[TowerTalk] Elevated Guys ??

[Lee Buller]

Alton,
   
  Take great care installing elevated guys.  There are a lot of vector forces to account for and Dave is right...get an engineer to do the design.  I did not do that thinking that 4 feet in concrete and 6 feet above ground would do.  It did not!  Do not use backyard engineering methods.
   
  I used 10 foot steel 8" pipes that were schedule 80....filled with concrete.  The pipes bend, but the earth moved.  You need a massive amount of concret under elevated guys.  I did not have enough concrete under mine.  I need to dig them out and redo them, but then again that is a lot of work.  You need to account for the "leverage" that is applied to the top of the elevated guy point and what it is doing through the fulcrum into the ground.  The ground cannot move and the pipe should not bend.  Most of the forces are along the line of the guy line...of course.
   
  If I were to do it again, I would triple the amount of concrete and make provision to weld on some braces that would be in the ground along the lines of the guy wires so when the energy is transmtted through the guy lines the braces would have to bare down from the fulcrum and the other would bare up.  The braces would be in the ground....and in concrete.  Think of burying a "T" upside down in the ground and the pouring concrete.  The top of the "T" would be in line with the guys.  That would give the elevated guy point something to push against in two directions...down thrust and up trust.  Gobs of concrete too.
   
  I would also would have used "H" steel beams with an extra 1/2" plate steel welded between the verticle component of the "H".  
   
  Dave is correct.  Get a PE to do the work.  Well worth the dollars. 
   
  Lee - K0WA
   


In our day and age it seems that Common Sense is in short supply.  If you don't have any Common Sense - get some and use it.  If you can't find any common sense, ask for help from somebody who has some common sense.