Working at average depths of 14-16m, the refurbished 6.52m-diameter machine has been installing the first lining rings for the 2km tunnel that will be bored between Vikaspuri and Krishna Park Extension. The 1.4m-wide universal reinforced concrete segments are placed in a 5+1 configuration to give a 5.8m inner diameter tunnel.
Terratec’s TBM is equipped with a spoke-type cutter head with a 57% opening ratio that has proved capable of excavating previous Delhi Metro (CC-34) and Lucknow Metro (LKCC-06) phases.
With a geology comprising silty sand, fine sand, sandy silt and clayey silt, the machine’s cutting tools can be replaced by 17-inch roller disc cutters, enabling the TBM to bore through diaphragm walls and any unexpected obstacles along the way.
