Has anyone heard of or have experience with lashing fiber optic cable to the shield wire on a transmission line? I'm mainly curious about what, if anything, happens to the fiber cable when lightning strikes the shield wire. Any references on this?
Lashing Fiber to Shield Wire
- Thread starter mudpuppy
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Slugger926
Well-known member
The heat from lightning may melt the fibers. I know this has happened on underground fiber fiber near other copper cabling.
Would the fiber cable have the tensile strength for doing this? I know corning makes some good crush resistant fiber bundles that are good inside facilities for running in cable ladder with copper cabling.
You may want to call a rep at Corning or Anixter to find out technical specs.
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Dark Knight
Silent Guardian
I am not sure if this will answer part of your question but many of the companies are using fiber for relaying communication (Guard Breaker Failure, etc).
I am still green in this area and am not sure how the fiber is protected but there has to be a way. I am just not aware about what is it. I will ask the question to a co-worker at the Telecomm Section.
Yes, this fiber would be used for communication for protective relay systems. I've heard of using underhung fiber (hung under the power conductors like a telephone company fiber), buried or otherwise underground fiber, and OPGW (the fibers are contained inside the shield wire), but I've never heard of lashing a fiber cable to the shield wire.
I personally don't have to worry about the physical/structural aspects of hanging/lashing the fiber, but I am a bit concerned about the reliability of the fiber due to the exposure to lightning strikes since the shield wire is intended to attract lightning. It would be particularly bad for the fiber to fail due to a lightning strike, because failure of the fiber could result in failure of the protective system to operate correctly and the fault caused by the lightning strike might not be cleared correctly.
I personally don't have to worry about the physical/structural aspects of hanging/lashing the fiber, but I am a bit concerned about the reliability of the fiber due to the exposure to lightning strikes since the shield wire is intended to attract lightning. It would be particularly bad for the fiber to fail due to a lightning strike, because failure of the fiber could result in failure of the protective system to operate correctly and the fault caused by the lightning strike might not be cleared correctly.
gymrat1279 PE
Well-known member
Have you seen just fiber cable for a shield wire instead of OPGW? I wouldn't think that would be very reliable at all. We haven't had many problems with OPGW. There was only one instance that I could think of where we had damage and that was a direct lightning strike that people saw hit the shield wire. We had enough fibers in there that we could use that the damage didn't cause any problems though.
I haven't seen just fiber cable in place of a shield wire. I'm not sure what I'd think about that. Since the fiber cable is an insulator it shouldn't attract lightning the way a shield wire would--but if it did get struck then the result would probably be catastrophic.
The situation I'm looking at is adding fiber to an existing line by lashing the fiber to the existing shield wire instead of replacing the shield wire with OPGW.
The situation I'm looking at is adding fiber to an existing line by lashing the fiber to the existing shield wire instead of replacing the shield wire with OPGW.
gymrat1279 PE
Well-known member
Have you looked into Skywrap by AFL/Alcoa? We've used that on a few lines already when we couldn't replace the shield wire because it was the neutral for the underbuilt distribution.
