Ananya Lohia , Mumbai - India's first bullet train project is set to cross another major milestone as Railway Minister Ashwini Vaishnaw will inaugurate underground tunnel-boring work for the Mumbai-Ahmedabad High-Speed Rail Corridor on Sunday.

The inauguration will mark the first-ever use of a Tunnel Boring Machine (TBM) for the country's bullet train project. The first TBM, stationed 56.6 metres below ground at Vikhroli, will begin excavating a 5.8-kilometre tunnel towards the Bandra Kurla Complex (BKC) station. Imported via the sea route from China earlier this year, the customised German-made machines are being used to construct a 20.37-kilometre tunnel, including a seven-kilometre undersea stretch beneath Thane Creek.

A second TBM, currently being assembled at Sawli, will soon begin tunnelling the remaining 9.7-kilometre section to Vikhroli. Each machine is expected to excavate nearly 300 metres every month, enabling around 600 metres of tunnelling once both are operational. The tunnel, built around 65 metres below ground level, will house twin railway tracks inside a single tube for bi-directional high-speed train operations.

Spanning 508 kilometres, the Mumbai-Ahmedabad High-Speed Rail Corridor will connect 12 stations across Maharashtra and Gujarat. With trains expected to run at speeds of up to 320 kmph, the project aims to reduce travel time between Mumbai and Ahmedabad to just over two hours, transforming high-speed rail travel in India.