Afcons records First NATM Tunnel Breakthrough for Mumbai–Ahmedabad Bullet Train Project

Mumbai, India (Metro Rail Today): In a major milestone for India’s first bullet train project, Afcons Infrastructure has successfully completed the first NATM tunnel breakthrough for the Mumbai–Ahmedabad High Speed Rail (MAHSR) corridor. This breakthrough marks significant progress on Package C-2, a 20.377 km underground stretch of the 508.17 km mega project.

The historic event took place adjacent to the Sawli Shaft in Ghansoli, Navi Mumbai, where a 1.62 km tunnel section was excavated using the New Austrian Tunneling Method (NATM). This specific segment connects the Additionally Driven Intermediate Tunnel (ADIT), completed in 2024, with the Sawli Shaft.

With this achievement, Afcons has now completed 4.32 km out of the 5 km NATM-mined section, showcasing the pace and engineering excellence behind the project. The NATM technique has been deployed due to the complex geological conditions in the Mumbai Metropolitan Region (MMR), especially between Bandra-Kurla Complex (BKC) and Shilphata, where Package C-2 is located.

Afcons was awarded the ₹6,397.27 crore contract for Package C-2 by the National High Speed Rail Corporation Ltd. (NHSRCL) in June 2023, with a deadline of 1,888 days (approx. 5.2 years). The company has also constructed three deep shafts at strategic locations—BKC Station (36m deep), Vikhroli (56m) and Sawli (39m)—to facilitate the complex tunneling work.

The broader tunneling plan for Package C-2 involves the deployment of three Herrenknecht mixshield Tunnel Boring Machines (TBMs), each with a diameter of 13.56 meters, to construct 16 km of twin tunnels. These TBMs were specially designed for the MAHSR’s demanding requirements. The first machine, S-1392, successfully passed its factory acceptance tests (FAT) in 2024 at Herrenknecht’s facility in China. However, it remains stranded due to export restrictions imposed by the Chinese government, which has also impacted similar projects like the Kanpur Metro Line-2.

India’s Railway Minister Ashwini Vaishnaw had earlier shared plans on social media for Herrenknecht to potentially manufacture larger TBMs domestically, a development that could resolve current bottlenecks and boost India’s tunneling capacity.

The Mumbai–Ahmedabad Bullet Train project is one of the most ambitious infrastructure undertakings in India, designed to cover 508.17 km through 12 stations and significantly cut travel time between the two financial hubs. Once operational, the trains are expected to run at speeds of up to 320 km/h, revolutionizing intercity travel in the country.

This NATM breakthrough in Ghansoli is more than just a technical achievement—it represents a symbol of momentum for a project that is poised to redefine India’s transportation future.