For heavy loads, consider rigging a 2:1 or 3:1 block system. Manipulating
by hand a heavier ham antenna with a 2:1 or 3:1 system
can be surprisingly easy and graceful.
Use blocks of appropriating ratings. The breaking load for the block should
be 10x times the weight being lifted. You can not
de-rate the block just because you are using 2:1 or 3:1 rigging (except in
certain cases which, for brevity, I won't go into here).
Expanding on Steve's tip: Learn how to use a Prussic hitch and have some on
hand. It's easy to apply with one hand while your
other hand is holding the load. A carabineer can then be clipped between the
installed Prussic hitch and a secure point. With the
Prussic hitch installed, it is easy to move the rope a few inches and then
slide the Prussic hitch to a new location to secure the
load at exactly the correct location for the next step.
Lastly, CMC Rescue www.cmcrescue.com is a good source of snatch blocks that
can be easily installed around ropes for rigging.
Good examples are found under the Equipment menu: click on 'hardware' and look
for "rescue pulleys". The RA/SMC rescue pulleys,
SMC/RA 2-inch aluminum rescue pulleys, and CMC rescue pulleys are all good
examples. You may think they are a bit expensive
($30-50), but you will be buying this only once. Larger sheave diameters have
significantly less friction, by the way.
-- Eric K3NA
-----Original Message-----
From: towertalk-bounces@contesting.com
[mailto:towertalk-bounces@contesting.com]On Behalf Of K7LXC@aol.com
Sent: 2003 December 19 18:46
To: mark@concertart.com; towertalk@contesting.com
Subject: Re: Fw: [TowerTalk] Tram nightmares
In a message dated 12/19/03 2:10:02 PM Pacific Standard Time,
mark@concertart.com writes:
> > "wrapped in around their hips" THIS WORSE THAN USING A TRUCK !!
Well, he said "wrapped" and not tied. Actually that's how you do it. Wrap
the rope around your hips and bring the dead side in front of you. Hold both
parts in one or two hands- it's a good brake. I also wrap the dead side around
the live side a couple of times - it adds some friction to the arrangement so
not all of the weight is held by your hands. In any case, if you simply let
go - the rope drops to the ground and you're not in it.
>
> If I may say, this is beginning to sound like a bunch of OSHA employees
> sitting around for a cold one with some insurance agents and some
attorneys.
>
Still better safe than sorry.
> Steve ('LXC), I know you're very experienced, and you advise against using
a
> truck to pull the rope - how do you power the lift?
For commercial jobs I used to use a powered capstan winch. For ropes it's
fabulous and is easy to control the load by tightening or loosening the load
line. They ain't cheap but very useful.
For typical ham jobs, several guys on the haul rope is usually
sufficient. For full-sized 3L 40's and other big antennas, some sort of winch
makes it
easier. Also a fluid drive lawn tractor works FB. But my preferred method is to
hire a crane!
Here's a tip. When the load is at the approximate destination, tie the
rope off. The load will normally be too low so if you need a couple inches of
"up", just push on the horizontal haul line between the bottom snatch block and
where it's tied. It doesn't take much to get a couple of inches at that point
plus the load is secured while you're doing it and isn't going anywhere.
Cheers,
Steve K7LXC
TOWER TECH -
Professional tower services for commercial and amateur
888-833-3104
Cell; 206-890-4188
_______________________________________________
See: http://www.mscomputer.com for "Self Supporting Towers", "Wireless Weather
Stations", and lot's more. Call Toll Free,
1-800-333-9041 with any questions and ask for Sherman, W2FLA.
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TowerTalk mailing list
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_______________________________________________
See: http://www.mscomputer.com for "Self Supporting Towers", "Wireless Weather
Stations", and lot's more. Call Toll Free, 1-800-333-9041 with any questions
and ask for Sherman, W2FLA.
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