TERRATEC's Hard Rock Double Shield TBM is making great progress for the Vishnugad-Pipalkoti Hydropower project.

TERRATEC is delighted to announce that the Ø9.86m Hard Rock Double Shield TBM has made significant progress for the Vishnugad-Pipalkoti Hydropower Project in India. The machine excavated an impressive 431 meters in January 2024.

TERERATEC Ø9.86m Hard Rock Double Shield TBM is the largest Double Shield Machine in the Indian Himalayan Region. The machine is presently working for Hindustan Construction Co. Ltd. of India, the primary contractor for this project. Situated in the Uttarakhand state, approximately 500 kilometers northeast of Delhi, the project encompasses the construction of dams, waterway tunnels, vertical shafts, and a powerhouse boasting a generating capacity of 444 MW.

The Double Shield TBM has been specifically designed for the construction of a crucial low-pressure head race tunnel, integral to the hydroelectric power system. This TBM is outfitted with customized features aimed at efficiently completing the 13km tunnel.

The project entails the implementation of a run-of-river scheme, incorporating the construction of a diversion dam measuring 65 meters in height across the Alaknanda River, with power generation facilitated by a gross head of 237 meters. The reservoir is slated to hold a gross storage capacity of 3.63 million cubic meters, of which 2.47 million cubic meters will serve as live storage. A diversion cum spill tunnel, intake tunnels, underground sedimentation chambers, a headrace tunnel, a surge shaft, pressure shafts, and penstocks, along with two separate underground caverns for turbine and transformer installations, constitute the water conductor system.

The alignment for the Vishnugad-Pipalkoti Hydropower project primarily traverses Dolomitic Limestone (33%) and Slates (64%), with the remaining 3% passing through critical geological sections. These sections include Thrust Zones, Shear Zones, and Fault Zones, which pose significant challenges necessitating the TBM's specialized engineering. Moreover, TERRATEC is providing the Continuously Advancing Tunnel Conveyor for the project.

Designed to meet the specific demands of the project, the TERRATEC Continuously Advancing Conveyor will have a length of 13 km and operate at a rate of 1200t/h. The conveyor is capable of efficiently handling the various materials extracted by the Tunnel Boring Machine along the entire length of the tunnel. The conveyed materials are expected to vary from sandy gravel to boulders, showcasing the robust capabilities of TERRATEC's conveyors.

TERRATEC’s unique and patented design of the Advancing Tail Piece levels the Tunnel Conveyor using an active hydraulic system to match the steering/ rolling position of the TBM. This enables the smooth negotiation of any horizontal and vertical curves. 

The TBM's CutterHead boasts 19'' disc cutters and twelve large bucket openings, facilitating excavation through expected hard rock with its 4,200kW electric main drive delivering a torque exceeding 22,000kNm. As the TBM advances, universal reinforced concrete lining rings, 1,500mm wide and 350mm thick, are installed, each comprising five segments plus a key.

The addition of 444 MW capacity in the Northern region will significantly alleviate peaking power shortages, with the project designed for 1657.09 MU energy generation. Notably, 13% of free power allocated to Uttarakhand will allocate 1% for local area development.

TERRATEC has been chosen for the tunnel package in Vishnugad-Pipalkoti Hydropower Project due to TERRATEC’s track record, including successful projects like Phase III & IV of the Delhi Metro, Lucknow Metro, Pune Metro, Kanpur Metro, Ahmadabad Metro, and Mumbai Metro, attributed to its robust TBM design, onsite assistance, readily available TBM spares, and highly skilled specialized TBM support throughout tunnelling operations.

words and photograph from TERRATEC https://terratec.co/NewsInfos/detail/116