CHENNAI: Chennai Metro Rail Limited (CMRL) has achieved the first tunnel breakthrough on Corridor-5, marking a major step in the city’s expanding metro network.
The Tunnel Boring Machine ‘Kurinji’, on Thursday, completed a 246-metre drive from the Kolathur ramp to the north shaft of Kolathur station. The drive, which began in February, was completed under unusually difficult conditions: A minimal soil overburden of just 1.8 metres, a steep 3.8% gradient and the need for ground protection under the busy Inner Ring Road.
Despite these constraints, CMRL said the work was completed without disrupting traffic. Corridor-5, spanning 47 km, is a crucial part of Chennai Metro’s Phase II expansion. It comprises 41.2 km of elevated track and 5.8 km underground, where four tunnel boring machines - Kurinji, Mullai, Neithal, and Marutham - are being deployed. The Kolathur breakthrough is the first achieved under the underground package.