Page 26 - D. Raleigh "Knots and ropes for climbers"

Alpine Butterfly Knot or Austrian guideman

Alpine Butterfly Knot

Like canned food and satellite TV, this knot originated in war, where it was used to join man to rope so
he could drag cannons through bogs. In peacetime, this Alpine Butterfly Knot, or Lineman's Loop (on
old), is useful to the climber wishing to anchor himself to the middle of the rope, a common practice in
glacier travel. To do so, clip yourself to the knot with two carabiners that have their gates reversed and
opposed. In the ideal scenario, one of the carabiners will be locking. You may also use this knot to tie
out a damaged section of rope; just know that the knot won't slide through your protection or rappel
device.

Common Uses
Middleman's tie-in knot
Tying out damaged section of rope

Square Fisherman's

The maxim of rope strength states that the strength of a knot depends on the ease of its curves. In
simpler terms, all this really means is that knots with sharp turns are weaker than those that make
gradual bends. That said, the Square Knot, which bends a sharp 45 degrees not once but four times, is
about the weakest knot you can tie. I've heard that the Square Knot retains only 45 percent of a rope's
strength, whereas other knots such as the Double Bowline retain 75 percent. Besides being hopelessly
weak, the Square Knot is also easy to tie wrong. Reverse one of the crossing passes, and the knot will
hold just long enough to get you into troubleor killed.

You would think, then, that the Square Knot's crippling flaws would preclude it from climbing. They
do, but a variation, the Square Fisherman's, works well to join two rappel lines. Used for this purpose,
the knot is easy to untie when you're finished, and it's safe provided you leave long tails and anchor
these with a Double Fisherman's backup. Do not use the Square Knot without the backup knots.