Bullet Train: NHSRCL floats tender for 21 km Tunnel, includes 7 km Undersea Tunnel in Maharashtra

New Delhi: NHSRCL invites bids for the tunneling works for 21 km (approx.) long tunnel including a 7 km undersea tunnel using Tunnel Boring Machine (TBM) and New Austrian Tunneling Method (NATM) for the Mumbai-Ahmedabad High-Speed Rail corridor (Package No. MAHSR-C-2). 

The 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 tunnel to come up in the country. 

The tunnel will be a single tube tunnel to accommodate twin tracks for both up and down the track. 39 equipment rooms at 37 locations will also be constructed in 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 the New Austrian Tunnelling Method (NATM). 

This tunnel will be about 25 to 65 Meters deep from the ground level and the deepest construction point will be 114m below the Parsik hill near Shilphata.

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 Meter at Ghansoli and the Tunnel portal at Shilphata will facilitate the construction of approx. 5 km of the tunnel through NATM tunneling method. (refer plan at Annexure 1)

The bid submission end date for C2 package is 19th Jan 2023.

The bids for the design and construction of the underground Bandra Kurla Complex high-speed rail station Including cut and cover length of 467m and ventilation Shaft of 66m in Mumbai, Maharashtra, under C1 package was floated on 22nd  July 2022 and bids submission end date is 20th Oct 2022.