Chilime-Trishuli transmission line construction in final stage

The construction of the 220 KV Chilime-Trishuli transmission line has entered its final stage. This line will facilitate the transfer of electricity from both ongoing and completed hydropower projects along the Trishuli River and its tributaries to the national grid.

The last phase of construction involves a 28 km stretch between the Chilime Hub Substation in Thambuche, Amachhodingmo Rural Municipality (Rasuwa), and the Trishuli Three B Hub Substation in Pahrebensi, Kispang Rural Municipality (Nuwakot). Work is progressing rapidly, with the goal of completing it by Dashain festival in October.

Under the Chilime-Trishuli project, the Chilime Hub and Trishuli Three B Hub Substations (220/132/33 KV) have already been completed. Of the 76 towers required for the line, 75 are fully constructed, with the final tower nearing completion. Out of the 28 km transmission line, only 5 km of wire remains to be installed. Currently, about 200 workers are involved in connecting the last tower and laying the remaining wires.

A high-level team, including Nepal Electricity Authority (NEA) Managing Director Kulman Ghising and Broadcasting Directorate Deputy Managing Director Dirghayu Kumar Shrestha, visited the construction site to monitor progress. After discussions with project management, consultants, and contractors, they set a firm deadline for completing the remaining work before Dashain. The team also reviewed the area where the last tower is being connected and the wires are still to be pulled.

The transmission line will connect 111 MW of electricity from the Rasuwagadhi hydropower project and 42.5 MW from the Sanjen hydropower project, both developed under the leadership of Chilime Hydropower, a subsidiary of the NEA. With these projects ready to start power generation, there is growing pressure to complete the transmission line swiftly.

Ghising acknowledged the challenges faced in constructing the line through the dangerous and rugged Himalayan region but noted that progress has been made through continuous effort. “Due to the delay, the two hydropower projects have been unable to begin generating electricity. However, we are now close to completion despite the challenging terrain. Let's work together to finish the construction before Dashain,” he said.

In Uttargaya Rural Municipality-1, a 1.2 km stretch of wire from Tiru to Siruchet will be pulled using drones across the Mailung River, with all preparations for this crossing complete.

The project has faced numerous challenges, including difficult terrain, the need to transport tower materials by hand or mule due to lack of road access, floods, contractor delays, forest land use issues, and the impact of Covid-19. The line spans altitudes ranging from 680 to 2,600 m above sea level, with 33 towers constructed in areas with no road access, requiring the project to build over 20 km of access roads.

Nine towers were built by transporting materials via mules and manual labor, while two were constructed using helicopters. The transmission line includes a 20 km double-circuit section from Chilime to Mailung and an 8 km multi-circuit section from Mailung to Trishuli Three B Hub. Korean companies are leading the construction of a multi-circuit line to connect the 216 MW Upper Trishuli-1 hydroelectric project, which will cover 60 percent of the cost.

The contract for the transmission line and substations was awarded to the Chinese company Pinggao Group of Companies in October 2017, with implementation beginning in December 2017.