1st TBM Commissioned for Mumbai Metro’s Line-3 towards Dadar
Following a small puja, engineers and workers from the CEC-ITD Cem-TPL JV at the Nayanagar Shaft this afternoon commissioned S-1073 – the first of 17 tunnel boring machines (TBM) for building a part of Mumbai Metro’s new 33.5 km Line-3’s tunnels.
The Ø6.61m Herrenknecht earth pressure balance machine passed factory acceptance testing in June, arrived at Mumbai Port in early September and was lowered into the Nayanagar Shaft for its final assembly in mid-September.
S-1073 on its first assignment will excavate and build the 2484m long up-line tunnel towards Dadar Station, through the Shitladevi Station, as part of the 6.081 km package UGC-04 between Worli-Dharavi. After that, it’ll be relaunched for a 1116m drive from the Siddhivinayak Station towards Dadar Station, again for the up-line tunnel. Finally, it’ll be brought back to the Nayanagar Shaft for its last 578m drive towards Dharavi Station for the down-line tunnel.
Summary of S-1073’s 3 drives in a simple table:
| Launch Site | Destination | Length | Tunnel |
| Nayanagar Shaft | Dadar Station | 2484m | Up |
| Siddhivinayak Station | Dadar Station | 1116m | Up |
| Nayanagar Shaft | Dharavi Station | 578m | Down |
The first tunnel ring segment for the entire package was cast in March – see images here.
Package UGC-04 (Dharavi – Worli) – view Mumbai Metro map & information
Within the shaft, the TBM will first erect 9 temporary rings before its cutterhead starts boring and permanent ring building activity begins. Some images –
S-1073 & 1st ring segment
3 rings erected
Video – S-1073’s cutterhead being tested with a glimpse of TBM S-1074 which just got lowered into the shaft –
#Mumbai Metro’s TBM S-1073 will 1st erect 9 temp rings within Nayanagar Shaft. Video shows cutterhead being tested with a glimpse of S-1074 pic.twitter.com/wkkfE33Wff
— The Metro Rail Guy (@TheMetroRailGuy) November 6, 2017
Meanwhile, here’s an excellent birds-eye view of the Nayanagar Shaft which has been carved out of slum land and continues to be surrounded on 3 sides. The site constraints here are unlike any I’ve seen elsewhere.
For more updates, check out the Mumbai section of The Metro Rail Guy!
– TMRG
Congratulations to MMRCL and MAPLE team. It’s time to dig dig dig now. All the best.
Why cant they simply continue the TBM at Dadar towards Sidhivinayak, instead of taking it out and re launch it at Siddhivinayak towards Dadar, given that its building the same up line tunnel ?
Navnit, in considering the reasons it is not enough to simply think in a linear fashion, there are many factors in deciding drive lengths and turn around of a TBM. Time, Logistics and ground condition are just some of the factors involved.
MartynG
I understand, and so i was wondering what were those time, logistics and ground conditions, that made them take that decision ?
Good question. Not sure, but I believe it’s primarily due to Dadar Station’s congested site.Till they now they’ve only managed to barricade a part of it and haven’t begun excavation.The tunneling plan probably takes into account that the station’s basic shell won’t be ready by the time S-1073 arrives.So instead of losing time while waiting for that to happen (and losing additional time while dragging the TBM about 200m across the station’s floor on rails), they chose to relaunch from Siddhivinayak. My 2 cents…
Siddhivinayak launching Shaft shall be ready within 2 months, But dadar excavation will take a lot of time to start as lots of buildings are to evacuated,,so TBM shall be launched from sidhivinayak, and shall be retrieved at dadar. We are hoping till the time TBMs reach Dadar, shafts may get ready(impossible task though)
Thanks for confirming!
Cutting Speed of TBM is very less , the distance btw nayanagar and sidhivinayak is too much, TBM may get stuck/ timeline shall become too long. On the other hand Sidhivinayak Shaft will be ready in no time. So while 2 TBMS are still in cutting rock in btw strech of Shitladevi and Dadar, simultaneously, 1 TBM shall be launched at sidhdhivinayak , after retriving the TBM at dadar, it will again be launched at sidhivinayak towards dadar for 2nd tunnel. Its not as simple like driving a car that we may launch 2 TBMs at nayanagar shaft and let them go on and wait for them to come out at cuffe parade.
Congratulations to the team. All the best.
Congratulations to the team. All the best