Key Milestone: Cutterhead Lowered at Vikhroli
Marking a major milestone in the Mumbai-Ahmedabad bullet train project, a 350-tonne tunnel boring machine (TBM) cutterhead was lowered at Vikhroli, initiating the assembly of the underground tunnelling system for the high-speed rail corridor. This critical phase development work sets the stage for one of India's most ambitious infrastructure projects.
Massive Cutterhead Dimensions and Assembly
The cutterhead, weighing 350 tonnes and measuring 13.6 metres in diameter, forms the front end of the TBM. It was delivered in five separate consignments and is being assembled using precision welding techniques at the worksite. The sheer scale of this component underscores the engineering complexity involved.
Large-Scale Mumbai Tunnel Construction
The Mumbai tunnel spans 21 kilometres, with 16 kilometres constructed using two massive TBMs, each weighing over 3,000 tonnes. These machines are designed to excavate a single tunnel that will carry both up and down railway lines, optimising space and efficiency in the dense urban environment.
Undersea Tunnel Beneath Thane Creek
The project includes a 7-kilometre stretch beneath Thane Creek, marking India's first undersea rail tunnel. This section forms part of the high-speed corridor’s most complex underground development, presenting major engineering challenges due to water pressure and geological conditions.
Largest TBMs in India’s Rail History
These TBMs are the largest ever deployed in India for rail tunnel construction, setting a new benchmark in scale, capacity, and engineering capability. The project represents a significant leap forward for underground infrastructure development in the country.
Advanced Cutterhead Engineering Design
The cutterhead features 84 cutter discs, 124 scrapers, and 16 bucket lips, designed to break through rock and soil efficiently. It also clears excavated muck and guides material into the chamber pipeline system, ensuring smooth tunnelling operations.
Excavation Route from Vikhroli to BKC
From Vikhroli, the TBM will excavate nearly 6 kilometres towards Bandra-Kurla Complex (BKC), passing beneath dense urban areas and the Mithi River. The machine will be retrieved at the under-construction station complex site upon completion of this segment.
