TBM Lands for Crucial Excavation
A significant milestone has been reached for India's ambitious bullet train project with the arrival of the Tunnel Boring Machine (TBM) destined to excavate
a vital section of the Mumbai-Ahmedabad High-Speed Rail (MAHSR) corridor. This colossal machine, weighing a staggering 3,000 tonnes and manufactured by the German firm Herrenknecht, is specifically engineered for the demanding task of creating tunnels. Its deployment is essential for the 21-kilometer tunnel segment planned for Mumbai. The TBM arrived at the port late on a Monday night, having been shipped from China. The LOA Fortune vessel, carrying the machine's components, departed from Guangzhou last month, making its way to India. This arrival signifies a crucial advancement in the project's timeline, particularly for the underground network that forms a substantial part of the overall high-speed rail alignment.
Undersea Tunnel's Complex Construction
The TBM's primary mission involves the intricate construction of a 21-kilometer tunnel for the MAHSR project, including a remarkable 7-kilometer undersea section that will traverse beneath Thane Creek. This submerged segment is a critical component, enabling the bullet train to pass under the Arabian Sea. While 4.88 kilometers of this tunnel have already been completed using the New Austrian Tunnelling Method (NATM), which relies on controlled blasting, the remaining excavation will now be entrusted to the TBM. The overall bullet train project encompasses 508 kilometers, with tunnels accounting for 27.4 kilometers in total, comprising both underground and surface sections. The recently completed breakthrough between Ghansoli and Shilphata highlights the ongoing progress in this challenging underground alignment.
Technological Marvel Deployed
This project marks a pioneering deployment of a mixed-shield TBM of this magnitude in India, boasting a substantial diameter of 13.65 meters. Such advanced machinery is essential for navigating the diverse geological strata encountered during tunnel construction. The logistics of transporting the TBM's components to the designated sites, including Vikhroli and Savali, are considerable, requiring over 150 trailers. The assembly process itself is an extensive undertaking, anticipated to take approximately 90 days. Project authorities are optimistic about commencing TBM operations by the first week of July, underscoring the commitment to efficient progress. The adoption of a TBM is paramount for ensuring a safer excavation process, especially given the densely populated areas the tunnel passes through, where conventional blasting methods would present unacceptable risks.
Project Milestones and Timelines
The MAHSR project, designed to connect Mumbai and Ahmedabad, spans a total of 508 kilometers, with 352 kilometers in Gujarat and Dadra & Nagar Haveli, and 156 kilometers in Maharashtra. As of February 2026, significant progress has been made across various infrastructure elements, including the completion of 430 kilometers of piers and 341 kilometers of girder casting. Furthermore, 174 kilometers of track bed and 153 kilometers of Overhead Electrification (OHE) masts have been installed. OHE masts are vital steel structures supporting the necessary wires for powering the electric trains. The project aims for a phased completion, with the first stretch from Surat to Bilimora in Gujarat slated for August 15, 2027, and the entire 508-kilometer corridor expected to be operational by December 2029. This timeline reflects the government's dedication to modernizing India's railway infrastructure and fostering economic growth, with substantial technical and financial backing from Japan.
