Any links or pictures to this subject? The longest unsupported cable in the world, be it for electricity, telegraph or otherwise.
Oh my. You’ll fit in well here.
Gee, that’s useful, eviladam. What will you do for an encore?
Looks like the longest unsupported cable is 3 miles long.
Longest span in a powerline is about 3.3 miles.
My my, are you always this helpful? :rolleyes:
Anyway, to actually answer the question, it’s the White Sands Missile Range’s Aerial Cable Range. There’s a photo on page 8 of this .pdf file
More photos of the White Sands cable here.
Interesting. The White Sands cable is made of Kevlar as steel can’t hold its own weight for the distance. Makes me wonder what that 3.3 mile Ameralik line is made of as Kevlar doesn’t carry electricity too well. Of course, it could be that whover wrote the wiki has it wrong. I’ve not had any luck confirming that length.
More accurately, a steel cable of constant thickness couldn’t hold its own weight. If it were thicker at the ends and thinner in the middle, however, it could. But the taper might be impractical for a sufficiently long cable.
If you want a cable to carry a current, you could have a wire held by a stronger but unconductive support cable. In fact, this is routine for electrical wires over shorter distances: Even though they’re all metal, some metals are stronger than others, and some are more conductive than others. So one often sees a steel cable fixed to a copper one to support it.
duhhh… forgot all about strand or messenger wires. Yah, just look at pretty much any cable TV line in the air, and it’s attached to a steel strand wire. :smack:
Another “end-run” is copperweld, where a strong steel wire is plated or jacketed with more-conductive copper. This stuff used to be popular for making ham radio antennas or even rural power lines as it reduced the amount of copper needed for a given mechanical strength vs current capacity.
If you want to run a cable long, you either bury it in the ground or lay it on the ground. Someone once posted here a link to worldwide fiber optic cable laying on ocean floors. If someone in Africa accesses my website (common enough with my site), the data will get between my server and them via some monster trans-Atlantic fiber optic cable. While the idea oftrans-oceanic cables seems quaint, they are used a lot. Actually cheaper than satellites. And the latency of satellite carrying Internet traffic (due to the speed of light being slowish) causes a shitload of problems. With the Internet, the other side frequently has to send acks back to the sender “got that, send more”.
True, there are dozens of fiber and metallic cables in the oceans, but they’re supported by the seafloor. They’re not just floating in the water.
My vote would be some trans-oceananic cable which might be suspended between two u/w peaks.