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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