Stan Griffiths wrote:
>
> Hi Hans,
>
> I can't disagree with you strongly enough. I'm right, and I know
> it. The question is, what will happen when all you guys who are
> disagreeing with me finally discover that I AM right? Will anyone
> actually admit it?
>
> This is basic high school physics stuff . . .
>
> I am sorry if I insult you, but I am 100% certain of my position on
> this . . .
>
> Stan w7ni@teleport.com
>
> Hans K0HB wrote:
>
> > On Friday, April 02, 1999 7:37 PM, Stan Griffiths
> > [SMTP:w7ni@teleport.com] wrote:
> >
> > > Here is what you are missing: The gin pole has to support
> > > TWICE the weight of the load since the load pulls down on
> > > one side of the gin pole and the rope you are pulling on to
> > > raise the load is pulling down on the other side of the gin
> > > pole. The gin pole sees both of these down pulls and has to
> > > hold them BOTH, or twice the weight of the load.
> >
> > >
> > > By using a block and tackle, you can reduce the pull on the
> > > rope you are using to lift the load. If you use a 3 to 1
> > > block and tackle, you reduce the pulling force to 1/3 of the
> > > weight and reduce the total load carried by the gin pole.
> >
> > > Here is an example:
> > >
> > > Supposing your big mast weights 200 pounds. Pulling it up
> > > with a normal gin pole with nothing but a pully at the top
> > > means it must support 400 pounds. If you use a block and
> > > tackle, you can cut the pulling force
> > > down to 67 pounds and the gin pole now has to support only
> > > 267 pounds instead of 400 pounds.
> >
> > Wrong. Just plain wrong. While the block and tackle gives
> > you a mechanical advantage, the gin pole is carrying
> > *only* the weight of the antenna (200 pounds), either with
> > a single pulley at the top, or with the multiple pulley
> > arrangement of the block and tackle. In fact, the added
> > weight of the extra pulleys and rope places a greater
> > strain on the gin pole than just a single pulley at the
> > top.
> >
> > 73, Hans, K0HB
Hi Hans,
I can't disagree with you strongly enough. I'm right, and I
know
it. The question is, what will happen when all you guys who
are
disagreeing with me finally discover that I AM right? Will
anyone
actually admit it?
This is basic high school physics stuff . . .
I am sorry if I insult you, but I am 100% certain of my
position on
this . . .
Stan w7ni@teleport.com
Hans K0HB wrote:
> On Friday, April 02, 1999 7:37 PM, Stan Griffiths
> [SMTP:w7ni@teleport.com] wrote:
>
> > Here is what you are missing: The gin pole has to support
> > TWICE the weight of the load since the load pulls down on
> > one side of the gin pole and the rope you are pulling on to
> > raise the load is pulling down on the other side of the gin
> > pole. The gin pole sees both of these down pulls and has to
> > hold them BOTH, or twice the weight of the load.
>
> >
> > By using a block and tackle, you can reduce the pull on the
> > rope you are using to lift the load. If you use a 3 to 1
> > block and tackle, you reduce the pulling force to 1/3 of the
> > weight and reduce the total load carried by the gin pole.
>
> > Here is an example:
> >
> > Supposing your big mast weights 200 pounds. Pulling it up
> > with a normal gin pole with nothing but a pully at the top
> > means it must support 400 pounds. If you use a block and
> > tackle, you can cut the pulling force
> > down to 67 pounds and the gin pole now has to support only
> > 267 pounds instead of 400 pounds.
>
> Wrong. Just plain wrong. While the block and tackle gives
> you a mechanical advantage, the gin pole is carrying
> *only* the weight of the antenna (200 pounds), either with
> a single pulley at the top, or with the multiple pulley
> arrangement of the block and tackle. In fact, the added
> weight of the extra pulleys and rope places a greater
> strain on the gin pole than just a single pulley at the
> top.
>
> 73, Hans, K0HB
--
FAQ on WWW: http://www.contesting.com/towertalkfaq.html
Submissions: towertalk@contesting.com
Administrative requests: towertalk-REQUEST@contesting.com
Problems: owner-towertalk@contesting.com
Search: http://www.contesting.com/km9p/search.htm
|