Upper Tamakoshi Project: Penstock installation delayed by crane wire rope failureThe installation of penstock pipes at the Upper Tamakoshi project hit a setback after the steel wire ropes of the crane lifting and placing the pipe sections broke. Each 5-metre section weighs 27 tonnes. Workers had planned to start installing the pipes in the lower vertical shaft—through which water will run from the reservoir to the turbines—by the first week of May.
The installation of penstock pipes at the Upper Tamakoshi project hit a setback after the steel wire ropes of the crane lifting and placing the pipe sections broke. Each 5-metre section weighs 27 tonnes. Workers had planned to start installing the pipes in the lower vertical shaft—through which water will run from the reservoir to the turbines—by the first week of May.
After the technical mishap, project officials say the installation will likely take two more weeks, and the project completion deadline will have to be pushed back accordingly.
“The wire ropes of the crane slipped and failed, and we had a new set flown in from India by Thai Airways today,” said Bigyan Raj Shrestha, project director. “We will transport the equipment to the construction site tomorrow and test it before installing the pipe which is likely to resume within two weeks.”
Fitting the penstock pipes in the lower shafts is considered to be the most challenging part of the hydro-mechanical component of the 456 MW peaking run-of-the-river project located in eastern Nepal.
According to Shrestha, construction crews will first ensure all safety compliances at the site before restarting the installation process. “It is an extremely challenging task as we have to lower the 27-tonne pipes down a 400-metre well which requires precision work.”
Construction had come to a standstill earlier because the hydro-mechanical contractor, Texamo Railway Engineering, failed to execute the installation, pushing back the project’s completion deadline for the fourth time. To avoid further delays in the execution of the hydro-mechanical component, the project developer asked the Indian contractor to reassign the crucial task of installing the penstock pipes to Austrian firm Andritz Hydro.
In January, Upper Tamakoshi Hydropower Limited, Texamo and Andritz signed a tripartite agreement under which the Indian firm subcontracted the task of installing the penstock pipes to the Austrian company. Immediately after signing the pact, Andritz mobilised workers at the project site and construction work resumed.
The project has faced massive cost overruns as its completion was delayed due to natural disasters, logistical challenges, design changes and poor work by the contractor. Initially, the project was planned to be built at a cost of Rs35 billion, but the price tag has now doubled to an estimated Rs70 billion.
The national pride project is taken as a role model project because it is being built with domestic resources and a high-level of participation from all stakeholders. After Upper Tamakoshi roars into life, Nepal is projected to have surplus energy at least during the wet season, and the Nepal Electricity Authority, the state-owned power utility which is the sole off taker of power in the country, will be in a position to export electricity.
Officials plan to start commercial generation of electricity after switching on the first unit which will generate 76 MW by the end of December. But after the rope mishap, authorities are hopeful that work can be expedited to meet the completion deadline.