Two sites you might look at. The one at W5UN is not a tower raise but is
using a falling derrick for bringing up a tall 160 m vertial. It is a video
and neat to watch. The second one is of a tower raise by falling derrick.
GL
http://www.sitetrai.com/w5un.net
http://www.n6rk.com/falling_derrick_gme/falling_derrick_gme.html
-----Original Message-----
From: Tad Williamson
Sent: Wednesday, August 24, 2011 2:56 PM
To: sedxc at yahoogroups.com ; sedxc at contesting.com ; secc at contesting.com
Subject: [SEDXC] Question about raising a 90' (maybe shorter)
tilt-overaluminum tower
I've been exploring the possibilities of putting up a Universal 90' aluminum
tower that tilts over at the base. This won't happen for a while, but I am
thinking about this for my property out near Eatonton. The plan for this
particular tower will be to add a horizontal "X" at the top for a
capacitance hat and shunt feed it for a transmit antenna on 160 meters.
Universal's 2-90 tower weighs 259 lbs and add a few lbs for the cap hat and
it should be under 270 lbs total.
Anyway, over the last few days I've been trying to figure out how to raise a
tower like this. I know once the shunt is in place, a crane can be brought
out and the tower raised and it probably wouldn't need to be lowered/raised
much after that.
But I started reading about the "falling derrick" method of raising towers
and masts and thought it might work, but I couldn't find any formulas to
figure out the height of the derrick, length of the ropes/cables and
distances between components.
Does anyone have experience with this and/or formulas to calculate the
lengths/values?
Thanks, 73, Tad, WF4W
"What a long, strange trip it's been"
The Grateful Dead
Truckin'
_______________________________________________
SEDXC mailing list
SEDXC at contesting.com
http://lists.contesting.com/mailman/listinfo/sedxc
|