Rope instead of wire for guys
Rick (W-A-one-R-K-T)
What do you all think of using heavy duty nylon rope instead of wire for
guys?
I have a Rohn 25G up 50 feet with a 2M/220/440 vertical on a 10-foot mast
on top of the tower. It is guyed at 30 feet with standard steel guy wire.
I was just up the top of it two days ago installing the vertical, and it
seems rock solid.
Now my next project is to put up a 3-element tribander, and while my guess
is it'll probably be OK without any additional guying, the paranoid in me
says "hey, bozo... put up another set of guys!".
I'm wondering if heavy duty nylon rope will be sufficient. It'll sure be
easier to work with, and there won't be the issue of having to break up
the guys every so often to keep them from resonating.
There is a ham on the other side of town that has FOUR (4) Rohn 25G's up
120 feet each, arranged in a square, and fed with a phasing network as
phased verticals for 80 meters. Each of the four towers is guyed in two
or three places with polypropylene rope. Been up a long time and seems
OK. But, there isn't a tribander and rotator on top.
ji...@specsol.spam.sux.com
Well, it depends...
Not all plastic rope is UV resistant, so you need to check.
For a given strength, the rope will be thicker and more visible, which
may or may not be a concern to you.
Rope will stretch quite a bit by comparison so the overall structure
won't be as rigid unless you put a LOT of tension on the rope.
Having said that, I have a 40M vertical made of aluminum tubing
guyed with UV resistant rope.
I have to replace the guys every 5 years or so.
--
Jim Pennino
Remove .spam.sux to reply.
Bryan
The advantage of using rope is that it's nonconductive, which won't distort
the HF yagi's radiation pattern. If you are going to use rope, I recommend
you take a look at the comparison chart listed on McMaster-Carr's website
(http://www.mcmaster.com/). The material and the construction will have
something to do with the amount of stretch, UV resistance, etc. You'll see
that double-braided polyester or nylon would appear to be good choices for
their UV and stretch resistance.
If you don't place the guys immediately under the yagi, metal guys will work
fine if you break up any in-band resonances with insulators. For safety, use
*only* compression insulators (not strain insulators). I used to have a
homebrew 3-el 15m yagi at 38' (26' mast + 12' roof). Originally, I guyed it
w/ #14 solid galvanized steel wire. Eventually, the wire rotted-thru, and
down she came (it was not a good day). After repairing the yagi, I replaced
the guy wire with 1/16" 1x19 strand stainless steel wire rope (500# breaking
strength). That lasted another 15 years until I moved. The wire is still
like new -- no signs of rot. It was a worthwhile investment. Because of
your increased loading, you'd want to use something stronger than what I
used.
Bryan WA7PRC
Ralph Mowery
"Rick (W-A-one-R-K-T)" <get.my...@from.qrz.com> wrote in message
news:pan.2007.08.11....@from.qrz.com...
>
> What do you all think of using heavy duty nylon rope instead of wire for
> guys?
>
> I have a Rohn 25G up 50 feet with a 2M/220/440 vertical on a 10-foot mast
> on top of the tower. It is guyed at 30 feet with standard steel guy wire.
> I was just up the top of it two days ago installing the vertical, and it
> seems rock solid.
>
> Now my next project is to put up a 3-element tribander, and while my guess
> is it'll probably be OK without any additional guying, the paranoid in me
> says "hey, bozo... put up another set of guys!".
You don't want to use the nylon. In a few years the uv rays of the sun will
weaken it. You want to use something made for guying towers. Phillystran
is on type. It is expensive.
http://www.texastowers.com/philly.htm
Has it listed.
Rohn recommends guying a 50 foot tower at the 23 and 45 foot levels. That
is for 3/16 inch steel wire and that cable is rated for about 4000 pounds.
You normally put about 400 pounds of tension on the guy wire. While most
towers will stay up with much less, you can never tell when an ice storm
will hit and a big wind at the same time unless you are in an area that
never gets ice.
You may want to go here and read up on towers.
Highland Ham
> or three places with polypropylene rope. Been up a long time and seems
> OK. But, there isn't a tribander and rotator on top.
