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Re: [TowerTalk] Tower base "challenge"

To: "Steve Oksala" <ni3p@comcast.net>, <towertalk@contesting.com>
Subject: Re: [TowerTalk] Tower base "challenge"
From: "Dan Cisson" <n4gnr@windstream.net>
Date: Wed, 12 Mar 2014 17:54:36 -0400
List-post: <towertalk@contesting.com">mailto:towertalk@contesting.com>
Steve, first of all,, you did make a big mistake guying to the trees...trees move and pull on the tower....You said you used a screw in for an anchor into one stump...that was surely going to pull out eventually. Anyway, the task and situation at hand-What to do ??You need some good earth anchors...like 6 ft long with 8 inch augers on them-They are TOUGH to get in, especially if the ground is somewhat hard. But, they won't come out-not for 50 ft of Rohn 25. If the tower base is hard to move back to vertical, then it likely will suffice to do the job. But you will need to tamp down the ground once you get the base straight. Sounds like you originally did not make the base big enough. That base should have been 3 X 3 ft cubed-which is one yard of concrete. Basically, all you are asking the foundation to do from this point on is keep it from sinking any at all...if it does sink any at all from being too small, you need to re-do the foundation. Again, 3 ft X 3 ft and 3 ft down is enough. You can go with elevated anchors which requires a heavy section of I-beam concreted into the ground, and up above ground probally 5 ft or so which allows you to get under the wires with lawn mower and walking clearance.This option is somewhat expensive-concrete and steel, and getting it installed.Overall, if that base as it is now moves easily, you likely need to re-do it.. But if you can plum the tower straight, and shore up the ground around the base, you may be able to get by with that...The first and the top set of guy wires will hold the tower stable. Be sure to use a good grade of galvanized guy cable like 3/16(minimum) ,or 1/4 inch. Use good galvanized turnbuckles,minimum 3/8 X 6. NO MORE TREES !!!
Good Luck,, Dan N4GNR
----- Original Message ----- From: "Steve Oksala" <ni3p@comcast.net>
To: <towertalk@contesting.com>
Sent: Wednesday, March 12, 2014 4:45 PM
Subject: [TowerTalk] Tower base "challenge"


I have a problem, and hopefully the experts on this forum will be able to
help.

My tower is 50 feet of Rohn 25, with a Force  12 C-3 on top. The tower has
been up for around 30 years. It has been guyed at 25 and 45 feet with
standard steel cable. The guys were anchored as follows: Guys A were into a pine tree at about six feet; some years ago the tree died, and the stump was
left to hold the anchors. Guys B were also into a pine tree at about six
feet, and like Guy A the tree died and the stump was left with the anchors.
Guys C were about six feet into a large maple tree.

At the end of fall, I disconnect the lower guys as I planned to replace
them. However time was limited, and the tower was guyed only at the 45 foot
level. Earlier this winter, we in the Philly area had a severe ice storm.
The result was that - I think - that the ice load on the guys was very high.
The result was that the screw-in for Guy A pulled completely out of the
stump; the stump which contained Guy B pulled completely out of the ground, with the screw-in still attached; and Guy C was still connected. However the
tower now has a distinct tilt. Just recently I was able to examine it, and
the cement base in which the tower was set has actually tipped somewhat, so one side is about an inch up above the ground and the other side is a little
bit below. The base is tilted toward the maple tree where Guy C remained
intact, and I can only assume that the weight of the ice on the guy wire
pulled it into this new position. (The antenna held up fine.)

The question I have now is what to do next. I do need to climb the tower to
replace the rotor cable (unrelated issue) and install an inverted V around
40 feet. But I don't know if I should simple reguy it as is, or fix it - and
if I fix it, what does that mean? Do I need to dig up all around the base,
straighten it out (by pulling on the top guy wire, which is still attached
to the tower), and then filling in around it with new concrete?  Demolish
all that concrete and replace (a huge job, I would think)? What other
options exist? I should also note that when I put it up I did not use any
rebar, just the hole and concrete I mixed and poured.

Any advice would be appreciated. If there is a consensus that this should be
left to an expert (I am 70 years old and used my brain for a living; no
construction skills)?  If so, any recommendations?

Thanks in advance for your expertise.



Steve Oksala

NI3P

Ni3p@comcast.net



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