Chennai completes metro tunnel between Kodambakkam and Panagal Park under Phase II
In a significant step forward for Chennai’s expanding public transport network, metro authorities have successfully completed a two-kilometre tunnel connecting Panagal Park to Kodambakkam under Phase II of the Chennai Metro project. The breakthrough, achieved after 14 months of underground boring work, marks a major milestone in Corridor 4—linking Poonamallee in the west to Light House in the east. Once completed, the route will provide seamless access between bustling residential areas like Kodambakkam and commercial hubs such as T. Nagar, reducing traffic stress and cutting carbon emissions.
Officials confirmed that the tunnel boring machine (TBM), nicknamed Peacock, completed its passage through densely built urban areas—including beneath two flyovers, a railway station, and nearly 190 buildings. The route posed considerable engineering challenges, especially as the TBM had to tunnel just three metres from an active suburban railway line. For two weeks, train speeds on the Kodambakkam section were limited to ensure safety during excavation. Despite these complexities, engineers maintained structural integrity in one of the city’s most congested zones, showcasing careful planning, modern tunnelling techniques, and precision in civil infrastructure. The soil conditions added further difficulty to the project, varying from clay and sand to hard rock along the stretch. In some parts, the machine encountered mixed layers, which required frequent tool adjustments and replacement of cutting discs.
Experts said the stretch between Panagal Park and Kodambakkam represents one of the longest and most technically complex tunnel segments between two stations in Chennai’s metro history. Yet, despite these odds, there were no major disturbances to surrounding structures, many of which were decades old and potentially vulnerable to vibrations or structural shifts. The tunnel will eventually become part of the underground section of Corridor 4, which transitions from an elevated to a subterranean track at Kodambakkam. This design helps preserve surface space and supports Chennai’s broader goal of sustainable urban mobility. By pushing ahead with underground metro expansion in dense neighbourhoods, the project avoids displacing communities or interfering with existing road infrastructure. When operational, the line is expected to significantly reduce reliance on private vehicles, particularly in areas notorious for narrow roads, bottlenecks, and pollution from traffic congestion.
As Chennai works towards building an inclusive and carbon-conscious transit ecosystem, this tunnel breakthrough signals more than just engineering progress. It highlights the city’s commitment to long-term, people-focused infrastructure development that respects both urban density and ecological limits. Once operational, the line will improve last-mile connectivity and offer climate-friendly commuting options to thousands of residents every day, further solidifying metro rail’s role as a backbone of equitable mobility in Indian cities.
