Boyau de londres

A tunnel runs perpendicular to the front and leads to the trenches. It enabled troops and equipment to be moved close to the front line, sheltered from the various projectiles. The movement of men in these trenches was no easy task: continuous or untimely bombardments, sectors under fire from snipers on the lookout, rain and mud, telephone wires on which infantrymen stumbled, night-time conditions that encouraged them to lose their way, were all pitfalls that made movement perilous.

It was used to relieve regiments, supply food and ammunition, and transport the materials needed to build and repair trenches and shelters. Liaison officers also used them to carry written orders. In the Douaumont sector, in order to prevent the walls from collapsing, the sides of the trench were reinforced with a concrete structure. The walls of the casing were shored up by reinforced cement U-bolts holding plates of the same material