After a little more thought, the simplest fix might go something like this:
Devise a clamp on leg reinforcement that would be SECURELY bolted to the
legs above the splits and would rest on the concrete via small foot
plates (to distribute the weight a bit). This would forever relieve the
bottom of the tower legs of any responsibility except that the splits
would inadvertently take over water dispersion duties. Holes could be
drilled at the leg-to-concrete interface to make that process more certain.
The only caveat is that during tower de-install at some future date,
temporary guys (or a boom truck or something) will be MANDATORY to get
the last few sections down, but that would apply to any pier pin
solution as well. Of course one can always just let the last 30' fall
over :-)
-Steve K8LX
On 4/20/2013 7:37 PM, Steve Maki wrote:
It COULD be done without a crane, but obviously by someone with experience.
The idea would be to rig up clamps on the tower and three hydraulic
jacks. On a calm day the guys could all be loosened up enough to jack
the tower up enough to effect the modification of choice. There are a
number of upgrades that might be reasonable - I would favor a pier pin
mod of some sort.
-Steve K8LX
On 4/20/2013 12:20 PM, Gary K9GS wrote:
Hi Jerry,
Some head scratching here and some ideas.
First, the towers legs split because the base was installed incorrectly
without adequate drainage in the legs. Water/condensation filled the
base section and when the water froze it split the legs.
Even if you were somehow able to repair the splits you still have the
drainage problem.
Here's a suggestion...I'm not a tower guy but maybe others will chime in.
1) Rent a big crane. I don't know what you have on top for weight and
antennas but the idea is you want to be able to pick up the whole tower
enough so that you can un-bolt the damaged section.
2) With the tower suspended by the crane, torch off the stubs sticking
out of the concrete.
3) Drill a hole between the torched-off stubs and epoxy in a pier pin.
While you're at it, seal off the holes left where the cut of stubs were
to eliminate water getting inside the old buried base. This assumes the
base is adequate to begin with.
4) Replace the damaged tower section with a brand new Rohn 25 section
fitted with a pier-pin plate.
5) Lower the tower back onto the pier pin, re-tension the guys and you
should be good to go.
This is NOT a simple repair job and must be done by a professional that
knows what they're doing. A 180 ft tower, or any tower for that matter,
is nothing trivial to deal with. You've got a very dangerous situation
on your hands.
It might just be simpler to replace the whole tower. Especially since
the original installation was faulty to begin with I'd be worried about
what other mistakes were made, such as inadequate base, guy anchors, etc.
Again...call in a pro and see what they say.
On 4/20/2013 7:48 AM, Jerry Head II wrote:
I have a 180' Rohn 25g, the bottom section is cemented in the ground.
This section has developed a 1" split in two of the legs. Is there a
safe way to repair these splits?
My apologies if this has been covered before, I am fairly new here.
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