> There are a lot of windmill monopoles for sale on the web
> that use this method of tilt up. Suggest you read about
> them. I've used this technique many times. The "rigging"
> matters a lot. The other pitfall is that the "stub mast" (also
> known as a "falling derrick") can buckle. This buckling is
> encouraged if it sags from its own weight. The fix for this
> is to put a mid span guy on it connected to the tower.
There were several towers that used this method for "folding over" available
back in the 60s and 70s as I recall. I thought ROHN even offered one at
some time, but I may be confusing it with a similar set up.
These towers used a truss arrangement that looked almost like an add on to
the upper portion of a standard tower. This truss extended down almost all
the way to the base from the hinge point. They used a winch to pull the
truss down which raised the upper portion. I've seen tubular towers
constructed in much the same manner.
Triasto I believe was one manufacturer.
73
Roger (K8RI)
>
> One fortunate aspect of buckling is that if the falling
> derrick is going to buckle, it will do so as soon as you
> try to lift off the tower. Always lift the tower a foot
> or so and check for buckling.
>
> If you have a big yard, like I do, where you have room to
> lay down a tower, I highly encourage this methodology.
>
> On my web site (www.n6rk.com) there are photos of my 50 ft
> Glen Martin tower being erected with a falling derrick.
>
> Rick N6RK
>
>
>
>
>
> John Tait wrote:
>>
>>
>> Barry Kirkwood wrote:
>>> Greetings:
>>> Has anyone experience or comments on non telescoping tilting towers?
>>> That is: A rigid tubular or lattice mast with a stub mast and hinge.
>>> In the down posture looks like an assymetrical seesaw.
>>> Remember years back in a photo in the front pages of QST saw one of
>>> tubular
>>> steel maybe 100ft tall.
>>> In my case have a rugged lattice tower, 6x 10ft sections, wondering
>>> about
>>> making it a tilt tower.
>>> Would value any opinions, reports on experience before I spend money on
>>> calculations by a professional engineer.
>>> tnx es 73
>>> Baz ZL1DD
>>>
>>>
>> In one of the old ARRL handbooks, there was a design for a tiltover
>> tower made of well casing. I've drawn a pic from memory at
>> http://www.iol.ie/~bravo/Well%20Casing%20Tower.htm. A friend EI9FE,
>> successfully built a scaled up version of this, in the region of 90ft .
>> Vy 73
>> John EI7BA
>> _______________________________________________
>>
>>
>>
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>>
>
>
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