NHSRCL Signs Contract For Construction Of 21 Km Tunnel Including India’s First 7 Km Long Undersea Rail Tunnel

National High Speed Rail Corporation Limited (NHSRCL) has signed a contract with Afcons Infrastructure Limited, on Thursday (8 June) for the construction of 21-km long tunnel including India’s first 7 km Long Undersea Rail Tunnel in Maharashtra — for Mumbai-Ahmedabad High Speed Rail Corridor under MAHSR C-2 package.

The technical bids of this tender were opened on 9 February 2023, and financial bids were opened on 6 April 2023, NHSRCL Managing Director Rajendra Prasad said

“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 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.

• In order to construct this tunnel, TBMs with a cutter head of 13.1 metre diameter will be used. Usually 5-6 metreDiameter 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 metre deep from the ground level.

• Three shafts at BKC (under package C1), Vikhroli, and Sawli at approximate depths of 36, 56 and 39 metre depths respectively will facilitate the construction. Inclined Shaft of 42 metre 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 Contract agreement was signed on 20 March 2023.

Construction of tunnel for double line between Mumbai HSR Station and Shilphata (21 km approx.) Contract agreement signed on 8 June 2023

Civil and building works with three stations -

Thane, Virar, Boisar between Shilphata and Zaroli village on Gujarat-Maharashtra border (135 km) — technical bids were opened on 12 April 2023.