STN: The Chennai Metro Phase 2 project reached a key stage on July 23, 2025. A tunnel boring machine (TBM), named Peacock, completed its journey at the Kodambakkam Ramp near Meenakshi College. The work was part of Package C4-UG02, which belongs to Line 4 of the metro’s second phase.
Line 4 Project Overview
Line 4 runs between Light House and Poonamallee Bypass, covering 26.8 km. It includes 12 stations below ground and 18 above ground. The underground section from Light House to Kodambakkam Flyover is being built in two parts: C4-UG01 and C4-UG02. ITD Cementation is responsible for both packages.
The scope of C4-UG02 includes five underground stations:
- Boat Club
- Nandanam
- Panagal Park
- Kodambakkam
- Kodambakkam Flyover
This part also includes tunnels, ramps, and crossover tracks.
Details of the Chennai Metro TBM Breakthrough
The TBM named Peacock began drilling from Panagal Park on May 2, 2024. It moved toward the Kodambakkam Ramp, completing a 2,047-metre drive. This was the longest single tunnel done so far in Chennai Metro Phase 2.
This Chennai Metro TBM breakthrough shows progress in one of the most difficult sections of the project. The TBM went under over 190 buildings, including more than 50 old houses that needed extra care.
Urban Challenges Faced During Tunnelling
The path of the tunnel was through a tight urban zone. It passed near an active railway track and later crossed other running lines. Teams had to work carefully to prevent any impact.
Other tricky spots included:
- Two churches on the tunnel path
- The base of the existing Kodambakkam Flyover
Engineers used safety tools and checks to make sure nothing was damaged. Work went on without stopping road or rail traffic above ground.
Contract Award and Timeline
Chennai Metro Rail Limited (CMRL) gave the contract for Package C4-UG02 to ITD Cementation in January 2022. The value of this package was Rs 1,846.86 crore. The company was also working on the neighbouring section under C4-UG01.
Together, these two packages cover about 10.03 km of underground tunnels.
Chennai Metro TBM Breakthrough Marks Milestone
The Chennai Metro TBM breakthrough at Kodambakkam adds to the list of achievements in Phase 2. The project continues to move forward, despite the complexity of building below busy city zones.
More breakthroughs are expected in the coming months. Each one gets Chennai closer to a better and faster public transport network.
