108700017836Prophet of Pit-1Proteins0.000description1
239000002023woodSubstances0.000description1
Classifications
E—FIXED CONSTRUCTIONS
E21—EARTH OR ROCK DRILLING; MINING
E21D—SHAFTS; TUNNELS; GALLERIES; LARGE UNDERGROUND CHAMBERS
E21D11/00—Lining tunnels, galleries or other underground cavities, e.g. large underground chambers; Linings therefor; Making such linings in situ, e.g. by assembling
E21D11/14—Lining predominantly with metal
E21D11/34—Joints between vertical props and horizontal top bars