I would do one of the following:
1. Move over 10' or so and dig a new hole. If you have the room you could
end up with two bases and two towers.
2. Dig out all around the existing base and remove it. Finish resizing the
now larger hole and pour the new base in the now properly sized hole.
I think that fooling around with the existing base is probably possible but
it would require quite a bit of work to do it right. The end result would
probably not be cost-effective. By the time you dig out enough around the
existing base to do any retrofitting right you will already have most of the
digging done (except for total depth) to just pour a new base.
----------------- Wes Attaway (N5WA) -------------------
1138 Waters Edge Circle, Shreveport, LA 71106
318-797-4972 (Office) - 318-393-3289 (Cell)
Computer Consulting and Forensics
-------------- EnCase Certified Examiner ---------------
-----Original Message-----
From: TowerTalk [mailto:towertalk-bounces@contesting.com] On Behalf Of Jim
Thomson
Sent: Thursday, January 31, 2013 12:02 PM
To: towertalk@contesting.com
Subject: [TowerTalk] Trylon self supporting tower 80 ft fall report
Date: Thu, 31 Jan 2013 09:07:17 -0600 (CST)
From: Gene Smar <ersmar@verizon.net>
To: k4vud@hotmail.com, towertalk@contesting.com
Subject: Re: [TowerTalk] Trylon self supporting tower 80 ft fall
report
Charles:
Sorry to learn of your Trylon problems. Of course, you know it was
overloaded. Based on your estimate that the top was 12 inches across you
probably have a Titan T-300-80
http://www.trylon.com/lightdutytowers/pdfs/80ft%20Titan%20Profiles.pdf . If
you look at the specs
http://www.championradio.com/T300-80-Trylon-Self-Support-Tower.52 it's
really a light duty tower. At 85 mph winds it is rated to support only 6
sqft of anenna, and that's within two feet of the top shelf. My T-500-64
Trylon holds only a Skyhawk tribander, D40 dipole and GP-15 V?UHF vertical.
I calculated that I could add a long-boom VHF and UHF Yagi and that's it.
The design of Titan towers virtually guarantees that they will fold in half
as you experienced. The upper sections' legs and cross bracing are made from
thinner gauge steel than the lower sections. If you use Trylon's design tool
http://www.trylon.com/lightdutytowers/towercalc.asp you will see that the
mid sections have the least safety margin. They will fail first upon
overloading.
73 de
Gene Smar AD3F
### That tower was beyond grossly overloaded ! What on earth were you
thinking of. You also had a whopping 17 feet of mast above the top of the
tower. You effectively just added two full tower sections !! Your 6 sq
foot rating just
dropped to well below ZERO. Even the T-400-80 with it's 15" C-C wide
top and 45" C-C wide base would still be overloaded. The 80' tower is
only 76' 8" due to the 4.5" section overlaps. Toss in the 17' of mast
above the tower, and you
are now sitting at 93' 8" . A better tower would have been the
T-500-72 ..with a 18" C-C top and 45" C-C base. The T-500-72 is 69'
tall.....and 86' with your 17' mast. Even that is pushing your luck.
The T-600-64 would have been the ideal
ticket. 21" C-C top and 45" C-C base. It would be 61' tall..then add
17' of mast = 78'.
## The weak point is 38' above the ground on these towers. IE: Junction
of 5th + 6th section. They are designed that way so they fold in the
middle....and not full length at the base. The HDX-689 by UST is similar.
It's a 5 section tower,and the
weak section is the 3rd one up from the bottom.
## These wind ratings for these Trylons is only 2' above the top... NOT
17' . On a UST tower it's only 1' above the top.
## Think of the tower as a giant torque wrench. Your 94' tall torque
wrench won't handle the strain. Simple math exercise really. Watch out on
the trylon towers. They are as streamlined as a brick. At 100 mph the
wind rating will fall through the floor.
Even the T-500-72 is only good for 6 sq feet (2' above tower top) in a 100
mph gust. And none of that factors in ICE.
## Trylon does make heavy duty freestanding towers...in 10' sections..that
will handle huge loads..and are rated for 1 inch of ice. ( that's 1 inch of
ice on each side). AN wireless makes a similar heavy duty tower.
If you want to put big windloads on tall free standing tower's, they have
to be engineered for those loads. Then you also have to factor adding in a
tall mast.
Jim VE7RF
On 01/31/13, Charles Harpole<k4vud@hotmail.com> wrote:
I put up a used Trylon self supporting 80ft tower that I do not have the
Model number of. It was about 36 inches from leg to leg at the base and
tapered to about 12 inches at the top, each section nesting inside the next
larger one, forming one shipping package. The cross members were angle iron
galv. steel and the uprunning three legs were U channel, not tubular. It was
loaded, or over loaded, with one each 20m 5 el, 15m 5el, and 10m 5el HyGain
yagi in the HyGain Christmas Tree pattern with a very heavy (I could not
lift it) 23ft chrom molly mast, six feet down inside the tower with two
thrust bearings and the T2X rotor below. All the bolts throughout were
replaced with new galv correct sized bolts and it had no rust. Mounted in a
six by six solid concrete base. Four years after installation, I noticed two
bowed cross members next to each other on horiz. at about the 40ft level and
one bowed at about the 70ft level, all of which were replaced with similar
steel angle iro
n, bolted as the original. After seven and a half years, a very powerful
straight line wind with near horiz rain for about five minutes caused the
tower to fold over at about the 40 foot point, the lower sections standing
ok, and only the one bent section destroyed. All yagi sustained total loss
of front half of each, with the ten getting more bending. Rotor and mast
were ok. The break point showed about 30 degrees of twisting. Seventy feet
away is a 70ft US Tower crank up free standing with a two el 40m quad and
inside elements for 30 17 12, made by Cubex, T2X rotor. This tower was
cranked to full height and sustained no damage. My conclusion is that the
Trylon was very loaded and that its weakness was to twisting forces, which
it hinted at earlier and showed conclusively upon it folding over. Because
it failed, I also concluded that "it was high enough." Replaced it all this
week with new tower and rebuilt yagis. 73,
Charles Harpole
k4vud@hotmail.com PS... if you have never dis assembled a T2X rotor, be
POSITIVE to read hams reports of how to do that prior to opening the bell.
Those in the know are now smiling.
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