Tunnel between T. Nagar and Kodambakkam for Metro Rail Phase II to be ready by March 2025

Chennai Metro Rail's Phase II Project includes tunnel connecting T. Nagar with Kodambakkam, set for completion by March 2025.

The first tunnel connecting T. Nagar with Kodambakkam will be ready for Chennai Metro Rail’s Phase II Project will be ready by March 2025.

In January, ‘Pelican’, a tunnel boring machine (TBM), started drilling towards Kodambakkam from Panagal Park in T. Nagar. A few months later, ‘Peacock’, another TBM, was also launched on the stretch. Both the machines have bored underneath the Usman Road flyover and will soon pass under the Kodambakkam suburban railway track and flyover, before reaching the station at Kodambakkam Power House.

This tunnelling work is part of corridor 4 of the ₹63,246-crore Phase II Project, which runs from Light House to Poonamallee via T. Nagar and Kodambakkam. In the other corridors — Madhavaram to SIPCOT (corridor 3) and Madhavaram to Sholinganallur (corridor 5) — construction work is in full swing at some parts and lagging behind at others.

According to officials of Chennai Metro Rail Limited (CMRL), ‘Pelican’ has tunnelled a distance of 880 m and ‘Peacock’ 860 m so far.

“While crossing sensitive structures such as flyovers, hospitals or old heritage buildings, we monitor the process closely. We check the vibration parameters to avoid soil settlement. At the Usman Road flyover, there were no issues since the machine was not close to the foundation, yet we kept watch frequently,” an official said.

Sources said the machines had been encountering mixed soil conditions thus far, and beyond 880 m, they were expecting to drill through hard rock. “Sometime in February, we will cross the railway line. We are drilling at a depth of about 25 m now. We will inform Southern Railway authorities and implement any necessary precautions that they advise. Usually, the train speed may be decreased for a few hundred metres where the work is ongoing. We will take additional care,” the official added.