TBM S711 – a Herrenknecht tunnel boring machine operated by Afcons Infrastructure today made a successful breakthrough at Chennai Metro’s Korukkupet Station in north Chennai – 5 months ahead of its scheduled target of February 2018.
After building tunnels for Chennai’s UAA-01 project, this TBM was commissioned on April 25 2017 from the Washermenpet Station to build the 1818.6m down-line tunnel of the 2.4 km UAA-08 project between Washermenpet and Korukkupet on the 32.10 km Line-1 between Chennai Airport and Wimco Nagar. The earth pressure balance machine built a total of 1299 rings in just 5 months aided by north Chennai’s favorable soil profile which comprises of silty sand, fine sand and clay. Along the way, it made a ‘hidden’ breakthrough at Sir Theagaraya College Station in June as the station’s excavation was still underway.
Local news coverage –
The 1st TBM on this section, a Robbins EPB machine, was commissioned in March 2017 to build its parallel up-line tunnel and has another 330 rings (approx 462m) left to reach Korrukupet Station.
For more updates, check out the Chennai section of The Metro Rail Guy!