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Patent classifications
E
FIXED CONSTRUCTIONS
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E21
EARTH OR ROCK DRILLING; MINING
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E21D
SHAFTS; TUNNELS; GALLERIES; LARGE UNDERGROUND CHAMBERS
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11/00
Lining tunnels, galleries or other underground cavities, e.g. large underground chambers; Linings therefor; Making such linings in situ, e.g. by assembling
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