TBM Peacock records longest Tunnel Breakthrough for Chennai Metro Phase 2

Chennai, India (Metro Rail Today): Chennai Metro Rail Limited (CMRL) continues to make impressive strides in transforming the city’s urban mobility landscape, with a major engineering milestone achieved today, 23rd July 2025. Tunnel Boring Machine (TBM) “Peacock” (DL 1074) successfully completed its 2.047 km drive and broke through at the Kodambakkam Ramp Retrieval Shaft near Meenakshi College on Arcot Road. This is the longest single tunnel achieved in Phase 2 and marks a momentous step in the construction of Corridor 4 of the 118.9 km Phase 2 Metro network.

The breakthrough is particularly noteworthy due to the highly complex and densely populated terrain the tunnel traversed. The TBM was launched from Panagal Park Crossover on May 2, 2024, and during its journey, it passed beneath 190 buildings — over 50 of which were decades-old residential structures — and navigated alongside an operational railway line before crossing multiple active railway tracks. The tunnel alignment also passed below the historic Kodambakkam Flyover and under two churches, all without causing surface disruption or traffic diversions, a remarkable feat of precision engineering and urban coordination.

Corridor 4 of Phase 2, which stretches from Light House to Poonamallee Bypass over a length of 26.8 km, is one of the most ambitious legs of CMRL’s expansion and includes 12 underground and 18 elevated stations. The 10.03 km underground portion between Light House and Kodambakkam Flyover is being executed by ITD Cementation India Limited using four advanced TBMs. This corridor is being funded through strategic financial partnerships with leading global institutions including the Asian Development Bank (ADB), Asian Infrastructure Investment Bank (AIIB), and New Development Bank (NDB), reinforcing Chennai’s position on the global infrastructure map.

“This breakthrough is more than just an engineering success — it is a statement of what urban India can achieve through bold planning, world-class technology, and public-focused execution,” said Mrs. Mamta Shah, MD & CEO of Urban Infra Group. “CMRL’s achievement with TBM Peacock is symbolic of Chennai’s transformation into a modern, accessible, and sustainable city. Such milestones not only inspire confidence in large-scale infrastructure but also pave the way for replicable models in other Indian metros.”

With Phase 2 progressing rapidly, Chennai is set to emerge as a leader in sustainable transit development. As traffic volumes continue to rise and the city grows, projects like Corridor 4 promise to provide seamless, efficient, and environmentally responsible transportation, while preserving the fabric of the city's bustling neighborhoods. The success of TBM Peacock’s journey is a powerful testament to CMRL’s commitment to building a metro system that serves both the present and future needs of Chennai.