A Terratec dual mode TBM was chosen for the 6.68m-diameter drive. A spokesperson for the manufacturer said, “The single shield TBM is equipped to operate in either Open or Closed mode in the predominantly fresh and slightly to moderately weathered Basalt and Breccia expected on [the Mumbai] contracts. The robust hard rock cutterheads are mounted with 17” disc cutters, which are interchangeable with ripper tools, and feature large bucket openings that provide a 10% opening ratio.”
When complete, the 33.5km-long Mumbai Metro’s Line 3 will be the first underground metro line in the city. It will have 26 underground and one at-grade station. Construction of the line is divided into seven tunnel-and-station packages that were awarded to five contracting joint ventures in 2016. These five contractors will deploy a total of 17 TBMs
