Bob Gates had an interesting idea, using his new home as a
guy-anchor for folding over rohn 55g.
A quick stab at the loads:
120' of tower: 1200lbs spread over 120'...
we can assume uniformity, and calculate the mass at the
midpoint moment: 1200 x 60 = 72,000
to which we add antennas, masts, rotor...
yagis @ #95 & 55#, plus rotor @ 12 and
mast @ ..what...50? = 212 at the top..
212 x 120 = 25,440
plus yagi @ #95 @ 90... 95 x 90 = 8550
and yagi @ #55 @ 60'... 55 x 60 = 3300
Then, the weight of the guysets...
I have no idea how to estimate this, so this is an absolutely
wrong guess....
#400 lbs @ 120 = 48,000
#300 lbs @ 90 = 27,000
#200 lbs @ 60 = 12,000
#100 lbs @ 30 = 3,000
(remember, these have to be 4 way guys, or there will be no
lateral support as the tower comes down....errr, "goes up" might be
a better choice of words, in this case.)
So...the lateral load imposed on the house/guyanchor, as the
tower is lowered toward the horizontal is....
72,000 + 25,440 + 8550 + 3300 + 48,000 + 27,000 + 12,000 + 3,000
which equals....154,290 pounds.
(I'll ignore geometry and the varying horizontal component as the
tower is raised...and just consider how it's going to get up there
the first time.)
As I said in my initial post....better back-guy the house, the
trusses aren't designed for lateral load resistance! Even if I'm
wrong by a factor of 2 on the dead-weight of the guys, it's still
over 100k lbs.
This is a 5 am swag, and I haven't had coffee yet, so I may
have missed something.
n2ea
jimjarvis@ieee.org
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