[TowerTalk] a really big falling derrick tiltup (104 meter)

[Jim Lux]

At 02:12 PM 6/13/2005, knormoyle at comcast.net wrote:
>after my last post about falling derricks
>what kind of big tiltups others (wind turbines, wind speed) do,
>
>I looked some more.
>
>
>these guys talk about a 341 ft tiltup. Really!
>
>Some good data in there. (interesting where
>they have redundancy, guys, and manpower..and calculated forces)
>
>apparently they make a tower out of composite material...so it's light
>but stronger than steel? ...so it's not really fair :)
>
>http://www.isotruss.com/pdf/guyed%20towers%20installation%20manual%20030916.pdf
>
>
>They don't mention windload, but page 15 has this as the biggest
>example:
>500 lbs on top of tower.
>104 meter tower (supposedly the tower only weighs 575 lbs)
>60 ft gin pole (multiple attach points from gin pole to tower is key)
>7748 lb winch pull (and that's with a compound pulley?)
>
>
>general pics at http://www.isotruss.com/gallery.asp
>
>a photo spread of a BIG tiltup..you gotta click on the pics..insane!
>
>http://www.isotruss.com/photo-gallery.asp
>
>Now THAT would be a field day antenna!



Look how much that thing flexes while being hoisted. I'll bet the guy 
cables weigh more than the tower itself.  82 meter high tower, 4 guy 
directions, 8 guys, probably averaging 60m long each.  That's almost 2000 
meters of guy cable, mostly 1/4", call it 6000 ft.  Probably about 1 pound 
per 10 ft, so that's 600 pounds of guy cable.