It appears that all railroad tracks have telephone poles paralleling them. What circuits are carried on the wires? I would suspect signal systems would be one of them and maybe communication lines between stations. I'm thinking of using telephone poles to run switch machine wiring and power feeds, along with power for lighting. What do you think? It seems like a lot of work, but I'm trying to keep all wiring above the layout and not under it. Using LEDS for lighting would use very small wire size.

Hi Ron
To use telephone wires to carry lights is possible if you use LEDs and thin enameled wire using 0,1 mm wire like this https://www.ebay.de/itm/25300272...32f33:g:4c0AAOSw9~5ZRN6l
The troubles with this solution:
- you need to have a lot of patience to make it
- you can't use it for electromagnetic articles (current is too high
- it is not elastic so any distubance will make the wires hang

There is another solution:
- to add decoders inside your M Track switches
- to suppress all stop sections
- to drive your trains in digital.

Sounds bizarre I know but this way you can avoid almost all the wiring (maybe add a feeder each 2 m of track.
Drawback: you probably want to avoid automatic operation (because it calls for ùmany feedback sensors that require wiring).

I know you have Märklin M but here is a British Railfan with Hornby Dublo (3 rails with Märklin-like rails)
He has ABSOLUTELY NO WIRING under the table

Maybe it will give you the inspiration you need
You may find tiny decoders to install under the M switches to suppress wiring, etc
Cheers
Jean

And that doesn't stop them being pinched ...

I am not familiar with telegraph poles in the UK. By "up" side, does that mean the cross tree is mounted on the side facing London?

To reduce the noise fill the cavity under the track with felt, styrofoam, or anything that will kill the resonant chamber under the track and damp the metal roadbed from vibrating.