TunnelTec has supplied the 2.46m diameter cutterhead and tools for Canadian contractor Dibco Underground’s TBM drives on the 15th Street Sanitary Sewer Siphon Upgrade project in Calgary, Alberta (T&TNA, March, p22).
Varied ground conditions called for the cutterhead and tools on the American Auger TBM to be re-configurable for rock or soft strata, or to operate in combination mode, during the two 300m long drives below the Bow river. The second tunnel will be excavated over the first in the US$14M contract.
TunnelTec, through its US representative American Commercial Inc (ACI), is supplying 12” front-loading disc cutters, scrapers and rippers with bolted connections as requested by Dibco to ease change in excavation mode. The tunnel lining will be ribs and lagging, and a 1.5m diameter pipelines will be installed and backfilled in place.
Dibco felt the existing soft ground cutterhead on the TBM would not be adequate for the ground conditions as presented in the bid documents. The order for the cutterhead and tools was placed in January.
