Mumbai-Ahmedabad Bullet Train: First Breakthrough Achieved In 21 Km BKC–Shilphata Tunnel With Completion Of 2.7 Km Section

A major milestone has been achieved in the Mumbai-Ahmedabad bullet train corridor, with the successful completion of a 2.7 km tunnel section between Bandra-Kurla Complex (BKC) and Shilphata — the first breakthrough in the ambitious 21 km tunnel underground stretch in the Maharashtra section of the project.

"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," the NHSRCL said in a statement.

The tunnel includes a 7 km undersea segment beneath Thane Creek and is being built using two techniques: 5 km with the New Austrian Tunnelling Method (NATM) between Shilphata and Ghansoli, and 16 km with Tunnel Boring Machines (TBMs).

To speed up NATM works, engineers constructed an Additional Driven Intermediate Tunnel (ADIT), allowing excavation from both Shilphata and Ghansoli ends.

So far, 1.62 km has been excavated from the Shilphata side, with total NATM progress reaching approximately 4.3 km.

Advanced safety protocols — including ground settlement markers, piezometers, inclinometers, strain gauges, and biometric access control — have been deployed to ensure secure tunnelling without disturbing surrounding infrastructure.

According to National High Speed Rail Corporation Limited (NHSRC), the implementing agency for the bullet train project, 309 km of viaduct and 392 km of pier work for the project have been completed.

The agency said that 406 km of piers foundation work has been completed and 331 km of girders cast is finished.

Further, over 3.6 lakh noise barriers have been installed across the high-speed rail corridor.

RC trackbed construction is well underway, with 176 km completed so far, according to NHSRCL.

Over 44,600 track slabs have been cast for the project, covering around 213 track km.

Meanwhile, the bullet Train project's power Infrastructure has also begun to take shape with installation of over 1,000 overhead equipment (OHE) masts.

OHE masts are now rising along the Mumbai-Ahmedabad Bullet Train corridor in Navsari district, Gujarat, marking a key step in the electrification of India's first high-speed rail line.

These precision-engineered steel structures, essential for delivering power to trains running at 320 kmph, are part of a larger rollout of more than 20,000 masts planned across the entire corridor.

According to the National High-Speed Rail Corporation Limited (NHSRCL), over 1,000 OHE masts have already been installed, covering 25 km of the viaduct in the Navsari section.