Tunnel Boring Machines for Bull
The much-awaited tunnel boring machines to build the country’s first undersea rail tunnel for the Mumbai-Ahmedabad high-speed bullet train project are on their way and will be delivered to the Jawaharlal Nehru Port Trust in Mumbai on Monday, sources said.
The customized TBM was manufactured by German company Herrenknecht at its facility in China.
Officials said these TBMs are the largest and most expensive in the country, measuring 13.1 meters in diameter, making it one of the largest TBMs used in any rail project in India.
Typically, TBMs with 5 or 6 meter diameter cutter heads are used for urban tunnels used in the MRTS metro system.
Package C2 of the Mumbai-Ahmedabad High Speed Rail Project, which involves undersea tunnel, is being executed by Afcons Infrastructure Limited. The entire package includes a 20.37 km long tunnel.
“Of this, 4.8 km has been completed through the New Austrian Tunneling Method (NATM) in September 2025, while the remaining 15.489 km will be bored through these TBMs (tunnel boring machines). The tunnel will go to a depth of about 25 to 65 meters below ground level,” an official said.
“The tunnel will be a single tube tunnel to accommodate twin tracks for both the up and down tracks. Two shafts at Vikhroli and Savli at a depth of 56 and 39 meters respectively will facilitate the construction,” he said. Additionally, 39 equipment rooms will also be built at 37 locations adjacent to the tunnel location as part of the package.
Notably, the cutter head of one of the two TBMs was sent from China to Mumbai in September 2025, after the issue was raised during Prime Minister Narendra Modi’s talks with Chinese President Xi Jinping in August 2025.
However, the remaining components, as well as the second TBM, were stuck due to custom clearance.
Sources said the matter was pursued proactively through diplomatic channels, with the Railway Ministry closely coordinating with the Ministry of External Affairs.
“Finally, we have cleared all the hurdles and the consignment will reach JNPT tomorrow afternoon,” a Railway Ministry source said.
“This delay has given us sleepless nights as the Bullet Train project is the most ambitious and dream project of this government,” he said. India’s first bullet train project – the Mumbai – Ahmedabad High Speed Rail Corridor, spanning 508 kilometres, will provide faster connectivity between the states of Maharashtra and Gujarat in western India.
According to the National High Speed Rail Corporation Limited, starting from the Bandra Kurla Complex (BKC) area in Maharashtra, the high-speed train running at a speed of 320 km/hr will revolutionize intercity travel in the region and integrate the economies of Mumbai, Vapi, Surat, Anand, Vadodara and Ahmedabad.
“It will stop at 10 cities in between, Thane, Virar, Boisar, Vapi, Bilimora, Surat, Bharuch, Vadodara, Anand, Ahmedabad and will terminate at Sabarmati,” an NHSRCL official said.
“The entire journey will be completed in approximately 2 hours 7 minutes with limited stops (Surat, Vadodara and Ahmedabad), which is much less than the time taken by conventional trains or road travel,” he said.
