Trench construction was difficult. According to the British trench guidelines, it took nearly six hours for 450 men to construct 250 meters of trench. After this they would have to add the other materials necessary: barbed wire, board walks, and sand bags, for example. There were three main ways of constructing trenches: entrenching, sapping, and tunneling. Entrenching is the “normal” method of digging that you and I would use: standing on the ground, and digging downwards. This method was most efficient, as it allowed for many men to construct a trench at once. However, it also left the men exposed to the enemy above ground. Sapping involved digging at the ends of the trench inwards. Only a few men could do this at a time. Tunneling is exactly as it sounds like: it is like sapping, but leaving ground overhead that would later be removed.