In a significant leap forward for India's ambitious infrastructure landscape, the Mumbai-Ahmedabad High Speed Rail (MAHSR) corridor, popularly known as the bullet train project, marked a crucial engineering achievement on Friday. The project witnessed the breakthrough of its first mountain tunnel, located in the Palghar district of Maharashtra.
A Major Engineering Feat
This event, termed a 'tunnel breakthrough,' signifies the moment when excavation from both ends of a tunnel successfully meets, connecting the bore and marking the completion of a critical phase. The specific tunnel, designated as Mountain Tunnel No. 5 (MT-5), is the longest mountain tunnel on the entire project at 1.5 kilometres. It is situated between the proposed Virar and Boisar stations in Palghar.
Railways Minister Ashwini Vaishnaw, who monitored the event via video conference from New Delhi's Rail Bhawan, hailed it as a major milestone. He noted that the project involves a total of seven mountain tunnels and one undersea tunnel. The excavation of MT-5 was completed in 18 months using the advanced New Austrian Tunneling Method (NATM), a technique ideal for non-uniform rock formations.
Progress Across All Tunnels
The 508-kilometre bullet train corridor will feature 27.4 kilometres of tunnelling. This includes a 21-kilometre underground tunnel and 6.4 kilometres of surface tunnels. Of the eight mountain tunnels, seven are located in Maharashtra with a combined length of 6.05 km, and one is in Gujarat, spanning 350 metres.
Current progress on the mountain tunnels in Maharashtra is as follows:
- MT-1 (820m): 15% complete.
- MT-2 (228m): Preparatory works are underway.
- MT-3 (1.4km): 35.5% complete.
- MT-4 (1.26km): 31% complete.
- MT-5 (1.5km): Approximately 55% complete post-breakthrough.
- MT-6 (453m): 35% complete.
- MT-7 (417m): 28% complete.
This follows the earlier breakthrough in September 2025 of a 4.88-km underground tunnel between Ghansoli and Shilphata, which is part of the 21-km underground section that includes a 7-km undersea passage beneath Thane Creek.
Overall Project Status and Timeline
As of November 2025, the bullet train project has achieved 55.63% physical progress and 69.62% financial progress. Significant groundwork has been accomplished, including 412 km of foundation work, 405 km of piers, 344 km of girder casting, and 330 km of girder launching.
The project's geographical spread covers 352 km in Gujarat and Dadra & Nagar Haveli, and 156 km in Maharashtra. Minister Vaishnaw has announced that the first operational section, from Surat to Bilimora in Gujarat, is slated to be ready by August 15, 2027. The entire 508-km corridor is expected to be completed by December 2029.
Laid in September 2017 with an estimated cost of Rs. 1.08 lakh crore, the Mumbai-Ahmedabad High Speed Rail corridor continues to be a flagship project symbolizing India's advancing technological and infrastructural capabilities.
