Terratec TBMs enroute to Kanpur metro project

Terratec’s extensive global operation allowed the machines to undergo factory acceptance testing at two different locations – one in India and one in Guangzhou, China, which will allow two TBMs to be delivered almost simultaneously.

Contractor Gulermak-Sam India JV will use the 6.52m-diameter machines to bore the first underground tunnelling package (KNPCC-05) of the 32.4km-long Kanpur Metro Phase 1. This will involve work on the 23.8km Orange Line 1 connecting IIT Kanpur to Naubasta which has a length of 3.62km and includes four stations at Chunniganj, Naveen Market, Bada Chauraha and Nayaganj – each 215m long. The contract, including construction of the four underground stations, was awarded to Gulermak-Sam India JV in Sept 2020.

The machines are currently being shipped to Kanpur and will be reassembled on site. The first of the two Terratec machines is due to be delivered to the Bada Chauraha station site in early 2022, with the second TBM expected to arrive on site in March. The machines will be launched initially on twin 989.5m drives towards Naya Ganj, where they will bore through a geology comprising soil, clay, silt and sandy silt.

To cater for the anticipated geological conditions, the JV chose two EPB machines equipped with a spoke-type type cutterhead with 57% opening ratios – proven to be very efficient for this type of soil. For added versatility, Terratec designed the cutterhead to enable cutting tools to be exchangeable for 17’’ disc cutters, allowing the machine to bore through diaphragm walls and any unexpected obstacles, such as old wells and foundations. Tunnel linings will comprise 275mm-thick x 1,500mm precast universal-style lining rings comprising five segments plus key.

During their drives, the machines will pass beneath buildings and densely populated areas, returning to the shaft at C&C tunnel to be deployed on their next drive toward Chunniganj. From there, the TBMs will be moved through the station excavation for 215m and will continue on a further drive to Naveen Market station. The TBMs will be moved again for 215m to start their final drives to Bada Chauraha station.