FWIW, I have used N6RK's method with the 4 foot aluminum mast.(photo
So far up to 55 feet total. Not sure I would try to go higher, or leave
it up permanently without a good security fence and plenty of warning
I used two sets of guys, with the top few sections un-supported. 15
sections total for a total height of (15*44")/12"=55 feet. To get to 68
feet it will be 18 or 19 sections of the 4 foot mast. [You only get 44
inches of height from each section-NOT 48"]
For anything permanent, that test of my hardware and set-up gives me the
general guideline of a set of guy lines at every fifth section. Also, 4
point guying is better than three point. 4 point guying is mandatory
for the falling derrick method.
I think the fiberglass mast will snap like twigs. The aluminum mast is
less fragile, but you will still need to have proper tensions on all of
the guy lines and the pull lines to keep it from failing in dramatic
tension filled seconds. Be safe.
Also FWIW, here is a page with the test set up we plan to use for the
IOTA contest next month.
The last two photos show the problem with selecting points for the
derrick lines. The last photo shows that placing the pull lines on the
5th and 11th section balanced the pull. The 2nd to last photo shows how
the mast sags like a noodle with the pull lines at section 5 and 10.
The four sections(no photo take with all 15 sections) above had enough
weight to bow the top down.
Yes, it would be best to have a third pull rope attached to the top
Previously, we have pulled up 30 to 36 foot of mast, no problems at
73 de w4kaz
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