> From: thomas@cybrzn.com
> To: Towertalk@contesting.com
> Subject: [TowerTalk] Crane lifting a Rohn 25G
To: <towertalk@contesting.com>
> Date: Monday, June 08, 1998 4:07 PM
> I have been given a 70' Rohn 25g tower, standing on a city lot.
> Being in the construction biz, I have several friends in the crane
> business. I thought I would cash in a favor and have one of them stop by
> the site some day while in the area and make quick work of dismantling
> the tower.
>snip
> 73.
> Tom Hellem K0SN
> Porterfield, Wi.
Tom,
You've already received several good suggestions.
When in doubt, take it down a section at a time. That's how I've nurtured
my tower inventory in the back yard. It's heavy on effort but, extremely
manageable.
I've done some quick calc's and you should be able to use the crane to take
the 70' 25G tower down in two picks.
You did not say in your post where the guys were located on the existing
tower, but I'd bet that it , at least has 2 sets, one at 35' and the other
very near the top.
Assuming the lower set is at 35', you'll have 3 full sections above the
middle guy point. Attach the crane sling 2 section joints above the guy
point and have the operator lift just until the slack goes out of the line.
Unbolt the 3 upper sections, at the joint above the guypoint, and manually
jack it up until free. You'll have to get the operator to lift a little bit
to keep the slack out of the lift line. Before starting the removal, attach
2 tag lines to the bottom of the sections being removed and have these in
capable hands on the ground. This lines should be equally spaced away from
the leg that the crane sling is attached to. This will allow for control of
the bottom of the sections being removed from violently swinging out when
the upper tower sections are free. The man on the tower must stay below the
separation joint!
The lower 40' of tower can be removed in a similar fashion. Crane lift
point would be about the center of the 3rd section.
You've got to jack it apart. Don't try to pull it apart with the crane!
73 Kurt
YagiStress - The Ultimate Mechanical Design Software for Yagi's
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