Which scenario, Stan's or Gordon's? Gordon didn't understand Stan's
(obviously). Stan is shearing grade 8 bolts with fiberglass (leg) rod
(c. 1-1/8" or so) in an unguyed situation, which kind of proves that
fiberglass rod is pretty damn strong and won't be a weak link.
Then he decided to guy the towers with 3/8" fiberglass rod. I'm guessing
that that would have avoided the need to beef up the leg insulators, but
he did both, now he's got a towers that will stay up in most strong breezes.
-Steve k8LX
On 9/1/2014 6:16 PM, Bill Aycock wrote:
Pardon me, but this looks like a disaster watching for a place to happen.
Bill--W4BSG
-----Original Message----- From: w2ttt@att.net
Sent: Monday, September 01, 2014 11:22 AM
To: Stan Stockton ; Grant Saviers
Cc: Gordon Beattie ; towertalk@contesting.com ;
comtechgroup@yahoogroups.com
Subject: Re: [TowerTalk] [Bulk] Re: tower insulators
Stan,
So you use 3/8 fiberglass rod into each leg and the rods go into the
concrete?
If you have photos, that would be helpful.
73,
Gordon, W2TTT
201.314.6964
Sent from Samsung tablet
-------- Original message --------
From: Stan Stockton <wa5rtg@gmail.com>
Date: 2014/09/01 11:35 (GMT-05:00)
To: Grant Saviers <grants2@pacbell.net>
Cc: "J. Gordon Beattie, Jr., W2TTT"
<W2TTT@ATT.NET>,towertalk@contesting.com
Subject: Re: [TowerTalk] [Bulk] Re: tower insulators
I have four 60 foot 25G towers that have a solid rod of fiberglass in
each leg. These towers were in guyed for several years in a pretty
harsh environment on top of a mountain. After having grade. 8 bolts
break several times I then bridged the upper and lower sections on each
leg with a piece of fiberglass plate which is something like 4 inches
wide, a foot long and about. 3/8 thick. It is held with galvanized. U
bolts. After seeing the towers bend in about a. 60 mph wind, I used 3/8
fiberglass rod to guy them to small, homemade anchors - rod welded to a
short piece of angle. Each anchor is in about a bag of Quickcrete.
Sent from Stan's IPhone
On Sep 1, 2014, at 10:12 AM, Grant Saviers <grants2@pacbell.net> wrote:
The max wind combined guy loads for a 100' tower can be around 4000#
downforce on the tower base (plus the tower weight) so something more
than 1" delrin will be required between the legs. That amount of
force obviously works ok with the tapered pier pin base, but the leg
span of straight R25 or larger will require some steel structure
behind whatever insulator is used. I think modifying a tapered pier
pin base section bottom plate for an insulator block of delrin/nylon
would be easier/cheaper.
Grant KZ1W
On 9/1/2014 7:29 AM, J. Gordon Beattie, Jr., W2TTT wrote:
Bob, Steve et al,
Any thoughts on what might be a good approach to insulating a Rohn 25
tower
from the ground?
I was thinking of a pin base in a lower slab of nylon or delrin
insulating
material sandwiched with another upper slab of insulating material
that has
bolts into the tower legs. These could be bolted together at the
corners.
When I say, "slab" I am thinking about 0.5-1.0 inches in thickness.
My concerns are that the might be stronger and possibly cheaper. Any
thoughts?
73,
Gordon, W2TTT
201.314.6964
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