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  1. #1

    Default down guy tension?

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    In "The Guidebook for Lineman and Cablemen" on page 522 under calculating tension on a loaded down guy is that formula correct? For the life of me i can't get their formula to work with their numbers based on their figure 15-39 on page 523.

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    Quote Originally Posted by scratchpad View Post
    In "The Guidebook for Lineman and Cablemen" on page 522 under calculating tension on a loaded down guy is that formula correct? For the life of me i can't get their formula to work with their numbers based on their figure 15-39 on page 523.
    Is it possible to give the formula & numbers for those who do not have the book?

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    don't recall ever using the formula.......seems like we pulled em until we got the pole where we needed or wanted it.....

    on many single phase DE and angles, we raked the pole back, made the down guy up and then after we got the wire pulled in, if we needed more, we just took some more up on the downguy.........

    We might have been cheating a little
    Old Lineman Never Die......We Just Don't Raise Our Booms As Often

  4. #4

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    Quote Originally Posted by Trbl639 View Post
    don't recall ever using the formula.......seems like we pulled em until we got the pole where we needed or wanted it.....

    on many single phase DE and angles, we raked the pole back, made the down guy up and then after we got the wire pulled in, if we needed more, we just took some more up on the downguy.........

    We might have been cheating a little
    exactly, and we could have 3 dead ends done before they get the formula figured out

  5. #5

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    Quote Originally Posted by lewy View Post
    Is it possible to give the formula & numbers for those who do not have the book?
    Guy Tension = T X square root of L sq. + H sq. / L

    H= height of guy attachment
    L= length of guy lead
    T= tension of the conductors held by the down guy

    Their figure has the guy attachment 50ft. from ground level, guy length at 58ft., guy lead at 30 ft. and conductor tension at 1,000lbs.

    so their answer to their figure is

    Guy Tension = 1,000 X square root of 30 sq. + 50 sq. / 30 = 1,944lbs.

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    Quote Originally Posted by scratchpad View Post
    Guy Tension = T X square root of L sq. + H sq. / L

    H= height of guy attachment
    L= length of guy lead
    T= tension of the conductors held by the down guy

    Their figure has the guy attachment 50ft. from ground level, guy length at 58ft., guy lead at 30 ft. and conductor tension at 1,000lbs.

    so their answer to their figure is

    Guy Tension = 1,000 X square root of 30 sq. + 50 sq. / 30 = 1,944lbs.
    I don't think my brain could take the calculations but heres what linemen need to see. I think!
    Change the lead from 30 ft. to 20 ft. and re-calculate.
    Why I say this is that often there isn't enough easement for a proper lead and I believe that is the reason the proper sag gets lost.
    The Old Lineman

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    Quote Originally Posted by scratchpad View Post
    Guy Tension = T X square root of L sq. + H sq. / L

    H= height of guy attachment
    L= length of guy lead
    T= tension of the conductors held by the down guy

    Their figure has the guy attachment 50ft. from ground level, guy length at 58ft., guy lead at 30 ft. and conductor tension at 1,000lbs.

    so their answer to their figure is

    Guy Tension = 1,000 X square root of 30 sq. + 50 sq. / 30 = 1,944lbs.
    The formula we use is line tension/anchor distance x guy length
    1000/30 x 58 = 1933lbs

    Usually the harder part is finding your guy length.

  8. #8

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    Quote Originally Posted by lewy View Post
    The formula we use is line tension/anchor distance x guy length
    1000/30 x 58 = 1933lbs

    Usually the harder part is finding your guy length.
    Thanks lewy i have that formula. I have no idea why this book would use this other more complicated formula that may not even be correct. It appears to me they misprinted something.

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    Quote Originally Posted by scratchpad View Post
    Thanks lewy i have that formula. I have no idea why this book would use this other more complicated formula that may not even be correct. It appears to me they misprinted something.
    I think that other formula is to find the length of your guy. attachment height sq + anchor distance sq , then take the square root of that answer.
    50 sq (2500) + anchor distance 30 sq (900) = 3400. The square root of 3400 is 58'

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    Quote Originally Posted by kooman View Post
    exactly, and we could have 3 dead ends done before they get the formula figured out
    Quote Originally Posted by old lineman View Post
    I don't think my brain could take the calculations but heres what linemen need to see. I think!
    Change the lead from 30 ft. to 20 ft. and re-calculate.
    Why I say this is that often there isn't enough easement for a proper lead and I believe that is the reason the proper sag gets lost.
    The Old Lineman
    Right on both counts!!
    Old Lineman Never Die......We Just Don't Raise Our Booms As Often

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