Chennai Metro Rail launches first tunnel boring machine for underground tunnelling in Kolathur

CHENNAI: For underground tunnelling, the Chennai Metro Rail Limited (CMRL) has launched its first tunnel boring machine (TBM) Kurinji in Corridor 5 at Kolathur ramp on Wednesday.

Corridor 5 begins at Madhavaram Milk Colony and connects through Koyambedu, Porur, Alandur and other residential/commercial areas of the city to Sholinganallur. This 47-km stretch comprises 5 underground stations and 39 elevated stations.

As per CMRL press note, four TBMs, each named after Tamil landscapes (Kurinji, Mullai, Marutham, and Neithal) are to be deployed in Corridor 5. “TBM Kurinji was launched on Wednesday. It will bore a 246-metre tunnel from Kolathur ramp towards Kolathur station (upline) and is expected to reach in June 2025. It will then be retrieved and relaunched from the south shaft to tunnel towards Srinivasa Nagar (1.06 km),” stated a CMRL press note.

Additionally, TBM Mullai is expected to arrive by the end of March. It will begin tunneling adjacent to Villivakkam Railway station towards Villivakkam bus terminus (603 metres). “The remaining two TBMs will be launched based on site readiness,” the note added.

The 7.8 km underground tunnel section with twin tunnels of 3.9 km each of Corridor 5, including 5 underground stations from Kolathur-Nathamuni ramps, is being executed through Tata Projects. It has to mobilise 4 TBMs for the works.

The underground metro stations are Kolathur Junction, Srinivasa Nagar, Villivakkam, Villivakkam Bus Terminus and Nadhamuni, name that was changed from Villivakkam MTH Road metro station. CMRL is constructing three corridors in the second phase for 118.9 km, and Corridor 4 between Poonamallee and Porur Junction.