Part 20 TRANSFER TUNNEL (WORK Nos. 18 and 27)
| (1) Item | (2) Diameter | (3) Height | (4) Depth to Invert (+ or – 0.5m) | (5) Existing and finished ground level (+ or – 0.5m) |
|---|---|---|---|---|
| Shaft 1 (interception shaft) (Work No. 18) | Maximum 9m | - | -11.0m AOD (18m below FGL) | 7m AOD (0m above FGL) |
| Shaft 1 vent stack and odour control height (Work No. 18) | 17m AOD (10m above FGL) | 6m AOD (1m below FGL) | 7m AOD (0m above FGL) | |
| Shaft 2 (Work No. 18) | 12m | - | -11.0m AOD (18m below FGL)
| 7m AOD (0m above FGL) |
| Shaft 1 and 2 combined option (Work No. 18) | Remaining shaft 9m – temporary excavation 20m x 10m | - | -11.0m AOD (18m below FGL) | 7m AOD (0m above FGL) |
| Shaft 3 (Work No. 27) | 12.5m | - | -11.5m AOD (21m below FGL)
| 9.5m AOD (0m above FGL) |
| Shaft 4 (Work No. 27) | 9.0m | - | -12.0m AOD (21m below FGL)
| 9.0m AOD (0m above FGL) |
| Shaft 5 (Work No. 27) | 12.5m | - | -12.5m AOD (23.5m below FGL)
| 11.0m AOD (0m above FGL) |