Bridging the Deep: TBM Eagle Links Lighthouse to Thirumayilai

Chennai Metro Rail Limited (CMRL) has achieved a significant milestone in its Phase-2 expansion with the breakthrough of Tunnel Boring Machine (TBM) ‘Eagle’ at Thirumayilai station on Corridor-4.

The underground stretch between Light House and Kodambakkam Flyover comprises nearly 4 km of twin tunnels. Tunnelling commenced in January 2024, and TBM Eagle completed its 1,981-metre-long drive on 9 February 2026. Executed by Cemindia Projects, the tunnel alignment passes beneath prominent landmarks such as the Lighthouse, All India Radio, and the Russian Embassy. The work encountered challenging geological conditions, including hard rock strata and instances of gas leakage. Operating in closed-face mode, TBM Eagle required 17 cutterhead interventions to successfully complete the drive.

Meanwhile, TBM ‘Pelican’ has begun tunnelling from Panagal Park towards Boat Club, and TBM ‘Peacock’ has already completed 370 metres of excavation. These advancements mark steady progress in the Phase-2 expansion, which will add 128 stations across a 118.9-km network upon completion.

News by Rahul Yelligetti.