[TowerTalk] guying a crank-up

Its from Onion aredandgold at msn.com
Thu May 8 02:59:22 EDT 2008


Not to start a big discussion, but as long as you 'ONLY' guy the bottom section of the tower It can be guyed.
That is to say, not guy any of the 'cranked up' sections.

Pinning the movable sections, like an extension ladder steps will only transfer the stress to the rung, cross member, ect 
that is rests on.  Something that is surly NOT designed for that stress.

Ya must remember its like building hot rod cars when we were kids:  big motor, runs fast.  but who thinks about upgrading the brakes
untill its time to  stop?  In other words, the tower companies spend a lot of mony engineering the tower.

UNLESS, you also do the same; what makes your design safe,  better, strong???

Just food for thought...  Have you ever SEEN a tower come down?  they twist into the ground.  


Lee
KE4VYN


  Message: 1
  Date: Wed, 07 May 2008 22:02:20 -0400
  From: jim Jarvis <jimjarvis at optonline.net<mailto:jimjarvis at optonline.net>>
  Subject: Re: [TowerTalk] ma550 guying
  To: towertalk at contesting.com<mailto:towertalk at contesting.com>
  Message-ID: <A8B77C17-F42C-4359-8934-C6F487BA0E15 at optonline.net<mailto:A8B77C17-F42C-4359-8934-C6F487BA0E15 at optonline.net>>
  Content-Type: text/plain; charset=US-ASCII; delsp=yes; format=flowed


  Ignoring, for the moment, the prime directive,  let's look at what  
  you're doing if you
  guy a crankup tower.

  The lateral forces on the tower, which cause it to flex and shed  
  load, are transferred to
  the guys, and to the vertical structure itself.   With a crankup,  
  that means to the hoist cable!
  The cable is not specified for anything more than lifting the weight  
  of the tube, with some
  safety margin.

  Thus, adding guys to the ma550, or any similar light duty tower, will  
  NOT increase its load
  capacity, or its safety, but will reduce it.

  Now, if you upgraded the winch cable, carefully calculating the  
  downforce resulting from the
  increased load area you plan, and the increased wind zone withstand  
  which the zoning requires,
  you COULD add capacity to the structure.    But in that case, be  
  prepared to present an engineering
  wet seal to your zoning people to justify the structural decisions.

  It's a whole lot easier and cheaper to follow the prime directive,  
  don't you think?

  N2EA

  Jim Jarvis, MBA
  President-Executive Coach
  The Morse Group, LLC
  732 548 5573 office
  908 410 9130 cell

  People-Process-Strategy
  Achieving Results in a Changing World
  www.themorsegroup.biz<http://www.themorsegroup.biz/> 


More information about the TowerTalk mailing list