J Kumar’s Mumbai Metro Line-7A TBM Disha Starts Tunneling

J Kumar Infraprojects (JKIL) on Friday officially started tunnel excavation works for Mumbai Metro Red Line’s 3.17 km Line-7A (Gundavali – CSIA) at Chhatrapati Shivaji International Airport’s Terminal 2 Station.

Workers commissioned the first of two TBMs, T62 nicknamed Disha, a Ø6.68m dual-mode Terratec machine that was previously deployed in 2018-2021 by JKumar – CRTG JV as Tapi-2 to build 3 tunnels for Package UGC-06 of the 33.5 km Line-3 (Aqua Line).

Following its final breakthrough at the Domestic Airport Station in February 2021, T62 was dismantled and taken to J Kumar’s casting yard (view on Google Maps) in Chenna village on Ghodbunder Road for refurbishment.

The machine, now nicknamed as Disha, has been launched to build the approximately 2.49 km up-line tunnel on Package CA-48 from CSIA’s Terminal 2 towards Airport Colony Station and onwards to a ramp on the Western Express Highway (WEH).

Mumbai Metropolitan Region Development Authority (MMRDA) had awarded J Kumar Infraprojects with Package CA-48’s Rs. 1,998 crore contract in September 2019.

Their scope of work, besides the 11.38 elevated Line-9 extension, includes building Line-7A’s viaduct, ramp and underground tunnels and 2 stations at Airport Colony and CSIA Terminal 2, where it’ll meet the under construction Line-3 (Aqua Line), and in the future Line-8 (Gold Line) linking to Navi Mumbai International Airport.

TBM Disha had passed factory acceptance tests (FAT) in January-end 2023 – view images here. Workers began lowering its parts into CSIA Terminal 2 Station’s site in May 2023.

J Kumar’s team had installed 2 temporary tunnel rings within the shaft in August. A cool video posted by MMRDA with the Disha’s cutterhead rotating can be viewed here on X (Twitter).

TBM T60 (Dhruv) for the parallel down-line tunnel is planned to be commissioned in mid-October.

At this time I see Line-7A becoming operational no sooner than mid-2026 looking at the performance of Aqua Line’s TBMs around the airport that I’ve tracked, and the standard system installation and station development work required.

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– TMRG