Superwinch = junk

I've seen pictures of broken tug/barge cables, too. Scary! Those things are BIG!!

That is NOT a 2:1 pull. Not if the two cable sections on the pulled vehicle (in this case, the pulling vehicle, too) don't both go in exactly the same direction. The pull is the combined vector created by the two individual pulls. If the cables go off at 90* from each other, the combined pull is the square root of 2, or 1.414:1. If the cables go off in opposite directions, or 180*, the combined pull on the vehicle is 0. Yes, the individual cables may rip the tow hooks off, but only if a single cable would rip the hook off when pulling in the same direction against a vehicle that was un-movable. (I probably shouldn't have added that last statement. I'm not sure anyone will understand it.) Any winch pull can be easily calculated by combining the vectors of each pulling cable directly or indirectly attached to the pulled vehicle. If you have three pulling cables all going in the same direction (out, around block, back, around block, out, attached) your pull will be 3:1. I don't care how many blocks you have in your rigging, if you only have one pulling cable attached to your vehicle, you have a 1:1 pull. Period. (When I say attached, though, I mean directly attached or indirectly attached (like via a block that is attached to the vehicle) and part of the pulling rigging.)

spam snipped-for-privacy@ev1.net

Umm Dave, look again at my string example.

If your left hand with the end of the string line is the tree or any other 'fixed object' like a tree, then when you loop the string around your foot (pulley on stuck vehicle) and pull 1' with your right hand (the winch), your foot only moves 6".

Mike

Dave Milne wrote:

I'm sorry, Mike. I have a lot of respect for you as an experienced jeeper and a long time member of this group, but you need to brush up on your physics. Especially force vectors. The angle between the two departing forces is the thing. Since the force of each cable is the same as the pulling force of the winch (disregarding losses in the blocks, etc.) the following is true: When the angle between the two cables is 0* (both pulling in the same direction), the pull is 2x the winch pull at 1/2 the speed. When the angle between the two pulling cables is 90*, you have a vectored force of the square root of 2, or 1.414:1 in the direction that is halfway between the two cables (45* from each). When the angle between the two cables attached to the jeep is 180*, there is no effective pull on the jeep and the speed is 0. No matter how much the winch pulls, it is also pulling in the opposite direction equally thus, the jeep sits. I'm not going to argue this any further. Try it yourself and see. I'm not trying to start a fight. I'm just trying to help people understand the effect of pulling with multiple cables.

MAybe next I should ask about the complex differences between the gas pedal and the brake pedal. :-)

You know, Cal, this is the internet and we can't see you - only what you type. Thus, most people wouldn't have any idea that you have a tiny penis and are emibttered toward the world, if only the pent-up hostility didn't ooze out of your every sentence.

Cheer up. Mathematically, half the population is below average.

I don't think that was necessary, Joshua.

Actually, they would.

A jacket laying across a winch cable will be the difference in the broken cable swinging wildly about, or dropping harmlessly to the ground.

I see that, I was assuming (I know, a mistake all the time) that it was a straight line self recovery, not some strange multivehicle snake pit of cables. Sorry.

(so far, the posts I have seen have done well to prove there are good many ways to hurt yourself with a winch... And that is about the only common "thread" in the thread.)

I would have to defer that question to my other half... the woman that confused them, and backed my mog through a pole barn wall.

the mog won...

Unfortunately that's not modelling the situation correctly as the foot doesn't move.

Dave Milne, Scotland '99 TJ 4.0 Sahara

: > look at where the cable ends, and don't be so hasty ! : >

: > Dave Milne, Scotland : > '99 TJ 4.0 Sahara : >

: > : > -- : > : > Dave Milne, Scotland : > : > '99 TJ 4.0 Sahara : > : >

: > : > : > it's a 2:1 ratio, since the cable is hooked back on the driving : > force : > : > : > (truck) the snatch block is not a simple re-vector of the force, : > since : > : > it is : > : > : > going back to the truck. If the cable went though the block, then to : > : > another : > : > : > tree it would be acting as a force vectoring point. Then, and only : > : then : > : > : > would it be a 1:1 ratio. : > : > : >

