Towards a Taxonomy of Manoeuvre Part 1 by fdh56iuoui


									                     Towards a Taxonomy of Manoeuvre: Part 1
                       Michael Ketemer with thanks to Doug Gifford for suggestions and graphics.
Since the object of Canadian style pad-         tially hazardous craft. The only way to          Manoeuvre Definitions
dling is the performance of manoeuvres,         sensitize others to the beauty of a canoe’s      All manoeuvres can be defined in terms
two questions come to mind - how many           movement is to present only the move-            of the following distinctions:
types of manoeuvre are there, and how           ment of the canoe. It is perhaps best to         1. Does the pivot point move?
may they be classified? These are not idle      keep stunts and paddling two separate            2. If the pivot point moves, is the path of
questions. An examination of the taxon-         disciplines for the time being, pending              the pivot point curved? Note that if the
omy of manoeuvre has implications for           wider acceptance of artsy paddling for its           path curves, further differentiation of
the terminology used to describe man-           own sake.                                            the curves could occur at a lower taxo-
oeuvre and communicate about it. Most               What, then, do we mean by                        nomic level (e.g., spiral, cycloid, para-
importantly, classification of manoeuvres      ‘manoeuvre’? In the real world, there is lit-         bola, hyperbola, etc.), but these taxa
by their geometry provides an analytical        erally an infinity of possible movements             would define only the rate of curva-
tool for the paddler: the geometry of a         of a canoe on the two-dimensional water-             ture as a new variable.
manoeuvre determines the options avail-         plane, so it would take quite a long time        3. Does the canoe rotate around the pivot
able for application of forces to effect that   for the ambitious style paddler to perform           point? Geometrically, the question is
manoeuvre.                                      every possible movement. However, one                expressed: is the manoeuvre a transla-
    This is important since perhaps the sin-    should most definitely applaud this ambi-            tion (every point of the canoe moves
gle major cause of difficulty in learning to    tion: the essential attitude of the style pad-       through the waterplane an equal dis-
perform a manoeuvre is the failure to visu-     dler is to try to exhaust the possibilities of       tance in the same direction) or is the
alize in one’s mind’s eye a clearly defined     the canoe for movement.                              motion angular (not all points of the
image of the pattern of movement of the             Fortunately, we can reduce the infinity          canoe travel equal distances, i.e., the
canoe. It is important to use easily under-     of possible manoeuvres considerably—in               canoe rotates during the manoeuvre)?
stood, yet precise and unambiguous              fact, to thirteen. By abstracting we can         4. Does the pivot rate equal the curve
terms to describe a boat’s motion when          define classes of manoeuvres which share             rate? This differentiates between
teaching, and especially when arguing           the same type of motion. An example is               straight lines and line pivots (no curve
technique with other paddlers. Another          the circle turn: it doesn’t matter whether           and some pivot), curve turns and
benefit of this kind of study is that it can    the circle is ten metres or fifty metres in          curve translations (some curve and no
be seen that there are several advanced         diameter, the geometry of the manoeuvre              pivot) and curve turns and curve piv-
manoeuvres which no-one to the author’s         remains the same (and by extension, the              ots (where the canoe is pivoting at a
knowledge has yet performed, because            placement and direction of forces                    different rate than it is curving).
there was no easy and systematic way to         required to perform the circles are similar,         By examining the combinations of the
conceive of them.                               though their magnitudes will differ). In         cases given above, a table of all possible
                                                the same way, if one paddles a canoe             manoeuvres can be developed. All of the
The Manoeuvre                                   diagonally it doesn’t matter whether the         distinctions can be expressed as a binary
A hierarchical taxonomy of manoeuvre hull is at an angle of 45 degrees or 60                     opposition; either the characteristic is
must firstly define manoeuvre as a subset degrees to the line of travel; each are mem-           there or else it isn’t. Thus we derive seven
of all possible activities performable by a bers of the same class of manoeuvre.                 basic manoeuvres: stationary, pivot,
canoeist. Besides the manoeuvre, which is                                                        straight line, line pivot, curve translation,
defined in terms of the movement of a Manoeuvre and Routine                                      curve turn, curve pivot.
canoe-shaped figure on the waterplane, We can reduce the number of possible                          In addition, we can further divide the
there are other possible classes of things manoeuvres considerably by recognizing                line and curve by the angle of the boat rel-
to do in a canoe: pastimes such as sleep- that manoeuvres can be linked to form                  ative to its direction of travel and the
ing, courtship, break dancing or diamond routines. For instance, a S-turn is a com-              curve pivot by the relation of its pivot to
cutting; and stunts, which include gun- pound manoeuvre comprised of an inside                   its curve for a total of thirteen theoretical-
wale bobbing, thwart jumping, hand- turn and an outside turn linked. All man-                    ly possible manoeuvres. Figure 1 shows
stands on the thwart, Eskimo rolling and oeuvres by definition can continue indefi-              the binary table and illustrations of the
the like. Although these are valid uses of nitely. The transition between man-                   thirteen basic manoeuvres.
the recreational canoe, pastimes and oeuvres is termed the change-up. The                            Note that this terminology differs from
stunts, however well executed, should notion of the change-up is important in                    standard ORCA usage, but is much more
not be confused with the manoeuvre, practice, for it is at these points that the                 logical (ORCA terminology has some glit-
which is the object of Canadian flatwater paddler must apply a different set of for-             ches: why is going sideways called a dis-
Canadian style paddling. Paddlers who ces on the canoe. Since the state of motion-               placement, and other movements are not?
think that a one-handed handstand on the lessness is defined as a manoeuvre, stops               Why is there no actual turn in a stop turn
bow deck is an impressive demonstration can be seen as a species of change-up.                   as defined by ORCA?).
of ability are right: but is it paddling? Pad-      So then, our basic taxonomic unit (tax-          So far we have covered the motion of
dlers should consider that stunts included on) is the manoeuvre. Manoeuvres can be               an idealized canoe on a flat surface. In
in performance merely reinforce the popu- linked by change-ups to form routines.                 part two we will add a paddler.
lar perception of a canoe as a tippy, poten-
                                                                                                                                                       Solo Canoe Manoeuvres

                                                                                Does the pivot rate equal the curve rate?
      Does the pivot point move?

