Arrival of tunnel boring machines for Bullet Train delayed

Mumbai: The National High Speed Rail Corporation Ltd (NHSRCL), which is executing the Mumbai-Ahmedabad Bullet Train project, has not yet received the Tunnel Boring Machines (TBMs) initially scheduled to arrive by Oct 2024. The machines are now expected to arrive after a delay of three months.
According to the original plan, two TBMs were expected to reach the site by Oct 2024, with the third arriving in 2025. TBM-1 and TBM-2 were planned to bore tunnels between Sawli and Vikhroli, and Vikhroli and Bandra-Kurla Complex (BKC), before the year-end. TBM-3 was slated to be deployed for tunnelling from the Vikhroli side to Sawli.
NHSRCL Managing Director Vivek Kumar Gupta said, “The TBMs are expected to arrive in two to three months.”
The tunnel construction will utilise TBMs equipped with a cutter head measuring 13.1 metres in diameter—substantially larger than the 5-6 metre cutter heads typically used for urban metro systems.
The tunnel will run at a depth of 25 to 65 metres below ground level, with the deepest point reaching 114 metres beneath the Parsik Hill near Shilphata.
Afcons Infrastructure Ltd has bagged the contract to build the 21km tunnel, including 7km undersea, between BKC and Shilphata.
On Saturday, railway minister Ashwini Vaishnaw inspected the ADIT (Additionally Driven Intermediate Tunnel) that will facilitate the construction of a 21-km-long tunnel between BKC and Shilphata.
Vaishnaw remarked, “The technology and design of the tunnel enable two trains to pass through at speeds of 250 kilometres per hour. Environment protection, ventilation, and lighting have been meticulously planned. Significant progress was made on 340 kilometres of the project.”
In tunnelling terminology, an ADIT tunnel is a horizontal or nearly horizontal passage that provides access to the main tunnel construction site.
The ADIT tunnel at Ghansali, constructed at a depth of 26 metres, has internal dimensions of 11 metres by 6.4 metres. It will provide vehicular access to the main tunnel during construction and operations. It may also serve as an evacuation route during emergencies.
Project Progress Overview
• Overall Physical Progress: 47.90% (as of November 2024)
• Gujarat:
• Civil work, including enabling works: 81.35%
• Overall progress: 58.31%
• Maharashtra:
• Overall progress: 28.53%