L&T’s TBM Records Chennai Metro Phase 2 TU-02’s 1st Breakthrough

Larsen & Toubro (L&T) today celebrated tunnel boring machine DZ1040’s first breakthrough at Sterling Road Station for the 116.1 km Chennai Metro Phase 2 project.

This exciting milestone marks the very 1st tunnel breakthrough for 45.8 km Line-3‘s 12 km Package TU-02 connecting Kellys and Taramani Road Junction.

Nicknamed TBM Siruvani, this Ø6.65m earth pressure balance (EPB) machine was manufactured by China Railway Construction Heavy Industry (CRCHI) and had passed factory acceptance tests (FAT) in the summer of 2022.

It was commissioned from Line-3’s Chetpet Station in September 2023 and travelled 703 meters to arrive at Sterling Road Station today. Along the way, it bored a 51 meter tunnel under Cooum River with an overburden of 8.0 meters.

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 Siruvani was L&T’s 3rd of 7 machines to get going for building approximately 12 km twin tunnels (total 24 km) between Kellys and Taramani Road Junction stations.

Video

L&T’s TBM Palar (DZ1041) working on the parallel tunnel was commissioned from Chetpet Station a few weeks after TBM Siruvani. I haven’t heard of any major issues being encountered, so we should expect it to arrive at Sterling Road by month-end.

With today’s development, 6 tunnels have been built so far. The prior 5 breakthroughs were all recorded on 9 km Package TU-01 on the northern-side of the line which is under construction by Tata Projects (TPL).

Recap of breakthroughs recorded so far:

• 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 DZ1040 (Siruvani) at Sterling Road – 703m (this post!)

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– TMRG