In a message dated 98-05-24 10:51:51 EDT, dbcolter@mail.tds.net writes:
> 260 pounds? It's back to 6th grade science class for you! Remember
> that lesson about a single pulley offering a 1:1 mechanical advantage?
> Other than the added friction of the pulleys, you will be lifting 130
> pounds.
Thanks to all who caught the error in my post. While the force necessary
to pull up the 130# mast is more than 130# in order to overcome the friction
of the pulleys, it is not 260#. The 260# figure is correct though for the
force on the pulley at the top of the tower.
>The garden tractor might be a good idea, EXCEPT that you have
> to be extremely carefull that the pipe does not snag on any rungs on the
> way up. Depending on the power and traction of the tractor and the
> speed at which you haul it, you could do real damage and possibly injure
> someone. I prefer to get a bunch of strong guys with gloves on the rope
> whenever hauling something that tricky, especially when guiding it into
> the thrust bearing.
The best way to use a tractor is to drive it in reverse so that the
driver is looking at the load and the haul system so that he/she can watch
everything closely. A bunch of grunt workers is okay too but I find that the
coordination of and getting everyone to show up for a ten minute job is often
impractical.
The higher on the mast that you have the choker, the more vertical the
mast will hang. Yes, the mast does bang around off of the braces occasionally
but no harm is done and I've rarely had one hang up. Needless to say, ALL
lifts should be done slowly and carefully and if something doesn't look or
feel right, it probably isn't.
Cheers, Steve K7LXC
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