Butterfly Bend
bend knot
The alpine butterfly loop's whole reputation rests on tolerating load from unpredictable directions without slipping or distorting - a property that riggers eventually adapted into a bend for joining two ropes, capturing a second rope's end inside the same folded-turn construction that makes the butterfly loop so reliable under off-axis loading.
The method starts identically to tying a standard alpine butterfly loop, but instead of finishing the loop on its own, the second rope's end is threaded through partway and the folding sequence completes around it - interlocking the two ropes rather than producing a free loop.
The payoff is a bend that shares the alpine butterfly's genuine multidirectional load tolerance - useful anywhere the joined ropes might see a load pulling from an angle other than straight along their length, a real limitation of simpler bends like the sheet bend, which are built assuming a more predictable, inline pull.
It remains a specialized, less commonly taught bend precisely because most rope-joining needs don't actually require multidirectional tolerance - a straightforward sheet bend or double fisherman's knot handles the common case fine. The butterfly bend earns its place specifically where load direction genuinely can't be predicted in advance, and it's a knot most people find considerably easier to learn by watching someone tie it than by working from a written description alone.
Rigging crews building a temporary anchor system from multiple rope sections sometimes favor it over the zeppelin bend specifically because the folding technique is already second nature to anyone who regularly ties alpine butterfly loops mid-rope for anchor equalization - learning the bend variant is mostly a matter of adapting a motion already in muscle memory rather than acquiring an entirely new skill from scratch.
Because both ropes are captured inside the same folded-turn structure rather than one rope simply hooking through the other's loop, the finished butterfly bend also tends to sit noticeably bulkier than a sheet bend of comparable rope diameter - a real, felt tradeoff wherever the joint needs to run smoothly through a narrow gap, pulley, or crevice rather than simply hold two ends together in open space.
How to tie the Butterfly Bend
Tie the first stage of an alpine butterfly loop in one rope's end, using its folded-turn method.
Strength & security
Approx. strength retained: 65-75%
Adapting the alpine butterfly loop's folded-turn construction to interlock two ropes rather than form a single loop gives this bend the same multidirectional load tolerance the butterfly loop is known for - a real advantage when the joined ropes might be loaded from an unpredictable angle.
Cautions: It's a less common, more specialized bend than the sheet bend or figure-eight bend, and the folded-turn tying method is one most people find easier to learn hands-on than from a written description alone.
Alternatives
- Zeppelin Bend
Both are less common bends prized for jam resistance and load tolerance; picking one over the other usually just comes down to which folding method a given rope worker finds more intuitive.
FAQ
What makes the butterfly bend different from a sheet bend?
It shares the alpine butterfly loop's ability to tolerate load pulling from unpredictable directions, where a sheet bend assumes a more straightforward, inline pull.
Is the butterfly bend hard to learn?
The folded-turn method is one most people find easier to pick up by watching it tied than by reading a description, similar to the alpine butterfly loop it's derived from.
When would I actually need a multidirectional bend like this?
Whenever the joined ropes might be loaded from an angle other than a straightforward inline pull - a genuine but relatively uncommon situation compared with everyday rope joining.
Does the butterfly bend sit bulkier than a sheet bend?
Yes, noticeably, since both ropes are folded into the same interlocked structure rather than one rope simply hooking through the other's loop - a real consideration if the joint needs to run through a narrow gap or pulley.
Can the butterfly bend join ropes of different diameters?
It works best with ropes of similar diameter, since the folded-turn construction assumes both strands behave similarly through the fold - a sheet bend or its doubled version remains the better choice for a significant size mismatch.
Is the butterfly bend commonly taught in general knot courses?
Rarely as a core skill - most general rope courses stop at the sheet bend and double fisherman's knot, leaving the butterfly bend as something climbers and riggers pick up specifically once they already know the alpine butterfly loop it's derived from.