----- Original Message -----
From: "Daron J. Wilson" <email@example.com>
To: "'jeremy-ca'" <firstname.lastname@example.org>; <email@example.com>
Sent: Wednesday, June 27, 2007 11:21 AM
Subject: Re: [TowerTalk] Tower ACCIDENT, engineering
>> If you read my comments again you will find that I said to use that same
>> base plate. Sorry, but I didnt think it was necessary to have to repeat
>> myself about the pin.
> OK, I read them again, and I got this:
> "The base should be a standard base plate but with one hole at each corner
> and secured to the concrete with 3/4" J bolts."
> Is there more than one standard base available from Rohn/Radian, perhaps
> with holes already drilled in each corner? Is there an engineered
> foundation drawing indicating "J" bolts in the pour? Or, are you
> drilling holes in the pre-engineered products for an engineered design?
If you are more concerned about potential liabilities then I suggest that
YOU hire a lawyer and a PE to examine all documents and be present at your
In the meanwhile those of us that care more about THEIR personal safety than
legal BS use a more common sense approach to THEIR specific install.
I also suggest that you take some time to read a Rohn manual and then tell
me how many average installations violate those specs, especially about 25G
wind loading but yet are failure free. Then tell me how "legal" it is to use
1/4" EHS on 25G even tho it makes for a steadier tower. And then there are
the torque arms which are in and out and in of the catalogs at the whim of
some corporate legal slime ball.
I over engineer my installs, within reason, based upon personal
conversations I had with Rohn back in the days before litigation became a
national sport. Ive never had a bit of static from any inspector or PE. A
well known fact among serious installers is that 25G is actually designed at
2.5 times the specs since they knew that hams would always push the specs
over the limit.
> My point was, and still is, it isn't wise advising people to drill holes
> stuff that has been engineered as part of a system. Of course this tower
> hot dip galvanized, and drilling anywhere will violate that. Sure you can
> cold galvanize it, but that is no substitute for the real thing.
It is well known that galvanizing is self healing and flows to an injured
section to a degree. Rust from an untreated point will not migrate under the
galvanizing. There are plenty of methods to treat bare metal against rust.
My favorite is ZeroRust http://www.zerorust.com/ since it was developed
for use in a salt water enviroment. The automotive restoration field has
many other speciality coatings available.
> If you drill a hole in the leg of a tower, you have decreased the strength
> and made a weak spot. Couple that with the lack of galvanizing protection
> where you drilled the hole, and you are creating a failure point.
Maybe in your dreams but in the real world a 1/4" hole will have no
detrimental effect. The Rohn base plate legs have holes drilled in it for
> "If house bracketed then a minimum of 2 brackets is required."
> I'm unable to locate any of Rohn's engineering drawings that support this
> either, perhaps you have something you can share to support it.
Then I suggest that you keep reading. Rohn requires 2 brackets for anything
40' or higher.
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