Dogus-Soma Restarts Mumbai Metro’s TBM 1238 towards Mahalaxmi

Workers from Doğuş-Soma JV on Tuesday recommissioned tunnel boring machine (TBM) 1238 from Science Museum Station’s southern-end towards Mahalaxmi Station for package UGC-03 of Mumbai Metro’s 33.5 km Line-3 (Aqua Line).

This Ø6.65m refurbished Robbins NFM slurry machine, nicknamed Tansa 1, passed factory acceptance tests in August 2017, and was first commissioned from Science Museum Station on August 17, 2018 to build the 2072 meter up-line tunnel through Acharya Atre Chowk Station’s box towards Worli Station.

After recording a breakthrough at Worli on January 29, 2020, the machine’s cutterhead and shields – weighing 480 MT – were retrieved as one complete unit in March, transported through the city’s streets, and lowered back into Science Museum in July.

On Tuesday, the TBM began its second assignment to build the 1136m down-line tunnel towards Mahalaxmi Station from where it will actually now be dragged to the station box’s southern-end and recommissioned onwards to Mumbai Central Station for its final 830m assignment – a tweak in the tunneling plan confirmed by Mumbai Metro Rail Corporation (MMRC) in their tweet about TBM Tansa 2.

Earlier this year, SUCG Infrastructure India Pvt. Ltd. had been subcontracted the Mahalaxmi – Mumbai Central section to expedite tunneling works, but that arrangement no longer stands. I reached out to MMRC two weeks ago for a comment on this, but haven’t heard back.

With this, development – here’s a table displaying UGC-03’s tunneling plan and status of each tunnel (best viewed on a desktop device). Note that TBM 1238 and 1239 have switched positions (up-line to down-line and down-line to up-line) for their onward journeys.

TBM	Line	From	To	Distance	Status
1	Up	Science Museum	Worli	2072m	Completed Jan 2020
1	Down	Science Museum	Mahalaxmi	1136m	In Progress
1	Down	Mahalaxmi	Mumbai Central	830m	Pending Start
2	Down	Science Museum	Worli	2057m	Completed March 2020
2	Up	Science Museum	Mahalaxmi	1118m	Pending Start
2	Up	Mahalaxmi	Mumbai Central	837m	Pending Start

Overall, 30 breakthroughs have been completed for Mumbai Metro’s Line-3, and there are now just 11 more pending – see a status table here.

For more updates, check out the Mumbai section of The Metro Rail Guy!

– TMRG