June 24, 2025: India’s flagship high-speed rail initiative—the Mumbai–Ahmedabad bullet train corridor—has hit a significant roadblock, with three vital Tunnel Boring Machines (TBMs) stranded at a Chinese port. The delay, attributed to a lack of clearance from Chinese authorities, jeopardises the timeline for the critical underground stretch between Mumbai’s Bandra Kurla Complex (BKC) and Shilphata in Navi Mumbai.
Manufactured by German tunnelling specialist Herrenknecht at its Guangzhou facility, these TBMs are the largest ever destined for use in India. Designed to tackle complex subsoil conditions, one of the machines features a cutter head with a diameter of 13.56 metres—nearly twice the size of those used in metro projects. This scale is essential for the 21-kilometre section that includes a 7-kilometre subsea tunnel beneath Thane Creek, one of the most technically demanding segments of the corridor.
Although one TBM was due for early delivery and two more were expected by October 2024, all remain stuck in China, prompting intervention at the diplomatic level. The Ministry of Railways has escalated the issue to the Ministry of External Affairs, which is pursuing a resolution through diplomatic channels. While the National High-Speed Rail Corporation Ltd (NHSRCL) has yet to comment officially, internal sources confirm growing anxiety over mounting delays.
The £6397 crore underground contract, awarded to Afcons Infrastructure Ltd, is pivotal to the corridor’s success. Afcons commenced work in mid-2023 and is constructing access shafts at BKC, Vikhroli, Sawli, and Ghansoli, with additional tunnelling underway at Shilphata using the NATM method.
This incident underscores the strategic risks of supply chain reliance on geopolitically sensitive nations. Though the TBMs are German in origin, their Chinese production site has become a critical bottleneck, drawing attention to the urgent need for diversified manufacturing and enhanced resilience in national infrastructure planning.
Source: Urban Acres
