Chennai Metro Rail Ltd (CMRL) has achieved another key construction milestone on Corridor-4 of its Phase-2 network, with the second TBM under the UG-01 contract breaking through at the Thirumayilai shaft.
The downline TBM, named Flamingo S-1352A, broke through at the Thirumayilai station on February 27, marking the completion of the first downline tunnel drive between Light House and Thirumayilai. The breakthrough follows the earlier completion of the upline tunnel by TBM Eagle under the same contract on February 9.
The 1.985km tunnel, executed by Cemindia Projects Ltd, passes beneath some of Chennai’s most and congested stretches, including the Lighthouse area, the All India Radio campus, the Russian Embassy zone, Rosary Church, and several heritage and important structures such as the MRTS bridge and Buckingham Canal.
The drive navigated challenging geological conditions, including rocky strata, shallow overburden, deep overburden to accommodate stacked tunnel configuration, and unforeseen gas pockets.
CMRL said TBM Flamingo’s breakthrough marked an important step in advancing Corridor-4, which will improve connectivity across Mylapore, Luz and Central Chennai.
TBMs Flamingo and Eagle will now be relaunched from Thirumayilai for the next drive towards Boat Club.
