L&T’s Chennai Metro TBM Kaveri Records Breakthrough at Adyar Junction

Larsen & Toubro (L&T) on Thursday celebrated tunnel boring machine S-1327A’s first breakthrough at Adyar Junction Station for the 116.1 km Chennai Metro Phase 2 project.

This event marks the 2nd tunnel breakthrough for 45.8 km Line-3‘s 12 km Package TU-02 connecting Kellys and Taramani Road Junction.

Nicknamed TBM Kaveri, this 100m long Ø6.65m Herrenknecht earth pressure balance (EPB) machine had passed factory acceptance tests (FAT) in July 2022, and parts of it were lowered into Greenways Road Station’s shaft in January 2023.

Kaveri was commissioned from Greenways Road in February 2023 and built a 1228m tunnel in 19 months which includes a roughly 300m tunnel below Adyar River with an overburden of 10-13m.

Per CMRL’s press release, the TBM passed through “mixed geological conditions like bottom of the tunnel is rock and top of the tunnel is sand. TBM also tunneled through full-faced hard rock below some portion of the Adyar River.  TBM underwent 65nos cutter head interventions (CHI) to replace cutting tools in the TBM face and consumed 178days for CHI. The TBM also passed below a few Petrol bunks, MGR Janakicollege, Andra Saba Hospital, Durgabai Deshmukh road and Adyar bridge ramp.“

Chennai Metro Rail Ltd. (CMRL) had awarded L&T with Package TU-02’s Rs. 2385 crore contract in May 2021 with a 42 month deadline.

Besides constructing twin tunnels between Kellys and Taramani Road Junction, they will build diaphragm walls, entry/exit structures of Chetpet Station, Royapettah Government Hospital Station, Thiruvanmiyu Station, and part diaphragm wall of Greenways Road Station, including launching and retrieval shafts at the above stations.

TBM Kaveri is 1 of 7 machines deployed by L&T for building approximately 12 km twin tunnels (total 24 km) between Kellys and Taramani Road Junction stations.

Per CMRL, TBM Adyar (S-1326A) working on the parallel tunnel is currently 277m away from arriving at Adyar Junction Shaft and is expected to breakthrough in November 2024.

With this development, a total of 8 tunnels have been completed so far. On the south-side, L&T has recorded two breakthrough for Line-3 on Package TU-02 (Kellys to Taramani Road Junction):

• August 2024: TBM DZ1040 (Siruvani) at Sterling Road – 703m
• September 2024: TBM 1327A (Kaveri) at Adyar Junction – 1228m (this post!)

While on the north-side, Tata Projects has built 6 tunnels for Package TU-01 (Madhavaram – Kellys). 4 of those connect Venugopal Nagar – Madhavaram Milk Colony – Madhavaram High Road stations on the extreme north side, a length of roughly 2.5 km including station boxes.

• June 2023: TBM S98 (Anaimalai) at Venugopal Nagar – 415m
• August 2023: TBM S96 (Nilgiri) at Madhavaram High Road – 1.4 km
• September 2023: TBM S99 (Servarayan) at Venugopal Nagar – 415m
• November 2023: TBM S97 (Podhigai) at Madhavaram High Road – 1.4 km
• June 2024: TBM S98 (Anaimalai) at Otteri Station – 925m
• August 2024: TBM S81B (Kolli) at Otteri Station – 903m

For more updates, check out the Chennai section or my Home Page! Sign up for free instant email notifications on new posts over here. Like this post? Get early-access to updates and support the site over here.

– TMRG