that the original problem of trench warfare was still around. Once Kaiserschlacht ran out of steam, the final Entente offensive practically washed away German lines, not with technological or tactical innovation, but because the Germans could no longer put up a meaningful fight.

The Legacy of the Trenches

The horror of trench warfare and the Western Front indelibly burned itself into the collective consciousness of western society, and is considered one of the darkest periods of the European twentieth century.

The remains of no man's land still exist today in some places. The most famous is the Zone Rouge (Red Zone), which holds an unknown amount of unexploded ordnance and is polluted by lead, chlorine, arsenic, mercury and various other chemicals. The zone originally covered 460 square miles (1,200 square km); it's being slowly reclaimed, but an official estimate states complete recovery will take another 300 to 700 years at the current pace.

Trench warfare, or more accurately, the efforts to solve it, helped form much of the fundamentals of modern warfare. Air power; tanks; many advancements in artillery; and the general concept of maneuver warfare, which places emphasis on mobility over fixed defenses, can all be traced back to World War I.

The memories of the Western Front also left a mark on culture, from the works of soldier poets who fought in the trenches to the countless films that depict the period. 1917 and the German film All Quiet on the Western Front are among the most recent movies (though have been criticized for historical inaccuracies, especially the latter).

Of course, static warfare, where frontlines change slowly and with heavy losses on both sides, is still with us, and is, in fact, making a comeback in Europe. The current war in Ukraine is seeing the construction of massive defensive lines which force any advancement to be slow and tragically bloody. Only time will tell how such warfare will end this time.

Visiting World War I Trenches Today

The remains of the Western Front are among the most easily reachable World War I sites. Our World War I tour includes visits to iconic locations such as the battlefields at Ypres, the Somme, Verdun, Belleau Wood (where the U.S. Marine Corps made its first major debut on the stage of warfare), along with related museums, monuments and cemeteries. If you are interested in tanks, you can join us on our Britain at War Tour to visit the world-famous Bovington Tank Museum to discover the evolution of armored warfare from the inception of tanks during WWI.

Save 25% until December 2!