TBM Makes 2nd Breakthrough at Delhi Metro’s Nehru Enclave Station
Tunneling works are slowly coming to a wrap! 😀
Yesterday afternoon, Tunnel Boring Machine S723 made a breakthrough for the down-line tunnel at Delhi Metro’s Nehru Enclave station! This EPBM TBM was commissioned on October 30 2015 by the Pratibha-FEMC JV (contract cc-23) from the Greater Kailash station, and completed building 778 rings (1089m) for the 38.235 km Magenta line of the Phase 3 project. This breakthrough comes just a couple months after the 1st breakthrough here was made by TBM S937 for the up-line tunnel.
The TBM actually reached the station’s diaphragm or “D” wall on May 8 and prior to the breakthrough, the crew deployed a drilling machine to assist with tearing it down. This should have taken a max of 3 days to accomplish, but the machine broke down and had to be hoisted back up & replaced with another one.
Satellite view of Nehru Enclave’s receiving shaft which is now covered up:
Alignment of Greater Kailash – Nehru Enclave section – view Delhi Metro map & information
Photo Copyright: Rahul Ranjan
Photo Copyright: Rahul Ranjan
Photo Copyright: Rahul Ranjan
After cleaning the cutterhead – Photo Copyright: Rahul Ranjan
Fun Fact: This TBM was used by the Pratibha-CRFG JV for excavating and building CC-01’s tunnels between Central Secretariat – Janpath – Mandi House for the Violet Line’s northern extension. That 3.3 km section opened for commercial operations on 26 June 2014.
With this breakthrough out the way, now only 4 more breakthroughs are left to be made on the Magenta Line:
| Contract | Contractor | Origin | Destination | Tunnel |
| CC-23 | Pratibha – FEMC | Chirag Delhi | Greater Kailash | Down-line |
| CC-27 | L&T – SUCG | Shankar Vihar | Aravali Mid-Shaft | Down-line |
| CC-27 | L&T – SUCG | Vasant Vihar | RK Puram Mid-Shaft | Up-line |
| CC-27 | L&T – SUCG | Vasant Vihar | Munirka | Down-line |
The TBM tunneling between Chirag Delhi & Greater Kailash has just another 35 rings (49m) to go and should reach the GK station’s diaphragm wall in another week’s time.
For more updates, check out the Delhi section of The Metro Rail Guy!
– TMRG
any idea about TBM breakthrough at Ashram vinobhapuri strech
Hi, that stretch is quite painful for the contractor due to hard rock. They’ve had to change the cutting discs (teeth) of the TBM every other day and are aiming for an October breakthrough for both TBMs.
does such kind of hindrance overuns the cost of tunneling.?
They’re definitely burning cash quite quickly and it’s not helping their bottom line. I don’t know if they’ll make a profit out of this project by the time tunneling ends.
What is the progress of tunnels under CC-27. From Shankar vihar shaft upto munirka…
Hi, here’s some info provided by the contractor on Wednesday. 1 ring=1.4m
Shankar vihar to Aravali Mid-Shaft (down-line)
595/630 rings completed
Expected breakthrough: 10th June
Vasant Vihar to RKP Mid-Shaft (up-line)
490/659 rings completed
Expected breakthrough: 15th July
Vasant Vihar to Munirka (down-line)
334/904 rings completed
Expected breakthrough: 30th Sept
Thanks TMRG for thus a great info.. Hope your estimation is correct..