International Guild of Knot Tyers Forum

General => Knotting Concepts & Explorations => Topic started by: xarax on October 10, 2014, 02:14:40 PM

Title: ABoK#1445 and its reverse
Post by: xarax on October 10, 2014, 02:14:40 PM
   Ashley calls this bend " The worst Single Carrick bend ", and he does not show its reverse. Miles spents a whole chapter discussing its symmetries ( rather, its asymmetries...  :)) ( M. ch.7.2. p. 137 ), and he calls it " Lesser Carrick bend ". Asher whimsically calls it " Boobash bend " ( KM 11, 1985, p.16-17 )
   However, as anybody can realize by himself in an instance, if this bend is properly dressed and pre-tightened ( or, of course, if it is seized, but let us not discuss this option here ) it becomes a quite secure compact bend - the smallest bend there is !
   The question is : Which of the two forms, the "normal", loaded as Ashley shows, or the "reverse" ( where the Standing and the Tail Ends of the "lower" link are swapped ) is the safest ? Which slips less, if heavily loaded - because, as they are obviously different, they should behave differently, and this difference will manifest itself during heavier loadings.
   If we learn which slips less, then we will be able to find an ad hoc "explanation" of the fact - because I can not see any way to predict the outcome of such a test, or to think about how this supposedly most simple mechanism really works ! That is telling of how inadequately we can "analyse" even the most "elementary" knots...

P.S. The simplest / dumbest way to tie those bends I always follow, is to first tie the Granny and the Grief / Whatknot knots, to which we are more accustomed, and then un-tuck the "over" or the "under" leg of the one link, and re-tuck it through the same opening of the other link, but now going "under" or over", respectably, of the other leg.
Title: Re: ABoK#1445 and its reverse
Post by: xarax on January 30, 2015, 08:32:20 PM
   I have noticed that the two links of the ( not seized ) ABoK#1445 Carrick bend, when heavily loaded, tend to behave differently : the inclination of the planes of the interlocked bights in relation to the axis of loading is different. At the loaded knot, for some reason I, for one, do not understand, the angle between the plane of the "lower" link ( as shown in Ashley s image ) is somewhat larger than the corresponding very small angle of the "upper" link. This tells me that, in fact, this bend is not symmetric. One could claim that this should have been anticipated, as the continuations of the Standing Ends follow different paths into the knot s nub. At the tips of the bights, the first curves, the continuation of the Standing End of the "lower" link meet first the Tail End of the other link, and then its Standing Part, while for the continuation of the Standing End of the "upper" link the situation is reversed. Well, I knew in advance that the angles would differ, but I could not imagine which one would be the greater - actually, I would had bet on the angle of the "upper" link.
   Is this asymmetry which makes this bend much more stable and secure than Ashley had thought ? Who knows ?