On Tue, 09 Sep 2008 17:48:49 GMT, with neither quill nor qualm, "Ivan
Vegvary" quickly quoth:


"Larry Jaques" wrote in message
.. .
On Mon, 08 Sep 2008 23:48:48 -0700, with neither quill nor qualm, JR
North quickly quoth:

I don't kniow what the tensile rating is of the chuck joint, but I bet
it's nowhere near that of a properly swaged coupling.

2,680 pounds weight capacity. I wonder if you're supposed to divide
that by the 4mm opening, which would cut it to 422 lbs. Still, that'd
hold a couple large guys standing on one strand of the railing wire.

Actually, no. When applying force perpendicular to a tight wire, the force
multiplies by a large factor. In a pinch, you can winch a vehicle out of a
tight spot by tightly tying a rope between the vehicle and a tree and
applying force perpendicular to the middle of the rope. Needless to say you
have to take up the slack between each push on the rope.

I don't grok that, Ivan. A pull on the middle of the rope would be
equal on all 3 ends, wouldn't it? Even if it were a nice round pulley,
it would not give you any force increase. The individual snatch
blocks (pulley with a hook) we used on the tow trucks (at Flynn's
Frame and Collision eons ago) would only give us the -same- pull the
winch had, but it would be at a different angle, better for that
particular extraction. Multiple pulleys (forming a block and tackle)
would multiply the force.

If you still disagree, please cite the formula/law for us.

For S&G, I asked the question to the guys at Feeney, the Cable Rail
people. I'll post their answer if/when I get one.

--
"Most Folks Are As Happy As They Make Up Their Minds To Be"
-Abraham Lincoln
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