CHENNAI: CMRL achieved a milestone in Phase II expansion on Tuesday, with a tunnel boring machine (TBM) completing a challenging underground drive beneath one of the busiest railway zones.
The TBM, named Kalvarayan, completed its 867-metre journey between Ayanavaram and Perambur stations, surfacing at the Perambur south shaft. This marks the seventh breakthrough under contract by Tata Projects Limited, and the 11th overall in the Phase II project, which aims to deliver over 118km of new metro rail lines.
The initial 9km underground stretch of Corridor 3, running from Madhavaram Milk Colony to Kellys, is being constructed by Tata Projects Limited, which has deployed seven TBMs. The Kalvarayan breakthrough forms a critical link within this section, which includes some of the most technically demanding alignments in the network.
Engineers had to navigate beneath heavily trafficked railway platforms at Perambur station and through densely populated urban neighbourhoods, while mitigating risks from more than 30 borewells along the route.
Despite these complexities, the TBM drive was completed without any incident, with ground settlement levels kept within permissible limits. Extensive instrumentation and continuous monitoring ensured safety throughout the operation.