Yes, the turnbuckles are rated to be stronger than the guy wire. But
stuff happens. The safety wires were cheap insurance.
73,
Scott K9MA
On 4/14/2020 21:48, Steve Maki wrote:
The purpose of the safety wire is to prevent vandals from unscrewing
the turnbuckle. Some say that it's also to prevent the turnbuckle from
unscrewing due to vibration - but I've never seen that tendency in
turnbuckles under guy wire tension.
Properly sized turnbuckles are not the weak link in the system - it's
the guy wire itself.
-Steve K8LX
On 04/14/20 22:16 PM, K9MA wrote:
I ran into the same problem when I replaced my tower last year. I
used Big Grips on the guys, but wanted to use cable clamps on the
safety wire through the turnbuckles, which was to be 3/16 EHS. Except
for some bare iron ones, none of the clamps I could find were rated
for 1X7 EHS; all were rated for 7X19, etc, with more strands. I
think the key is that the saddles have to be malleable, because it's
impossible to compress 1X7 EHS. (Ever try to cut the stuff?) I
finally ended up buying some finely stranded SS cable and clamps for
the safety wires. Overkill, maybe, but if a turnbuckle fails, I want
the safety wire to hold the tower up.
73,
Scott K9MA
On 4/14/2020 17:05, Donald Chester wrote:
Keith Dutson kdutson at sbcglobal.net Sat Apr 4 19:28:59 EDT 2020
wrote:
Good reminder to always use hot dipped galvanized hardware.
I re-guyed my Rohn 25 a couple of years ago. Big Grips are great
for attaching insulators breaking up
guy cables on my 160m vertical, but I use wire rope clamps on the
chains of 3 insulators next to the
tower because with Big Grips the insulators would be spaced too far
apart for my liking.
I ordered new clamps from Rohn, but the ones I received were cheap
zinc plated like something from
Ace Hardware, and the saddles are so poorly made that they slipped
on the cable when I tested
them under tension using a ratchet puller. I called the Rohn dealer
and they told me they couldn't get
the good hot-dipped clamps any more, since almost everyone now uses
Big Grips exclusively. I looked
on line and the good hot-dipped clips from Crosby are very
expensive, about $7 each (mine cost me
35¢ each in 1980).
I ended up re-using the old ones after carefully inspecting each
one, and painted over them with a heavy
coat of Rustoleum aluminium paint. I used some of the crappy ones I
got from Rohn for another
(non-tower) project, and sure enough, the U-bolts and nuts are now
heavily rusted after only two years,
much more so than the original clamps I had installed nearly 40
years ago. The re-used and painted ones
on the tower guy wires still look as good as the day I installed
them. I have found that ordinary aluminium
paint lasts longer before rust begins to peer through, than the
"Cold-Galv" stuff.
I still have a bucket full of the crappy ones I got from Rohn.
Haven't decided whether to take them to
a hamfest and sell for whatever I can get for them, or to toss them
in the dumpster. I would hate for
someone else to buy them from me and have a tower fail when the
cables slipped during a heavy wind-
storm. I would have returned them if I hadn't fooled around and
waited more than a year before opening
the box when I was ready to use them, and discovering what they sent
me. I didn't bother, since I doubt
they would have accepted a return after I had waited that long.
Don k4kyv
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Scott K9MA
k9ma@sdellington.us
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