[TowerTalk] Phillistran 4000 LB Thimble

[Grant Saviers]

Actually, none.  Neither old or new philli uses thimbles (except for the 
smallest size new).

I've done extensive tensile testing on 5/8" old philli with cable clips 
over a period of three months and will have a report on those tests 
shortly.  My tests achieved a no slip condition at 1/3 the rated 
breaking strength (6500 lbs for 25k philli) but that is all I need.  
Using clips to achieve near breaking strength terminations would be a 
complete guess.  Clips on wire rope achieve 80 to 90% of breaking 
strength.  Tapered socket (proprietary) terminations were the factory 
means for old philli terminations and are used (Spelter sockets) for 
wire rope as they achieve almost 100% of cable breaking strength.  I 
think swaged terminations are the most common for wire rope and they 
achieve 100% as well.

For old, parallel strand philli, it will take 4 (or 5 to be 
conservative) cable clips and 5 rounds of tightening spread over a week 
or two in room temperature conditions to get a secure termination that 
might not slip at some value of tension far less than rated breaking 
strength.  I checked the specs for torque levels on 1/2" wire rope (my 
Kevlar core diameter) clips and torqued to about 60% of that value.   40 
ft-lbs in my tests using 5/8" clips. Repeat.  You will be surprised at 
the relaxed torque level after a few days.

The problem is creep of the plastic jacket relaxes the forces on the 
core and the core slips inside the jacket.  Some clips cut through the 
jacket in my tests.  The core was undamaged as best as I can determine 
at both the clips and around the thimble.

For new (stranded) philli use their guy grips.  Period.

caveat emptor - using cable clips is something the factory doesn't 
recommend.  My testing indicates there are some risks, even for use at 
far less than rated cable strength.

Grant KZ1W

On 5/22/2014 3:52 PM, Jim W7RY wrote:
> What size thimble does 4000 Lb philli use?
>
> Thanks
> 73
> Jim W7RY
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