Here is a design for an old dutch overhead wire pole, for use in model railways. You can scale it to size.

More back-ground is here:

http://www.stationhollandscherading.nl/bovenleiding.html

https://encyclopedie.beneluxspoor.net/index.php?title=Bestand:HBW-portaal_3_sporen_hr.gif

https://encyclopedie.beneluxspoor.net/index.php?title=Bestand:HBW-portaal_3_sporen_hr.gif

Meer info op : HO_Rail_Overhead_Wire_Pole_Dutch_Portaal_Bovenleiding_1939_ir._J.L.A._Cuperus