NEW DELHI (Metro Rail News): Terratec has announced the delivery of the first of five 6.61m diameter Earth Pressure Balance Tunnel Boring Machines (EPBMs) that will be used by Tata Projects Ltd. for its underground works contracts on Chennai Metro Rail Phase-II Corridors India, following successful factory testing of the S96 machine this month.
The new TBMs will be used by contractor Tata Projects Ltd. on Chennai Metro Rail tunnelling contract for Chennai Metro Rail Limited (CMRL) to build Phase 2 – Corridor 3, from Venugopal Nagar Station to Kellys Station. The work involves the construction of 18 kms of bored tunnels. TERRATEC will provide five of the seven TBMs required for the package.
TERRATEC Mixed Ground EPBMs have been chosen to tackle this project because of the variable geological conditions (boreholes indicate sand, silt, clay on the tunnel drives with some weathered rock). The expected “mixed ground” will be dealt with by the TBM’s mixed-face dome-style cutterheads designed to work effectively in the geology on these contracts at pressures of up to 4 bar. Other features include VFD electric cutterhead drives, tungsten carbide soft ground cutting tools that are interchangeable with 17’’ roller disc cutters, high torque screw conveyors, active articulation systems and state-of-the-art guidance and control systems.
As the TBMs progress, they will install 1,400mm wide by 275mm thick universal reinforced concrete lining rings consisting of five segments plus a key.
Chennai Metro is the fourth longest metro system in India. The network currently consists of two lines covering a length of 54.65 kilometres. The new Line 5 of Chennai metro will have 48 stations and connect from Madhavaram to Sholinganallur. The project is anticipated to be completed in about four years.
In recent years, Terratec has emerged as the leading TBM supplier in the Indian market, having supplied 40 TBMs in the last nine years (more than all other TBM manufacturers combined over the same period). Terratec’s continuing success on projects such as Phase III of the Delhi Metro, Lucknow Metro, the Ahmadabad Metro, Pune Metro and Mumbai Metro is a result of tailor-made robust TBM design, prompt onsite assistance, readily available stock of TBM spares and highly-skilled specialised TBM support throughout tunnelling operations.
Source: Terratec press release