Mumbai-Ahmedabad bullet train project to accommodate India’s 1st undersea route

Construction work for Indian Railways' ambitious Mumbai-Ahmedabad high-speed rail project is on in full swing. According to reports, 21 km out of 508.17 km bullet train track is drafted underground while the rest will be elevated. One of the entry points to the underground tunnel will fall in Vikhroli (owned by Godrej), Mumbai.

Interestingly, the 21 km long tunnel will be built along 7 km under the sea, and is being built using Tunnel Boring Machine (TBM) and New Austrian Tunnelling Method (NATMA) and will be commissioned between BKC and Shilphata in Maharashtra. The 7 km long undersea single tube tunnel at Thane Creek will be the first of its kind in India to accommodate both up and down tracks, work on which commenced on February 9, 2023.

The tunnel will be about 25-65 meters deep from the ground level and the deepest construction point will be 114m below the Parsik Hill near Shilphata in Maharashtra. Further, the underground tunnel will ensure protection of the bird sanctuary and mangroves around Thane creek. 

Prime Minister of India and his Japanese counterpart - Shinzo Abe launched India’s first bullet train project between Ahmedabad and Mumbai in 2017. The said bullet train will run at a maximum speed of 350 km per hour, covering a distance of 508 km in three hours. Reportedly, Japan is giving a loan of  ₹88,000 crore to India for the project at a minimal interest of 0.1%.

National High-Speed Rail Corporation Limited (NHSRCL) has already floated technical bids for the construction of the 21-km tunnel, 7 km of which will be under the sea. The mega project is likely to be completed by 2026.