TBM T61 Records Breakthrough for Mumbai Metro Line-3 at CSIA T1
Moments ago, Tunnel Boring Machine (TBM) T61 nicknamed Tapi-1 operated by the J Kumar Infraprojects – China Railway Tunnel Group JV made a breakthrough at Chhatrapati Shivaji Maharaj International Airport’s Domestic Terminal-1 Station’s northern-end on Mumbai Metro’s 33.5 km Aqua Line (Line-3).
This was T61’s second (and final) breakthrough, J Kumar – CRTG’s fifth (and penultimate) breakthough for the 4.45km Santa Cruz Mid Ventilation Shaft – CSIA Terminal 2 Package UGC-06, and overall Mumbai Metro Line-3’s 31st TBM breakthrough.
This Ø6.68m dual-mode Terratec TBM had passed factory acceptance tests in September 2017 and arrived in the city in November 2017. For its first assignment, it was commissioned as TBM Godavari-1 from Package UGC-05’s Vidyanagari Station to the Santa Cruz Mid Ventilation Shaft (dead-end of UGC-05/06) and onwards to CSIA’s Terminal-1 Station for building the 2895 meter up-line tunnel, and recorded a joint breakthrough for UGC-05 and UGC-06 in April 2019.
For its last assignment that ended today – the machine was commissioned from Sahar Road Station towards Terminal 1 in September 2019 to build the 1512 meter down-line tunnel, and was in the process of looping around the airport’s Runway 14/32 when the COVID-19 related lockdown brought excavation to a halt. Work resumed in June with a severe shortage of man-power and gradually picked up pace as the city opened up.




With 31 breakthroughs completed, there are now just 10 more breakthroughs pending – the below table is best viewed on a desktop device. The next breakthrough is likely to be recorded in October at Dadar Station for the 1106 up-line tunnel connecting it to Siddhivinayak Station.
Package | Section | Distance, Status |
UGC-01 | Churchgate – Hutatma Chowk (up-line) | 660m, In Progress |
UGC-01 | Hutatma Chowk – CST (up-line) | 551m, Not Started |
UGC-01 | Churchgate – CST (down-line) | 1233m, In Progress |
UGC-03 | Science Museum – Mahalaxmi (up-line) | 1118m, Not Started |
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 (up-line) | 1106m, In Progress |
UGC-04 | Siddhivinayak – Dadar (down-line) | 1126m, In Progress |
UGC-06 | Sahar Road – CSIA T1 (up-line) | 1516m, In Progress |
For more updates, check out the Mumbai section of The Metro Rail Guy!
– TMRG