: > : > : > > The first snatch block is just an angle changer, you can have : > twenty : > : > of : > : > : > > them, but if the end of the cable doesn't hook back on itself, the : > : 20 : > : > : > > blocks will still be 1:1. : > : > : > >

: > : > : > > Mike : > : > : > >

: > : > : > > "L.W.(ßill) Hughes III" wrote: : > : > : > > >

: > : > : > > > The second snatch block would be 4:1 : > : > : > > >

: > : > : > > > Mike Romain wrote: : > : > : > > > >

: > : > : > > > > If they had a second snatch block on the recovered vehicle : > with : > : > the : > : > : > line : > : > : > > > > going back to the tree, then they would have a 2:1 ratio. : > : > : > > > >

: > : > : > > > > Think block and tackle.... : > : > : > > > >

: > : > : > > > > The more pulleys, the more reduction and more you can lift : > : easily, : > : > but : > : > : > > > > you have to have the pulley as an other end of the circuit, : > not : > : > just : > : > : > an : > : > : > > > > angle changer. : > : > : > > > >

: > : > : > > > > Mike : > : > : > > > > 86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00 : > : > : > > > > 88 Cherokee 235 BFG AT's : > : >

: > : >

: > : : > :

Winches scare the bajeezus out of me ! I don't want to be the cheese to the winches cheese-knife :-)

Dave Milne, Scotland '99 TJ 4.0 Sahara

: >

: > Dave Milne, Scotland : > '99 TJ 4.0 Sahara : >

: > : > -- : > : > Dave Milne, Scotland : > : > '99 TJ 4.0 Sahara : > : >

: > : > : > it's a 2:1 ratio, since the cable is hooked back on the driving : > force : > : > : > (truck) the snatch block is not a simple re-vector of the force, : > since : > : > it is : > : > : > going back to the truck. If the cable went though the block, then : to : > : > another : > : > : > tree it would be acting as a force vectoring point. Then, and only : > : then : > : > : > would it be a 1:1 ratio. : > : > : >

: > : > : > > The first snatch block is just an angle changer, you can have : > twenty : > : > of : > : > : > > them, but if the end of the cable doesn't hook back on itself, : the : > : 20 : > : > : > > blocks will still be 1:1. : > : > : > >

: > : > : > > Mike : > : > : > >

: > : > : > > "L.W.(ßill) Hughes III" wrote: : > : > : > > >

: > : > : > > > The second snatch block would be 4:1 : > : > : > > >

: > : > : > > > Mike Romain wrote: : > : > : > > > >

: > : > : > > > > If they had a second snatch block on the recovered vehicle : > with : > : > the : > : > : > line : > : > : > > > > going back to the tree, then they would have a 2:1 ratio. : > : > : > > > >

: > : > : > > > > Think block and tackle.... : > : > : > > > >

: > : > : > > > > The more pulleys, the more reduction and more you can lift : > : easily, : > : > but : > : > : > > > > you have to have the pulley as an other end of the circuit, : > not : > : > just : > : > : > an : > : > : > > > > angle changer. : > : > : > > > >

: > : > : > > > > Mike : > : > : > > > > 86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in : '00 : > : > : > > > > 88 Cherokee 235 BFG AT's : > : >

: > : >

: > : : > : : >

: >

: :

Well, 'let' you freaking foot (stuck vehicle) move then. If it don't move, that stuck vehicle in the swamp ain't moving either... ;-)

Mike

Dave Milne wrote:

nah, the right hand is the stuck vehicle in the example. I really don't see the benefit of this "technique" ; the tree seems irrelevant.

