Transmission towers, much like other steel lattice towers including broadcasting or cellphone towers, are marked with signs which discourage public access due to the danger of the high voltage.OverviewA transmission tower (also electricity pylon, hydro tower, or pylon) is a tall, usually a or tubular made of, that is used to support an. In, transmission towers carry. Transmission tower is the name for the structure used in the industry in the United States and some other English-speaking countries. In Europe and the U.K., the terms electricity pylon and pylon derive from the ba. systems are used for high voltage (66- or 69-kV and above) and extra-high voltage (110- or 115-kV and above; most often 138- or 230-kV and above in contemporary systems) transmissio.