Page 183 - J. C. Turner "History and Science of Knots"

174 History and Science of Knots

Perhaps the belay system most interesting to knot tiers is the use of a
karabiner with an Italian Hitch (Fig. 48), developed by Miinter in the 1970s.
The karabiner is anchored at the belay point and the rope attached to it as
shown. The rope is paid out in the direction shown by the arrow; the belayer
may need to feed the slack into the knot to minimise the load on the climber.

Fig. 47. Belay Plate Fig. 48. Italian Hitch
If the belayer wants to take in the rope, as would happen if the climber reverses
his moves, the free rope is pulled, the knot capsizes into the reverse formation,
allowing free movement, though again it may be necessary to feed in the slack.
In the event of a fall, the free rope is grasped by the belayer (gloves are
essential!) and, for greater friction, swung forward until nearly parallel with
the live rope leading to the climber. Under ordinary climbing conditions, the
force provided by this knot is about 2.5 kN, providing a valuable lessening
of the shock force. Once the fallen climber is held, the rope may be tied off
with an appropriate hitch. Under some conditions the friction in the knot may
generate enough heat to lightly glaze the nylon sheath of the rope, but this
is in no way dangerous; twists or kinks may also develop in the rope [10, p.
123] [20, p. 35] [29, p. 129]. Greater friction can be obtained by making an
extra turn [25], forming the Double Italian Hitch (Fig. 49).
The Italian Hitch or Double Italian Hitch on a karabiner may also be used
for abseiling or lowering a load [13, p. 236] [25] [27, p. 134], in a similar way to
the descenders; but the twists formed, specially in a long abseil or lower, are
a disadvantage, indeed a danger in some circumstances. It seems best to use
these applications of the knot only when no other method is available. Some
other belay systems can also be used as descenders for abseiling and the like.