From deep urban shafts to mountain tunnels and marine crossings, the Bullet Train project is progressing fast, with 80 per cent of excavation work completed at the Bandra Kurla Complex (BKC) station in Mumbai, an official release said on Saturday, reported news agency PTI.

Of the 21-km-long underground and undersea tunnel between BKC and Shilphata in Thane district, 16 km is being excavated using Tunnel Boring Machines and 5 km with the help of the New Austrian Tunnelling Method, said the National High-Speed Rail Corporation of India Limited (NHSRCL) in the release, reported PTI.

The NHSRCL, which is implementing the 508-km rail corridor between Mumbai and Ahmedabad, said that base slab casting has already commenced at both ends of the BKC station site, at a depth of 100 feet below ground level.