I’ve seen the word several times in different discussions. What does it refer to?
Jarrell
I’m sure someone else will have a better definition, but it is the ‘overhead’ network of wire and support structure for powering Interurban and heavy electric motive power. Trolley and Interurban was generally less complicated than that used for heavy electric. For the lighter use, trolley poles were common with pantographs used in heavier intercity electric trains.
In general terms it is the wire above railroad tracks to carry electrical power for engines and trolleys. The term is from the curve formed by the wire. It included the main current carrying wire and the supporting wires. In europe they tension the wire at a fixed height with pulleys and weights. This allows for temperature changes to happen and keep the wire at a fixed height. Most systems in the US allow the wire to move up and down with temerature changes.
Thanks for the explanations. I had done a google search on the word and I got the math explanation for it as it relates to a curve etc. Now I understand it.
Jarrell
Just for the record because I agree with the above definitions Catenary refers to the arc the top wire takes when strung due to gravitational pull on it. It is impossible to pull a wire with enough forces so it is straight. hence the structure with the top wire arced and straight wires hung at smaller intervals from it to hold a perfectly horizintal contact wire.
Threre are two basic types of overhead systems. Single wire and catenary. Single wire systems are low tension wires supported from the side and occasionally from above. Catenary refers to a two wire system that uses the curved top wire to support the bottom wire. These systems are more robust and generally used for high speed, heavy use areas using pantographs as pick ups. Single wire is most common in trolley systems using poles in lower speed urban settings. And of course there are tons of variants.
Many of us refer to any overhead wire as catenary…
The catenary system works like a suspension bridge. The top wire, the curved one, supports the weight of the contact wire. Normally the catenary systems used higher voltage and were used on higher speed, heavier duty lines.
Dave H.
Good explanation of catenary…Marklin has a nice book out on the histroy of prototype and model catenary…as well as a how-to build it. http://www.eurorailhobbies.com/erh/eurorailhobbiesdetail.asp?pageid=&erh_find=catenary%20handbook&stock=03902
For an example of European (German) style catenary. Check out the photos of my European layout:
http://ca.pg.photos.yahoo.com/ph/davezeurorail/album?.dir=/9843&.src=ph&.tok=phsXBUDBhfAFzUSK
A catenary is simply a cross between a cat and a canary, or a symbolic representation of something that consumes itself. [:)]
I thought it was the cat that swallowed a canary???