I've mentioned before about using nylon guyed verticals in 40 meter
phased arrays back in the 60s and 70s.. I never though to photograph
them, but if we had some wind right after they went up, they would be
laying down the next morning. I just stood them back up and tightened
the guys. More wind and they would develop a drastic lean making them
non functional even if they weren't flat. After several days, most of
the stretch was gone, but the Nylon rope had taken on a whole new set of
characteristics. It was now, stiff, dull colored, and rough. All nylon
lines did this whether subjected to the extremes of guying the
verticals, or the end lines for wire antennas. It happened with line
just coiled up and left on a trailer outside, but the lower layers (more
protected) kept the original characteristics longer. IR? Rain?
temperature changes? Don't know, but nylon made a very poor guy line
They were handy for field day, but you basically had to retention those
lines every hour or two. As others have said, early on the stuff was
like a rubber band. The double braid Dacron has little stretch, lasts
for years, and it's cheap.
Phillystran is better, but costs a lot more. All the guys on my 100'
45G are Phillystran.
73
Roger (K8RI)
On 8/31/2015 5:12 PM, Grant Saviers wrote:
As a many year sailor and power boater, Patrick's advice is right on.
In fact there are web posts of nylon guyed structures on the ground
with intact guys nylon attached. Nylon will stretch well more than
30% before breaking and has considerable stretch at 10% of break
strength. (do the trig for guys!) The amount of energy stored in a
tensioned nylon rope is awesome, as I saw a 1 1/2" hawser break under
load. Folks have lost fingers when nylon rope was used in a tug of
war and broke and much worse has happened to deck hands hit with the
recoil of a breaking tow line.
The Synthetic Textiles lines are great, I used 1000's of ft over the
past 30 years. Usually they wear out at some rub point, I not seen a
UV failure.
If you need more capacity than the 5/16" from S.T. then look at West
Marine and other chandlers for low stretch lines, usually available to
5/8" and larger. The really good Kevlar and better stuff ($$$)
stretches less than steel wire rope.
btw line for gin poles is better in low stretch since for tall towers
the load can get to bouncing around on nylon.
Grant KZ1W
On 8/31/2015 13:26 PM, Patrick Greenlee wrote:
Nylon is used on boats because it stretches like a rubber band and
when used for an anchor line does not transmit much shock to the deck
hardware. For hoisting sails (halyards) and for sheets (lines used
to control sails) Dacron is used for its minimal stretch (desirable
characteristic.) Steel cables (wire ropes) are sometimes spliced to
rope "tails" for better manual handling characteristics and the rope
of choice is Dacron.
Nylon is useful for towing a boat because of it stretchiness not
putting shock loads on deck hardware. Great heat is generated by
inter-fiber friction when the nylon is stretched and when wet the
nylon shows its heat by copious quantities of steam. Failure to let
the tow rope contact the water for cooling purposes can result in
melting the nylon rope leading to catastrophic failure.
I have considerable experience as a rag sailor and 10 years in
maritime search and rescue. I advise folks wanting rope for guys to
avoid nylon if it will be loaded such that it stretches and recovers
as in variable wind. Dacron is a far better choice.
Patrick NJ5G
On 8/31/2015 12:08 PM, Bryan Swadener via TowerTalk wrote:
In other words, "double-braided Nylon" rope.The Nylon material does
well with UV.The double-braided construction is bestto limit
stretch. It is used a lot on sailboats.You'll find it in a marine
supply store.McMaster-Carr sells it as well.
I've used it for decades to support wire andvertical antennas.
vy 73 es gl,Bryan WA7PRC
> In a message dated 8/30/2015 8:11:33 A.M. Central Daylight
Time,
co8dm@frcuba.co.cu writes:
I am trying to get the "550 Paracord"...it is not available here
but will
see what i can do to get it...
I read/hear many people used in verticals and it is strong and UV
resistant
and very cheap compare with Dacron and Kevlar.
I have looking on ground, water and air here and it is not
available...unbelievable but it is the true !!!
73....Douglas, CO8DM
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73
Roger (K8RI)
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