04-09-2016, 09:02 AM
(04-08-2016, 10:44 AM)timc Wrote: I don't know the technical term here, but I think I saw ropes up on the poles for pulling wires yesterday. I don't think they were actual wires.
That's right; in your photos, you can see the pulleys hanging off of the catenary arms. These are just used for pulling the two wires: The messenger wire, and the contact wire. The messenger wire sags between the arms in a catenary curve - hence the name catenary. Smaller wires hang down off the messenger wire, like a suspension bridge, and support the contact wire.