Mumbai-Ahmedabad Bullet Train Project: Second Mountain Tunnel Breakthrough Achieved in Palghar
In a significant development for India's ambitious infrastructure initiatives, the Mumbai-Ahmedabad High Speed Rail project, commonly known as the Bullet Train, has achieved the breakthrough of its second mountain tunnel in Palghar, Maharashtra. This milestone, announced on Friday, represents the third tunnel overall to be completed in the project, underscoring steady progress in this high-profile endeavor.
Details of the Tunnel Breakthrough
The newly connected tunnel, designated as MT-6, measures 454 meters in length and 14.4 meters in width. According to officials, it is currently almost 47% complete, with excavation work having been carried out over a period of 12 months. A tunnel breakthrough refers to the critical moment when excavation from both ends meets at the center, creating a clear passage through the mountain. This achievement follows last month's breakthrough of the first mountain tunnel, MT-5, located between Virar and Boisar stations in the same district.
Construction Methods and Geological Challenges
The second mountain tunnel was excavated using the advanced drill and blast method, also known as the New Austrian Tunneling Method (NATM). This technique is particularly suited for irregular geological conditions, where traditional tunnel boring machines (TBMs) may not be effective. NATM allows for flexible strategies as work progresses, ensuring stability and safety in challenging terrains.
Overview of Tunnel Network in the Project
Of the total 508-kilometer length of the Mumbai-Ahmedabad Bullet Train corridor, tunnels account for 27.4 kilometers. This includes 21 kilometers of underground tunnels and 6.4 kilometers of surface tunnels. The surface tunnels comprise eight mountain tunnels, with seven situated in Maharashtra's Palghar district, spanning 6.05 kilometers, and one in Gujarat, measuring 350 meters.
Progress on Other Tunnels and Infrastructure
Work is ongoing across all tunnels in the project. In Maharashtra, the progress varies: MT-1 (820 meters) has achieved 16% physical progress, MT-2 (228 meters) is under preparatory works, MT-3 (1.4 kilometers) is 41% complete, MT-4 (1.26 kilometers) is 32% complete, MT-5 has reached 57% progress, and MT-7 (417 meters) is 29% complete. Additionally, significant strides have been made in other aspects of the project. The longest river bridge over the Vaitarna river has reached pier level, and foundation work on the Ulhas and Jagani rivers has been completed. The first breakthrough in the project was a 4.88-kilometer underground tunnel between Ghansoli and Shilphata, achieved in September 2025, which is part of a larger 21-kilometer tunnel between Bandra-Kurla Complex and Shilphata, including a 7-kilometer undersea section beneath Thane Creek.
Broader Context and Future Plans
The Mumbai-Ahmedabad corridor is part of a larger vision for high-speed rail in India. In the Union Budget 2026-27, the Centre announced seven more high-speed rail corridors as "Growth-Connectors," spanning 4,000 kilometers and requiring an estimated expenditure of Rs 16 lakh crore. These corridors include routes such as Mumbai-Pune, Pune-Hyderabad, and Delhi-Varanasi, aimed at enhancing connectivity and economic growth. For the Mumbai-Ahmedabad project, around 334 kilometers of viaducts, 17 river bridges, and 12 major crossings over national highways and railways have been completed. Track laying and electrification are currently underway, with the first operational section from Surat to Bilimora in Gujarat scheduled to launch by August 15, 2027. The entire 508-kilometer project is expected to be completed by December 2029.
Cost Escalation and Financial Implications
The cost of the Mumbai-Ahmedabad Bullet Train project has seen a significant increase since its inception. Initially estimated at Rs 1.08 lakh crore, the project cost has now escalated to approximately Rs 1.98 lakh crore, reflecting the complexities and scale of this transformative infrastructure initiative.
