Chennai Metro Rail Limited (CMRL) achieved a milestone with the Tunnel Boring Machine “Kurinji” completing its first breakthrough at Kolathur Station on Corridor-5 of Phase-2. Despite complex geological and engineering challenges, the breakthrough marks significant progress in Chennai’s metro expansion, strengthening CMRL’s effort to safe and sustainable urban transport.
Introduction:
The Chennai Metro Rail Limited (CMRL) has marked another remarkable achievement in its ongoing Phase 2 expansion with a successful tunnel breakthrough at Kolathur Station. On August 21, 2025, Tunnel Boring Machine (TBM) “Kurinji” completed its first breakthrough at the North Shaft of Kolathur Station on Corridor-5, a critical section of the city’s expanding metro network.
Significance of Corridor-5:
Corridor-5 of Phase-2 spans 47 km, including a 5.8 km underground (UG) section and 41.2 km elevated section. This corridor is a vital part of Chennai’s metro development strategy, designed to provide faster, more reliable, and environmentally friendly connectivity across the city. Four TBMs—Kurinji, Mullai, Neithal, and Marutham—have been deployed to advance tunneling works in the underground stretch.
Details of the Breakthrough:
The tunnel drive by TBM “Kurinji” commenced on February 20, 2025, from Kolathur Ramp towards Kolathur Station, covering a tunnel length of 246 meters before its successful breakthrough. This marks the first breakthrough in Corridor-5 under Package C5-UG06. The achievement demonstrates the progress of Tata Projects Limited, the executing agency for the underground works, supported by funding from the Japan International Cooperation Agency (JICA).
Overcoming Key Challenges:
The tunneling process was far from easy. Engineers faced:
- Low overburden of 1.8 meters, posing structural and operational risks.
- Steep gradient of 3.8%, demanding precise control over TBM operations.
- Ground protection requirements in the middle of the heavily trafficked Inner Ring Road (IRR).
Despite these challenges, the team completed the drive without causing disruption to traffic or inconvenience to the public—a testament to CMRL’s careful planning and execution.
Presence of Key Officials:
The milestone was celebrated in the presence of senior officials from CMRL, Tata Projects, and General Consultants. Distinguished attendees included Mr. T. Archunan, IRSE, Director Projects of CMRL, Mr. T. Livingstone Eliazer, CGM (PP&D), Mrs. S. Rekha Prakash, CGM (P&D), and Mr. Karthikeyan M., JGM. From Tata Projects Ltd., Mr. K. Ramesh (Project Director) and Mr. Natthapong Katkaew (Project Manager) participated, along with General Consultant representatives Mr. Ian Watson (Team Leader) and Mr. Usman Sheriff (Chief Resident Engineer). Their presence underscored the importance of this accomplishment in Chennai’s infrastructure journey.
Broader Impact:
This underground section, comprising five stations and two ramps, plays a vital role in connecting key urban nodes. By ensuring seamless progress, CMRL demonstrates its commitment to delivering sustainable and efficient mobility solutions for Chennai’s growing population. The project also highlights international collaboration, with JICA’s funding support bolstering India’s urban infrastructure expansion.
Conclusion:
The successful breakthrough of TBM “Kurinji” at Kolathur Station marks a significant achievement for CMRL’s Phase 2 project. Overcoming complex technical challenges, the achievement underscores Chennai Metro’s dedication to sustainable urban transport. With further breakthroughs expected, Corridor-5 is poised to enhance the city’s connectivity and commuting experience.
Source: CMRL | Featured Image Credit (representational): CMRL
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