National High Speed Rail Corporation Ltd (NHSRCL) signed a contract with Afcons Infrastructure Ltd for constructing a 21-km tunnel between Bandra Kurla Complex and Shilphata on Thursday, June 8, 2023.
This tunnel includes India’s 1st seven km long undersea rail tunnel as part of the Mumbai-Ahmedabad High Speed Rail (MAHSR) corridor. This tunnel is being built under MAHSR C-2 package. Technical bids were opened on February 9, 2023, and financial bids on April 6, 2023.
“Construction of 21-km of tunnel is one of the most challenging contracts of Mumbai-Ahmedabad HSR corridor, which includes construction of country’s first twin track under sea rail tunnel of 7 km at Thane Creek,” said Rajendra Prasad, Managing Director, NHSRCL
Tender Status in Maharashtra
Mumbai HSR Station [MAHSR Package C-1]– contract agreement was signed on March 20, 2023. Construction of tunnel for double line between Mumbai HSR Station and Shilphata (21 km approx.) [MAHSR Package C-2] – Contract agreement signed on June 8, 2023.
Technical Bids (under MAHSR package C-3) for civil and building works of three railway stations at Thane, Virar and Boisar situated between Shilphata and Zaroli village on the Maharashtra Gujarat border (135 km) were opened on April 12, 2023.
Tunnel features
The 21-km long tunnel will be constructed between underground station at Bandra-Kurla Complex and Shilphata in Maharashtra.The 7-km undersea tunnel at Thane Creek (inter-tidal zone) will be India’s 1st under sea rail tunnel. This tunnel will be about 25 to 65 Meters deep from the ground level.
A single tube tunnel will accommodate both up and down tracks. As part of the package, 39 equipment rooms at 37 locations will also be constructed adjoining the tunnel location. To construct this tunnel, tunnel boring machines (TBMs) with a cutter head of 13.1 Meter diameter will be used.
Three TBMs will be used to make about 16-km of the tunnel portion while the remaining 5-km will be done using New Austrian Tunnelling Method (NATM).
Three shafts at BKC (under package C1), Vikhroli, and Sawli at approximate depths of 36, 56 and 39 meter respectively will facilitate the construction. An inclined Shaft of 42 meter at Ghansoli and tunnel portal at Shilphata will facilitate the construction of about 5-km of tunnel through NATM tunnelling method.
