This project involved reinsulating an existing dual circuit 230kV transmission line due to the deteriorating condition of the existing polymer insulators.  As part of the project, the existing transmission structures were modeled in PLS-POLE from the fabrication drawings and analyzed under the new design criteria of the utility.  A PLS-CADD model was developed using these Method 4 structures from PLS-POLE, and a design criteria file was developed for the transmission line utilizing the latest transmission loading and clearance standards for the utility.  Toughened glass insulators were chosen for the replacement insulators.  Hardware was selected to match the existing dimensions of the deadend insulators and V-string assemblies to minimize changes in conductor sag and tension.

Permits had to be obtained for multiple highway crossings, including permitting for access to structures located inside the right-of-way of I-95.  There were also multiple crossings of interstates and restricted federal properties such as the USDA campus and a National Archives facility that required permitting for construction.

There were 11 structures on the project that had cellular antenna array attachments at the top of the structures.  These structures were analyzed for EIA/TIA222 load and deflection requirements in addition to the standard design criteria for the utility



































Please contact David S. Huffstetler at 919.851.8770 for more information about our Transmission Services or email huffstetlerds@booth-assoc.com


Line Voltage

Dual Circuit 230kV

Length of Project

9.7 miles

Engineering Challenges

Modeling and Analysis of Existing Structures, Multiple Permits


Raleigh, NC

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Raleigh, NC 27607

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