Chennai Metro Completes Crucial Tunnel Between Ayanavaram and Perambur in Phase II Expansion

Chennai Metro Rail Limited (CMRL) has achieved a major milestone by completing an 867-meter tunnel between Ayanavaram and Perambur as part of its ambitious Rs 63,246-crore Phase II expansion. The May 13, 2025, breakthrough followed more than 18 months of round-the-clock tunneling work.

The tunnel was bored using the Tunnel Boring Machine (TBM) named ‘Kalvarayan’ and marks the 11th tunnel successfully finished in the ongoing project. Phase II aims to expand Chennai’s metro network by 118.9 kilometers across three corridors: Madhavaram–SIPCOT, Light House–Poonamallee, and Madhavaram–Sholinganallur.

42.6 kilometers out of the total network length will be underground, with 48 stations. The newly opened Ayanavaram–Perambur tunnel is on the Madhavaram–SIPCOT corridor, a major route aimed at enhancing connectivity in northern and western Chennai.

CMRL officers mentioned the engineering complexities at, particularly, the Perambur station site. The building team was required to finish the diaphragm wall, a vital underground structural support, before the breaking through by the TBM. This resulted in delays since the TBM had bored more than 95% of the tunnel length but was forced to stop owing to delayed station work.

Delays were attributed to the previous cancellation of tenders for station construction, which had slowed progress. Despite these obstacles, the successful breakthrough of the tunnel marks steady progress in Phase II, which brings Chennai nearer to a modernized and expansive metro rail network.

With 11 tunnels already completed and under construction, the CMRL Phase II project remains on track, holding out the promise of improved urban mobility and lower congestion upon commencement.