Vimy was the spot where the two fronts were the closest in all the war, the German trenches and the Allied Trenches were only 25m apart. Down in the tunnels there were small rooms for the officers, planning, and the Runners quarters. there were 4 ways of communication: telephone, telegraph, pigeons, and runners. The telephone and telegraph weren't good because they made noise that the Germans might hear and the wires often got blown up. Pigeons worked most of the time, but you couldn't really control where they flew to and the messages might go to the wrong person or even to the enemy. Below on the right are telegraph mountings.