[TowerTalk] guying a crank-up

[Dick Green WC1M]

Aha! That's the tower I was thinking of.

Thanks for the post.

73, Dick WC1M

> -----Original Message-----
> From: WA3GIN [mailto:wa3gin at comcast.net]
> Sent: Thursday, May 08, 2008 8:00 AM
> To: Its from Onion; towertalk at contesting.com
> Subject: Re: [TowerTalk] guying a crank-up
> 
> Interesting thread.
> 
> The Triex CT-100 is a 100ft crank-up tower. It is a guyed tower (at
> three
> locations). The tower sections are lifted by a single cable. Each
> section
> raises the next section by use of a pair of cables that run from the
> bottom
> of the preceeding section over a pulley at the top of that section and
> down
> to the bottom of the next section. When the tower is fully extended
> there is
> a locking pin (fashioned from a 2" x 2" x 1/4" piece of angle that is
> used
> as a pin under a welded piece of 2" x 1/4" bar that is welded on "one"
> tub
> of the second section from the bottom section.  So, the entire weight
> and
> stress of the 80ft of tower (rated at 40sq ft and 600lbs of dead
> antenna
> weight) is supported by the welded 2" x1/4" x 1/2" latch.
> 
> There are two amazing things about steel. Check out the ratings of
> 1/4"
> steel rope and 3/8" or 1/2" bolts.  It takes a lot of force (several
> thousands of lbs) to bring a fault.  These towers we use for our
> antennas
> are pretty amazing!
> 
> Have Fun,
> dave
> wa3gin
> ----- Original Message -----
> From: "Its from Onion" <aredandgold at msn.com>
> To: <towertalk at contesting.com>
> Sent: Thursday, May 08, 2008 2:59 AM
> Subject: [TowerTalk] guying a crank-up
> 
> 
> > 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/>
> > _______________________________________________
> >
> >
> >
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