Mumbai Metro’s TBM Surya-1 Records Breakthrough at Hutatma Chowk

Moments ago, Tunnel Boring Machine XRE 2114-408 (Surya-1) operated by the Larsen & Toubro – Shanghai Tunnel Engineering Company (L&T – STEC) JV made a breakthrough at Hutatma Chowk Station’s southern-end on Mumbai Metro’s 33.5 km Aqua Line (Line-3).

This was TBM Surya-1’s third (and penultimate) breakthrough, 4.25 km Package UGC-01’s 6th of 8 (earlier 7) planned breakthroughs for the Cuffe Parade – CST section, and overall Line-3’s 34th of what will now be 42 (earlier 41) planned breakthroughs.

This Robbins Crossover XRE TBM with a 6.65 meter diameter was originally launched from Cuffe Parade to build Line-3’s up-line tunnel, and recorded breakthroughs at Vidhan Sabha Station in April 2019 and Churchgate Station in October 2019.

For its third of four assignments that ended today – the machine was recommissioned from Churchgate in January 2020 and traveled 649m to build Line-3’s up-line tunnel.

Last month, TBM Surya-2 recorded a breakthrough at the NATM-mined tunnel on the down-line (shown on the left in the above graphic), while today’s breakthrough by Surya-1 was recorded at the adjacent cut and cover station-box.

More on details on the unique Hutatma Chowk Station can be viewed here.

Here’s a status of package UGC-01 between Cuffe Parade and CST stations where 2 breakthroughs are now pending, both at CST Station. This table is best viewed on a desktop device –

TBM	Line	From	To	Distance	Status
1	Up	Cuffe Parade	Vidhan Bhavan	1128m	Completed
1	Up	Vidhan Bhavan	Churchgate	498m	Completed
1	Up	Churchgate	Hutatma Chowk	649m	Completed (This Post!)
1	Up	Hutatma Chowk	CST	551m	Yet to Begin
2	Down	Cuffe Parade	Vidhan Bhavan	1254m	Completed
2	Down	Vidhan Bhavan	Churchgate	481m	Completed
2	Down	Churchgate	Hutatma Chowk	653m	Completed
2	Down	Hutatma Chowk	CST	556m	Yet to Begin

With 34 breakthroughs completed, there are now 8 more breakthroughs pending on Mumbai Metro’s Line-3:

Package	Section	Distance, Status
UGC-01	Hutatma Chowk – CST (up-line)	551m, Not Started
UGC-01	Hutatma Chowk – CST (down-line)	556m, Not Started
UGC-03	Science Museum – Mahalaxmi (up-line)	1118m, In Progress
UGC-03	Mahalaxmi – Mumbai Central (up-line)	837m, Not Started
UGC-03	Science Museum – Mahalaxmi (down-line)	1136m, In Progress
UGC-03	Mahalaxmi – Mumbai Central (down-line)	830m, Not Started
UGC-04	Siddhivinayak – Dadar (down-line)	1126m, In Progress
UGC-06	Sahar Road – CSIA T1 (up-line)	1516m, In Progress

Contractors on Package UGC-04 (definitely) and UGC-06 (likely) will record their final breakthroughs by the end of the year. All tunneling works are expected to be completed only in Q4 2021 if no major hiccups arise.

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

– TMRG