The first of two Herrenknecht Tunnel Boring Machines, (S-711) operated by Transtonnelstroy Afcons JV, broke through the headwall of the cut-and-cover station at Chennai Central to complete its drive from Washermenpet to Central Metro covering a total of 3.4km-long drive.
According to a press release, during the drive since its launch at Washermenpet, the S-711 has travelled beneath around 850 buildings, several arterial roads including the Poonamallee High Road to reach Central Metro, railway lines at Fort MRTS station, bridges and the Buckingham Canal in the stretch along Mannadi, High Court to reach Chennai Central as part of Corridor 1 of Phase 1 of the Chennai Metro Rail Project.
It is a major milestone in the tunneling works. From here onward, the works to get the TBM out, cover up the shaft, complete cross passage works, clean up the tunnel, complete architectural detailing, lay track, install all critical electrical-signalling-telecommunication systems, conduct trials, obtain necessary approvals and commence commercial operations are all coming up next in line, it said.
Underground construction of Chennai Metro Rail Project as part of Corridor 2 has already been completed upto Egmore and the stretch is getting ready for commissioning and trials in this stretch are in progress, said the release.
With this breakthrough out of the way, tunneling on only 5 more sections out of 16 is left in order to complete Phase 1’s tunnels. Around 3.9km of the tunnel drive is left to complete the 36.5km tunnels of the CMRL Phase 1 underground network, it added.