The Rover-Landers of BC

I went to this site and couldn't believe the missunderstanding about mechanical advantage and winching. The main person in the thread is a rigger, who does this sort of thing (rigging) for a living. He HAS IT WRONG, and he even has an engineer agreeing with him.

Makes me want to open a winching school. YES, a pulley on a tree with the line going back to the vehicle with the winch on it, DOES increase the strength of the pull. Theoreticly by 2. Start with that as FACT then go here and read the thread. http://www.landroversonly.com/forums/sh ... php?t=5684

If you go to the Ramsey site mentioned in one of the postings, the 3 part recovery technique does work and make scense but they didn't explain or demonstrate enough of the theory. Their example looks like they are putting 140% of the load on the pulley & redirect truck when in fact they should be setting it up to reduce the load on the redirect, doesn't look like they are though.

Oh boy, I could hardly restrain myself from wading in...

FrankS and his pals need to use the SOP method...

Tie a rope to the seat of pants of your 200 pound friend, then through a snatch block hanging from the garage roof, and down to your hand. Now pull. MA=1.

Now tie the same rope to the seat of your own pants, and you will find when you pull, its much easier to pull yourself up. MA=2.

That's how I've always understood it, but do we really want to get the same thread rolling over here? :wink:

Dave

Wow... what an exhaustive discussion on the other web-board about the winching topic. Seems to me that some of them are forgetting the difference between the snatch block as a leading block (redirecting the the line with no mechanical advantage) and using the snatch block as a standing block (with mechanical advantage) attached to the load AND the pull as one unit, reducing the movement (and the effort) by about half. The rope to the pants is a good illustration... though you'll eventually wind-up hanging with your butt in mid-air!

Funny thing though... I didn't see any discussion about the mechanical DISADVANTAGE when the dam cable is two feet too short to reach the nearest tree!

Rob
83 88
88 RR
both winchless :cry:

Oh, Man, don't debates over simple concepts drive you crazy. Kind of like arguing over the last year of the millenium, the one thousand nine hundred and ninety-ninth year vs. the two thousandth year. Hello :roll: should be simple you'd think. Maybe this rigger and the engineer are both veterans of the Ironworkers Memorial Bridge design team. No disrespect intended to those who lost their lives as a result of such misunderstandings. God help us.

That is funny. It is rare that people don't understand that simple one.

Now this one confuses people. Pulling yourself backwards.
http://i2.photobucket.com/albums/y45/Re ... gnback.jpg

Hmmm.... depending on the power of the winch this might be a good way to stretch an 88 into a 109!

I wondered if you could pull yourself backward but have never really tried to figure it out. Thanks for the tip!

Now if I can only find a couple more pullies.

So---- how do I rigg to keep from sliding down a side-hill? Is there a trick or do you just go forward and to a high-side pulley, to a rear, high-side pulley, and then drive? Snug the winch a couple times to keep the tension on?