[AMRadio] Gin Pole for folding tower question - OT

[Rick Brashear]

My personal opinion is it will not withstand the first half of the 
lift.  I had a similar situation and it did not work.  You might 
consider using "drill stem".

Rick

Brian Sherrod wrote:

> Sort of off topic, however I know there are some really smart guys on 
> here
> that may know the answer to this;
>
> I've got a Rohn bx48 (48' light duty tower) that I would like to be 
> able to
> fold over/up for any maintenance.  It will have a Ham IV rotor/3 el.
> tri-bander and dipole pulley at the top.  I plan to mount in the concrete
> base a 25' steel pipe 4 1/2" diameter with 1/4" walls directly behind the
> tower for raising and lowering to tower.  The pipe will be 20 feet 
> above the
> ground level with 5 feet embedded in the concrete tower substructure.  It
> will have a pulley at the top of the pipe and a hand crank at about 4 
> feet,
> with steel cable attached to the tower at the 20 foot level.  Question 
> is;
> will 1/4" walled 4 1/2" steel pipe be able to withstand the foot lbs.
> required to raise and lower this tower below the 45 degree mark without
> buckling?  Seems I can not find any pipe this size with larger wall 
> diameter
> around here.  I could guy the pipe in the opposite direction if needed...
>
> Any mechanical engineers out there know the answer??
>
> Thanks,
>
> Brian / w5ami
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