[TowerTalk] Thanks: Rasing fixture strength

Al Williams alwilliams at olywa.net
Fri Aug 19 12:04:18 EDT 2005


----- Original Message ----- 
From: "Al Williams" <alwilliams at olywa.net>
Sent: Thursday, August 18, 2005 9:45 AM
>
> 4. The second leverage is an angular one caused by lifting the load at an
> angle away from vertical.  In this case the height of the raising fixture 
> is
> about the same as the distance from the bottom of the tower that the cable
> is attached resulting in and angle of about 45 degrees.  This means that 
> the
> only .707 of the pull of the cable is applied to lifting the tower.  Also
> .707 of the pull of the cable is applied to trying to pull the tower 
> towards
> the concrete base.  I need some help here.  Does this mean that the 
> leverage
> is 1/.707 or 1/(.707 + .707)?

I meant to say that the leverage of the two pulls have to be taken into 
account (added) but mathematical the formula should have been 1(.707 * 
.707).

Whether the leverage is 1/.707 or 1(.707 * .707) is very puzzling.  If for 
example 1000lb pull at 45 degrees is applied to lift the tower assembly, 
then there is 707 pounds applied to lift the tower and 707 pounds applied to 
pull the tower toward the concrete base.  Adding these two results in 1404 
pounds obtained by only a 1000 pound pull!  If one were to put scales on all 
three places wouldn't
they confirm the above forces.  How can 1404 pounds of pull be generated 
from a 1000 lb pull.  Doesn't that violate the principal of equal and 
opposite forces. Help!?

k7puc 



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