National High-Speed Rail Corporation signs contract for constructing India's first 7-km undersea rail tunnel

New Delhi [India], June 8 (ANI): The National High-Speed Rail Corporation Limited (NHSRCL) signed a contract with M/s Afcons Infrastructure Limited on Thursday for the construction of a 21 km long tunnel. The major part of this contract is to construct India's first 7-km long undersea rail tunnel in Maharashtra for Mumbai-Ahmedabad High-Speed Rail Corridor under the MAHSR C-2 package.

As per the official information, the technical bids of this tender were opened on February 9, 2023, and financial bids were opened on April 6, 2023.
Talking about this contract, Managing Director of NHSRCL, Rajendra Prasad said, "Construction of 21 km of the tunnel is one of the most challenging contracts of Mumbai- Ahmedabad HSR corridor, which includes the construction of country's first twin-track undersea rail tunnel of 7 km at Thane Creek. Three Tunnel Boring Machines and New Austrian Tunnelling Method will be used for the construction of this tunnel."
It is pertinent to note that the 21 km long tunnel will be between the underground station at Bandra-Kurla Complex and Shilphata in the State of Maharashtra. The 7 km (approx.) undersea tunnel at Thane Creek (Intertidal Zone) will be the First undersea rail tunnel to come up in the country.

The tunnel will be a single tube tunnel to accommodate twin tracks for both-up and down track. 39 equipment rooms at 37 locations will also be constructed adjoining tunnel locations as part of the package. To construct this tunnel, TBMs with a cutter head of 13.1 Meter diameter will be used.
Usually, 5-6 Meter Diameter cutter heads are used for urban tunnels used in MRTS - Metro system. Three Tunnel Boring Machines will be used to make about 16 km of the tunnel portion and the remaining 5 km will be through New Austrian Tunnelling Method (NATM).
This tunnel will be about 25 to 65 Meters deep from the ground level.
Three shafts at BKC (under package C1), Vikhroli, and Sawli at approximate depths of 36, 56 and 39 Meter depths respectively will facilitate the construction. The inclined Shaft of 42 Meters at Ghansoli and the Tunnel portal at Shilphata will facilitate the construction of approx. 5 km of the tunnel through the NATM tunnelling method.
According to NHSRCL officials, tendering status of the project in the part of Maharashtra state is on the right track. As per the detailed information, Mumbai HSR Station [MAHSR Package C-1]- Contract agreement was signed on March 20, 2023.
Also, the Construction of a tunnel for the double line between Mumbai HSR Station and Shilphata (21 km approx.) [MAHSR Package C-2] - Contract agreement signed on May 8, 2023.
Civil and building works with 3 nos. of stations i.e. Thane, Virar, Boisar between Shilphata & Zaroli village on Gujarat-Maharashtra border [MAHSR Package C-3] - Technical bids were already opened on April 12, 2023.
The MAHSR project will span a distance of approximately 508 kilometres and will have 12 stations along the route, including major cities like Thane, Virar, Boisar, Vapi, and Surat.
The Mumbai Ahmedabad High-Speed Rail project is a visionary initiative that aims to revolutionize transportation in India. Once completed, it will provide a safe, efficient, and fast mode of travel between two major cities, setting a new benchmark for high-speed rail infrastructure in the country. (ANI)