Second mountain tunnel breakthrough in India advances Mumbai–Ahmedabad bullet train

Credit: Ministry of Railways

The Mumbai–Ahmedabad High-Speed Rail (MAHSR) project has achieved a significant milestone with the breakthrough of the second mountain tunnel in Palghar, Maharashtra. Union Minister for Railways, Information & Broadcasting, and Electronics & Information Technology, Shri Ashwini Vaishnaw, announced that Mountain Tunnel 6 (MT-6) has been successfully completed. Spanning 454 metres in length and 14.4 metres in width, the tunnel will accommodate both up and down tracks for the high-speed rail corridor.

This breakthrough is the second in Palghar district within a month, following the completion of MT-5 near Saphale on 2 January 2026. MT-6 was excavated using the New Austrian Tunnelling Method (NATM), a drill-and-controlled blast technique suited for complex geological conditions. Excavation teams worked from both ends of the tunnel and met at the centre, forming a continuous passage through the mountain. The tunnel took 12 months to complete, highlighting both engineering efficiency and technological expertise.

Minister Ashwini Vaishnaw congratulated the high-speed rail team for their progress and noted that the pace of work has boosted national confidence. He also highlighted that many of the advanced construction technologies and large machines used for the project are manufactured in India, attracting global attention for innovation in high-speed rail construction.

The Union Minister further stated that the Gujarat section of the project is expected to begin commercial operations next year. High-speed rail services are projected to extend to Thane by 2028, with full connectivity to Mumbai by 2029. Dr Hemant Vishnu Savara, Lok Sabha MP for Palghar, expressed gratitude for the tunnel breakthrough and noted that railway investment in Maharashtra has accelerated development. He highlighted the impact of several projects in the region, including the Dedicated Freight Corridor (DFC), the high-speed rail corridor, and the upcoming Vadhvan Port.

The NATM was chosen for MT-6 due to its flexibility in handling irregular tunnel shapes and varying geological conditions. This method does not require very heavy machinery and allows for real-time adaptation using shotcreting, rock bolts, and lattice girders. Worker safety inside the tunnel has been ensured through geotechnical monitoring, fire safety measures, proper ventilation, and controlled access arrangements.

In Maharashtra, work is progressing rapidly across the corridor. Construction of the project’s longest river bridge over the Vaitarna river has reached pier level, while foundation work continues on the Ulhas and Jagani rivers. Major national and state highway crossings are being constructed using long-span steel bridges, alongside the 21 km tunnel between Bandra Kurla Complex and Shilphata. Overall, seven mountain tunnels are under construction in Palghar, with MT-1 to MT-7 varying in length from 228 metres to 1.48 km and progress ranging from 16% to 57%.

The MAHSR corridor spans 508 km, with 352 km in Gujarat and Dadra & Nagar Haveli, and 156 km in Maharashtra. The project aims to boost economic activity, enable knowledge transfer, and support new industrial and IT hubs along the route. Major cities including Sabarmati, Ahmedabad, Anand, Vadodara, Bharuch, Surat, Bilimora, Vapi, Boisar, Virar, Thane, and Mumbai will be connected, marking a transformative step in India’s transportation infrastructure.

As of 27 January 2026, around 334 km of viaducts, 17 river bridges, and 12 major crossings over highways, railways, and other infrastructure have been completed. Track laying and electrification are progressing rapidly, particularly in the Gujarat section, underscoring the project’s steady advance toward operational readiness.