Okay....So over many a picture of PRR rail yards I've seen form the 1920's through the 1940's, it looks like vertical "hanging" short booms, connected to chain or cable, going over switches. Maybe ten feet of cable/chain, attached to who knows what made of maybe another ten feet? Sixteen to eighteen of these hanging from a bar, maybe thirty feet across, and these drag over the train as it goes through.under. Is there a particular name for these? Thank you. I want to do them in a correct manner when i work on my layout this winter.