Optical cable diagonal wrapping

Optical cable diagonal wrapping is a method of installing fibre-optic cables by helically wrapping them around a host conductor on overhead power lines, providing a secure and efficient communication link.Overview of Diagonal WrappingDiagonal or helical wrapping involves attaching a fibre-optic cable to a host conductor—such as a ground wire or phase conductor—by spiraling the cable around it along the span of the line. This method was first developed in the 1980s in the UK (SkyWrap) and Japan (GWWOP) and remains widely used today due to its reliability and ease of installation . The cable is typically wrapped using specialized equipment that moves along the conductor, ensuring consistent tension and spacing.Installation ProcessThe installation process uses a spinning or wrapping machine that feeds the cable from a drum and helically applies it to the host conductor. For medium or low voltage lines (up to 50 kV), the machine can sometimes be pulled manually from the ground. For high-voltage transmission lines, a radio-controlled power unit powered by batteries or a petrol engine is generally required . The cable is positioned at a safe distance below the high-voltage conductor, often around 0.5 meters, to maintain electrical safety and minimize interference .Cable Types and ApplicationsWrapped cables are a type of Optical Attached Cable (OPAC) and are suitable for a wide range of voltages:AccessWrap: For phase conductors up to 50 kVSkyWrap: For distribution lines up to 150 kVHigh Voltage SkyWrap: For phase conductors up to 300 kV These cables are lightweight, robust, and designed to withstand environmental challenges such as wind, ice, and mechanical stress. They are commonly used in areas where access to overhead lines is difficult, providing a low-cost, reliable communication link without requiring line shutdowns.AdvantagesMinimal load on the host conductorRapid deployment, even in challenging terrainReduced need for power outages during installationProtection from environmental hazards and mechanical damageCompatibility with high-voltage lines while maintaining safety standards Operational ConsiderationsWrapped optical cables can operate independently of high-voltage lines, allowing maintenance and upgrades without significant service interruptions. Proper training and pilot installations are recommended to ensure safe and efficient deployment, especially on newly modernized or high-value lines . The method also supports compliance with safety regulations, such as maintaining a minimum height above ground (typically 6 meters) and protecting wildlife in certain regions. In summary, diagonal wrapping of optical cables is a proven, versatile method for deploying fibre-optic communication systems along overhead power lines, combining safety, efficiency, and adaptability to various voltage levels and environmental conditions .