Mumbai Ahmedabad Bullet Train Delayed as TBM Machines Stuck at Chinese Port

The Mumbai Ahmedabad High-Speed Rail (MAHSR) project faces a critical delay as three Tunnel Boring Machines (TBMs) remain stranded at a Chinese port, raising concerns over the project's timeline and highlighting geopolitical tensions.

Mumbai Ahmedabad Bullet TrainTunnel Boring MachinesChina Port DelayIndian RailwaysHighspeed RailReal Estate MumbaiJun 24, 2025

Mumbai Ahmedabad Bullet Train Delayed as TBM Machines Stuck at Chinese Port

Real Estate Mumbai:The Mumbai Ahmedabad bullet train project has hit a critical snag as three giant German-made tunnelling machines remain stranded at a Chinese port, triggering diplomatic manoeuvres and raising fears of a delay in India’s first high-speed rail corridor’s underground works between BKC and Shilphata. The stalled shipment includes three Tunnel Boring Machines (TBMs) manufactured by Herrenknecht AG, a German tunnelling technology leader.

While the machines were custom-built for India, they were produced at Herrenknecht’s factory in Guangzhou, China. Despite completion of manufacturing and readiness for shipment, Chinese customs have yet to clear the consignment, citing no official reason. The delay threatens to derail the underground section of the ₹1.08 lakh crore Mumbai Ahmedabad High-Speed Rail (MAHSR) project, especially the strategically crucial 21-kilometre stretch from Bandra Kurla Complex to Shilphata, which includes a 7-kilometre undersea tunnel beneath Thane Creek. Two of the TBMs were scheduled to reach India by October 2024, while the third was expected earlier this year. However, none have left Chinese shores.

With no formal response from Chinese authorities, India’s Ministry of Railways has involved the Ministry of External Affairs to resolve the matter through diplomatic channels. Officials familiar with the situation confirmed that engagement at multiple levels is ongoing to secure the release of the machines and associated critical components, which are indispensable to the pace and safety of the construction. The National High Speed Rail Corporation Ltd (NHSRCL), which is overseeing the project, had awarded the ₹6,397 crore underground Package C-2 to Afcons Infrastructure Ltd in June 2023. The contract involves tunnel boring between BKC and Shilphata, including segments under dense cityscapes and ecologically sensitive zones. Preparatory works are underway, including the construction of launch shafts at BKC (36 metres deep), Vikhroli (56 metres), and Sawli (39 metres), but these cannot proceed to active tunnelling without the TBMs.

One of the machines is especially significant—it holds the distinction of being the largest TBM ever designed for Indian soil, with a cutter head diameter of 13.56 metres. In comparison, metro TBMs used in urban transit projects range from 6.45 to 6.68 metres. The TBMs have been engineered with a mixshield configuration, ideal for managing complex geological transitions across the Mumbai Metropolitan Region. The delay underscores a strategic vulnerability in India’s infrastructure supply chain—global dependency on geopolitical adversaries for critical equipment. While the TBMs were ordered from Germany, the use of China as a manufacturing base has proven problematic amid the strained relations following the 2020 Galwan Valley clash. Since then, India has implemented tighter scrutiny on Chinese investments and consignments, leading to several high-profile cancellations and import bottlenecks.

In 2020, MMRDA cancelled tenders involving Chinese firms for the Mumbai Monorail project, and the Maharashtra government froze MoUs worth over ₹5,000 crore under the Magnetic Maharashtra 2.0 initiative. The current impasse over the bullet train TBMs is being viewed in this wider context of bilateral caution and economic disengagement. The tunnelling section where the machines are to be deployed is one of the most technically challenging parts of the MAHSR corridor. The tunnels will reach depths ranging from 25 to 65 metres, dipping to 114 metres beneath Parsik Hill near Shilphata. Such terrain demands precision engineering and uninterrupted schedules, making timely equipment availability non-negotiable.

Herrenknecht has previously supplied TBMs for Indian metro and road projects, but in recent years, production has gradually shifted closer to Indian soil. For instance, the TBM used in the Thane-Borivali twin tunnel project was built at Herrenknecht’s Alinjivakkam plant in Tamil Nadu, a move that insulated that project from external geopolitical risks. Afcons Infrastructure Ltd, which has been contracted to carry out the Mumbai Ahmedabad bullet train’s underground section, has not publicly commented on the equipment hold-up. However, sources confirmed that the firm is continuing with ancillary works such as shaft development and portal creation using the NATM (New Austrian Tunnelling Method), where applicable, in anticipation of eventual TBM delivery.

If the issue persists, India may have to explore alternative logistics or even consider partial domestic assembly of such machines in future infrastructure ventures. The current situation has renewed calls from experts and planners for building indigenous capabilities in high-end tunnelling technologies, particularly for projects contributing to sustainable and low-carbon urban growth. Despite the delay, NHSRCL has maintained that the overall project completion deadline remains unchanged. This may be a strategic stance aimed at avoiding public perception of failure or cost overruns, but insiders warn that cascading effects are likely if resolution is not achieved in the coming weeks.

The Mumbai Ahmedabad bullet train is not just a symbol of transport modernisation but a cornerstone of India’s push towards climate-aligned infrastructure. The project is expected to reduce road and air traffic between the two megacities, significantly lowering carbon emissions. A disruption in its execution not only impacts mobility timelines but delays India’s transition to greener urban corridors. As diplomatic backchannels work to resolve the impasse and engineering teams await critical equipment, this episode serves as a powerful reminder: achieving net-zero, gender-neutral, and equitable cities must be built on self-reliance, resilience, and strategic foresight—not just engineering ambition. For now, the machines remain stuck, the shafts stand ready, and the future of India’s high-speed rail hinges on a clearance from across the border.

Frequently Asked Questions

What is the Mumbai Ahmedabad High-Speed Rail (MAHSR) project?

The Mumbai Ahmedabad High-Speed Rail (MAHSR) project is India’s first high-speed rail corridor, connecting Mumbai and Ahmedabad. It includes a 21-kilometre underground stretch from Bandra Kurla Complex to Shilphata, which features a 7-kilometre undersea tunnel beneath Thane Creek.

What is the current issue with the project?

Three Tunnel Boring Machines (TBMs) required for the underground section of the project are stranded at a Chinese port, leading to delays. Chinese customs have not cleared the consignment, and the reason is not officially known.

What steps are being taken to resolve the issue?

India’s Ministry of Railways has involved the Ministry of External Affairs to resolve the issue through diplomatic channels. Multiple levels of engagement are ongoing to secure the release of the TBMs and associated critical components.

Why is the TBM delay significant?

The TBMs are essential for the tunnel boring works, particularly for the technically challenging 21-kilometre stretch from Bandra Kurla Complex to Shilphata. Without the TBMs, active tunnelling cannot proceed, potentially derailing the project timeline.

What are the broader implications of this delay?

The delay highlights a strategic vulnerability in India’s infrastructure supply chain and the risks associated with global dependencies on geopolitical adversaries. It also underscores the need for building indigenous capabilities in high-end tunnelling technologies.