TBM Servarayan achieves Tunnel Breakthrough on Corridor 3 of Chennai Metro Phase 2

Chennai, India (Metro Rail Today): Chennai Metro Rail Limited (CMRL) has achieved another major construction milestone in its ambitious Phase-2 expansion programme with Tunnel Boring Machine (TBM) “Servarayan” successfully completing its breakthrough at the Moolakadai North shaft. The achievement marks significant progress on Chennai Metro’s underground Corridor-3 works and highlights the project’s engineering capabilities in overcoming highly challenging tunnelling conditions beneath dense urban infrastructure.

The breakthrough forms part of the first underground package of Corridor-3, stretching from Madhavaram Milk Colony to Kellys, being executed by Tata Projects Limited. Chennai Metro Phase-2, one of India’s largest metro expansion programmes currently under implementation, spans nearly 118.9 km across three major corridors and is expected to transform urban mobility across Chennai.

TBM “Servarayan” (S99) began its tunnel drive from Madhavaram High Road Metro Station towards Moolakadai Station on the down line and successfully completed an underground bored tunnel section measuring approximately 824.6 metres before reaching the breakthrough point at Moolakadai North shaft.

With this achievement, Tata Projects Limited has now completed nine TBM breakthroughs under the TU-01 contract package, while Chennai Metro Rail Limited has recorded a total of 23 TBM breakthroughs under the larger Phase-2 project, reflecting steady momentum in underground construction activities across the city.

Complex Underground Engineering Beneath Active Urban Zones

The tunnel section between Madhavaram High Road and Moolakadai was considered one of the most technically challenging stretches under the TU-01 package. The tunnelling operation required the TBM to pass beneath the Buckingham Canal as well as under active traffic corridors, demanding highly precise engineering execution and continuous monitoring.

Project engineers faced additional challenges due to the presence of more than 14 bore wells along the alignment. According to officials, alternate water supply arrangements were provided to nearby residents and establishments to ensure uninterrupted public services during construction activities.

Despite the difficult geological and operational conditions, the tunnel drive was completed while maintaining settlement values well within permissible safety limits. Extensive instrumentation systems and real-time monitoring technologies were deployed throughout the tunnelling operation to ensure structural safety, ground stability, and uninterrupted urban activity above the tunnel alignment.

Senior officials from Chennai Metro Rail Limited, Tata Projects Limited, and the General Consultant teams were present during the breakthrough event, which has been described as another critical engineering success for the Phase-2 expansion project.

Chennai Metro Phase-2 Gains Momentum

Chennai Metro Phase-2 is being developed as a transformative urban transit project aimed at significantly improving connectivity across residential, industrial, commercial, and IT corridors of Chennai. Corridor-3, connecting Madhavaram Milk Colony to SIPCOT, is among the most important routes under the expansion programme and will provide seamless integration with existing metro corridors and suburban transport systems.

The underground section from Madhavaram Milk Colony to Kellys is being constructed using seven Tunnel Boring Machines deployed by Tata Projects Limited under the TU-01 package. The corridor is expected to ease traffic congestion, reduce travel time, and support sustainable urban mobility across northern and central Chennai.

Mrs. Mamta Shah, MD & CEO of Urban Infra Group, said, “The successful breakthrough of TBM ‘Servarayan’ demonstrates the growing technical maturity of India’s metro rail construction ecosystem. Executing underground tunnelling beneath canals, dense traffic corridors, and complex urban environments reflects world-class engineering capability and strengthens Chennai Metro’s position as one of the country’s most ambitious urban mobility projects.”

As tunnelling and station construction activities continue across multiple sections of Chennai Metro Phase-2, the project is steadily moving closer to delivering a faster, safer, and more integrated public transportation network for millions of commuters in the city.