Construction of India’s Vishnugad-Pipalkoti Hydropower project has kicked off with Hindustan Construction Co. Ltd. of India – the main contractor responsible for this project – launching its Terratec 9.86m diameter Hard Rock Double Shield TBM on the scheme’s 13km low pressure headrace tunnel.
The alignment for the Vishnugad-Pipalkoti Hydropower project comprises primarily of Dolomitic Limestone (33%) and Slates (64%), with the remaining 3% passing through critical geological sections. These sections include Thrust Zones (with shallow overburden of 150m), Shear Zones (consisting of 5 zones), and Fault Zones (totalling three zones). These areas present significant challenges, and as a result, the TBM has been specifically engineered to handle these conditions. Additionally, Terratec is providing the Continuously Advancing Tunnel Conveyor for the project.
The Cutterhead of the TBM features 19” disc cutters while maintaining twelve large bucket openings. The 4,200kW electric main drive is designed to help the TBM to excavate through the expected hard rock, delivering a torque of over 22,000kNm. As the TBM progresses, universal reinforced concrete lining rings, measuring 1,500mm wide and 350mm thick, are installed. These lining rings consist of five segments plus a key.
The TBM is equipped with features such as a high-speed regripping system, single-shield advancing mode, high-pressure emergency thrust, flood control doors, and numerous others. The key components of the TBM were manufactured in Australia and Japan, while the assembly took place in China.
The addition of 444MW capacity in the Northern region will significantly reduce peaking power shortages in that area. The project has a design energy of 1657.09MU. Out of the 13% of free power allocated to the home state of Uttarakhand, 1% will be utilized for local area development.
The ongoing project takes place in the state of Uttarakhand, around 500km Northeast of Delhi. The work involves the construction of dams, waterway tunnels vertical shafts and a powerhouse with a generating capacity of 444MW.