Towertalk
[Top] [All Lists]

Re: [TowerTalk] Phillystran Cable Question

To: Cqtestk4xs@aol.com, TOWERTALK@contesting.com
Subject: Re: [TowerTalk] Phillystran Cable Question
From: Grant Saviers <grants2@pacbell.net>
Date: Wed, 26 Feb 2014 08:14:08 -0800
List-post: <towertalk@contesting.com">mailto:towertalk@contesting.com>
I talked to the factory this month about old (pre 1991) Phylli. I've also taken some of the 5/8" dia apart since I have about 1800 feet of it and would like to use it on a Rohn 65G project. The factory no longer sells the epoxy or terminals (spelter sockets), but will pot ends if you send the PS to them. They claim is the process is too tricky.

I purchased a Crosby spelter socket for wire rope to see if it might work. There are quite specific instructions for cleaning and splaying wires into the socket before potting. A review of epoxies and ways to clean kevlar causes me to believe this is doable with old PS. Some test lab data also indicates that the grip strength is developed in the first inch or so in the taper of the socket which is important since the Crosby socket taper is much shorter than the PS one I removed. Load testing will be needed to find out if this is so. Kevlar seems to be friendly to a variety of epoxies and solvents (MEK was recommended by one poster). However, how to splay the very fine Kevlar fibers and wetting them with epoxy with no air entrapment in the socket feels challenging.

I think there is no way to use grips on the old PS. Simple bends cause the fibers to retract in the sheath, there is no grip by the sheath on the fiber bundle which is all parallel laid and continuously tied with what appears to be a lacing cord. I'm in process of building a test stand to see if saddle clamps will work (loads to 24,000lbs). Any experiences with saddle clamps on larger diameter PS would be appreciated.

Grant KZ1W


On 2/26/2014 5:00 AM, Cqtestk4xs@aol.com wrote:
The old style (1970's and 1980's) was meant to be used with potted  ends.
The newer stuff is made to be used with the specially made PLP  grips.
People don't always follow the instructions from the factory on many
things relating to towers....reusing guy grips, going higher than they  should
with a tower, etc.  Many times these experiments work, until  they don't one
day  Check my info with the manufacturer, Phlly Rope Works  for the scoop on
the old style stuff.
Bill K4XS In a message dated 2/26/2014 5:50:19 A.M. Coordinated Universal Time,
K8RI-on-TowerTalk@tm.net writes:

On  2/25/2014 10:15 PM, Cqtestk4xs@aol.com wrote:
I had a chance to pick  up some of the old style Philly without ends.
This
stuff  needs to have "potted" ends.  Plan on spending at least $35 for
each
"empty" end and at least $70 for the resin potting  compound.  You will
find the cost is prohibitive unless you are  pouring a dozen or so ends,
since
the potting mix has to mixed all at  once.
With out ends?  All the Phillystran I have which is all the  guys, use
only a plastic cap, RTVd in place.  14 years and no  problems. For the
smaller stuff (less than 1/4" use the cable clamps with  the "U" bolt on
the dead side. Do not over tighten. Typical is 4 cable  clamps and 1 end
cap  Because it's the jacket that compresses, not  much strength is lost
compared to cable clamps on wire.  For anything  other than small loads,
I'd use 1/4" and larger with big grips and cap the  ends by RTVing the
caps. Don't forget to use the proper size thimble and  guy brackets.
Don't just wrap it around a tower leg.  The guy bracket  removes the side
stress from the tower legs.

I've not seen any,  including the older phillystran that couldn't be used
with big grips and  capping the ends. Big grips should be installed with
the Phillystran under  working tension. IE 1/4" at 440# and 5/16ths at 600#

Kevlar does not  stand up well to moisture, so if the cable is old and
the ends were not  capped, I'd cut at least several feet off each end.
Hopefully it hasn't  been stored outside and uncapped. In that case you
might need to cut back  quite a bit and I don't know how to tell.  The
Kevlar core is made up  of many very fine strands. If they are still
flexible and strong, I'd  think they are good.

On the 45G the bottom two tier I use HTPG40001 ant  the top tier is
HTPG67001.  Texas towers has end caps for all sizes  and I'd assume Davis
does as well.

73

Roger  (K8RI)

The factory can give you the details. Bill K4XS/KH7XS In a message dated 2/26/2014 2:38:46 A.M. Coordinated Universal Time,
Gunsrus1942@Comcast.net  writes:

I'm  going to be using Phillystran Cable .22 size  and am not able to use
the  "Big Grip" on a couple of the ends  & was wondering if a standard
"guy  wire clamp" can be used  and what is the recommended configuration?
It  appears that DX  Engr. recommends that guy wire clamps only be used on
.17  and  smaller.

Thanks for your input.

73, Tom   W1ALZ
  _______________________________________________



  _______________________________________________
TowerTalk   mailing  list
TowerTalk@contesting.com
  http://lists.contesting.com/mailman/listinfo/towertalk

  _______________________________________________



  _______________________________________________
TowerTalk mailing  list
TowerTalk@contesting.com
  http://lists.contesting.com/mailman/listinfo/towertalk

_______________________________________________



_______________________________________________
TowerTalk  mailing  list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk

_______________________________________________



_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk


_______________________________________________



_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk

<Prev in Thread] Current Thread [Next in Thread>