When I tie a bend I do not recognize, I realize two things : first, that we have too many bends, and too small a brain, which is not evolved to remember complex 1D patterns in 3+1 D space-time ! Second, that I am too old, and if one should really remember all the existing knots, he should learn them at a very early age. With most kids using their cell-phones to find something in the multiplication table, I do not believe we are going to see young boys learning knots any time soon...
When I first tied the bend shown in the attached pictures, I thought that it is too loose to be capable to secure the tails - and that the tension on the standing parts ( that are not interlinked near the axis of the bend ) could spread the two links, and release the grip of the nipping bights on the nipped pair of tails. Well, I was wrong, again. We can never be sure how a knot will behave, so anything we say in advance in not much more than guesses, at best. We have to tie the knot, because, in a simple tangle of ropes, it is unbelievable how much some minor details can make or break its integrity, as we have seen time and again. This knot can be elongated a lot, but its security is not jeopardised in any way. The two tails remain encircled by the two bights, and they do not show any sign of early slippage.
We know that many knots can be tied so that their tying diagrams, their initial, loose forms ( their topology) will remain identical, yet their final, tightened forms ( their geometry ) will be different - and they may differ a lot ! In some cases, the only change is the relative position of the tails, as they exit the knot s nub - the way they cross each other ( the one "over" and the other "under", or vice versa). This "minor" detail is sufficient to force the tightening knot shrink differently, and to settle in a different final form. That is the case with the bend shown in this thread.
It is topologically identical to the Carrick bend, yet the relative position of the tails is different. I had not realized to this day that the exact way tails of the capsised Carrick bend cross each other, can change the final form of the knot so much ! I used to tighten the Carrick bend without paying any attention to the relative position of the tails, so I guess I was tyimg the "other" version all the time - so I had not recognized this bend when I first tied it ! Moreover, I had noticed that the mechanics of the bend were different from most bends I know, so I had not related it with the Carrick bend at all ! ( until Luca mentioned the fact - thanks Luca ).
Now, one may argue that "this one" is the "original" capsised Carrick bend, and " the other one" is the X variation ( X = crossed tails). I have no idea which knot most people tie most of the time, so I only wish to point out the difference here, not to make any suggestions how each of the two knots should be named.
The reader is advised to tie the two capsised Carrick bends on the ends of the same pair of ropes, so he would be able to have them tied side by side on the same material, and examine their differences in detail.
