CMRL to deploy three more tunnel boring machines for Phase II Metro Rail works

Chennai Metro Rail Limited (CMRL) is set to deploy three additional tunnel boring machines (TBMs) for its Phase II expansion works, officials said on Sunday. The move marks the next phase of tunnelling activity across the city as the metro network pushes deeper into the urban core.

The new machines will join the existing fleet already working on the underground sections of the Phase II corridor. CMRL has not yet disclosed the exact routes or launch sites for the fresh TBMs, but sources indicate they will be assigned to stretches where tunnelling is yet to begin.

Expanding the underground network

Phase II of the Chennai Metro is a major expansion that includes three new corridors spanning over 100 km. A significant portion of this alignment runs underground, requiring extensive tunnelling through the city's varied soil and rock conditions.

The deployment of additional TBMs is expected to accelerate progress on sections that have faced geological challenges. CMRL has previously used tunnel boring machines for the Phase I extension and the current Phase II work, with each machine capable of excavating several metres a day.

Why more machines now

Officials said the decision to bring in more TBMs comes as several launch shafts are ready and the pace of construction needs to pick up. With multiple fronts open simultaneously, the additional machines will allow CMRL to bore tunnels in parallel rather than sequentially.

This is a standard approach in metro construction globally, where multiple TBMs are deployed to shorten project timelines. The machines, which are assembled on-site, are typically lowered into launch shafts and operate round-the-clock once commissioned.

Impact on commuters and city traffic

As tunnelling activity increases, some stretches of major roads may see temporary diversions or increased construction activity. CMRL has said it will coordinate with traffic police to minimise inconvenience, though specific details on road closures are yet to be announced.

For commuters, the Phase II network promises faster connectivity across Chennai, linking areas such as Madhavaram, Sholinganallur, and SIPCOT to the existing metro grid. Once completed, the expanded system is expected to carry lakhs of passengers daily, easing pressure on the city's roads.

What lies ahead

The arrival of the new TBMs will be followed by their assembly and trial runs at designated sites. CMRL is expected to release a detailed timeline for the deployment and the specific corridors where the machines will operate.

As Phase II progresses, officials will also focus on completing the remaining underground stations and integrating the new lines with the existing network. The next few months are likely to see visible progress in tunnelling activity across the city.

With tunnelling set to intensify, the coming quarters will be crucial for CMRL to meet its targeted deadlines. The completion of this phase is seen as a key step in transforming Chennai's public transport landscape, though exact completion dates remain subject to construction realities.