[Robert A.M. Stephens]

Originally posted by derf
Yup.

Back in high school, we rigged up multiple pulleys with fish scales between them and the bar it was pulling. We also had a fish scale connecting the bar to a fixed point. We were able to see the force applied at each pulley, the force applied to the end of the string and the total force applied to the bar. It was very educational.

In the cited example, if one were to put some way to measure force on all the attachment points, you would find that:

1) each snatch block applied roughly 24,000 pounds of force to the object it was attached to.

2) each end of the cable applied roughly 12,000 pounds of force to the object it was attached to.

Given that the truck had two snatch blocks on it, it would have 48,000 pounds of force applied to it.

Given that the Jeep had 2 cable ends and one snatch block, we would have the other side of that 48,000 pounds of force applied to it.

The forces equal each other so this system can exist in real life.

Q.E.D.

I'll be damned. Thank you.

And then, as in the original pull by using 3 blocks and 4 lines, all blocks static (not traveling, single sheave), what is the rated gross available pull?

Additionally, if you would like to speak with an engineer at The Crosby Group, who I interface with, with their's and other HD industrial products and applications, the contact person and point is here below (a super knowlegeable guy, I might add):

Brad Beall
Product Engineer
bradbeall@thecrosbygroup.com
phone: 918-834-4611 x322
fax: 918-834-9447

And, sadly, I am correct, of you will check and listen to Brad very carefully. I have invited him to post here and verify.

I've also added more information at Behold, here, if this is of interest to you and others:

http://behold-the-rage.com/jeep_page22.html