By 1915 the bolt Lee Enfield Rifle with a range of nearly a mile could fire 25 rounds a minute. Even more devastating was the Vickers Machine Gun which fired 600 rounds a minute. The howitzer could fire shells eight miles. Add grenades, flame throwers and eventually gas and it's no surprise that by the end of 1914 both sides had dug into the earth like moles in a desperate attempt to stay alive.
The resulting trench system on the Western Front covered 25,000 miles (enough to encircle the world) but also stretched non-stop from Belgium to Switzerland. Each trench was approximately 10 feet deep. The soldiers lived their lives in these trenches. They slept, ate, fought, and even entertained themselves in these narrow holes in the ground. Halfway up the trench were ledges called "fire steps" where the soldiers could shoot from. In many of the trenches the soldiers would look over the top with a periscope; they would sleep in holes dug into the sides of the trench called dugouts. Front line trenches were separated by an area called no-man's land which could vary in width from a few hundred yards to a mile. Each side protected their trenches with masses of barbed wire. Behind the trenches were the heavy guns of the artillery, designed to weaken the enemy before an attack. They usually failed.
During the winter heavy rain flooded trenches and turned them into mud pits. This was especially the case towards the Netherlands ('low lands') which are prone to flooding, and reverted to swamp when artillery fire destroyed the sophisticated irrigation networks built up over the centuries. .
'The moment you set off you felt that dreadful suction. It was forever pulling you down, and you could hear the sound of your feet coming out in a kind of sucking 'plop' that seemed much louder at night when you were on your own. In a way, it was worse when the mud didn't suck you down; when it yielded under your feet you knew that it was a body you were treading on.