text: how on earth do they insulate transmission towers? transmission towers carry cables which, as we know, like to take a 40kv short cut to earth if they get hit with a kite or whatever. yet one can go up to one of these towers and touch it quite safely... that's because there are ceramic insulators that hold the wires/cables to the tower.  you will notice something that has a jagged-looking profile between the metal of the tower and the wire, that is the insulator.  insulators are up to several feet in length, depending on the designed voltage potential in the wire.  the higher the voltage, the longer the insulator.  high voltage transmission lines, the types you commonly see on metal towers are usually in the range of 115kv (kilovolts) to 320kv.  in air, it takes roughly 5000 volts per inch for an arc to develop.  at 320kv, you need an insulator over five feet long just to prevent the electricity from arcing to the tower and grounding out.    with this in mind, you do not even need to touch a high voltage wire to get electrocuted, just close enough for the electricity to arc to you.