The AM Forum

I am wondering what methods are used for tensioning and un-tensioning Guy Wires for towers??

Also, if things like chains and/or "load binders" (like used on flat bed trucks to hold the cargo) are ever used?

The use of large turnbuckles seems to me old school and maybe not the best practice, since ur relying upon the threads to hold an awful lot of force - and they don't make this stuff like they once did. And even with turnbuckles, the range is limited, so what is the methods of taking up the slack initially and getting "in range"?

                  _-_-bear

  122 pages of everything you may want to know
about Guyed towers..  

"Insert Tommy Boy line here"

/Dan



http://k7nv.com/notebook/topics/TowerTips.pdf

Real towers and real tower guys always source hardware from certified suppliers:

Crosby saddle clamps, Kellems grips, forged turnbuckles.

Not much comes from Home Despot or Ace.

Contact Rohn, Nello, Pirod Valmont, eTc for parts.

73DG

I'm more interested in the procedures based on experience and variations on the methods used. Suppliers based on the method's requirements, sure.

But as I asked, has anyone ever used chain and a load binder for the anchor to guy section? Seems like a natural on the surface.

            _-_-bear

Guy tensioning is done with a cable dynamometer and hand winch.

http://www.cranescale.com/products/dynamometers/details/?productid=3342

Fine tuning is done via the turnbuckle.

Nobody uses chains or binders on towers, least not professionally.  Binders are not rated for continuous use.

For one thing, the liability issue comes to the forefront if certified parts are not installed properly.

liability is created any time any tower is put up, even yours.....

I've seen HB ham towers made of conduit and rebar, guyed with galvanized fence wire.  I asked the ham what about the liability issue, he said "anybody inside my fence will be shot, so I won't be sued for that"..Duh...

Bottom line, don't go cheap (read sub-standard) on your tower.

73DG

Any company that services the trade, such as Graingers, can supply whatever you need.

A high quality USA or Korea forged turnbuckle will last until its time to take the tower down. Ive been recycling some here since 1964 and they are at their 5th location. The newest ones are 22 years old.

I'd say that properly sized chainbinders would work but they aren't really designed or suited for guy wire application...There are much better alternatives.....

alternatives, such as??

              _-_-

Silly string, chow line, audio chain, audio couplers, radar contact cement.... 

You know, anything but properly engineered equipment.   You might even qualify for this years' Darwin Award if you get it installed and failed before the end of the month!

...oh thanks...

What do you think about used elevator cable/steel rope?

                 _-_-

Proper galvanized stranded guy wire is the cheapest part of a tower install.

73DG

Some random thoughts and thangs about tower and  guy alignment...

It's importatnt to develop a good eye for sighting the straightness of your tower, especially if it is over 80' or so.  Alignment of each set of guy cables takes time after the installation is done. Some do it by standing next to the tower and looking straight up, like a ruler edge.  Others use a transit and sight up the tower from a distance away.

I have seen some towers over the years that zig zag their way up. This causes unneeded stresses without wind - add the wind and it gets worse.

With a crew of four, one man can stand at the tower base and direct - the other three play with the guy tensioning and tower straightness.

As far as guy tensioning, one can use the tensioning measurement devices available. Or, over time, one can learn the technique of giving the guy cable a shake and seeing how it swings. I find my guy cables  are very close to measured spec just by feel.  It's easy to see one that is very sloppy or too tight.  The idea is to keep them all the same tension and the result is a straight tower with no "bulges" as it goes up.  Remember that the longer guys will swing more than the shorter ones, so there is a feel factor that must be learned.  But for a new installation, it may be wise to set everything up with a gauge intially - and then use feel after that for upkeep, once learned.

Since wind is random and can push in certain directions more than others, there is a tendency for tower drift. After a number of years, using a transit, I found my 150' tower had leaned 2" to the southwest, due to the northeastern storm wind bias. It was just a matter of tweaking up the NE guys until the tower was straight again.   Guys can and do stretch over time, so need to be checked periodically.

One last thing to watch:  There is a difference between a straight tower and one that is leaning.  A tower can be straight relative to itself, but be leaning 12" to one side relative to the Earth/ gravity.  A well calibrated transit can see the lean easily.  But the snaking/ zig zagging of the tower sections due to guy cable differences can best be seen by looking straight up the tower. So it can be a jungling act.  I once erected my 100' Rohn 45 and thought it looked straight.  The transit showed it was leaning to the south by about 3". Surprise, surprise.

T

Isn't there a way to measure the guy tension and then set them all the same?

Pardon the nube question, just how much tension is there in the guywires at the proposed height?
Just askin'.
Thanks, Roland

They sell tension gauges.

The other method is like JJ said, you pluck the thing like a guitar string and count the beats with a stopwatch...

As far as how tight? Probably there is a spec somewhere, maybe with the tower mfrs sites?

                    _-_-bear

Roland,

For any tower height, the rule is to tension each guy to about 1/10 of its breaking strength. For Rohn 45, using 1/4" EHS,  is about 6650 pound test. So we would tension all guys to about 665 pounds.  Personally, I find this to be too tight for my taste and make mine closer to 400 pounds.

Using 3/16" EHS for a Rohn 25 tower would mean about 400 pounds tension using 4,000 pound test.


Steve: If I am reading your comment correctly,  I think we still need to sight the tower with a transit because the difference in guy cable tension is extremely small (immeasurable with any meaningful accuracy) between guys if the tower is leaning slightly, say only 3" to one side. As it leans farther, then of course there will be a bigger detectable difference in cable tension.


T

FYI...those Loos tension gauges do NOT work on the EHS cable we use for guying.  That gauge is designed for the flexible cable typically used on sail boats for rigging which is many fine strands of SS, not the 7 twisted strands in our very stiff EHS guy wire.

The way most tower professionals set tension is with the use of a dynamometer, the best ones are made by Dillon and you can get them reasonably on Ebay.  I have a couple of them, one with a 2000 lb FS and one with 1000 lb FS.  Very accurate and easy to use.

Chuck

Thanks for the info, Chuck.  I deleted that line in my last post to reflect this.

T