TH

Support Frames, Caps, Props, Laggings, Bolting, and Structural Profiled and Other Parts Thereof for Supporting Roadways, Shafts and Coal Faces of Mines, Adits and Tunnels and for Supporting Air Raid Shelters, and Bulkhead Doors and Pressure Doors for Roadways, Adits and Tunnels of Mines and for Air Raid Shelters