Chennai Metro Phase II: TBM Kalvarayan Achieves Breakthrough at Perambur Metro (South) Shaft
In a significant milestone for Chennai Metro Rail Phase II, Tunnel Boring Machine (TBM) Kalvarayan (S 1331) achieved a successful breakthrough at the Perambur Metro (South) shaft today, May 13, 2025.
Chennai Metro Rail Limited (CMRL) is undertaking a massive infrastructure expansion, adding three new corridors spanning a total length of 118.9 km, with funding from multiple international agencies including GoI, GoTN, JICA, ADB, AIIB, and NDB.
The tunnelling work for the first 9-km underground section of Corridor 3—from Madhavaram Milk Colony to Kellys—is being executed by M/s Tata Projects Limited, which has deployed 7 Tunnel Boring Machines (TBMs) for the task.
TBM Kalvarayan, operating between Ayanavaram Station and Perambur Station (Up line), completed a tunnel stretch of 867 meters, marking the 7th TBM breakthrough under the TU-01 contract by Tata Projects. This also represents the 11th TBM breakthrough completed under the Phase II project of CMRL.
The tunnel section between Ayanavaram and Perambur posed considerable engineering challenges. The TBM had to navigate beneath active railway tracks and platforms at Perambur Railway Station and densely populated residential zones. The construction team also had to manage and relocate more than 32 borewells along the alignment without causing any disruption to public water supply.
Despite these challenges, the tunnel drive was executed with precision, maintaining minimum allowable ground settlement levels. The success was made possible through extensive instrumentation and continuous monitoring throughout the tunnelling process.
Officials from CMRL, the General Consultant, and Tata Projects were present at the site to witness the breakthrough.
This achievement marks yet another step forward in CMRL’s commitment to enhancing Chennai’s urban mobility with safe and efficient underground metro connectivity.
