Why is optical fiber cable called a ground wire

An optical fiber cable is called a ground wire because it functions as both a grounding conductor for power lines and a high-speed data transmission medium.Dual Functionality of OPGWAn Optical Ground Wire (OPGW) is installed at the top of high-voltage transmission lines and serves two primary purposes. First, its metallic outer layers act as a ground wire, safely conducting lightning strikes and short-circuit currents to the earth, thereby protecting the phase conductors below and bonding adjacent towers to ground . Second, the cable contains optical fibers within a protective tube, allowing utilities to transmit voice, data, and control signals over long distances without installing separate communication lines .Structural DesignOPGW cables typically consist of a central tube housing optical fibers, surrounded by layers of aluminum-clad steel or aluminum alloy wires. This design ensures mechanical strength, electrical conductivity, and durability under harsh environmental conditions such as wind, ice, and extreme temperatures . The optical fibers themselves are insulators, immune to electrical interference, while the metallic sheath performs the grounding function .ApplicationsPower Transmission Protection: Shields high-voltage lines from lightning and conducts fault currents safely to the ground.Telecommunications: Provides high-speed data links for utility operations, SCADA systems, and can be leased to third parties for broadband services .Infrastructure Efficiency: Combines grounding and communication in a single cable, reducing installation costs and complexity . In summary, the term "ground wire" in optical fiber cables refers to the metallic component that performs electrical grounding, while the embedded optical fibers enable telecommunication capabilities, making OPGW a dual-purpose solution for modern power and communication networks .