Date: Sun, 19 Jul 2015 15:07:44 -0500
From: Lee George AK4QA <ak4qa@msn.com>
To: Kelly Taylor <ve4xt@mymts.net>, Bill Aycock
<baycock@mediacombb.net>
Cc: Tower Talk List <towertalk@contesting.com>
Subject: Re: [TowerTalk] guy posts math
Is amazing that you get anything built. so I transposed A Ad hoc formula
Email That I'm sending from my Telephone Yeah. Yes it should be one foot down
for every three foot up For a wooden pole. Read my page And let's see if you
can do what I've done With what I have.Thank you guys for nothing. One of these
days I'm gonna learn That's These Newsgroups Are useless.
## I worked for the local telco for 34 years. heres the formulae for wooden
poles...used since day 1..and used across canada and the usa..and still used
today. . Depth into ground = 10% of the height above ground..PLUS 2 feet
!
IE: for a 40 ft pole above ground, depth into ground = 4 + 2 = 6 ft. For a
30 ft pole its 3+2 = 5 ft. For a 100 ft pole its 10+2 = 12 ft. For a 20
ft pole its 2+2 = 4 ft.
## For elevated guy anchors radio towers whole different ball game, since the
steel tubes are into concrete. wooden poles are NOT into concrete. 1st,
u didn’t tell us what kind of 100 ft tower your buddy has. next we have no
clue of the total windload
on the tower.
## A friend in wash state has a 100 ft of rohn 45... with several yagis on
the top and on the sides. He used 6 inch OD tubing, sched 80, implanted 6
feet into the concrete..and 6 ft above the ground. Hole in grnd is 3 ft
square and 6 ft deep. Just over 2 yards of concrete used. Steel plate,
aprx 2 ft square is welded to the bottom of the 6 inch tube. Then 4 x
rocket fins welded between lower portion of steel tube and the base plate.
Entire mess was hot dipped galvanized. 4 inch wide x 12 inch tall x 1/2 inch
thick steel plate is welded to side of steel top..at the top. Holes punched
into the 4 x 12 plate..... b4 welding. holes used for guy anchor
terminations. Concrete dumped into hole. Vibrator used on the concrete.
NO back guy required. The tube is shimmed slightly such that its JUST 1/4
inch back from dead plumb. Ok, once concrete dried.....the inside of the
steel tube is filled with concrete. u do a bit at a time..and its tamped
down.
## he had the above config designed by a professional engineer. Been up for
years, doesn’t budge. held everything from stacked optibeams to monster
steppir to m2 4 –el 40m yagis. snow loads, ice loads..and high winds.
zero problems.
## other friend has 190 ft of rohn 55 up. 14 yagis on the rotating
tower..including 80m yagi on top. . 3 x elevated guy anchors used. But
these are 10 inch diam, sched 80. Same deal with base plate and rocket fins.
5 ft square x 6.5 ft deep concrete base. tube is 7 ft above grnd.
inside of tube filled with concrete. Tube is slightly out of plumb by 3/8
inch. no back guy used. Welder stuff some steel plate inside the top of
the tube and welded that in.... to beef it up a bit more. 4 x sets of guy
wires. Guy anchors in that case are 175 ft out from the base of the tower.
been up for several years now. Doesn’t budge. The base of the concrete
hole can be flared a bit..and ditto with the rebar. That increases the
strength by a bunch. typ base flare is an extra 1 ft on all 4 x sides....
and starts 18 inchs up from the bottom.
later............ Jim VE7RF
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