Starting the Viessmann Overheads
Hi all, yesterday I started to install the 4 track cross span masts to my layout. I found this bit quite straight forward. The only thing I cant quite imagine yet, is that the wires will tension properly. The ends of the system are fixed to a solid wooden 'bridge' and I am working from there from left to right. If anyone here has experience in overhead wires, can you assure me that when I get to the other end and apply a little tension, that the wires will tighten up a bit a support a pantograph !! Cheers for now David

Hi David, My brother-in-law scratchbuilds catenary, and always tensions it. Although he models UK outline 00, the same techniques will apply. http://dagworth.fotopic.net/p46655439.html is an example of his work. Drop him a line through andi (at) dagworth (dot) net, he might be able to offer some guidance. Cheers Rich

Hi David: Tensioning catenary is a serious concern. To do it properly, you have to have both ends of each wire mounted securely to a mast, and one end should be connected to the mast through some sort of spring. On the prototype they use a gravity tensioner, where the running wire rounds a pulley and is attached to some hanging concrete weights. Details like this can be bought from Viessmann, but they are purely cosmetic. One thing Viessmann suggests is using the adjustablily of their single track masts on curves. You can push the masts slightly toward the outside of the curve after they are installed to tighten the wire. This isn't so relevant to your tower mast/straightaway situation. Another detail of catenary to remember is that no wire ever ends in mid-air. If you have a crossover between two tracks, the wire for the crossover starts at a tower at one side of the track and runs all the way across to another tower at the other side. The parts of the wire not needed for contact are raised slightly above the running wire height so the pantograph doesn't snag it. If there's a single turnout, the wire again starts at a tower and crosses the main route wire before starting down the diverging route. If you don't anchor both ends, there will be uneven tension at the starting point, because you have twice as much pull to one side as the other. Jurgen

Thanks
Thanks for the advice folks. Good suggestion to make the wires more realistic by adding tensioning masts. I see now why they supply spare single masts. Cheers David