CMRL Begins Second Tunnel Boring Drive from Tirumayilai to Boat Club on Chennai Metro Corridor 4

Chennai Metro Rail Limited (CMRL) has launched the second tunnel boring drive between Tirumayilai Metro Station and Boat Club Metro Station as part of the underground section of Corridor 4 under the ambitious Chennai Metro Phase II Project.

The Tunnel Boring Machine (TBM) "Eagle" commenced excavation from Tirumayilai Station on Friday and will construct a 2,274-metre-long underground tunnel towards Boat Club Station. This marks another significant milestone in expanding Chennai`s modern metro rail network.

A key highlight of this tunnelling operation is the drag-through process at Alwarpet Metro Station and Bharathidasan Metro Station. Instead of dismantling and reassembling the TBM at intermediate stations, the machine will continue its journey seamlessly through both stations, reducing construction time and improving overall project efficiency.

The tunnelling drive also includes a technically challenging 586-metre fully stacked tunnel section between Alwarpet and Bharathidasan Metro Stations. This complex underground alignment requires precise engineering and continuous monitoring to ensure accurate tunnel positioning and structural safety.

According to CMRL, the tunnel passes through mixed geological conditions, presenting significant engineering challenges. The upper layers consist of soft alluvial soil, while the deeper sections contain hard rock formations. Engineers will continuously monitor the excavation process to maintain ground stability, prevent settlement, and ensure the tunnel remains aligned throughout the construction.

The successful commencement of this second tunnelling drive is another major step forward in the Chennai Metro Phase II project. Once completed, Corridor 4 will enhance connectivity across Chennai, reduce road congestion, shorten travel times, and provide commuters with a faster, safer, and more sustainable public transportation system.