                                                         Does the boat pivot?
                                   Is the path curved?

1     no                           —                     no                     —                                           stationary
2     no                           —                     yes                    —                                           pivot
3a    yes                          no                    no                     yes                                         straight line                                    7c
  b                                                                                                                         diagonal line
  c                                                                                                                         sideways line
4     yes                          no                    yes                    no                                          line pivot
5     yes                          yes                   no                     no                                          curve translation
6a    yes                          yes                   yes                    yes                                         curve turn
  b                                                                                                                         diagonal curve
  c                                                                                                                         pinwheel
7a    yes                          yes                   yes                    no                                          curve pivot a: pivot rate > curve rate
  b                                                                                                                         curve pivot b: pivot rate < curve rate
  c                                                                                                                         curve pivot c: pivot direction ≠ curve direction




                                   7a                                                                                              2




                  Towards a Taxonomy of Manoeuvre: Part 2
           Michael Ketemer with thanks to Doug Gifford for suggestions and graphics

   Last issue we dealt with the             forward/backward and inside/outside.          forward and outside backward. To
movements of an idealized canoe shape       Forward and backward are easily               specify a manoeuvre in the real world,
on a plane. By working through a            grasped descriptors. Inside and outside       the use of the full manoeuvre definition
binary table of possibilities, we came up   can refer to three things. They can refer     (e.g. inside line pivot) is required.
with thirteen basic manoeuvres.             to the paddler’s side in linear                  The thirty-seven subclasses
   By placing a paddler in the canoe,       motion—if the paddler is moving the           generated by the application of these
several other directional descriptors can   canoe in the direction of his/her             descriptors to the basic thirteen classes
be generated to describe the motion of      paddling side, that motion is termed a        are illustrated below and on the next
the canoe in terms of the paddler’s         inside sideways line. Inside and outside      page.
orientation in the boat. The use of these   also refer to the paddler’s paddling side        Any manoeuvre can move into any
terms is rationalized by the fact that a    in a curve: if the paddler is doing a         other through a change-up. By
canoe shape viewed in plan is               circle with his/her paddling side on the      combining maneuvres, we can construct
organized around two axes, the              inside of the circle, then that circle is     routines.
centreline and a transverse axis which      termed an inside curve turn. Pivoting so         Note that all “manoeuvres”
divides the canoe in fore and aft.          that one’s bow rotates towards one’s          previously defined in the literature are
Putting a paddler amidships gives us        paddling side is termed an inside pivot.      subsumed under these subclasses (e.g.,
terms for the motion of the canoe which        Application of these descriptors will      what the rest of the world calls a stop
can be stated in terms relative to the      define a number of subclasses of each of      turn under this schema is a line pivot
paddler’s body, which displays              the basic thirteen manoeuvres, with the       that changes up to a stop), and that
analogous organization into quarters        several directions relative to the            there are several manoeuvres which
(anterior/posterior and left and right)     paddler in which the manoeuvre can be         have not—to my
when viewed in plan.                        performed. For instance, one can paddle       knowledge—previously been defined
   The two pairs of descriptors which       a canoe in a straight line forward or         or attempted (the curve pivot).
categorize manoeuvre in terms of the        backward; a circle turn can be inside
paddler’s orientation are                   forward, inside backward, outside

              1: stationary              2: pivot                                 4: line pivot




                       3a: straight line                                        3b: diagonal line
                                                                                        inside forward
                                                                                    inside backward
                      3c: sideways line

                                                                                   outside backward

                                                                                   outside backward
                          Solo Canoe Manoeuvres: Curves

                   6a: curve turn                                             6b: diagonal curve

                    f o r w a r d i n si d e                                  -in bac
                                                                                      k    w a r d o u t si d e
                 back w a
                             rd outside
                                                                              -i    n b a c k w a r d i n si d e
                    forw ard outside

                   back w ard inside                                       stern
                                                                                    -i n f o r w a r d i n si d e

                                                                                   -in forward outside
                    6c: pinwheel

                         bow-in inside                                       bow
                                                                                   -in backward inside

                    stern-in inside                                                -in backward outside

                                                                           stern                                    e
                                                                                 -i n    forward outsid
                     bow-in outside
                                                                                 in forward inside
                    stern-in outside

                                                                       e     pivot b: pivot rate<curve
               5: curve translation                                curv                                                 rate

        w ar                                      )                  insid                                t
               d out                  ide                                    e forwa                pi v o
                    side (backward ins                                              rd curve/inside

                                                       )                  ide fo                        ivot
       w ar
              d i n si                      ts                                     rward curve/outside p
                         de (back w ard o u

        e      pivot a: pivot rate>curve                                  ot c: pivot direction ≠ curv
    curv                                          r at e            ve piv                             e di
7a:                                                              cur                                        r ec
                                                           ≠ 7c:                                                 ti o

              e forw                     ivot                        insi
                                                                         d                                          ivot
                       ard curve/inside p                                    e forw
                                                                                      ard curve/outside p

          ide fo                        ivot                          outs
                   rward curve/outside p                                  ide fo
                                                                                      rward curve/inside piv

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