[TowerTalk] More Rohn

Wilson Lamb infomet at embarqmail.com
Thu Jan 14 04:43:42 PST 2010


Trying again on this post...

Well, I have enjoyed studying all the thoughtful replies to my questions
about 25G and its installation.  Thanks.
Funny thing, though.  I don't KNOW any more than before.
Some people don't go above a guypoint at all.  They install temporaries on
every section when it goes up.
Other people routinely work 20-30 feet above the last guys!
I got a pretty good windload analysis from a vendor site, covering BX tower,
but nothing on 25G loading.
Rohn says 25G is not self supportiing, at all, but I have in my hand a
drawing of a Rohn "Self Supporting Base Plate"!!

SO, keep 'em coming.  I'm sifting all the data to decide what I want to do.
It's obvious that 25G is a strong tower that can do way more than they say.
I'm not trying to cut corners and be unsafe, but would like to know the real
structural responses in a real tower.  Maybe I should use some of my
considerable experience with strain gages!

What I really want, of course is a spreadsheet or drawing giving windload,
bending, and shear at all points on a 70' stick of 25G!  Who knows, I may
have to buckle down and do it myself.

Does anyone have experience with Blaw Knox?  A friend has 60' standing up in
his yard for me to take if I want it.  It's VERY heavy, 2-3 times 25G
although about the same size as 25G.  The joints are plates with several
bolts at each leg, not telescoping like Rohn.  I know it's at least 50 yr
old, and probably a good bit more!

This message has been scanned for netiquette problems.
73,
Wilson
W4BOH



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