Solution to OPGW Cable Breakage Due to Lightning Strikes in Transmission Lines: Technical and Economic Evaluation of Alternatives

Colombia’s Caribbean Coast and to improve the reliability and coverage of the telecommunications network. Once the project was in operation, failures were identified in the

Optical Ground Wire (OPGW) cable due to the high incidence of lightning strikes, which caused breakages and unscheduled disconnections. After analyzing the causes, it was determined that the OPGW cable needed to be replaced to improve its resistance to such events.

Initially, alternatives such as replacement with a de-energized line and the Carrier methodology, which allows replacement with an energized line, were considered; however, their high costs prompted the search for other options. An innovative and economically viable solution was chosen by shielding the OPGW cable with a second conventional Alumoweld 7#7 AWG shield wire, acting as a sacrificial element against lightning strikes. This solution was designed to be implemented with the line energized, minimizing service interruptions. To ensure the technical and economic feasibility of the solution, several analysis stages were developed. First, an electrical modeling was performed to verify the shielding level of the line. Then, a structural modeling of the towers was carried out, evaluating the new loads resulting from the installation of an additional cable not considered in the original designs. Based on these loads, an additional arm was designed to support the shield wire at the top of the structure, and structural 1 reinforcements were applied to the towers. As part of the process, a business case was prepared considering environmental, social, land acquisition, and construction variables, and a pilot was planned to identify and mitigate risks. The installation procedure for the new shield wire includes stringing with a drone and transferring it to the saddles. Expected results include cost reduction, lower safety risks for personnel and assets, shorter construction times, continuity of telecommunications services, and greater ease of construction.