Page 185 - J. C. Turner - History and Science of Knots
P. 185

A  History of  Life Support  Knots          175
             When making a long hoist  by  hand, it is often convenient  to have  a de-
        vice which will automatically hold the load to allow changing the grip or the
         attachment point  of  tackle.  Some of  the friction hitches  have  been  used  for
         this purpose, but they seem to need constant watching.






















         Fig. 49.  Double Italian Hitch   Fig. 50. Alpine Clutch   Fig. 51. Stuflesser Hitch
         Two hitches  that seem to need less attention have been  devised by  climbers:
        the Alpine Clutch (Fig. 50) [13, p. 2441 [14, p.  1371 [29, p. 521 and the Stuflesser
        Hitch  (Fig. 51)  [13, p.  243][14, p.  1381.  Both use a pair  of  karabiners  which
        need  to  be  selected  to have  the  appropriate  size  and  shape.  If  the  end  is
        pulled  in the direction  of  the arrow, the rope will move fairly  freely, though
         the friction developed  will reduce  the efficiency of  any tackle used.  If  the end
        is  released,  the load  pulls  down on the rope, jamming  it; the jam  is  readily
        released  when hauling is resumed.
             The Alpine Clutch, in particular, can be used in the place of a Prusik Hitch
         and sling in a number of  applications  [29, p.  1431, but it must be remembered
        that it works in one way only and the movement of  the rope through the knot
         cannot be reversed  without  a very great degree of  difficulty.


         Other Applications of Life Support Ropes and Knots

         Abseiling has developed as a sport in its own right in some places, though few
         can maintain interest in it for long if  it is not combined with other activities.
         However, abseiling is the major ropework component of  canyoning, a growing
         adventure sport in the French  Alps and Pyrenees, the Spanish Pyrenees,  the
         Australian Blue Mountains  and perhaps elsewhere where appropriate terrain
         exists.  This  sport  involves  following  down  steep and  narrow  watercourses,
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