Polypropylene rope is usually coloured ,blue or yellow or orange or red
. The pigment causes the material to deteriorate due to exposure to UV
(sunlight) .....even here in northern Scotland.
Result : life is approx 8 years
If they would use carbon black (soot) as pigment/filler life of the
material would be infinite ..........but then they wouldn't be able to
sell the rope any longer in reasonable quantities.
More expensive alternatives are (black) dacron or polyester rope (the
latter as mostly used for sailing yachts) ;these last for ever.
I currently use polypropylene for guying a 13 metres (43 ft) mast .
The guys have been in use for 7 years and will need to be replaced next
year . I probably will be using polyester rope.
Frank GM0CSZ / KN6WH
Owen Duffy
>
> What do you all think of using heavy duty nylon rope instead of wire
> for guys?
>
Synthetic guy material is not new, but I have not seen a commercial
structure secured with nylon rope, or any other synthetic cable laid
rope.
That might just show my lack of experience, but...
I have seen commercial structures secured with synthetic material
designed for the purpose, Phillystran is one of the products that you can
Google for more information. They are typically a bundle of straight
fibres (Kevlar???) enclosed in a continuous waterproof, UV, acid, alkali
resistant plastic sheath and special terminals that achieve high strength
and prevent ingress of water (which could support mildew, ice damage
etc).
Galvanised HT guy wire is much cheaper than Phillystran.
In this part of the world, permanent guys using (natural or synthetic)
fibre rope is not generally permitted, so you would need engineering
support to justify such an installation. There are good reasons for this.
Owen
Hal Rosser
"Rick (W-A-one-R-K-T)" <get.my...@from.qrz.com> wrote in message
news:pan.2007.08.11....@from.qrz.com...
>
> What do you all think of using heavy duty nylon rope instead of wire for
> guys?
>
Paint it black - and that will strengthen it and protect it from crumbling
from the uv .
Owen Duffy
news:6ervi.17616$eO1....@bignews6.bellsouth.net:
It seems it is popularly believed that black rope is more likely to be
weatherproof than other colours.
There are a range of ropes with good UV resistance that are white, not by
accident, the white colour is a result of the technique used to give them
enhanced UV resistance. Look around at ropes used in maritime
environments and that last for years, they aren't all black, in fact it
is rare to see a dark coloured rope at all.
As to the wisdom of taking a rope of known chemistry, then applying paint
of non-specific chemistry to protect it without proper regard to the
effect on strength or life... I will leave you to think about that.
In this part of the world, riggers are supposed to inspect working fibre
ropes and condemn rope that is contaminated with paint or any type of
solvent.
Owen
Hal Rosser
>>> What do you all think of using heavy duty nylon rope instead of wire
>>> for guys?
>>>
>>
>> Paint it black - and that will strengthen it and protect it from
>> crumbling from the uv .
>>
>
> It seems it is popularly believed that black rope is more likely to be
> weatherproof than other colours.
>
> There are a range of ropes with good UV resistance that are white, not by
> accident, the white colour is a result of the technique used to give them
> enhanced UV resistance. Look around at ropes used in maritime
> environments and that last for years, they aren't all black, in fact it
> is rare to see a dark coloured rope at all.
Especially at night.
=============
>
> As to the wisdom of taking a rope of known chemistry, then applying paint
> of non-specific chemistry to protect it without proper regard to the
> effect on strength or life... I will leave you to think about that.
Its an antenna rope - so no dangers lurk.
I did not really check its chemistry.
===========
>
> In this part of the world, riggers are supposed to inspect working fibre
> ropes and condemn rope that is contaminated with paint or any type of
> solvent.
They ought to give those condemned ropes to hams, so they can paint'em and
give'm new life holding up antennas.
=================
>
> Owen
Kool - I'm glad I didn't let one of the riggers from your side of the world
inspect my work. Guys for an antenna will be pretty static so the resulting
stiffness after painting the rope (1/4" cord actually) should not be a
problem.
I used a black latex enamel, strung the rope up and used a "glove" paint-pad
to paint the rope. after it dried, the rope was stronger, and the black
coating kept UV from the sun from hitting the nylon directly.
