The Phase-2 corridor will span 118.9km, 42.6km of which will be underground, with 48 stations. The project is expected to be completed by 2026. To facilitate this, two tunnel boring machines (TBMs) have been assembled at the Greenways Road metro station construction site at the RA Puram corporation playground. The first TBM has begun work on the stretch from Greenways Road metro up to Adyar junction, 1.8km. The second TBM will begin work within the next two weeks, with both machines set to drill through the soil below the Adyar riverbed.
The corporation currently has two TBMs at work between Madhavaram Milk Colony and Madhavaram High Road. A total of 23 TBMs are expected to be used in tandem to construct tunnels for the underground section of Phase-2. This includes at least 15 TBMs that will be used to build tunnels covering 26.7km on the 45.8km Corridor-3 from Madhavaram to Siruseri Sipcot, four TBMs for the 10.1km underground line of the 26.1km Corridor-4 from Lighthouse to Poonamallee bypass, and a 5.8km underground line on the 47km Corridor-5 from Madhavaram to Sholinganallur.
