On 9th July 2025, the first breakthrough was achieved in the 21 km long tunnel being constructed between Bandra-Kurla Complex (BKC) and Shilphata in Maharashtra, marking the successful completion of a 2.7 km continuous tunnel section.

Out of the total 21 km tunnel, 5 km is being constructed using the New Austrian Tunnelling Method (NATM) between Shilphata and Ghansoli, while the remaining 16 km will be built using Tunnel Boring Machines (TBMs). The tunnel also includes a 7 km long undersea section beneath Thane Creek.

To expedite tunnelling in the NATM portion, an Additionally Driven Intermediate Tunnel (ADIT) was constructed, allowing simultaneous excavation towards Ghansoli and Shilphata sides. So far, about 1.62 km has been excavated from the Shilphata side, and the total progress in the NATM section stands at approximately 4.3 km.

Comprehensive safety measures have been implemented at the site, including ground settlement markers, piezometers, inclinometers, strain gauges, and biometric access control systems to ensure safe and controlled tunnelling activities without disturbing nearby structures.

(Release ID: 2143795)