Archive · 2 Oct 2026
Chennai Metro Phase II Records Three TBM Breakthroughs
Chennai Metro is building underground train tunnels in several parts of the city.
Three large tunnel-making machines reached stations on three days in a row.
Kaveri reached Kilpauk Medical College station.
Maruthan reached Villivakkam station.
Adyar reached RK Salai station after digging a 915-metre tunnel.
Adyar had to pass under or near important buildings and roads.
Chennai Metro Rail Limited said the work caused no major ground settlement or damage to existing infrastructure.
The three breakthroughs are being treated as an important step in building Phase II.
Chennai Metro Phase II recorded three tunnel boring machine breakthroughs between September 29 and October 1.
TBM Kaveri reached Kilpauk Medical College, Maruthan reached Villivakkam, and Adyar reached RK Salai.
TBM Adyar completed a 915-metre downline tunnel between Royapettah and RK Salai stations.
The tunnel passed Peters Bridge, Andhra School, the EPFO building and shop lots without major ground settlement, according to CMRL.
The work is part of Corridor 3’s 12-kilometre underground section, where Larsen & Toubro has mobilised eight TBMs.
- Who
- Chennai Metro Rail Limited, Larsen & Toubro Limited and the TBMs Kaveri, Maruthan and Adyar.
- What
- Three tunnel boring machines achieved breakthroughs at stations during Chennai Metro Phase II construction.
- When
- The breakthroughs were reported on September 29, September 30 and October 1; the article also dates Adyar’s completed drive to October 1, 2026.
- Where
- Kilpauk Medical College, Villivakkam and RK Salai stations in Chennai, including the Royapettah–RK Salai underground stretch.
- Why
- To advance construction of Chennai Metro Phase II’s underground sections, including Corridor 3 and Corridor 5.
- Breakthroughs
- Three TBMs reached stations on three consecutive days.
- TBM locations
- Kaveri reached Kilpauk Medical College, Maruthan reached Villivakkam and Adyar reached RK Salai.
- Adyar tunnel length
- 915 metres between Royapettah and RK Salai stations.
- Construction conditions
- The tunnel passed through silty sand with approximately 9 to 13 metres of overburden.
- Cutterhead interventions
- CMRL reported 11 cutterhead interventions during Adyar’s drive.
- Project section
- The work is part of Corridor 3’s 12-kilometre underground section between Kellys and Taramani.
- TBMs under TU02
- The Adyar breakthrough was described as the 10th TBM breakthrough under the TU02 contract.