National High Speed Rail Corporation Limited (NHSRCL) has annonced on 8 June 2023 that they have signed contract with M/s Afcons Infrastructure Limited, for the Construction of 21 km Long Tunnel including India’s First 7 km Long Undersea Rail Tunnel in the State of Maharashtra for Mumbai-Ahmedabad High Speed Rail Corridor under MAHSR C-2 package.

The technical bids of this tender were opened on 9th February 2023, and financial bids were opened on 6th April 2023.

Quote from Shri Rajendra Prasad, Managing Director, NHSRCL

“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. Three Tunnel Boring Machines and New Austrian Tunnelling Method will be used for the construction of this tunnel.”

Salient Features:

• The 21 km long tunnel will be between 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 under sea rail tunnel to come up in the country.
• The tunnel will be a single tube tunnel to accommodate twin track for both-up and down track. 39 equipment rooms at 37 locations will also be constructed adjoining tunnel location 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. Inclined Shaft of 42 Meter at Ghansoli and Tunnel portal at Shilphata will facilitate the construction of approx. 5 km of tunnel through NATM tunnelling method.

Tender Status in Maharashtra

Mumbai HSR Station [MAHSR Package C-1]– Contract agreement was signed on 20th March 2023.

Construction of tunnel for double line between Mumbai HSR Station and Shilphata (21 km approx.) [MAHSR Package C-2] – Contract agreement signed today i.e. 08.05.2023

Civil & building works with 3 nos. of station i.e., Thane, Virar, Boisar between Shilphata & Zaroli village on Gujarat-Maharashtra border (135 km) [MAHSR Package C-3] – Technical bids were opened on 12th April 2023.

Source: National High Speed Railway Corporation Limited (NHSRCL)