[TowerTalk] Crank up / guy wires..

[Jim Lux]

At 04:14 PM 2/26/2007, Rick Karlquist wrote:
>Guyed crank ups used to be available until the 1970's.
>The advantage of guying is that the base is much smaller
>and the tower can be a lot lighter for the the same
>windload.  To really take advantage of guying, some
>towers had locks that took the stress off the raising
>cable after the tower was cranked up.  It is not entirely
>clear why they stopped making them, but the unpopularity
>of guys due to XYL/neighbor complaints was probably
>a factor.


The engineering of a guyed crankup is also a bit complex, especially 
if the guys attach on the extending part. There's that whole bending 
vs compression loads thing. It's possible that with newer standards, 
it's not cost effective to make one strong enough, or that the 
complexity and strength of the locks raises issues, in a 
"residential" kind of application.

They still do exist: I have seen recently manufactured guyed crankups 
in a tower trailer configuration, but it's a pretty big structure 
(45m tall when erected) with hydraulic assists, etc., and can hold a 
fairly good sized antenna up on top.  Way out of most ham budgets.
(google for "MOSS tower radar" or "Moghaddam tower radar")