Page 52 - Nate Fitch, Ron Funderburke "Climbing Knots"

Bowline with a Bight

It is particularly advantageous to know how to tie a
bowline with a bight of rope. In the construction of
many anchors, the rope end may be preoccupied, so
the anchor may need to be tied around objects with
a remaining bight of rope. It is also commonly the
case that a bowline with a bight proves to be more
durable when tied around abrasive objects because
two strands of rope end up rubbing against the object
instead of one.
Properties: A bowline with a bight can be
regarded as having twice the strength of a bowline in
a single strand. It is weakening the material strength
of two strands of rope instead of just one. Similarly,
its security and failure mechanisms mirror those of
the bowline in a single strand, but twice the load is
needed to create those failures and insecurities. As
a result, it is just as important to tie a backup knot.
In terms of efficiency, the bowline with a bight uses
twice as much material to circumnavigate an object as
a bowline with a rope end.

Essentially a
bowline with two
strands of material,
a bowline with a
bight is a redundant
knot with twice
the strength of
its single-strand
counterpart.
Tying the Rope to Other Things 39