It was very terrible. Often the other side used poison gas to kill the soldiers.
The type and nature of the trench positions varied a lot, depending on the local conditions. For example, in the area of the River Somme on the Western Front, the ground is chalky and is easily dug. The trench sides will crumble easily after rain, so would be built up ('revetted') with wood, sandbags or any other suitable material. At Ypres, the ground is naturally boggy and the water table very high, so trenches were not really dug, more built up using sandbags and wood (these were called 'breastworks'). In parts of Italy, trenches were dug in rock; in Palestine in sand. There were rats constantly gorging on remains of dead men
The bird's-eye view (below, from an official infantry training manual of March 1916) shows a typical but very stylised trench layout. There is a front line, or "Main Fire Trench" facing the enemy. It is not straight, but follows contours or other natural features allowing good defence or a view over the enemy lines. Thousands of men became casualties in fighting for, or making small adjustments to their lines, to give this cover or observation. It also is dug in sections rather than a straight line, so if a shell explodes inside one of these 'bays' (also called 'traverses'), or an enemy gets into one, only that section is affected. Behind it is another line, similarly made, called a support line. In this would be found 'dugouts' cut into the side of the trench wall, often very small but with room for perhaps three or four men to squeeze in for shelter, or for a telephone position for a signaller, or for a Platoon or Company HQ. Communication trenches linked the rear areas with both lines, and it was along these that all men, equipment and supplies had to be fetched, by hand. Probing out from the front line were trenches usually called 'saps', which often went beyond the protective belts of barbed wire, terminating somewhere in 'no man's land' between the two opposing front lines in a listening post, manned by one or two infantrymen. The cross-section shows how the front and rear of the trench was ideally protected and built up using sandbags at the front and rear, or 'parapet' and 'parados'.
The enemy had a very similar system of trenches. The distance between the two lines varied from as little as 30 yards (just under 30m) to several hundred yards. The space between the two opposing lines was called no man's land.
As defensive and offensive tactics developed later in the war, trench positions became formidable fortresses with barbed wire belts tens of yards deep in front of them, and concrete shelters and emplacements, often below ground level. Machine guns would be permanently trained on gaps deliberately left in the wire, and the artillery would also have the positions registered for firing at short notice.
Trench cross-section Where possible, the floor of the trench was made by using wooden duckboards. One of the features the diagrams above do not show is the latrine, which had to be dug somewhere close to hand. This was generally as deep a hole in the ground as possible, over which was mounted a plank to sit on. Men would, with permission, leave their post to use the latrine. This rough form of snaitation was often a target for enemy snipers and shellfire, and was also a considerable smell and health hazard for the men in the trenches.
The conditions of the trenches in WW1 were very poor. Whenever it rained, the water would pool up down towards the bottom of the trenches,and all of the soldiers had to step in all that water everyday until it dried, which took a very long time.
Life in the Trenches was extremely bad. When it rained the ground would flood. The soldiers would have to walk through the water and that would end up causing TRENCHFOOT. Trenchfoot was when the foot was wet all the time and ended up rotting away. There were also Rats that would eat off the dead bodies and sometimes the live bodies. It is said that the Rats got as big as a normal size CAT!!!! There were also many diseases spread from one to the other. Mainly through the bathroom use. They had no showers so they began to smell, and lice spread quickly
Rats and lice filled the first world war trenches, and there was a huge stench. Rats ate from dead soldiers, and if they were very hungry, males would sometimes attack injured or sleeping soldiers. Beds were on ground level, and one had to be aware when asleep, as rats would eat through your boots and clothes. An injured soldier was a treat for the rats, and they would eat from the bare wound.