The nylon rope I used was cheap - so probably not UV-resistant on its
own. The paint was left over from painting something around the house - so
the experiment did not cost too much. But it worked. The paint stayed on -
did not flake off, try it.
Jim Lux
> What do you all think of using heavy duty nylon rope instead of wire for
> guys?
Nylon degrades in UV
Nylon is quite stretchy, so you'd better be willing to tolerate a lot of
deflection under load.
Nylon is challenging to attach without severely weakening it (i.e. you
can't just tie any old knot)
OTOH, if you're talking about using something like 11mm static climbing
line and a short tower, you'll probably survive.
>
> I have a Rohn 25G up 50 feet with a 2M/220/440 vertical on a 10-foot mast
> on top of the tower. It is guyed at 30 feet with standard steel guy wire.
> I was just up the top of it two days ago installing the vertical, and it
> seems rock solid.
>
> Now my next project is to put up a 3-element tribander, and while my guess
> is it'll probably be OK without any additional guying, the paranoid in me
> says "hey, bozo... put up another set of guys!".
Run the calculations and see..
Make your own risk assessment..
Your guys attach about halfway up, so you've got a situation where
there's a fair bending moment on the tower, as well as the usual
compression loads on a guyed tower. Bending loads are bad, because they
tend to aggravate the existing tendency to buckle.
>
> I'm wondering if heavy duty nylon rope will be sufficient. It'll sure be
> easier to work with, and there won't be the issue of having to break up
> the guys every so often to keep them from resonating.
>
> There is a ham on the other side of town that has FOUR (4) Rohn 25G's up
> 120 feet each, arranged in a square, and fed with a phasing network as
> phased verticals for 80 meters. Each of the four towers is guyed in two
> or three places with polypropylene rope. Been up a long time and seems
> OK. But, there isn't a tribander and rotator on top.
Sure.. but what you describe is an anecdote, not an analysis. Compare
the kinds of rope (polypropylene vs polyamide (nylon)) and their
respective strengths, aging properties, and elasticity. Compare the wind
loads and their distribution, etc.
The short answer is "probably".. how close to "sure" do you need to be?
A temporary tower in the middle of a cow pasture for a weekend is a lot
different than a permanent installation in a suburban area.
Jim Lux
Buy UV resistant rope and the mfr will have pigmented it for you
Roger (K8RI)
<get.my...@from.qrz.com> wrote:
>
>What do you all think of using heavy duty nylon rope instead of wire for
>guys?
I use it in areas where the stretching and elasticity is not a problem
such as guying to the middle of my AV640 vertical which is on top of a
40 foot tower. I put them up knowing they will stretch a *LOT* and
have to be re tightened several times in the first couple of weeks.
>
>I have a Rohn 25G up 50 feet with a 2M/220/440 vertical on a 10-foot mast
>on top of the tower. It is guyed at 30 feet with standard steel guy wire.
"Standard steel guy wire" is a pretty broad statement, but without a
whole lot of information. Steel guys vary from soft steel to the
Extra High Strength (EHS) that ROHN recommends. The steel guy wire
sold by Radio Shack can be pulled in two with just two men pulling.
I've done it. Galvanized wire rope is much better and easier to work
with, but it still has less strength than EHS or Phillystran.
>I was just up the top of it two days ago installing the vertical, and it
>seems rock solid.
I would not use Nylon rope on a tower as it would allow too much
flexing should you get a strong wind before the rope has aged and
finally taken a set. Nylon is not UV proof, but it will last a few
years.
You essentially have a 60' system and ROHN recommends two level guying
using 3/16" EHS steel tensioned to 400#. That means it's probably
4000# working strength or the same as HPTG40001 Phillystran
Even going to the 50' tower they still say guying at two levels with
3/16" EHS at 23 and 45 feet. With the array on top of a 10' mast I'd
put the top set one foot below the top of the tower and the other at
roughly 27 or 28 feet.
Why not use Phillystran (http://www.texastowers.com/philly.htm ). I
use it on a 100' ROHN 45G with a very large array on top.
