Lifting a guyed tower "a few inches" is MUCH more difficult
than it sounds. W1EVT told me he did this to one of his
140 ft R25 towers (supporting only WIRE antennas) and they
had to loosen the guys to where they were almost vertical
against the tower before they could raise the tower to install
base insulators. Sounds pretty tricky to me.
Tom N4KG
On Sun, 6 Oct 2002 "Stan & Patricia Griffiths" <w7ni@easystreet.com>
writes:
> I like Tom's suggestions for THOSE towers. The base problems with
> those
> towers was either rust or shearing. The tower in question had
> standing
> water in the leg and it froze, splitting the leg. The only real
> solution to
> making sure this will not happen again is to make sure there is NO
> standing
> water in the legs. I don't know how to do that without replacing
> the base
> section completely. It is probably plugged at the bottom, far
> underground.
>
> You COULD actually loosen the guys wires a little, unbolt the tower
> from the
> base, jack up the tower a few inches, and remove the base entirely.
> With
> the tower supported by a framework, you could jackhammer out the
> concrete
> and totally install a new base, this time with proper attention paid
> to
> drainage of water from the legs. In this instance, the other
> solutions I
> have heard just sound like the same trouble all over again the next
> time it
> freezes . . .
>
> Stan
> w7ni@easystreet.com
>
> ----- Original Message -----
> From: <n4kg@juno.com>
> To: <TOWERTALK@contesting.com>
> Sent: Friday, October 04, 2002 6:27 AM
> Subject: Re: [Towertalk] Cracked Leg on Rohn 45G
>
>
> > 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
>
>
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