I have been hesitant to talk about this, for fear of incurring the wrath
of the purists, but since Lloyd went first...
I obtained a quantity of new-old-stock of the old 15000 pound
Phillystran a few years ago. I had the same issue - the ends. It dawned
on me that in my application, the
On 01/13/2014 04:15 PM, Lloyd Berg - N9LB wrote:
Hi Grant!
I worked at WDAE Radio in Tampa, FL back in the 80's and 90's. The
engineer before me decided to try the new technology Philly-strand guy
lines on the AM directional towers because they had constant problems
with the original
To clarify, it was the original straight fiber version of Philly-strand that
we had problems with at WDAE AM 1250 KHz.
We were able to successfully compensate for the inner strand slippage
characteristic by adopting a greatly lengthened foldback, large thimbles,
and lots of clamps.
If you do use
I would never design and especially never test for the maximum steady
working load at a wind speed. The shock load of a bounce can strip the ends.
I had a friend who lost a tower from a straight line wind in a normal
thunderstorm because the outer layer stripped off. He used three saddle
The bar idea would probably significantly reduce the allowable tension on the
cable, similar to what knotting does, due to the force at each bite point
weakening the cable. I suppose if the cable was sufficiently oversized this
wouldn't pose a problem, but I'd certainly expect such a clamping
We sailors would wrap a line twice around the eye and then leave a longer tail
and clamp that with some space between each clamp. The increased friction of 2
wraps around an eye/block/winch substantially reduces the pull on a knot,
cleats or (in this case) clamps. It could be that the
Thanks to all who provided info and suggestions.
I plan to run some tests, starting with a modification to my 20T H
frame press so I can tension test specimens up to 10k lbs or so and
measure force with a simple Dillon mechanical 5k# force gauge I have. A
lever arm will give me 2x and maybe
Large guy insulators may pass two turns of your Phillystran.
They're always available on ebay for reasonable prices.
If it would help, I have several guy insulators with one inch diameter holes
that I never expect to use.
73
Frank
W3LPL
- Original Message -
From: Grant Saviers
The bar idea would probably significantly reduce the allowable tension on
the cable, similar to what knotting does, due to the force at each bite
point weakening the cable. I suppose if the cable was sufficiently
oversized this wouldn't pose a problem, but I'd certainly expect such a
clamping
As a very crude analogy what you want to be able to do is use a steel cable
from the anchor through the middle of something like an automobile wheel, Then
the Phillystran wants to take a couple of lazy turns around the rim of the
wheel and then get clamped to itself. While there are probably
Another alternative is to wrap two turns of the Phillystran around a short
length of three inch diameter steel pipe or tubing.
Then pass a large shackle through the tubing to fasten it to the steel cable.
Cut the tubing to fit the shackle, so that the Phillystran can't slip off the
end of the
I'm actually a little surprised a dead end / preform isn't supposed
to be used with the straight-strand version of the cable.
This discussion really belongs on TowerTalk, but
If the straight-strand cable is bent around something, be it
an insulator, guy grips, woven in and out of
It looks like everyone is trying to reinvent the wheel. What is wrong with
terminating Phillystran
the way the manufacture says.
I have been using 6700 lb Phillystran for over 30 years for my 80 ft of Rohn
45G tower. At that time
the termination kits were a thimble and 4 cable clamps. The
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