The simple solution:
Drill a hold through the upper end of the mast and insert a long 'screw eye'.
Hook the crane cable to the 'screw eye' and haul it up.
Most cable operators will know how to release this when it's in place.
73
Don
N8DE
Quoting n4zkf <towertalk@n4zkf.com>:
We haul stuff up towers everyday with the Marline Hitch or Single Hitch as
it's called. A Little tape at the bottom so it doesn't slip in the
beginning and your off to the races.
73 Dave n4zkf
e-mail: n4zkf@n4zkf.com
web: http://www.n4zkf.com
AR-Cluster node: 145.05 Mhz. or telnet://dxc.n4zkf.com:23
N4ZKF/R 147.375 Mhz. Tone 103.5
On 11/8/13 8:21 AM, "Earl Morse" <kz8e@wt.net> wrote:
I'm going to be installing a 20' heavy steel mast in my tower (a Trylon
72' self-supporting tower). I will be renting a crane to lift the mast
and drop it from above. What >kind of rigging do I use on the mast so
it can be lifted up vertically, without the sling slipping up off the
top of the mast?
I have always used a clove hitch with an extra turn (
http://www.realknots.com/knots/hitches.htm#mwvsl ) which I tie just
above center of gravity on the mast to prevent tipping on the way up.
Never knew it was called a rolling or magnus hitch. To ensure that this
doesn't slide I usually put a muffler clamp on the pipe for the knot to
pull against. A 22 ft. mast is just about at the limit of my gin pole so
sometimes I tie a tag line (loop) from the lifting line to the top of the
mast in order to prevent tipping.
Tie it good. If I remember right that mast weighed nearly 200 lbs and
was quite a pull.
Earl
N8SS
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