Chennai Metro’s TBM S711 Starts Tunneling to Theagaraya College

Workers from Afcons Infrastructure today commissioned their S711 Herrenknecht Tunnel Boring Machine to build the down-line tunnel of Chennai Metro’s 2.4 km UAA-08 project from Washermenpet to Korrukupet as part of the 9.1 km northern extension of the 23.10 km Chennai Airport – Washermenpet line to Wimco Nagar. The 1st TBM on this section’s parallel up-line tunnel was commissioned just last month.

The S711 TBM was previously used by the Afcons-Transtonnelstroy JV to build 3 down-line tunnels between Washermenpet – Mannadi – High Court – Central on package UAA-01, and after its final breakthrough at Central Station in November 2016, it was dismantled and then brought back to the Washermenpet Station’s northern shaft.

The TBM on its new assignment will first excavate towards Sir Theagaraya College Station and build 613 rings (1 ring = 1.4m) along the way for the down-line tunnel. At the time of writing this piece, the TBM has built 5 permanent rings.

Package UAA08: Washermenpet – Korrukupet – view Chennai Metro map & information

Some images from on top of Washermenpet Station’s North Shaft:

Concrete slabs over the up-line (top) & down-line (bottom) tunnels

TBM S711 is right below this concrete slab

Here are some views from inside the TBM’s trailing gear. The 1st ring segment can be seen below, towards the back:

Inside TBM S711’s back-up/trailing gear

Meanwhile, the Robbins TBM on the parallel up-line tunnel is achieving great advancement rates and has completed building 156 rings (1 ring=1.4m) since it was commissioned on March 27. Some images:

For more updates, check out the Chennai section of The Metro Rail Guy!


written by

Global traveler who prefers mass rapid transit

6 Responses to "Chennai Metro’s TBM S711 Starts Tunneling to Theagaraya College"

  1. Navnit S says:

    Should we expect tunnelling on this stretch to be completed about 1 year ?

    • TMRG says:

      Afcons is targeting an August breakthrough for the Robbins TBM to show its pretty face. S711 will follow soon after that if the soil conditions on its route are favorable.

      Message/tweet to me in a month’s time and I’ll find out how they’re doing.

  2. kumaran says:

    this tunneling for one way or both(up and down line)?

    • TMRG says:

      One way only.

      – HK S711 TBM is building the down-line tunnel. Trains in it will run from Korrukupet to Washermenpet.
      – Robbins TBM is building the up-line tunnel. Trains in it will run from Washermenpet to Korrukupet

  3. maheep says:

    Dear Sir
    Can you give the start and end dates of launching and breakthrough of each pkg of Chennai metro.


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