[TowerTalk] Mast Raising Fixture
Mark - AA6DX
aa6dx at pacbell.net
Tue Aug 17 12:35:49 EDT 2004
Before someone hurts themselves --
How you lift a mast that is inside a tower. You tie a pulley with a long
line through it on top of the tower. You then drop the line down the tower
center with a correct sized pulley (with an eye on top, naturally). The
pulley is placed upside down underneath the mast, and the line goes up on
the inside to the top of the tower to be fastened. The loose end of the
line is thru the first pulley to the bottom, and is then ready for the
ground crew to hoist away, the tower monkey only has to guide the mast. A
small line ran thru the mast allows this to happen even from the cat bird's
seat. I also have a snatch block at the tower base, so the land crew is
pulling OUT, not down. Once in place, the mast can be kept from making an
unwanted return trip down the tower with a muffler clamp, the thrust
bearing(s), the antenna(s), etc. Now ... another advantage is that you can
have the antenna on top of the tower FIRST, and feed the mast through the
antenna! How kewl is that? Using it to put up stacks is neat, too. Put
first aerial in place, ground crew does its work, then next, etc...... you
get the picture! To easily raise the antennas, if the situation allows, I
use the old contesters' method ... you connect a short mast to the TOP HALF
of the boom to mast clamps, and haul the antenna up that way, so it is more
or less parallel to the ground and elements not flopping all over. Drop and
reconnect guys, if you have them, on the way. At the top, simply slide over
the mast, and tighten the pre-positioned clamps and saddles! The take the
top ones loose, get rid of the temporary mast, and do the obvious. In the
case of putting the antenna on a mast instead of over it, use extra long
temporary u-bolts (allthread works here) for the bottom half of the b-t-m
bracket, until top ones are in place, then re-place with the correct ones.
Using this method, once the mast is in its correct place, it can easily be
used as the gin pole for raising the yagis, etc.. a nice strong hook clipped
on the top works swell ... easier yet, use a pulley / snatch block that has
a hook on it to begin with! And ... again .. use a block at the bottom of
the tower so the ground crew, winch, whatever is not underneath the
worker(s) on the tower, and also that makes it very much easier for them to
see what is going on and to communicate.
And that's how it is done EASILY. Never ever had a problem doing it that
way. Let the retorts begin! HIHI
73 y'all Mark AA6DX
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