Description

Kusaha Biratanagr 132 kV Transmission Line Project under NEA has been facing some issues in its 33kV Transmission Line sections which emerges from under construction Biratnagar Substation to Rani Substation and Tanki Substation at Biratnagar. Being 33kV, the line route has to pass along the sideways of road up to its destination substation, such that, major issues were regarding line route corridor, tower locations and design of 33 kV towers. The towers were designed for ruling span of 200m, resulting in larger tower base, which was impractical for such tight corridor.

Contract Agreement was signed between NEA Engineering Company Ltd. And Kusaha Biratnagar 132 kV Transmission Line Project, NEA on 26^th September, 2019 for 6 months for Review of Line Survey and Tower Design Works of 33kV Double Circuit Transmission Lines from Biratnagar Substation to Tanki Substation and Rani Substation. The Scope of consulting services is as below:

Survey Review:

• The consultant shall review and verify the survey report for both sections of transmission line submitted by the contractor.
• The consultant shall verify and recommend the transmission line route for 33 kV Double Circuit Transmission Line from under construction Biratnagar Substation to Rani Substation and Tanki Substation, which is approximately 22 km in total.

Design Check:

• The consultant shall review, verify and recommend the tower design of the proposed 33 kV lattice towers using wolf conductor submitted by the contractor.
• The consultant shall verify and recommend the tower spotting and tower scheduling for both sections of 33 kV Transmission Line using lattice towers.

As per the scope, the personals from NEC reviewed the existing line routes and tower design of DA type submitted by the contractor, which was designed for 200m ruling span, and visited the site along with personal from Client and the Contractor to verify the line route.

 After the visit and detail study of line route and its issues, the NEC team has submitted a report incorporating possible solutions to the difficult sections along with tower locations and has proposed a different tower family of reduced span limits which could be a practical solution for compact and limited corridor.

Now, the NEC team is to verify the tower designs submitted by the contractor and revisit the site for finalizing the tower locations, once the tower design is finalized.