On Wednesday 30 November (30 November) Mumbai Metro Rail Corporation (MMRC) completed 100% tunneling of the Metro-3 corridor.
MMRC achieved its 42nd and final breakthrough in the Colaba-Bandra-SEEPZ corridor of Mumbai’s central metro station.
The Tunnel Boring Machine (TBM) Tansa-1 completed an 837-meter drive from Mahalaxmi Metro Station to Mumbai Central Metro Station in 243 days using 558 concrete rings.
“I was very happy to witness the final breakthrough today. Tunneling under Mumbai’s heritage districts, close to old and dilapidated buildings, existing metro lines, railway lines, and bodies of water with different and sometimes difficult geological conditions, was a difficult task,” said Dr. Ashwini Bhide, MMRC.
This brings the overall project progress to 76.6%.
Workers attending TBM (MMRC)
According to the MMRC, the average production speed of each tunnel excavator (TBM) is 5 to 6 meters per day. About 100 operators worked on each TBM machine for tunneling over the entire length of the Metro-3 corridor.
A total of 2,86,000 cubic meters of concrete and 29,500 MT of steel were used in the tunnel segment rings.
Excavated tunnels are lined with segmented rings. A total of 2.8 lakh segment rings were manufactured for the entire project.
Mumbai metro lines
The 33.5 km Metro-3 corridor along Colaba-Bandra-SEEPZ is Mumbai’s first metro corridor.
It consists of 27 metro stations, 26 of which are underground and 1 above ground.
The first section of Mumbai Metro Line 3 between Aarey Colony and Bandra-Kurla Complex (BKC) is expected to operate until December 2023.
And the second phase between BKC and Colaba will take another six months and could be completed by mid-2024.
For the first time, this subway line connects to the airport, Nariman Point, Cuffe Parade, Kalbadevi, Worli, BKC, Airport, SEEPZ and MIDC.
Additionally, two important heritage stations in Mumbai, CSTM and Churchgate, will also be connected through alignment.
Siddhivinayak Metro Station (MMRC) under construction
The project deployed 17 TBMs in 7 civil works contracts to perform a 55 km tunnel with a 5.8 m finished diameter.
The first TBM Krishna arrived at Naya Nagar in Package 4 in September 2017 and the first breakthrough was achieved by TBM Wainganga-1 in Package 7 at Mumbai Airport Terminal 2.
Track laying work is progressing rapidly on this line with nearly half (455.6%) of the track laying work completed.
Tracked Tunnel Ready (MMRC)
Test runs of Metro-3 started on 30 August on a 3 km section between Sariput Nagar and Marol Naka metro stations.
Originally, the line construction was scheduled to be completed in 2021, but the deadline was missed due to work delays, raising the cost of the project from Rs 23,136 crore to Rs 38,000 crore.