Mumbai Metro Line-3’s Final TBM Breakthrough Recorded by Tansa 1

What a moment. Tunnel Boring Machine 1238 operated by Doğuş-Soma JV on Wednesday afternoon arrived at Mumbai Central Station on Mumbai Metro’s new 33.5 km Line-3 (Aqua Line).

This historic 42nd and final tunnel breakthrough was recorded by a Robbins machine nicknamed Tansa 1. It was its 3rd breakthrough and Doğuş-Soma JV’s 6th breakthrough planned for package UGC-03 tunnels connecting Worli and Mumbai Central stations.

This Ø6.65m Robbins slurry machine had previously achieved a breakthrough at Mahalaxmi Station in August 2021. It was then was recommissioned in October 2021 for its final assignment to build the 837m up-line tunnel towards Mumbai Central Station, which was completed in 243 days using 558 concrete rings.

A video posted by MMRC can be viewed here.

With this development, all 54.5 kms of TBM-bored tunnels (up-line and down-line) for Line-3 have been completed using 17 machines – all the way from Colaba in the south to Sariput Nagar Ramp, near Aarey Colony Station, in the north. The only tunneling works left are minor mining works for a total of 91 emergency cross-passages.

Here’s a table displaying UGC-03’s tunneling plan and status of each tunnel (best viewed on a desktop device).

TBM	Line	From	To	Distance	Status
1	Up	Science Museum	Worli	2072m	Completed Jan 2020
1	Down	Science Museum	Mahalaxmi	1136m	Completed August 2021
1	Up	Mahalaxmi	Mumbai Central	837m	Completed Nov 2022 (this post!)
2	Down	Science Museum	Worli	2057m	Completed March 2020
2	Up	Science Museum	Mahalaxmi	1118m	Completed July 2021
2	Down	Mahalaxmi	Mumbai Central	832m	Completed June 2022

On the Aqua Line’s information page, I’ve got a section with details of final breakthroughs recorded on all 7 civil packages of the line.

MMRC is now chasing a December 2023 deadline to commission the Sariput Nagar Ramp – Bandra-Kurla Complex section. That of course depends on the completion of Aarey Depot where construction work still has to resume.

The assignment of a new contractor to build its sheds is pending, so meeting that timeframe seems unlikely to me. Depot issues aside, with pending civil, system and architectural work – I see the entire line becoming operational no sooner than Q3 2024. I’ll take this because half a year ago the entire line’s future was uncertain. Cheers!

For more updates, check out the Mumbai section or my Home Page! Sign up for free instant email notifications on new posts over here. Like this post? Get early-access to updates and support the site over here.

– TMRG