New Delhi: A major engineering milestone has been achieved in the Mumbai–Ahmedabad Bullet Train Project with the successful breakthrough of the third mountain tunnel (MT-07) at Ambesari village in Dahanu Taluka of Palghar district, Maharashtra.
With this achievement, three mountain tunnel breakthroughs have now been completed in Maharashtra within the last five months, reflecting rapid progress in one of the most technically challenging sections of India’s first high-speed rail corridor.
The newly completed MT-07 mountain tunnel is 417 metres long and 14.4 metres wide, designed to accommodate both up and down tracks of the Bullet Train corridor. The tunnel was excavated through a controlled drilling and blasting method from both ends, supported by advanced engineering and safety protocols.
Throughout the excavation process, sophisticated monitoring systems and geotechnical instruments were deployed to ensure structural stability, worker safety and precision execution. Real-time monitoring arrangements including Surface Settlement Points (SSP), 3D targets, strain gauges and seismographs continuously monitored vibrations, tunnel behaviour and surrounding structures. Comprehensive worker-safety measures including ventilation systems, fire-safety arrangements, controlled access and continuous geotechnical supervision were maintained during tunnelling operations.
Earlier Tunnel Breakthroughs in Maharashtra
The latest breakthrough builds upon earlier milestones achieved in the Maharashtra section of the project. The first mountain tunnel breakthrough (MT-05), spanning 1.5 km, was achieved near Saphale in Palghar district on 2 January 2026, marking the first successful mountain tunnel breakthrough for the Bullet Train Project in Maharashtra. This was followed by the second breakthrough (MT-06) on 3 February 2026, involving a 454-metre-long tunnel excavated using New Austrian Tunnelling Method (NATM), resulting in two breakthroughs being achieved within about one month in Palghar district.
Among the seven mountain tunnels under construction in Maharashtra, MT-05, MT-06 and MT-07 have now achieved breakthroughs, MT-08 (350 metre) already achieved breakthrough on 5 October 2023, MT-03 has crossed 80% excavation progress, MT-04 has reached nearly 60% progress, while MT-01 and MT-02 are progressing steadily. Of the total eight mountain tunnels in the Mumbai–Ahmedabad Bullet Train Project, seven are located in Palghar district of Maharashtra and one in Valsad district of Gujarat, where tunnelling work has already been completed.
All three mountain tunnels between Vapi and Boisar Bullet Train stations have been successfully excavated. The Mumbai–Ahmedabad Bullet Train corridor passes through an important industrial region between Boisar in Maharashtra and Vapi in Gujarat, where construction work is progressing rapidly. The route between these two cities include three (03) mountain tunnels (MT 08, MT-07 & MT-06).
The Mumbai–Ahmedabad Bullet Train Project continues to drive adoption of advanced tunnelling, monitoring and construction technologies, strengthening India’s capabilities in high-speed rail infrastructure and laying the foundation for safe, modern and future-ready rail mobility.
