I see that the utility companies are using the "Grips" extensively which
probably adds up the million + amount used. I use them on my 85 foot tower and
have seen no problems. I even had one of them intentionally slip to adjust its
position. That probably wore off the inside coating. Still I have seen no
problems with slipping or anything else.
Go for it! They are easy to install, just follow the instructions and don't
leave a too short part of the guy wire inside the Grip.
Good Luck and best 73 de,
Hans - N2JFS
-----Original Message-----
From: jimlux <jimlux@earthlink.net>
To: towertalk <towertalk@contesting.com>
Sent: Thu, Jan 7, 2016 8:57 pm
Subject: Re: [TowerTalk] [Bulk] My first introduction to guy-wire dead end grips
On 1/7/16 2:50 PM, Grant Saviers wrote:
>
> There are several ways to terminate a wire rope cable and not degrade
> the breaking strength. Grips are one. Cable clamps or clips are not
> one. The inside of the grip wires are coated with an abrasive which aids
> in the grip. Hence, they are generally considered a "one time use"
> product. A problem with clamps/clips is insuring proper spacing,
> orientation and the nut tightened to the specified torque, and then
> re-torqued as the assembly relaxes a bit. Hence, variability in
> retention strength occurs. If you've tried to hold a wire rope and
> tighten the clamp/clip nuts you understand the problem ie Crosby
> specifies 30 ft-lbs for 3/16 and 1/4 wire rope clips.
There's also crimped on sleeves. They solve the bolt/nut loosening
thing, because they're essentially spring loaded.
>
> Clamps are mostly obsolete in commercial use, if you see them on a power
> pole guy they probably were installed sometime last century.
>
> There are easily millions of grips in use, certainly hundreds of
> thousands just on ham towers.
probably not hundreds of thousands.. we hams are radio-active, but I
doubt there's even 50,000 towers, especially with grips (or we wouldn't
be getting all these questions about saddling dead horses, bail to the
tail, torque specs, etc).
There are about 140k Extra and 173k General, so let's say there's 300k
licensees that potentially would be interested in a tower (there's
probably some technicians, too).
I would suggest that about 1/3 of those licensees have actually used HF
in the last 5 years. The rest are dead, doing something else, or whatever.
So now you're to a population of tower potential hams of about 100k.
I'd guestimate that about 75% of the HF operating hams I know do NOT
have a tower: they use dipoles in trees, verticals, mobile, etc.
Of course, the tower owning hams do somewhat make up for it: they might
have multiple towers (would that I had the room for that).
So now we're down to a few tens of thousands of ham towers.
In zipcode 91360, there are 105 licensees with Extra, Advanced, or
General. From a casual driving around and being aware of tower issues,
I'd guess that there are probably 20 towers in that zip code. Households
with a tower often have multiple hams there, for what it's worth.
Some are self supported. Some are "guyed" with baling wire and rope. A
fair number are guyed with real cables. Of those, I'll bet most use clamps.
There's some folks on the list who actually SELL these things.. without
giving away their proprietary info, it might be interesting to know what
kind of volume there is.
On commercially installed towers, no question, grips probably rule the
day (Although, I do see regular old Crosby style clips on a tower across
from my office here at work, and it's less than 10 years old).
>
> A Klein cable grip (aka "Chicago Grip") is used to provide temporary
> tension when needed on a wire rope guy. google it
>
> Grant KZ1W
>
> On 1/7/2016 10:49 AM, dw wrote:
>> I'm trying to understand the use of pre-formed wire-wrap dead-ends for
>> guy-wires.
>> If I understand the install process, the guy-wire itself doesn't wrap
>> around the lower anchor fixture.
>> But the dead-end goes into the lower anchor fixture and the dead-end
>> then wraps around the guy-wire.
>> First the guy-wire tension is pulled up to pre-tensioned position.
>> Then the dead-end is fed through the anchor fixture.
>> Then one leg of the dead-end is wrapped around the guy-wire...either
>> wrapped all the way or part way.
>> Then the other leg of the dead-end is wrapped.
>> And then the wrapping is complete....I think that approximates the
>> installation steps.
>>
>> The question I have is, what is supposed to keep that wrapped dead-end
>> from slipping off the guy-wire?
>> Hard for me to believe it will grip the guy-wire just being wrapped
>> around it, especially when the guy wire is fully tensioned.
>> Why not put forged guy-wire clamps around the dead-end after its wrapped
>> to ensure it won't slip off the guy-wire?
>> What am I missing?
>>
>> Also, companies like Hubbell and AED manufacture straight-type bolt-on
>> clamps that come in different lengths....like 6 inches with 3 bolts.
>> How does the bolt-on clamp assembly compare to the dead-end, in terms of
>> reliability and pull strength?
>> Thanks!
>> N1BBR :-]
>
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