Apologies for the late post – it’s been a little hard to get these images.
On this past Tuesday, Tunnel Boring Machine S718 – a Herrenknecht EPB Tunnel Boring Machine operated by the Afcons-Transtonnelstroy JV for Chennai Metro’s package UAA-01 made a successful breakthrough at Central Station just weeks after S717 arrived here while building the parallel tunnel. The TBM was commissioned from the Egmore Station in March 2016 and traveled roughly 1 km while building 715 rings along the way for the 22 km Chennai Central – St. Thomas Mount line.
This is the 5th of 6 TBM breakthroughs scheduled to take place at Central Station’s TBM receiving shafts. The first breakthrough was achieved in July 2014, 2nd in January 2016, 3rd in October-end and the 4th in mid-November.
There are now just 3 more TBM breakthroughs left for tunneling to end on Chennai Metro’s 45.1 km Phase 1 project:
|UAA-01||S710||High Court||Central||145 m|
|UAA-02||S703||Thousand Lights||AG-DMS||1.55 km|
|UAA-02||S704||Thousand Lights||AG-DMS||1.67 km|
The contractor (Afcons Infra) is expecting TBM S-710 to arrive at Central Station by February 2017.
TBM S703 has commenced tunneling works towards AG-DMS station for 1 final drive after undergoing maintenance via a small overhaul shaft at the Thousand Lights station. Afcons was initially able to achieve amazing rates of 32m/day, but work has since slowed down due to old equipment & frequent OS failures.
TBM S704 is still undergoing maintenance at Thousand Light station and will restart tunneling in the coming weeks.
For more updates, check out the Chennai section of The Metro Rail Guy!