Uses of the butterfly knot

The butterfly knot is generally not one of the standard climbing knots beginners learn, but it’s well worth learning once you have mastered the basics. It’s useful for several things.

1. It’s the best tie in knot for the middle members on a rope team climb. While a figure eight on a bight is acceptable for this middle person tie in, it’s designed to be weighted in only one direction. The butterfly is designed for the rope to be weighted in on either strand.  As the middle person on a rope team, you do not know which strand will hold you in a crevasse fall.
2. The butterfly is generally easier to untie after it’s been weighted.  Use it anytime you are significantly weighting a loop of rope (like fixing ropes for a big wall, or tying off one end of rope for snow anchor testing or crevasse rescue practice.)
3. A great time to pull the butterfly out of your bag of tricks is if you need to isolate a damaged part of the rope. Through stepping on the rope with a crampon, an ice tool puncture or maybe rock fall, a rope might get damaged so you are not comfortable using it anymore. Without knowing the butterfly, you’d have to cut off the damaged part and hope you have enough cord to continue the climb. With the butterfly, just isolate the damaged part of the rope inside a loop of the knot and you’re good to go, with a near full strength rope. (Now you need to figure out how to pass the knot while you are on rappel or belaying . . . but that’s a different topic!)