Re-using Guy Grips?

[k4kyv]

My tower uses 3/16" guy cable.  A few days ago I walked around and inspected the tower, and noticed that one of the guy insulators is cracked.  Don't know if it was lightning or if someone took a potshot at it, but it needs to be replaced.

I have the spare insulator, and the old one is installed using Guy Grips, also known as pre-forms.  Has anyone had any experience re-using them?  I am wondering if I should order a new set (not expensive just for only one insulator), or if I re-used the old ones would they hold ok?

[VE1IDX]

I would not really reccommend it based on what a professional rigger told me.I was a commercial broadcast engineer for 22 years and had a lot of tower work done over the time and each time the riggers would install new preforms.The reason,they said was once they are wrapped and unwrapped the "sugar" comes off.The "sugar" being the granular gritty crystals that bite into both the cable and preform.Just how much of a differance it makes I do not know but just relaying what professional riggers told me.Of course being in the business they consider the very worst case situations all the
 time.I would go for new preforms if they are cheap,probably cheaper than the insulator.

[K1JJ]

Yes, I would agree, and have been told the same things by two pros. The "sugar" is what dissolves and makes a solution that produces a chemical bonding/roughing as well as physical grip.

I HAVE re-used old (sugar-less) grips here myself, but only in less critical situations where the load was very low, like overhead-trussed Yagi booms with tiny loads, and they have never slipped. But for holding up a tower that may see the guy wires stressed to their maximum rated load during a high wind storm, go with new grips.

What could happen is the old ones slip only a few inches, but that will compromise the whole tower.

T

[WD8BIL]

Agreed ! 
Within the tower support structure I always use new when repairs are to be made.

[WA1GFZ]

I don't trust them I use clamps. Don throw a pair of clamps on each one and reuse them.

[Mike/W8BAC]

I have used mainly one kind of clamp. It is a cast bracket and a U bolt with nuts. I was told this type of clamp, and maybe other types, have a specific way they are meant to attach.

If we agree to terms, the main guy line and the painter line (the painter being the short end that has passed through the anchor eye). The cast saddle is meant to be on one of the lines and the U bolt on the other. I was taught this in a rigging class and should have taken notes. I'm not sure which line gets the saddle and which gets the U bolt. Thats the question.

Question two. How is a pre form differant from the clamp discribed above?

Thanks

Mike

[WA1GFZ]

Mike that is how I use a clamp also. Flipping it around puts a dimple in the main cable.

[Mike/W8BAC]

See my edit above, Thanks.

Mike

[k4kyv]

I noticed in the latest ad from Texas Towers they sell the cable clamps, but they are described as "electroplated," whereas the ones I bought in 1980 when I originally built the tower were hot-dipped galvanised.  There is a big difference.  The hot-dipped ones have a heavy coating of zinc that  lasts for years, but the zinc-plated ones begin to rust after a year or two of exposure.

The guy grips are made by a company called Big Grips.  They hold the guy wire sort of like a Chinese finger trap.  You can see them almost everywhere as they have become the standard hardware on utility pole guys.

According to a tower erector I talked to, the main sources of failure with the cable clamps are forgetting to tighten all the u-bolts securely, or else tightening them too much so that the threads are stripped.

Actually, the most secure method to attach guy ends is to "serve" the cable, by unravelling the strands of the dead end of the cable after it is passed through the insulator, then wrapping each strand tightly around the remaining strands until you run out of strands to wrap.  But this has two disadvantages, (1) the served ends cannot be re-used in the event of failure of the insulator, so that you have to clip off the old served end and completely re-do it, leaving the section of guy several inches shorter than it originally was, and (2) modern guy wire is made of EHS steel (Extruded Hardened Steel), which is very brittle and springy, much like Copperweld.  The strands tend to break while wrapping them, and once the served strand is firmly wrapped, it tends to spring back the instant you release it, leaving the served ends loosely wrapped.  If you could find some of the older HS (Hardened Steel) guy wire material, it is much more malleable, and the wrapped ends stay tightly wrapped.  I have seen decades-old broadcast towers with the insulators attached by nothing  more than serving the stranded guy wire ends.

[WA1GFZ]

Don,
I sprayed galvanized paint over the electroplated clamps. The old hot dipped clamps are big bucks and hard to find. My plated clamps still look fresh after 10 years since I rebuilt my tower. I went around and checked each clamp after the cables were up in the air for a while. The strands do move a bit so need about a quarter turn or so.
I'm guyed every 17 feet so no risk releasing a turn buckle to check them.
I made the cheap ass mistake of using rohn 25 and it is maxed out with the log antenna. I used twice the guys required to keep the tower from twisting. Also have a 25 foot drive shaft up the center putting the torque load lower to the ground with better angles on the antitwist brackets.

[K1JJ]

Don,
 The old hot dipped clamps are big bucks and hard to find.

