I have been visiting tesla coil sites and have become very curious: Photos of 500kV tesla coils in operation show sparks of around two or three feet in length. However, UHV linemen tell me that all utilities have the 11'-3" rule for 500kV transmission maintainence. If you are in 'energised-mode' (clamped on) and are working on 500kV conductors, the rule is not to come any closer than 11 feet, three inches to tower stucture or ground. The voltage will jump from you to ground if you get any closer. Eleven feet is a heck of alot more distance than the sparks thrown by the big 500kV teslas. Is the fact that there is 2000 to 8000 amps behind the utilities' 500kV cause the voltage to jump farther? I had always been under the impression that its voltage, not amperage that cause the electricity to jump across air to ground, then the amperage is what enables the arc to be drawn out (50' arc video on this board being a perfect example) Note the two horizontal gas interuptors on that switch. Small though they look, each is over 6 feet long! When one fails the 500kV doesn't hesitate to leap that 6 foot gap on the good interuptor! OK, so there is 6 feet. With two in series operating normally, there is 12+ distance and the voltage cannot jump. My question is: Are the teslas really putting out 500kV, or are they outputting considerably less, and those giant teslas that are throwing 10 to 12 foot sparks and rated at 1.5 megavolts really only throwing 500 to 600kV?