Basically, Stan's approach is to TAKE DOWN the tower and
reinstall it. Here are two alternative approaches:
N4AR discovered his 200 ft R45 tower with a 4 high stack of 4L20's
had rotated at the base following a near pass by a tornado, sheering
the R45 legs at the top of the concrete. He made a form and poured
a block of concrete around the base.
N4KG discovered two legs of a TV tower (similar dimensions to
R25 but no diagonal bracing) RUSTED through at ground level.
Three 3 ft lengths of 2" angle iron were pounded halfway into the
ground to prevent the legs from moving out. H braces made of
2X6 pressure treated lumber were placed inside the tower legs
at right angles to each other to prevent the legs from moving in.
These wooden braces extended up to the next steps which will
support the vertical load in case the tower sinks. This tower is
still standing 2 years after discovery of the rusted through legs,
supporting 3 tribanders at 40, 60, and 80 ft. with guys every 20 ft.
Note that both of these 'solutions' are probably violations of
'the Prime Directive', but the towers are still standing.
Remember, for a GUYED Tower, nearly all of the forces at the
base are VERTICAL. Horizontal forces are primarily handled
by the GUY Wires. Remember to ALWAYS install temporary
low guys when removing ANY guyed tower.
Tom N4KG
On Sun, 29 Sep 2002 "Stan & Patricia Griffiths" <w7ni@easystreet.com>
writes:
> I think you need to dig out the tower base and redo it . . . at least
> plant
> a new base next to the old one and transfer the tower to it. The
> problem is
> that any repair you do to the old base does nothing to prevent the
> same
> problem happening in the other two legs or happening again in the
> same leg.
> Weep holes at ground level, even if they work and don't get plugged
> up, only
> drain water out of the legs to ground level. I am sure the ground
> freezes
> down to some level below the surface. The next crack that forms in
> a tower
> leg will probably be just under the surface and you won't know about
> it . .
> . until its too late . . . and you find it while doing a "tower
> autopsy".
>
> Stan
> w7ni@easystreet.com
>
> ----- Original Message -----
> From: "Chuck Sudds" <Chuck@dxham.net>
> To: <Towertalk@contesting.com>
> Sent: Friday, September 27, 2002 8:19 AM
> Subject: [Towertalk] Cracked Leg on Rohn 45G
>
>
> > Greetings Towertalkians
> >
> > I just returned from a good friend of mine's place where we did
> some tower
> > work. Upon a close inspection of his tower, we found a 2 1/2"
> split on
> the
> > inside of one of his Rohn 45G tower legs! The split appears to
> have
> > happened from water in the leg where it froze and expanded. Other
> than
> > this vertical crack, the tower is in great shape and is well guyed
> and is
> > definitely NOT overloaded.
> >
> > Is there anything that he can do to repair this crack (with
> bracing and
> > such) to make sure that this leg does not give way? It is about
> 3ft from
> > where the tower goes into the concrete. We drilled a super-small
> "weep
> > hole" in that leg of the tower to see if there was any more trapped
> > moisture and there was none. He really would hate to have to dig
> another
> > tower hole close by and rent a crane to lift the tower to a new
> location
> > right now. I realize that anything that he can do will not be to
> Rohn
> > specs, so we're kind of flying by the seat of our pants here,
> folks, so
> ALL
> > ideas are welcomed. Thanks and 73.
> >
> > Chuck KØTVD
> >
> > _______________________________________________
> > AN Wireless Self Supporting Towers at discounted prices,
> > See http://www.mscomputer.com
> >
> > Wireless Weather Stations now $349.95. Call Toll Free,
> > 888-333-9041 for additional information.
> > _______________________________________________
> > Towertalk mailing list
> > Towertalk@contesting.com
> > http://lists.contesting.com/mailman/listinfo/towertalk
> >
>
> _______________________________________________
> AN Wireless Self Supporting Towers at discounted prices,
> See http://www.mscomputer.com
>
> Wireless Weather Stations now $349.95. Call Toll Free,
> 888-333-9041 for additional information.
> _______________________________________________
> Towertalk mailing list
> Towertalk@contesting.com
> http://lists.contesting.com/mailman/listinfo/towertalk
>
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