Chennai Metro Begins Underground Tunnelling for Corridor 5 with TBM Kurinji

Chennai Metro Rail Limited (CMRL) has commenced underground tunnelling for Corridor 5 by launching its first tunnel boring machine (TBM) Kurinji at the Kolathur ramp. This marks a significant milestone in Phase 2 of Chennai Metro’s expansion.

Corridor 5 spans 47 km, connecting Madhavaram Milk Colony to Sholinganallur via Koyambedu, Porur, and Alandur. It includes five underground stations and 39 elevated stations. The underground section, stretching 7.8 km with twin tunnels of 3.9 km each, is being executed by Tata Projects. The tunnelling work will involve four TBMs, named after Tamil landscapes—Kurinji, Mullai, Marutham, and Neithal.

TBM Kurinji was launched on Wednesday and will bore a 246-metre tunnel from Kolathur ramp towards Kolathur station (upline). It is expected to reach its destination by June 2025, after which it will be retrieved and relaunched from the south shaft to tunnel 1.06 km towards Srinivasa Nagar.

The second TBM, Mullai, is scheduled to arrive by the end of March. It will be deployed near Villivakkam Railway Station to tunnel 603 metres towards Villivakkam Bus Terminus. The remaining two TBMs, Marutham and Neithal, will be launched based on site readiness.

The underground stations on this stretch include Kolathur Junction, Srinivasa Nagar, Villivakkam, Villivakkam Bus Terminus, and Nathamuni (previously Villivakkam MTH Road). This expansion is part of CMRL’s Phase 2 project, covering 118.9 km across three corridors. In addition to Corridor 5, Corridor 4, connecting Poonamallee to Porur Junction, is also under construction.

The project is expected to enhance urban connectivity and ease congestion in Chennai. With tunnelling operations now underway, CMRL aims to complete major underground works within the next few years, facilitating better public transport for residents.