Topic summary
Square set timbering
Extracted from the Wikipedia article Philip Deidesheimer.
Square set timbering
Deidesheimer invented a system, now known as square set timbering, using heavy timber "cubes" as supports for underground mining tunnels and shafts, that enabled skilled miners to open three-dimensional cavities of any size. In large openings, the cubes could be filled with waste rock, creating a solid pillar of wood and rock from floor to roof ("back" in miner's terminology).