[Towertalk] Rohn tip-over base failed

[n4kg@juno.com]

A Mechanical Engineer friend built a tilt mechanism for a 70 ft
R25 Tower using VERY HEAVY DUTY material.  I *think* the
basic R25 Tiltover mechanism is meant for 40 ft or less.

Tom N4KG

On Mon, 27 May 2002 20:39:44 -0400 "Guy Olinger, K2AV"
<k2av@contesting.com> writes:
> You drill a 3/4 inch hole through the bottom of a Rohn 25 section and
> you sure don't have much left over. It will just balloon worse when
> you load it up.  Rohn 45 maybe you might get away with this, but not
> 25.
> 
> Dunno, it might even be that he's got some of that old stuff that
> LOOKS like Rohn 25, which would be even worse.
> 
> Of worse import on reflection, the overload involved in this may 
> have
> done worse things elsewhere which are not as obvious. The whole
> structure is due a very careful inspection.
> 
> 73, Guy.
> 
> ----- Original Message -----
> From: "Lee Noonan" <vk2lee@maxnet.net.au>
> To: <towertalk@contesting.com>
> Sent: Monday, May 27, 2002 7:18 PM
> Subject: Fw: [Towertalk] Rohn tip-over base failed
> 
> 
> > Ford Peterson
> >
> > > There is NOTHING that can't be repaired ...Hi Hi...
> > > Reinforced with steel plate and LARGER BOLT holes....
> > > My tower isn't a ROHN but I used 3/4 bolts in the base of Mine. 
> If
> they
> > can
> > > be done up tight ..... they shouldn't wear... I haven't actually
> seen the
> > > base of a ROHN tower though...
> > > 73
> > > Lee VK2LEE
> > > http://www.qsl.net/vk2lee
> > > http://wwwqrz.com/vk2lee/
> > >
> > > ----- Original Message -----
> > > From: "Guy Olinger, K2AV" <k2av@contesting.com>
> > > To: "Ford Peterson" <ford@cmgate.com>; 
> <Towertalk@contesting.com>
> > > Sent: Tuesday, May 28, 2002 8:38 AM
> > > Subject: Re: [Towertalk] Rohn tip-over base failed
> > >
> > >
> > > > I wouldn't fix it. It's complained to you loud and clear about
> the
> > > > overload. I'd call it "weakened".
> > > >
> > > > 73, Guy.
> > > >
> > > > ----- Original Message -----
> > > > From: "Ford Peterson" <ford@cmgate.com>
> > > > To: <Towertalk@contesting.com>
> > > > Sent: Monday, May 27, 2002 3:35 PM
> > > > Subject: [Towertalk] Rohn tip-over base failed
> > > >
> > > >
> > > > > A few weeks ago, my 68' tiltover tower failed in a huge wind
> from a
> > > > > microburst that came through.  One guy failed and the tower
> was
> > > > helpless
> > > > > against 100+MPH winds.  I was disassembling the base section
> today
> > > > and
> > > > > discovered something very interesting.
> > > > >
> > > > > For the last few years, I have been perplexed by the need to
> forever
> > > > be
> > > > > tightening up the guys.  All the guys would loosen about the
> same so
> > > > the
> > > > > conclusion I came to was that the base itself was sinking in
> the
> > > > moist loam
> > > > > each spring.
> > > > >
> > > > > What I discovered today is that the tip-over base section
> (Rohn's)
> > > > had been
> > > > > overloaded by the weight of the tilt-over with all the
> hardware.  If
> > > > you
> > > > > have never seen the swivels on a tip-over base, they are
> single 3/8"
> > > > > diameter bolts pinned through the 25G type base section
> tubing.  The
> > > > whole
> > > > > weight of the tower rests on a single set of 3/8" bolts.  
> The
> holes
> > > > in the
> > > > > base section tubes were elongated downward by about 3/16" in
> only a
> > > > few
> > > > > short years.  All three legs were worn about the same.
> > > > >
> > > > > I thought Towertalkians might want to know this so that you
> can run
> > > > out and
> > > > > check your hinged base bolts.
> > > > >
> > > > > Now, on to how to fix this base so I can use it again...
> > > > >
> > > > > Ford-N0FP
> > > > > ford@cmgate.com
> > > > >
> > > > > _______________________________________________
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> > > > > Towertalk@contesting.com
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> > > > >
> > > >
> > > >
> > > > _______________________________________________
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> > >
> >
> >
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> 
> 
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