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**Disney Guy**Sometimes a(n electric) locomotive has two trolley poles up (the front pole swung around to also drag behind) to get a better contact for higher current draw. Same idea with two pantographs up.

High voltage lines (sometimes around 10,000 volts AC even back int he 1920's) went from the generator to one substation to another to have a minimal loss (or dissipation) of energy in the lines due to voltage drop. Low voltage (600 or so DC) traction power ran just a few miles out from each substation so each substation territory was something like 5 miles across tops. Each territory was isolated from its neighbors using section breakers in the overhead.

The number of watts needed can be carried as a high voltage and fewer amperes, or a lower voltage and more amperes. If we supply more watts by raising the number of amperes, the number of volts dropped in the wires increases. If instead we raise the number of volts and keep the amperes the same, the same number of volts is dropped. Dropping 50 volts out of 10,000 is a much smaller percentage of energy lost than dropping 50 volts out of 600.

FFolz wrote:How are the loads balanced throughout an electric rail network? I imagine it's something of a massive parallel circuit with trolleys as the resistors, but you'd have to have drops in voltage the farther you go from the generator, plus the branch lines have to complicate things.!Dispatching should take into account the number of trains in each territory served by a substation so that substation is not overloaded.

High voltage lines (sometimes around 10,000 volts AC even back int he 1920's) went from the generator to one substation to another to have a minimal loss (or dissipation) of energy in the lines due to voltage drop. Low voltage (600 or so DC) traction power ran just a few miles out from each substation so each substation territory was something like 5 miles across tops. Each territory was isolated from its neighbors using section breakers in the overhead.

The number of watts needed can be carried as a high voltage and fewer amperes, or a lower voltage and more amperes. If we supply more watts by raising the number of amperes, the number of volts dropped in the wires increases. If instead we raise the number of volts and keep the amperes the same, the same number of volts is dropped. Dropping 50 volts out of 10,000 is a much smaller percentage of energy lost than dropping 50 volts out of 600.

Build something. Anything.