OPGW

Optical ground wire (OPGW) is a type of cable used in the construction of electric  power transmission and distribution lines. This cable combines grounding and data  transmission functions. The OPGW cable are located at the ends of high-voltage  pylons: its conductive part serves to bond adjacent towers to earth ground and shields  the high-voltage conductors from lightning strikes. The optical fibers within the cable  can be used for high-speed data transmission.