To many of the British tunnels and galleries appear as fairly spacious affairs resembling well structured underground coal mines. Such tunnels had to be built quickly and with a minimum of noise and spoil (removed earth). Timber supports were used as little as possible, as the appearance of large amounts of timber along a section of the front could alert the enemy to the presence of mining activity, and cause countermining. Mines were universally tiny, with the tunnels typically only a little larger than required for a person to wiggle through. Larger rooms occurred only at tunnel junctions where miners needed to pass each other and at the end galleries where explosives were to be placed.