India’s bullet train project has reached a key milestone with the successful completion of the first 2.7-km section of a 21-km undersea tunnel between Mumbai’s Bandra-Kurla Complex (BKC) and Thane. According to the Ministry of Railways, the 2.7-km tunnel section was constructed between Ghansoli and Shilphata in Maharashtra.

The entire 21-km tunnel is part of the Mumbai-Ahmedabad bullet train corridor and includes a seven-km undersea portion beneath Thane Creek. Construction is being executed using two techniques: five km of the tunnel is built with the New Austrian Tunnelling Method (NATM) between Shilphata and Ghansoli, while the remainder is being constructed with tunnel boring machines (TBMs). An Additional driven intermediate tunnel (ADIT) helped accelerate the 2.7-km NATM section.

Indian Railways has also completed 310 km of viaduct construction and is advancing with track laying, station building, and system procurement. The 508-km bullet train project will use Japanese Shinkansen technology, introducing the next-generation E10 trains.