Tunnel Boring Machine (TBM) S1331 achieved its breakthrough at Perambur station for package TU-01 on May 14, 2025 under the Chennai Metro Rail Phase II project. It was commissioned at Ayanavaram station and travelled for 867 metres till Perambur. This is the 11th breakthrough achieved under the project.
Package TU-01 involves construction of approximate 9 km long twin bored tunnels from TBM retrieval shaft near Venugopal Nagar metro station to Kellys metro station and construction of diaphragm walls of station box and entry/ exit structures of Madhavaram Milk Colony, Murari Hospital, Ayanavaram and Purasaiwakkam High Road stations, including launching and retrieval shafts as required. Tata Projects Limited was awarded the contract for the same in May 2021.
The project involves development of 118.9 km of three metro corridors (Corridor III, IV and V) in Chennai, Tamil Nadu. It is mostly underground with elevated section confined to a few short stretches and consists of 128 stations in total.