Chennai Metro Completes Tunnel Drive Beneath North Chennai Residential Area

Chennai Metro Rail Ltd (CMRL) has achieved a significant milestone in the second phase of its infrastructure expansion. The tunnel boring machine known as Kurinji successfully completed a 1.08-km underground drive beneath a densely populated residential area in north Chennai. This breakthrough marks a critical step for those tracking the development of the Metro North network, as the project navigates complex urban landscapes.

Advancing the Metro North infrastructure

The machine began its journey from the Kolathur station on November 27, 2025, and reached the Srinivasa Nagar North Shaft after 351 days of operation. The project required the team to manage challenging geological conditions, including transitions between soil, weathered rock, and hard rock. Furthermore, the route necessitated navigating a sharp curve with a 230-metre radius while passing beneath or near more than 70 borewells and open wells.

The Kurinji tunnel boring machine completed a 1.08-km underground drive in north Chennai after 351 days.

Kurinji is one of four machines deployed to excavate the 5.8-km underground section of Corridor 5. This corridor is part of a larger 47-km line, which includes 41.2 km of elevated track. The underground segment is designed to feature five stations and two ramps. The construction is being executed by Tata Projects with financial support from the Japan International Cooperation Agency (JICA).

In addition to the tunneling progress, CMRL is preparing for future operations. Alstom has commenced production of 32 three-car driverless trainsets at its facility in Andhra Pradesh. These trains, ordered under a $135 million contract, are designed for Grade of Automation 4, allowing for fully driverless operations at speeds up to 80 kmph. Each trainset will have a capacity of 900 passengers and include advanced features such as regenerative braking and cybersecurity protocols.

Why it matters

The completion of this tunnel segment represents a vital step in expanding the city's transit capacity. By successfully tunneling under a heavily built-up area, the project demonstrates the technical feasibility of extending modern rail infrastructure into dense urban centers.

This expansion is part of a broader 119-km Phase II project, which aims to improve connectivity across three major corridors. For residents and commuters, these developments signify a shift toward a more integrated and automated public transportation network in the region.