HCC-MMS JV achieves major milestone with Terratec machine
having broken through on the first full section of running tunnel to be
completed for Mumbai Metro Line 3, in India. In early-August, TERRATEC joined
workers from the Hindustan Construction Company (HCC) – Moscow Metrostroy (MMS)
Joint Venture to celebrate the breakthrough of a 6.68m diameter TERRATEC hard
rock Tunnel Boring Machine (TBM), named ‘Vaitarna I’, on Mumbai Metro Rail
Corporation Ltd’s (MMRCL) Line 3 project, in India.
The major milestone saw HCC-MMS JV complete the 3.82km
southbound running tunnel between Chhatrapati Shivaji Terminal (CST) and Mumbai
Central stations and become the first contractor on the project to finish an
entire section of tunnel for one of the line’s seven contract packages.
With production rates of up to 24m per day (holding the
production record for the project), the TBM tunnel was driven via NATM station
boxes at Kalbadevi, Girgaon and Grant Road, at an average depth of 20m. It was
successfully completed on schedule despite numerous geological and logistical
challenges, including the tunnel’s proximity to the ocean, tunnelling through
reclaimed land, congested working areas and excavating beneath some of the
oldest buildings in the city, many over a century old. “With TERRATEC’s
support, the HCC team completed this operation in a single drive, boring
through geology consisting of basalt, breccia and tuff and reclaimed sand with negligible
Settlement,” said Ravi Ranjan Kumar, MMRCL’s Chief Project Manager for UGC02.
“Most of the tunnel alignment is under the oldest and most densely populated
area of south Mumbai with many dilapidated residential buildings. The performance
of the TERRATEC dual-mode hard rock TBM in this geology was highly satisfactory
and we now look forward to the similarly successful completion of TBM 02
‘Vaitarna 2’.”
The machine is one of two new TERRATEC dual-mode TBMs being
used on contract UGC-02, which was awarded by MMRCL in July 2016. Five other TERRATEC
TBMs are also achieving good progress on the new 33.5km-long underground
corridor. The versatile TERRATEC single shield TBMs are equipped to operate in either
Open or Closed mode and have robust hard rock cutterheads that are mounted with
heavy-duty 17” disc cutters, which are interchangeable with ripper tools, and
feature large bucket openings that provide a 10% opening ratio.
Other state-of-the-art features include 2,000kW Electric
Variable Frequency Drives – that allow the cutterheads to cut efficiently in
harder rock zones at maximum speeds of 7rpm and deliver an exceptional torque of 8,500kNm
to cope with more fractured zones of ground along the alignment – as well as
active shield articulation and built-in two component backfilling grout
systems.
“Terratec supplied a robust, powerful, TBM for the recently
completed southbound tunnel on UG-02,” said Hemant Sanghvi, Assistant General
Manager for HCC. “The performance of the TBM, as well as the service and
support provided by TERRATEC’s field operations team, has been very
satisfactory. We look forward to TERRATEC’s continued cooperation and support
for the duration of the second TBM drive.”
When complete, Mumbai Metro’s much-anticipated Line 3 will
be the first underground metro line in the city. The 33.5km-long line will
connect Cuffe Parade business district in the far south to the Santacruz
Electronics Export Processing Zone (SEEPZ) in the northcentral with 26
underground and one at-grade station (see map). Construction of the line is
divided into seven tunnel-and-station packages that were awarded to five
contracting joint ventures in 2016. These five contractors have deployed a
total of seventeen (17) TBMs with TERRATEC being the lead TBM supplier on the project
with a 41% market share.
To date, the seven TERRATEC machines have completed 65% of
the 22.6km allocated to them – signifying almost half of the total 54km of
tunnelling on the Line 3 project – and hold the production records for best day
and best month on the project. A video of the TERRATEC dual-mode TBM breaking
through on UGC-02, in Mumbai, can be
found here: https://youtu.be/vj5DYVdM12M
For more information visit: www.terratec.co
