BackOTHER
Chennai Metro Rail to procure additional tunnel boring machines due to delays in Phase II network
Chennai Metro Rail Limited plans to procure additional tunnel boring machines (TBMs) for Phase II after underground construction delays. As of May 14, 2026, only 28.11 km of tunnelling has been completed out of 69.05 km planned, with 42.6 km underground, and 23 TBMs already purchased but some stranded awaiting breakthroughs.
Why It Matters
The delays affect Phase II timelines and commuter service expansion. Procuring more TBMs signals escalation in project complexity and potential cost and schedule implications.
Timeline
3 Events
Current status and TBM plan for Phase II
May 14, 2026
As of May 14, 2026, Chennai Metro Rail Limited plans to procure additional TBMs due to underground construction delays. Only 28.11 km of tunnelling has been completed out of 69.05 km required, with 42.6 km underground. Twenty-three TBMs were purchased initially, but some have remained stranded for extended periods while awaiting breakthroughs. In corridor 3, TBMs are idled at stretches such as Madhavaram to Moolakadai and Purasawalkam to Kellys awaiting the completion of station shafts. In corridor 5, tunnelling between Villivakkam areas paused due to the need for permission to bore under tracks. There is also a delay in starting tunnelling in stretches including Royapettah to Thousand Lights, Thiruvanmiyur to Indira Nagar, and Perambur to Perambur Market.
Cancellation and delays in underground station tenders
2021
Tenders floated for underground stations in corridor 3 and part of corridor 5 were cancelled due to inflated quotes; the process to cancel, refloat, and re-award contracts contributed to delays amounting to more than a year.
Phase II project work commenced
2021
Phase II project work commenced.