[TowerTalk] {SPAM} Re: hazer comments

[Roger (K8RI)]

Dan Hearn wrote:
> Dennis: You will find different opinions here on many subjects however I
> believe there is almost uniform opinion on guying crankup towers. Don't do
> it. That puts additional stress on the lifting cables when horizontal force
> is applied to the tower.  73. Dan, N5AR
>
>   
(If I did the math correctly)
Think of it this way.  Each 1/4" guy wire at 440# tension  (10% of 4400# 
strength) and 60 degrees  at the anchor = 30 degrees angle at the 
tower.  Neglecting the weight of the guy = 440*Cos(30) = 381#. There are 
three guys per level so that would be 1143# vertical load added to the 
tower and on the raising cables.
Say a second set at 45 degrees = 440#*Cos(45)= 311# or 933# vertical 
load added, so adding just two sets of 1/4" guys properly tensioned will 
add 2076# vertical load to the tower and cables. IOW adding guys to just 
two levels that move adds over a ton of load on the cables. Using steel 
guys would also add additional weight from the cables as would larger, 
stronger guys.

The strength of wire rope varies over a very wide range which makes the 
selection of the cables a primary consideration and pretty much 
eliminates what you find at the corner hardware, or big box store 
although the hardware store could likely order it to spec.  This is also 
why it's important not to oversize the guys on a tower. 

73

Roger (K8RI - ARRL Life Member)
www.rogerhalstead.com
N833R (World's oldest Debonair)