You could use the HPTG12001 which is 1200# test at 45 cents per foot,
or the HPTG21001 which is 2100# test at 59 cents a foot. IF the
loading is light and you don't live in a high wind area.
Don't forget to tension the guys at 10% of their working load.
http://www.rogerhalstead.com/ham_files/Tower29.htm
The tower is guyed at three levels using Phyllistran HPTG40001 @ 4000#
test at 32 and 68 feet and HPTG67001 @ 6700# test at 97 feet.(IIRC)
http://www.rogerhalstead.com/ham_files/Tower30.htm The bottom set of
guys is almost impossible to see.
Note the bend in the AV640 due to the strong winds when the photo was
taken. The Nylon guys are in place. It had only been up a month or
so. That tower has since gone through a game of "musical sections"
with the top and base sections being replaced and a straight section
added above the base section to make 40 feet.
>
>Now my next project is to put up a 3-element tribander, and while my guess
>is it'll probably be OK without any additional guying, the paranoid in me
>says "hey, bozo... put up another set of guys!".
A lot depends on the current installation, but you have the VHF/UHF
array at 60 feet. Being 10 feet above the top of the tower that is
quite a bending moment although to do that I'd assume you have the
rotator down inside the tower.
Rick (W-A-one-R-K-T)
> A lot depends on the current installation, but you have the VHF/UHF
> array at 60 feet. Being 10 feet above the top of the tower that is
> quite a bending moment although to do that I'd assume you have the
> rotator down inside the tower.
Good afternoon, Roger.
The VHF/UHF "array" is merely a vertical, Diamond X3200. I'm quite
certain it and the relatively thin wall mast supporting it will break LONG
before the tower does even with no additional guying.
However, today I started thinking about maybe putting up a 2-element
SteppIR, mostly because I need to operate on MARS frequencies that are
a ways outside the 20-meter band. No doubt that becomes a whole 'nother
ballgame. I'll start a new thread on that topic.
Roger (K8RI)
<get.my...@from.qrz.com> wrote:
>On Tue, 14 Aug 2007 22:31:58 -0400, Roger (K8RI) wrote:
>
>> A lot depends on the current installation, but you have the VHF/UHF
>> array at 60 feet. Being 10 feet above the top of the tower that is
>> quite a bending moment although to do that I'd assume you have the
>> rotator down inside the tower.
>
>Good afternoon, Roger.
>
>The VHF/UHF "array" is merely a vertical, Diamond X3200. I'm quite
>certain it and the relatively thin wall mast supporting it will break LONG
I think you'll be surprised at how much flexing tht antenna can take.
I've seen the one on the big tower bent over with the top appearing to
be 4 or 5 feet off from vertical. That's a long ways for a 21 foot
tall vertical.
>before the tower does even with no additional guying.
I have two of the big Diamonds up. One is at roughly 30 feet on the
side of the big tower and the other is on top of 20' of 1 1/2" TV
masting on the3 North side of my shop. A third is going up on the big
tower for digtital at roughly 60 feet and the lower one is going to be
moved directly under it.
>
>However, today I started thinking about maybe putting up a 2-element
>SteppIR, mostly because I need to operate on MARS frequencies that are
>a ways outside the 20-meter band. No doubt that becomes a whole 'nother
>ballgame. I'll start a new thread on that topic.
>
Good Luck, es 73
Jimmie D
> effect on strength or life... I will leave you to think about that.
>
> In this part of the world, riggers are supposed to inspect working fibre
> ropes and condemn rope that is contaminated with paint or any type of
> solvent.
>
> Owen
This is especially true of saftey harnesses. During annual harness
inspection there is always someone who wrote their name on the harness with
a marker.
This harness must be condemned.
Jimmie
Jim Lux
and write-on-able)
Roger (K8RI)
wrote:
It is and if they are condemning them for that I believe someone is
misinterpreting the regs.
Jimmie D
"Roger (K8RI)" <valida...@my.com> wrote in message
news:22mpc31v8p7cg67hk...@4ax.com...
Nope the reg is very clear on this issue though I know it has done no harm
to harness.
The harnesses dont have a sewn on label but we do have some wire on tags
that are applied after inspection.
Jimmie