{"id":30914,"date":"2026-07-31T06:16:36","date_gmt":"2026-07-31T06:16:36","guid":{"rendered":"https:\/\/doingcable.com\/?p=30914"},"modified":"2026-07-31T06:16:38","modified_gmt":"2026-07-31T06:16:38","slug":"what-is-optical-ground-wire-opgw","status":"publish","type":"post","link":"https:\/\/doingcable.com\/fr\/what-is-optical-ground-wire-opgw\/","title":{"rendered":"Qu'est-ce que le c\u00e2ble de garde \u00e0 fibre optique (OPGW) ?"},"content":{"rendered":"

Optical Ground Wire (OPGW)<\/a><\/strong>, also known as Optical Fiber Composite Overhead Ground Wire, is a dual-function metallic cable engineered for high-voltage and extra-high-voltage overhead transmission lines. It simultaneously serves as a conventional overhead ground (shield\/static\/earth) wire and a high-capacity fiber-optic communication medium.<\/p>\n\n\n\n

Installed at the top of transmission towers, OPGW intercepts lightning strikes, safely conducts fault currents to ground, and provides a secure, EMI-immune optical pathway for real-time grid protection, SCADA, teleprotection, and utility or third-party data transmission.<\/p>\n\n\n\n

Unlike traditional ACSR shield wires or separate fiber solutions, OPGW integrates both functions into a single robust conductor, reducing right-of-way requirements, installation costs, and long-term maintenance while delivering decades of reliable service.<\/p>\n\n\n\n

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Structure and Construction of OPGW Cable<\/h3>\n\n\n\n

OPGW is a fully metallic armored cable whose outer appearance closely resembles ACSR shield wire. Its core architecture consists of three primary functional layers:<\/p>\n\n\n\n

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  1. Optical Unit (Core)<\/strong> Optical fibers (typically single-mode G.652.D or G.657) are housed inside one or more hermetically sealed stainless-steel tubes, aluminum tubes, or aluminum-clad stainless-steel tubes. The tubes are filled with water-blocking gel to cushion the fibers, prevent moisture ingress, and relieve mechanical strain. Excess fiber length is provided so that tensile loads on the cable do not stress the glass.<\/li>\n\n\n\n
  2. Protective Metallic Tube \/ Thermal Barrier<\/strong> The laser-welded or seamless metal tube acts as a mechanical shield and thermal barrier. During a lightning strike or short-circuit event, heat is largely absorbed by the outer armor before it can reach the fibers.<\/li>\n\n\n\n
  3. Outer Armor Layers<\/strong> One or more concentric layers of aluminum-clad steel (ACS) wires and\/or aluminum-alloy (AA) wires are stranded around the optical unit. ACS wires supply high tensile strength for long spans and ice\/wind loading; aluminum-alloy wires provide the bulk of electrical conductivity required for fault-current and lightning performance.<\/li>\n<\/ol>\n\n\n\n

    Fiber counts commonly range from 12 to 144 (higher counts up to 216\u2013432 are available in multi-tube designs). Overall diameter, weight, and electrical\/mechanical parameters are engineered to match or closely approximate the existing shield wire so that tower loading remains within design limits.<\/p>\n\n\n\n

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    How OPGW Works in Transmission Systems<\/h3>\n\n\n\n

    When installed at the highest point of the tower:<\/p>\n\n\n\n