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## [TowerTalk] Erecting Rohn 55 and 65

 To: [TowerTalk] Erecting Rohn 55 and 65 n7vm@lgcy.com (Bill Ralston) Mon May 5 22:46:39 2003
 ```Bill, K4XS, asks: >What is the maximum height that one continuous length of Rohn 65 tower could >be 'walked up' and set by crane on top of the stub sticking out of the >ground? When I asked a similar question about Rohn 55, opinions were split as to whether I could do 100 at once or not. People reported doing the following successfully: 100' of Rohn 25 130' of Rohn 35 140' of Rohn 55 I picked up 90' of Rohn 55, about 10' from the top, and there was no appreciable bending. I put the top 10' on separately because it had a lot of added weight with rotors, etc, which in retrospect seems overly conservative. Unfortunately, my Rohn catalog doesn't have the specs on a 65 section. But, given that 65 has about 2x the wind load capacity of 55, arguably its 2x as strong as one could thus pick up about 2x as much. So 200' might be possible. Probably the more practical problem is how expensive a crane you are willing to hire; that may set the limit. Around here, a \$100/hr crane can only practically get up about 165' or so. I've been meaning to calculate how much bending moment a piece of 55 can take, but I never got around to computing it before it was time to put it up. (Not having a civ-e background, I have to do a bit of textbook work before I know I'm doing it right, so it will take me a bit longer...). It would be interesting if someone did this to supplement the anecdotal evidence. 73 de Bill N7VM ```
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