On 2/3/2012 9:31 PM, Rick Karlquist wrote:
> Gedas wrote:
>
>> Anyway, while it is not as elegant as the falling derrick method, here is
>> what I use on my 3 towers. Just a couple pressure treated 6"x6"x18'
>> timbers
>> bolted together and sunk into 5'-6' concrete at a slight angle. Heavy
>> chain
OK...I have to ask. Are you taking about a fold over, or a hinged base?
They are quite different.
I The question was about a fold over, not a hinged base so I doubt a
falling derrick would work well for that, but is excellent for the
hinged base.
Then again the above paragraph doesn't make a lot of sense if it is a
fold over as it says in the subject line.
BTW this entire tower was put up using a 4WD and a winch. Most of the
lift IIRC was done by the vehicle and the fine stuff done with the winch
on the front.
OTOH it was all piece-by-piece. This tower became available for free if
you'd take it down. They found no takers and finally the power company
took it down for the steel.
73
Roger(K8RI)
> That's fine if it works for you. I think what is underappreciated
> about the falling derrick is that you can have multiple ropes
> going from the falling derrick to different heights on the tower.
> This lessens the chance of the tower buckling. With a simple
> ginpole as you have, you can't have multiple ropes because there
> is no way to control the take up of them to maintain even pressure
> on the tower. The tower you have is a wide spaced self supporting
> one that would be less likely to buckle. But a guyed tower would
> be skinnier and more at risk of buckling. Irrigation pipe is
> totally as risk of buckling and the falling derrick become essential
> for the taller installations.
>
> The falling derrick also has the advantage that it can leverage
> the concrete base that you already have for the tower. On my
> 50 ft Glen Martin, a falling derrick pivot is frozen into the
> concrete.
>
> Rick N6RK
>
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