200 pounds is no load at all for a crane. I install a muffler clamp on
the mast just to ensure that it does not slip off the end. If you tie near
the top you'll have to climb the mast to disconnect.
John KK9A
To: <towertalk@contesting.com>
Subject: Re: [TowerTalk] rigging for lifting a heavy mast?
From: "Earl Morse" <kz8e@wt.net>
Date: Fri, 8 Nov 2013 05:21:34 -0800
List-post: <towertalk@contesting.com">mailto:towertalk@contesting.com>
>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
_______________________________________________
_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
|