Kolkata Metro’s TBM Urvi Passes Halfway to Bowbazar Shaft
ITD-ITD Cementation India’s tunnel boring machine S-616 (Urvi), en route to Bowbazaar Shaft, passed the halfway mark on Tuesday for building the final 800 meter west-bound tunnel of Kolkata Metro’s 16.34 km east-west Line-2.
This Ø6.65m Herrenknecht earth pressure balance (EPB) machine was recommissioned in January from Sealdah Station towards Bowbazar Shaft. Its final assignment involves building 553 tunnel rings, and at the time of writing this workers had completed erecting 283 rings with the 284th in progress.
Piling work for the 22 meter deep Bowbazar mid-shaft started in August 2020 and ended in early-February. This 40m x 15m “emergency” shaft wasn’t part of the original tunneling plan, but became necessary to construct after Urvi’s sister-machine, TBM Chandi, hit an aquifer and became immobile in August 2019 while tunneling for the west-bound tunnel from Esplanade to Sealdah.
Here are some snaps of the shaft shot on early Monday morning:
TBM Chandi (facing east towards Sealdah) will first be pulled out followed by TBM Urvi. I’ll share images via my Twitter handle as excavation progresses.
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Great news….congrats t all 🥰🥰
So when do you expect the breakthrough to take place on the other side?
Calculation kare to 4 Jan se tunneling start hui aur 3 months me half ho gya to 3 months bad yani July tak ho jayega
Should happen this summer, but maybe not in 3 months.
Really depends on the progress of excavation and how quickly Chandi is lifted out. Both are pending, so I have a hunch they’ll be slowing down Urvi as it nears the shaft.
Thanks a lot I didn’t get time since the morning it really made my day!
Hope Entire line 2 along with Line 3(Joka-Majherhat), Line 4(Noapara-Airport) & line 6(New Garia-Ruby/Sector 5) gets Operational in 2022
After the priority corridors get finished the remaining corridors could be finished by 2026
And then new metro lines will be taken up
Thanks for the information about TBM Urvi and excellent pictures of Bowbazar shaft. Can u tell whether Bowbazar shaft is being built over damaged TBM.
Yes, right above its shields
Can you please tell me when will Bowbazar residents get their homes back?
I wouldn’t know that. Something to ask local authorities
How long will it take do u think for reaching the damaged TBM by soil excavation over it.
Also there is water in the TBM from aquafier and when water was pumped in to stop leakage.
How do u think it will be pumped out out.
Excavation also involves adding new steel struts to reinforce the shaft. I’d say another 1-2 months to reach the top of the machine.
No idea about their pumping plan right now. Will check on that.
Is the tunneling by TBM Urvi going on smoothly and construction of shaft at Bowbazar, particularly monster corona wave is raging on chance of workers infections high?