Dave Milne, Scotland '99 TJ 4.0 Sahara

: > Unfortunately that's not modelling the situation correctly as the foot : > doesn't move. : >

: > Dave Milne, Scotland : > '99 TJ 4.0 Sahara : >

: > : > look at where the cable ends, and don't be so hasty ! : > : >

: > : > Dave Milne, Scotland : > : > '99 TJ 4.0 Sahara : > : >

: > : > : > -- : > : > : > Dave Milne, Scotland : > : > : > '99 TJ 4.0 Sahara : > : > : >

: > : > : > : > it's a 2:1 ratio, since the cable is hooked back on the driving : > : > force : > : > : > : > (truck) the snatch block is not a simple re-vector of the force, : > : > since : > : > : > it is : > : > : > : > going back to the truck. If the cable went though the block, : > then to : > : > : > another : > : > : > : > tree it would be acting as a force vectoring point. Then, and : > only : > : > : then : > : > : > : > would it be a 1:1 ratio. : > : > : > : >

: > : > : > : > > The first snatch block is just an angle changer, you can have : > : > twenty : > : > : > of : > : > : > : > > them, but if the end of the cable doesn't hook back on itself, : > the : > : > : 20 : > : > : > : > > blocks will still be 1:1. : > : > : > : > >

: > : > : > : > > Mike : > : > : > : > >

: > : > : > : > > "L.W.(ßill) Hughes III" wrote: : > : > : > : > > >

: > : > : > : > > > The second snatch block would be 4:1 : > : > : > : > > >

: > : > : > : > > > Mike Romain wrote: : > : > : > : > > > >

: > : > : > : > > > > If they had a second snatch block on the recovered vehicle : > : > with : > : > : > the : > : > : > : > line : > : > : > : > > > > going back to the tree, then they would have a 2:1 ratio. : > : > : > : > > > >

: > : > : > : > > > > Think block and tackle.... : > : > : > : > > > >

: > : > : > : > > > > The more pulleys, the more reduction and more you can lift : > : > : easily, : > : > : > but : > : > : > : > > > > you have to have the pulley as an other end of the : > circuit, : > : > not : > : > : > just : > : > : > : > an : > : > : > : > > > > angle changer. : > : > : > : > > > >

: > : > : > : > > > > Mike : > : > : > : > > > > 86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in : > '00 : > : > : > : > > > > 88 Cherokee 235 BFG AT's : > : > : >

: > : > : >

: > : > : : > : > :

Ahhh... Now I understand!

The stuck vehicle was the foot in the example I was referring to....

See:

"The video featured configuration was this:

truck [cableStart] -----> [ snatchblock vehicle] -----> [ tree, cableEnd]"

The truck with the cable start was the winch or your right hand, the tree, cable end is your left hand, the snatchblock vehicle is you foot.

The only advantage for this would be to pull the stuck vehicle out at a different angle than the tow vehicle could line up to with a pull increase of somewhere between a 2:1 and a 1.4 ratio.

Much easier to run the cable to the tree and then to the vehicle which is a 1:1 but even then maybe that tree wasn't in the right place to get the vehicle out safe, so they split the angle difference of the pull.

Mike

Dave Milne wrote:

I for sure missed that part! Actually I didn't, looking back at it, I got it right the first guess, then saw some other drawings and lost it somewhere in there...

My first thought was just an angle changer, but since that made no sense to actually do I figured the stuck vehicle had to be the snatch block one.

That is why I put out the two hands and a foot with a piece of string analogy to see if we were all on the same page.

We obviously weren't.

I thought they were doing some funky 3 point to get something out on a strange angle under extra power....

Yup, that was a total waste of time to hook to the tree, if he wanted the added power from a snatch block, he needed to run the cable back to himself.

He would have done better to have the snatch block vehicle hit it in reverse, then they would only need 3/4 or half the oomph depending on angles to pull him out.

Is this video online anywhere?

No wonder this thread is so damn confusing....

Mike

TJim wrote:

Here ya go. Topic under debate runs from min 4:17 to 9:26

Dave Milne, Scotland '99 TJ 4.0 Sahara

: > Except that the cablestart truck was the one pulling himself out. Instead : > of going through the block to the tree, he could have just as well attached : > his cable to the snatchblock vehicle. The cablestart truck only has one : > cable attached to him (the one from his own winch), so it is a 1:1 pull : > whether he goes directly to the other truck or through 16 snatch blocks to a : > tree behind him. He is still only pulling himself with one winch and one : > cable. : >

: > > The stuck vehicle was the foot in the example I was referring to.... : > >

: > > See: : > >

: > > "The video featured configuration was this: : > >

: > > truck [cableStart] -----> [ snatchblock vehicle] -----> [ tree, : > > cableEnd]" : > >