Ya just gotta go to the right place - the big boys at "E-Rigging"....  the reeeaal man's tower company.   

http://www.e-rigging.com/store_Categories.cfm?Cat_ID=56&Menu_Choice=Catalog

1/4" u-bolts, or "clips"  as the hardy riggers call them are only 63 cents each for hot dipped.

I bought a pile of turnbuckles, cable and assorted hardware from them a few months ago. Arrived in two days and everything had heavy dipped galvanizing. No need to pay top dollar at Texas tower.

Also, the Big Grips are sold by a company out of Florida.  I have their number here somewhere. Act like a big log tower rigger and they will sell them for about $2 each for 200 qty.  In contrast, Texas Towers gets $6-7? each these days? Same product.

73,
T

[WD8BIL]

That's a great suggestion. Reuse the grips and add the clamps for insurance.
At a buck a piece the clamps give cheap peace of mind.

[k4kyv]

Also, the Big Grips are sold by a company out of Florida.  I have their number here somewhere. Act like a big log tower rigger and they will sell them for about $2 each for 200 qty.  In contrast, Texas Towers gets $6-7? each these days? Same product.

Tom,

Do they sell in smaller quantities, and at what price?  I do recall finding a company on the web that sold them at about the same price, but did a search the other day and could not find anything.

I plan to buy new Big Grips, since I need only one pair, so even at Texas Towers'  price that's only 10 bucks plus shipping.  But I would like to find a cheaper source, in case I have to re-insulate a whole set of guys, as I did a few years ago when every single insulator in every one of the bottom set of guys got pulverised by a lightning strike.  It seems kind of JS to me to use clamps over Big Grips, whether new or used.  I did use the little sleeves that slip over the extreme ends to secure the grips from unraveling.  I plan to re-use those.  I have had professional tower riggers tell me that the sleeves were useless and unnecessary, and others to say they were essential.  I notice the utility companies don't use them on pole guys, but Rohn recommended them in their installation guide.  They were much cheaper at the time than one cable clamp.

This time it was only one insulator - in the bottom set of guys once again.  I inspected the cracked insulator closely, and I don't see any evidence of zorch marks.  I suspect the insulator (re-used from power company) may have already had a hair-line crack or else someone used it for target practice - but I didn't see any trace of metallic bullet residue.  Just looks like it fell apart on its own.

My upper level guys use the little size 500D insulators with u-bolt clips, but the re-insulated bottom set uses size 502's with Big Grips. 

When I put my tower up in 1980-81 the 3/16" hot-dipped clamps cost about 35 cents each.  Now Texas Towers wants about 65 cents each for the zinc-plated ones.  E-rigging certainly looks like the  place to buy these.  In the environment here, the zinc plated things rust within a couple of years.

If you were rigging towers for a living, the grips would no doubt be the way to go.  It takes a lot more time to properly install clamps so that when full tension is applied, the insulator doesn't cock at an angle.  I think I  had to loosen and re-tighten some of mine 3-4 times before I got it right.  I stretched each guy wire out between a utility pole and a tree, and used a come-along to apply tension on the wire to check for adjustment, then loosen and adjust, then  re-tension, until I got it right.  I suspect a commecial tower rigger would have been less picky about getting it exactly right.  But even so, the extra cost for the grips would be much less than paying hourly wages to the erection crew to fiddle-fart with adjusting the guy wires and clamps.

Tom, please post the name and contact info of that company that sells the Big Grips if you can find it.

[K1JJ]

That's a great suggestion. Reuse the grips and add the clamps for insurance.
At a buck a piece the clamps give cheap peace of mind.

Yes, that would probably work OK.  

One thing to be aware of is a clamp is usually attached to two leads... where the cable has run through the insulator and come back on itself. This clamped loop gives most of the friction and slippage is nill.

But with guy grips, they do not loop through anything and do not double back. So, if a clamp is used to help hold together a questionable "Chinese style" guy grip, the clamp's holding ability is greatly diminished when holding two leads side by side with no loop..

This combo would probably be just fine, but just wanted to point out that the clamp's holding power is greatly reduced in this configuration compared to a standard loop.

T

[K1JJ]

Tom, please post the name and contact info of that company that sells the Big Grips if you can find it.

Don,

The number and link are on my other retired computer. But I believe I've found the company. PLP use to be in FL, or maybe that was their distributor for USA.  Here's the main company in Ontario.

I was warned to act like I was a tower company when buying from them or else they would not sell them wholesale. I was told to buy the minimum 200 lot or they would not sell them. Maybe things have changed. But, if it is still 200 min, I would check on the BB to see who can use some. I can use another 25 here. At $2 each (the old price) it's hard to pass up.

See what they say. (You are KYV Tower Rigging Co.)   

http://www.preformed.on.ca/tower%20and%20attenna%20industruy.htm

T