Page 320 - J. C. Turner "History and Science of Knots"
P. 320

Trambles                           311

            Welcome back. You have completed a tramble. This route can, with
       practice, be covered in two minutes or less. Desmond Mandeville did it between
       stations on London's underground train system. And it can be reversed.

       Mapping the Bends

       Desmond Mandeville came to believe that trambles were a serious and sub-
       stantial field of study. He demonstrated many more of them [4], going off in
       all directions over an immense range.
           There are at least a dozen distinct routes from Reef Knot to Granny Knot
       [5, 6]. But there is no direct route, short of untying and starting afresh, from
       the Reef to the common Sheet Bend. Each attempt only produces the left-
       handed (wends opposed) variant. Shaw found this-look back at Fig. 1(a)-
       (b). So the Reef is close-measured in tucks-to some knots, but remote
       from others; although it can be a bridge between seemingly unrelated far-off
       neighbours.
           Bends are not simply strung together like beads; they have cross-linkages
       too. He charted one such network. The map (Fig. 7), based upon the Al-
       phabend, covered a small zone around the full Carrick Bends (Co)(Ca), and
       revealed an almost crystalline symmetry and logic.
       All the knots are reversible. That is, if both stands are shortened to become
       wends (and wends lengthened into stands), a similar knot results. A Reef (R)
       treated this way is another Reef (R'). Similarly G' and J' are bends created
       from G and J, and Hc, Hc' are forms of the half Carrick Bend (#1444). L
       and L', single Carrick Bends (#1445), are in practice identical.
           But swap just ONE stand and wend for a different knot to appear. The
       Reef turns into a Thief (R, T'). Fl is the Flemish or Figure of Eight Bend
       (#1411) and Fl', M', V are derived from Fl, M, V.
           All knots have a mirror-image, and this handedness has to be taken into
       account in trambling. Bends on the left of the chart are left-handed, those on
       the right are right-handed, except for certain neutral ones (R, R'; T, T'; L, L';
       and Fl, Fl').
           Si is the so-called left-handed Sheet Bend (#1432), but the name has
       nothing to do with handedness. It hints at an inferior performance (which irks
       left-handers like me). The basic tramble is shown by a broad line. It does not
       stop at Si or Hc, which are intermediate steps to other bends.
   315   316   317   318   319   320   321   322   323   324   325