IPC Subgroup
E21D 5/11 with combinations of different materials, e.g. wood, metal, concrete
Introduced: September 1968
Last revised: January 2006
Full Title
Lining shafts; Linings therefor > with combinations of different materials, e.g. wood, metal, concrete
Classification Context
- Section:
- FIXED CONSTRUCTIONS
- Class:
- EARTH OR ROCK DRILLING; MINING
- Subclass:
- SHAFTS; TUNNELS; GALLERIES; LARGE UNDERGROUND CHAMBERS