: > > The truck with the cable start was the winch or your right hand, the : > > tree, cable end is your left hand, the snatchblock vehicle is you foot. : > >

: > > The only advantage for this would be to pull the stuck vehicle out at a : > > different angle than the tow vehicle could line up to with a pull : > > increase of somewhere between a 2:1 and a 1.4 ratio. : > >

: > > Much easier to run the cable to the tree and then to the vehicle which : > > is a 1:1 but even then maybe that tree wasn't in the right place to get : > > the vehicle out safe, so they split the angle difference of the pull. : > >

: > > Mike : > >

: > >

: > > Dave Milne wrote: : > > >

: > > > nah, the right hand is the stuck vehicle in the example. : > > > I really don't see the benefit of this "technique" ; the tree seems : > > > irrelevant. : > > >

: > > > Dave Milne, Scotland : > > > '99 TJ 4.0 Sahara : > > >

: > > > : > Unfortunately that's not modelling the situation correctly as the : > foot : > > > : > doesn't move. : > > > : >

: > > > : > Dave Milne, Scotland : > > > : > '99 TJ 4.0 Sahara : > > > : >

: > > > : > : > look at where the cable ends, and don't be so hasty ! : > > > : > : >

: > > > : > : > Dave Milne, Scotland : > > > : > : > '99 TJ 4.0 Sahara : > > > : > : >

: > > > : > : > : > -- : > > > : > : > : > Dave Milne, Scotland : > > > : > : > : > '99 TJ 4.0 Sahara : > > > : > : > : >

: > > > : > : > : > : > it's a 2:1 ratio, since the cable is hooked back on the : > > > driving : > > > : > : > force : > > > : > : > : > : > (truck) the snatch block is not a simple re-vector of : > the : > > > force, : > > > : > : > since : > > > : > : > : > it is : > > > : > : > : > : > going back to the truck. If the cable went though the : > block, : > > > : > then to : > > > : > : > : > another : > > > : > : > : > : > tree it would be acting as a force vectoring point. : > Then, : > > > and : > > > : > only : > > > : > : > : then : > > > : > : > : > : > would it be a 1:1 ratio. : > > > : > : > : > : >

: > > > : > : > : > : > > The first snatch block is just an angle changer, you : > can : > > > have : > > > : > : > twenty : > > > : > : > : > of : > > > : > : > : > : > > them, but if the end of the cable doesn't hook back on : > > > itself, : > > > : > the : > > > : > : > : 20 : > > > : > : > : > : > > blocks will still be 1:1. : > > > : > : > : > : > >

: > > > : > : > : > : > > Mike : > > > : > : > : > : > >

: > > > : > : > : > : > > "L.W.(ßill) Hughes III" wrote: : > > > : > : > : > : > > >

: > > > : > : > : > : > > > The second snatch block would be 4:1 : > > > : > : > : > : > > >

: > > > : > : > : > : > > > > Think block and tackle.... : > > > : > : > : > : > > > >

: > > > : > : > : > : > > > > The more pulleys, the more reduction and more you : > can : > > > lift : > > > : > : > : easily, : > > > : > : > : > but : > > > : > : > : > : > > > > you have to have the pulley as an other end of the : > > > : > circuit, : > > > : > : > not : > > > : > : > : > just : > > > : > : > : > : > an : > > > : > : > : > : > > > > angle changer. : > > > : > : > : > : > > > >

: > > > : > : > : > : > > > > Mike : > > > : > : > : > : > > > > 86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to : > tail : > > > in : > > > : > '00 : > > > : > : > : > : > > > > 88 Cherokee 235 BFG AT's : > > > : > : > : >

: > > > : > : > : >

: > > > : > : > : : > > > : > : > :

I stand corrected, but I made my point as well...the pulleys in Joshua's example which I illustrated are not force multipliers to the degree he assumed...the range of force mutlipication in that example ranges from 2 to 0, depending on the angles of the lines from and to the vehicle.

• * * Matt Macchiarolo
  formatting link
  formatting link
  formatting link

If there are only two points involved it's easy to figure. The tension on the cable is multiplied by the total number of cable strands running back and forth between the two points.