My post shown below was in response K8RI's post regarding nylon rope.
http://lists.contesting.com/archives//html/Towertalk/2011-03/msg00471.html .
K8RI stated he had severe stretching in 24 hours when using nylon rope to
support a vertical antenna. I said nothing in my post about using nylon
rope for temporary tower guys. Actually for my pier pin installation, I
immediately installed the permanent guy wires after lifting the tower into
position with a crane. In the tower guy example K8RI described below, the
nylon rope would only stretch 10-15 feet if the temporary guy had zero
tension and then was subject to a 30% load (about 1200 pounds for 1/2"
rope). This is a huge load change! The original post by K7LXC
http://lists.contesting.com/archives//html/Towertalk/2011-03/msg00455.html
suggested a way to pre-tension the temporary guy ropes to minimize this
movement.
Nylon is resistant to sunlight damage.
John KK9A
To: towertalk@contesting.com
Subject: Re: [TowerTalk] Temporary guys
From: K8RI on TT <k8ri-on-towertalk@tm.net>
Date: Sun, 03 Apr 2011 13:36:13 -0400
List-post: <towertalk@contesting.com">mailto:towertalk@contesting.com>
On 4/3/2011 10:32 AM, john@kk9a.com wrote:
> I use nylon rope all the time for tower work and for supporting temporary
> antennas and I have never seen the stretch that you describe Roger.
> Actually I like a little stretch when installing large antennas as it
> allows
> for a little height adjustment while on the tower. According to the
> internet, nylon rope stretched 10-15% when under a load equal to 30% of
> it's
> breaking strength.
I don't think I'd want to be on a tower with temp guys that could easily
move 10-15 feet with a 100 foot guy line length. <:-))
Dacron and other synthetics give a little, but are far more stable than
Nylon which also deteriorates quickly in direct sunlight. I don't think
you'll find Nylon used by riggers very often.
73
Roger (K8RI)
_______________________________________________
_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
|