OPGW Optical Ground Wire

Optical ground wire (OPGW) is a dual functioning cable. It is designed to replace traditional static/shield/earth wires on overhead transmission lines with the added benefit of containing optical fibers which can be used for telecommunications purposes. OPGW must be capable of withstanding the mechanical stresses applied to overhead cables by environmental factors such as wind and ice. OPGW must also be capable of handling electrical faults on the transmission line by providing a path to ground without damaging the sensitive optical fibers inside the cable.
The OPGW cable design is constructed of a fiber optic core (with single tube optical fiber unit depending on the fiber count) encased in a hermetically sealed hardened aluminum pipe with a covering of one or more layers of steel and/or alloy wires. Installation is very similar to the process used to install conductors, although care must be taken to use the proper sheave or pulley sizes so as not to cause damage or crush the cable. After installation, when the cable is ready to be spliced, the wires are cut away exposing the central aluminum pipe which can easily be ring-cut with a pipe cutting tool. The color-coded sub-units are preferred by most users because they make splice box preparation very simple.