Trucker's hitch myths

[Tex]

Nobody was ever talking about motion, not beyond steady motion anyway, which is the same as static force, friction aside.  There was no implication of pressure waves being at issue.  I guess I'm just not sure what you're trying to add tos what I've said here.

You said you can count mechanical advantage in a very simple way, but you left out all the details that I spent many words discussing, details which we've now rehashed and now you say, well yes yes, of course that and that.  I'm not arguing that you understand.  I guess you do well enough.  I just, the only take home point I can try to make out is that you were trying to say this is all simple and oversimplified to the point that you can't draw any of the conclusions that I drew.

This isn't quantum gravity, but as knot USE goes, it's quite complicated to the average joe knot tyer and the whole point is that no, it's not just count ropes and 3x is your uncle.

There's an immediately evident caveat, more caveats if you care how tight you can tie it off (like when you're, I don't know, actually using it for a trucker's hitch or improvising and using it in similar but different ways), and more yet if you do something really different like tie it around a sleeping bag.

I would bet that I'm the only person who has ever bothered to calculate the 2 2/3 advantage for the rigid end, single-line tie off.  Is that so simple?

[xarax]

Nobody was ever talking about motion

I was just replying to your comment :

There is no mechanical advantage to a static knot.

Now, when we start pulling the very end of the Tail end..

Then we can start talking about mechanical advantage.

   My bold.
   
   My concern is that over-complexification would do more harm than over-simplification. Knots and knot tying is a simple thing, and perhaps the joy they offer is due to this simplicity, let us try to keep it that way.
   There have been many discussions about calculations of the mechanical advantage in the past in this Forum, which usually lead nowhere. Knot tyers are not interested about the exact mechanical advantage they get, they just want to get some ! 
   Moreover, when we distance ourselves from the "ideal" cases, the complexity of the things jump out of the roof. Nobody can calculate, and predict, the exact mechanical advantage of a real knot mechanism. I have not been able to calculate the mechanical advantage of the beautiful, ingenious Alaskan hitch, and I can not even explain why there is such an advantage there, to anybody ! The first "point"/tip of the Zig Zag can/does slide on the riding turn, and the whole thing gets very complex, even for this so simple knot.
   I had not tried to say something you had not said - and you had not said something the Wikipedia article about the block and tackle mechanism says, either. We always try to re-phrase some things, in our effort to reveal their inner reasoning, and to present them as simply as possible - but not more than that.

[Tex]

None of the things I'm describing dissappear when other complexities play in.  Friction makes it all worse (except for the lock-in and surge effect) but it makes it worse still relative to where you start.

I find it it pretty funny that you want to argue that any statistically unmeasurable change in the strength of the alpine butterfly is important simply because it's there but you think arguing about effects, the least of which is certainly > 1% probably > 5%, that this is well, nobody cares about that.  Maybe nobody cares about truth when its messy.  Anyone can appreciate the assymetry of a knot and "feel" clever for using it the right direction.  REAL gains that are much bigger though, if it takes any thought, nah, those aren't important.

[xarax]

any statistically unmeasurable change in the strength of the alpine butterfly is important

  First, do measure, then, do make statistics, and only at the very end dare to claim that they are "unmeasurable".

  Maybe nobody cares about truth when its messy.

   Perhaps this is a sad truth, but it is a truth nevertheless. Human mind can only appreciate, and enjoy, simple things !
   When something gets very complex, we simply ignore it - or we go the other way, we name it "God', and we worship it ! 

[Dan_Lehman]

Actually.. less than 1:1 IS possible on the 2 rope side of the hitch (zero is possible with infinite friction)!  However the statement as written, reducing from 3:1 down to less than 1:1, still did not make sense.

Rather, I think that in this case one simply doesn't
have a "trucker's hitch" but some other knotted
structure --which might look the same, until what
moves and what doesn't is made perspicuous.
The defining paradigm for the named structure is
that of building something at the end of a line
for the purpose of tightening that line.

--dl*
====

[Tex]

DL In some sense I agree but the point here is that the TH is not a chain hoist. If normal use gives 1.6 then hoisting gives 0.6. But if hoisting something with a rope is what you need, then the TH or similar will do it.  If tossing a rope over a tree works, then tossing it over twice won't work worse.

I'd calling tying a square knot as a bend dumb, but I'd call it a dumb use of a square knot.  This is less physically different even than that example, and probably more useful to.  It's true though that's it's not best use of a TH.

@xarax
You managed to simultaneously blow off intelligent thought and  without solicitation apparently also to needlessly insult religion in the same breath.  That's amusing in a couple of ways, but then the religious views you've expressed are also, well, intriguing.

[xarax]

...without solicitation apparently also to needlessly insult religion. That's amusing in a couple of ways, but then the religious views you've expressed are also, well, intriguing.

  I have never the intention to blame, as "intriguing" or otherwise, in any way, religious views of people ! If I have done it, I sincerely apologize to anybody who might have been offended. And I, myself, had NEVER expressed any religious "views" - only views of knots, on knots !
  Those days I study the temple od Gobekli Tepe (1), which is a monumental, literally and metaphorically, structure, built 12.000 years ago ! ! ! .
   "G?bekli Tepe is regarded as an archaeological discovery of the greatest importance since it could profoundly change the understanding of a crucial stage in the development of human society. "
   As archaeologist / excavator Klaus Schmidt put it, " First came the temple, then the city ."
   We have religious constructions even from the time humans were hunters... This is enough to respect religion - as the age of knotting is enough to respect knots ! 
   ( Unfortunately, Klaus Schmidt died one year ago.... (2))

  1. http://en.wikipedia.org/wiki/G%C3%B6bekli_Tepe
  2. http://en.wikipedia.org/wiki/Klaus_Schmidt_(archaeologist)

[Tex]

I said it was amusing, not that I was offended.  I am not so easily offended. I'll fully trust your word that you didn't mean it to be offensive.  By religion I was jokingly referring to your comments about life being some kind of video game or whatever it was.  No war intended.

[xarax]

   OK, sorry, end of the story.
   Read about Gobekli Tepe. Amazing ! 7.000 years ( SEVEN THAOUSAND ) before Stonehenge...
   50 ( FIFTY ) tons , 7 meters high columns ! Erected by hunter-gatherers... Possibly using ropes and knots ! 

[Tex]

But using which knots?

It's slightly bemusing (I think that rolls off less offensive than amusing, which is what I'm going for) to me to see people worrying too much about who gets credit for a knot.  People have been tying knots for 7,000 years before stone hinge, (you can be certain if they did that, they also tied a knot or two at some point)   and they didn't have TV or smartphones, so what are you gonna do when you're tired and bored after hunting all day and you've got nothing but sticks and ropes and rocks?  What do all of us do?  Pick up the best gadget we have and fiddle with it.  I'm sure every knot (not enourmous tangle, but knot) there is to tie has been tied.  Still we give credit  for discovering things FOR the world.  Cave dude should have carved a picture of his knot, but he probably wasn't worried about getting it named after him.

[xarax]

I'm sure every knot (not enormous tangle, but knot) there is to tie has been tied.

   Do not be sure about that... The number of simple knots ( that is, with few number of crossings ) is enormous, and if you include simple links ( two-rope knots ), the situation gets even worse. There were not so many people living in the planet before 1800, they had not so much free time, and, just as it happens today, I believe that, most of the time, they were tying the SAME knots, over and over again...