CHENNAI: Chennai Metro Rail Limited (CMRL) has crossed a key construction milestone on Corridor-4 of its Phase-2 network, with the first tunnel boring machine (TBM) completing a breakthrough on the underground stretch linking Light House and Poonamallee Bypass.
The upline TBM, named Eagle, broke through at the Thirumayilai shaft on Monday, marking the first completed tunnel under the UG-01 contract. Corridor-4 spans 26.1 km and forms part of the 118.9-km Phase-2 project that will add 128 stations across the city.
The 1.98-km tunnel between Light House and Thirumayilai, executed by Cemindia Projects, runs beneath some of Chennai’s most sensitive zones, including the Lighthouse, All India Radio, the Russian Embassy and several heritage schools and churches. The drive passed below 151 buildings, navigating shallow overburden and complex geology, including rocky strata and gas pockets.
CMRL has deployed four TBMs on this underground section, split between two packages, UG-01 and UG-02, to construct nearly 16 km of twin tunnels.
In parallel, tunnelling activity has begun on the Panagal Park-Boat Club stretch under UG-02, with TBM Pelican launched for its final drive. The section poses added engineering challenges, including tunnelling beneath operational Phase-1 Metro lines near Nandanam. Completion of this drive is targeted for December 2026, a release said.
Meanwhile, Chennai Metro Asset Management Limited, a joint venture of Chennai Metro Rail Limited and TIDCO, has awarded consultancy contracts to WAPCOS Limited for preparing detailed feasibility reports for two proposed cable-based transport projects in TN.
These include a high-altitude ropeway system in Kodaikanal and a cable-propelled transport system in Mamallapuram. The projects aim to promote sustainable, eco-friendly mobility, enhance tourism, and improve last-mile connectivity in high-footfall destinations. The consultancy, valued at Rs 78.28 lakh for Kodaikanal and Rs 71.93 lakh for Mamallapuram, will assess technical feasibility, alignment options, ridership potential, and environmental and social impacts over a 120-day study period.