Usage
The Alpine Butterfly Knot is used to form a fixed loop in the middle of a rope. Tied in the bight, it can be made in a rope without access to either of the ends; this is a distinct advantage when working with long climbing ropes. An excellent mid-line rigging knot, the Alpine Butterfly is easy to inspect for correctness, can be loaded in any direction, and can be easily tied with gloves on (hand method). In a climbing context it is also useful for traverse lines, some anchors, shortening rope slings, and for isolating damaged sections of rope. The knot can typically be used anywhere a fixed loop is called for and is often used as a component of the Trucker's Hitch.
Warning
Verify tying technique with a skilled instructor where knot failure could cause property damage, injury, or death.
History
The earliest known presentation of the knot was in A.A. Burger's 1914 work "
Rope and Its Uses". Burger called the knot a Lineman's Rider stating it was often used by "linemen and especially telephone men". The knot is mentioned in the 1944 Ashley Book of Knots as the Lineman's Loop. The knot's association with mountaineering—and with butterflies—originates from a 1928 article in Alpine Journal by C.E.I. Wright and J.E. Magowan. The authors claim to have developed the butterfly loop themselves while attempting to improve the selection of knots available to climbers. The name is "so styled on the basis of a more or less fanciful resemblance to a butterfly imagined in the form of the knot."
Also known as
- Lineman's Loop
- Butterfly Loop
- Lineman's Rider
ABOK
Structure
The Alpine Butterfly is symmetrical and handles multi-directional loading well. It is relatively easy to untie after loading.
Strength/Reliability
The Alpine Butterfly loop has a high breaking strength and is regarded by mountaineers as one of the strongest knots to attach climbers to the middle of a rope. It also is able to take strain in any direction.
