J Kumar’s Mumbai Metro TBM Disha Records Breakthrough for Line-7A

J Kumar Infraprojects (JKIL) on Thursday celebrated tunnel boring machine (TBM) Disha’s first and only breakthrough at the Airport Colony Shaft for Mumbai Metro Red Line’s 3.17 km Line-7A (Gundavali – CSIA).

TBM Disha (T62) of Package CA-48 is a Ø6.68m dual-mode Terratec machine that was previously deployed by JKumar – CRTG JV in 2018-2021 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, transported and refurbished at J Kumar’s casting yard in Chenna village on Ghodbunder Road.

The machine, renamed as Disha, was launched in September 2023 from Chhatrapati Shivaji Maharaj International Airport (CSMIA)’s Terminal 2 Station and built a 1.647 km tunnel towards Airport Colony Ramp for Line-7A’s down-line.

Along the way, TBM Disha passed passed above Line-3’s twin tunnels and beneath the Sahar Elevated Access Road (SEAR) and utilities.

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

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

A video of the breakthrough can be viewed here on X.

TBM T60 (Dhruv) for the parallel up-line tunnel was launched a few months after Disha in November 2023 and is expected to arrive at Airport Colony’s Shaft in June. I hear less than 100 rings are left to be built.

At this time I see Line-7A becoming operational no sooner than mid-2027 looking at the standard system installation and station development work required to make a line operational in Mumbai.

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– TMRG