The technical tenders were opened for the construction of a 21 km tunnel with a length of 7 km below Water, as part of the Mumbai-Ahmedabad high-speed rail line, popularly known as the bullet train project. For the C-2 package between Bandra-Kurla Complex in Mumbai and Shilphata in the Thane region, two proposals have been received from Afcons Infrastructure Limited and Larsen & Toubro Limited, according to a National High Speed Rail Corporation Limited. The financial bids will be available after the technical review, an official noted.

The tunnel, which will have a diameter of 13.1 meters and will be a single-track two-track structure, will be built between 25 and 40 metres underground, according to NHSRCL, the organisation in responsible for the complex project. Three tunnel boring machines (TBMs) will build 15.42 kilometres of the 20.37 kilometers of the structure, while the remaining 4.96 kilometers of the structure will be built using the New Austrian Tunnelling Method (NATM). "The tunnel will cross thane creek and the research under the creek was done using underwater static refractive technique and was successfully completed. The NHSRCL has shown façade designs of Bandra Kurla Complex, Virar, Boisar and Thane stations in Maharashtra," an official said.