Curious about how the electrics switch wires when switching tracks

[AmtrakBlue]

As I was riding SEPTA on the NEC the other day, I got to thinking about the switching of tracks. I know how the tracks work (switches), but am curious how the overhead wires "switch" (brain freeze re the name of the contraption that the train uses to get the electricity).

Can anyone give a layman's explanation?

Thanks.

 

[Ryan]

Pantograph on the locomotive, in contact with the catenary.

All of the tracks have wire above them, even the short ones between tracks.

 

[Ryan]

Gets complicated when there are a lot of switches:

 

[AmtrakBlue]

But how does the pantograph know which wire to follow?

 

[Ryan]

It just follows the train below it. It's not actually grabbing a wire, just pushing up against the bottom of it:



(not my picture)

When the wire splits, it just goes with the train.

 

[Thirdrail7]

The wires under roughly 9000psi of tension. I've actually stood on them. As Ryan says, the pantograph is just along for the ride. The tension in the wire will allow the pantograph to raise to meet the wire or push the wire lower as dictated by the crossover.

The problem is if the train is switched to a track without wire.

 

[AmtrakBlue]

Thanks. I did wonder if that was how it worked.

 

[NorthShore]

The conductor gently guides the trolley pole when switching tracks. Good conductors can do this on the fly.

Oh, wait, wrong decade!

 

[caravanman]

The pantograph is doing a good job, efficiently contacting the over head wires at high speed, to collect electric current.

On a long straight track, you may notice the overhead wire weaves back and forth slightly, this is to give even wear across the whole contact plate of the panto... a groove might be cut in the panto by the overhead wire if it was always touching the panto in exactly the same place.

Ed