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Author Topic: Question - 40 Foot Tilting Tower  (Read 407 times)
DAPAQ2
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« on: July 16, 2009, 09:57:24 PM »

Group,

I am dealing with a 40 foot tower that has the tilting base. It has the small round bars on the faces that are shaped like a "Z" pattern all the way down with horizontal sections every so often. Im assuming that its Rohn 25 or maybe Rohn 20? I dont know how to tell. I do know though that its too wobbly at the joints to climb, I tried and I thought the tower was going to collapse, or at least i didnt trust it to climb to the third section of four sections total. Got to the second section and climbed back down. I think the bolt holes are elongated from long time wear.

Anyway my question is this.

I want to try and tip the tower over and lay it on its side and then disasemble on the ground. How many people would you say it would require to safely lower this tower by pulling the one bolt and tipping it back and walking it down to the ground without loosing control? I dont know how heavy these are and i dont want it to over power us and come crashing to the ground. We want to use it in another location.

Is there anyone here with experience that could point me in the right direction on how to safely bring this tower down?

Thanks much

Doug
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K3GM
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« Reply #1 on: July 17, 2009, 06:56:51 AM »

If there is nothing mounted on it, no mast, rotator, or antenna, then 5 or 6 guys can walk 40' of 25G down.  A couple of 8' building studs with a "V" notched in them also help in taking the load off the group as they reposition themselves as it's walked down.  The task is made much easier if you can attach a rope to the top of the tower, and use a nearby roof peak or tree limb as a sort of fairlead and walk it over as one or two people man the rope.  Anything mounted on the tower changes everything.
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WB5JEO
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« Reply #2 on: July 17, 2009, 07:26:09 AM »

The classic method of getting past the breakover point in tower raising or lowering is a "gin pole." You can see here a ladder being pressed into service:
http://www.highhopesgardens.com/Blogphotos/2008/skystreamginladderraise.jpg

As recommended in the last post, it serves the same purpose of redirecting the vector so that you don't have the huge mechanical disadvantage of trying to hold it back before the ground crew can effectively take the weight. Of course, you have to have a line connected well up the tower, which means climbing, using a guy that you have faith in, or heaving a line with a hook to catch the tower. As said, it's nice if there's a nearby tree in which to hang a pulley. I raised forty feet of Rohn25 to a position beside a house once by putting a 4x4 inside a 2nd story window and running a line from a truck on the ground through a pulley on the 4x4 to about the middle of the tower. It came up and down nicely, with no need for anyone under it. Two people controlled lines to each side to make it thread the beam on top down between trees and fences, but the truck did all the work.

Whichever approach you use, have the ground crew reach an understanding about who with run which direction if things go wrong. Otherwise, they can be doing a Laurel and Hardy routine under the falling tower.
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N4UM
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« Reply #3 on: July 17, 2009, 07:29:29 PM »

Consider a small truck mounted crane.  Fasten the line above the mid section of the tower and stand clear.  It won't cost much and nobody will wind up in the hospital or on a slab.
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DAPAQ2
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« Reply #4 on: July 17, 2009, 07:35:14 PM »

Guys,

Beleive it or not, but a local person came over and helped take it down. He just removed the tilting bolt and layed it down without any trouble what so ever. 1 person! I was amazed, I thought that that tower would have been alot heavier and required at least 5 or 6 people to lay it down on its side.

Anyway this issue has been resolved.

Thank you to all who have replied and gave their advice.

Doug
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