Knot&Oak
Home How to Tie an Alpine Butterfly Knot
Specimen AB-1 · mid-line loop
Nodus papilio alpinus (the butterfly loop, the lineman’s loop)
A fixed loop tied in the middle of a rope, with no ends needed. Lift a bight, twist it twice, fold the top down and push it up through the bottom, then pull it tight.
The loopKnot bodyLeft legRight leg
Fig. 1 · the loop, the knot body and both legs
Tray 00The whole series
Lift, twist twice, fold down, through and up, pull tight. Watch the whole series once, then take it one specimen at a time.
The stage lights up as the clip reaches it
Tray 01Before you start
The bightLeft legRight leg
Fig. 2 · everything happens in the bight; the legs only lead in and out
Tie it anywhere along a line, even when both ends are tied off or out of reach.
The loop and either leg can each take the pull, so it works as a loop and as part of the line.
The bight you lift sets the loop, and you can draw more through in step 4. A hand’s width suits a carabiner.
Tray 02The series · each clip loops
Specimen 1 of 5 · 6 s clip
Pick up a bight from the middle of the line and lift it straight up, the two legs running out to either side.
Collector’s noteNo ends needed. This works anywhere along the line, even with both ends tied off.
Specimen 2 of 5 · 8 s clip
Twist the bight twice, both times the same way: two crossings stacked one above the other, and three openings, a small one between the legs, one in the middle and the top.
Collector’s noteTwisting the same way both times lines the openings up one above the other.
Specimen 3 of 5 · 7 s clip
Fold the top opening down in front of the twists, hinging it at the upper crossing.
Collector’s noteKeep it in front. It goes back through from the front in the next step.
Specimen 4 of 5 · 9 s clip
Push the folded top back through the lowest opening, between the legs, and draw it up behind the twists. This becomes the loop.
Collector’s noteDraw it through as far as you want the loop to be: a hand’s width is plenty for a carabiner.
Specimen 5 of 5 · 8 s clip
Hold the loop and pull the two legs apart, then pull the loop up, until the twists close into a compact, symmetric knot.
Collector’s noteSnug each of the three parts in turn, so the body sets evenly with no slack turns.
Tray 03Key to identification
Tray 04Field plates
Quick once learned, and handy with gloves on. Practise it beside the twist method: the knot that comes off your hand should look just like the one in step 5.
Found a cut sheath or a core shot partway along a rope? Tie a butterfly so the damaged length sits inside the loop.
The pull now runs leg to leg through the knot body and the loop carries nothing, so the line stays usable until it can be replaced. Clip nothing to that loop.
A loop load pulls the loop against one leg or both: the loop is fixed, so it neither shrinks nor slips.
A ring load pulls the two legs apart, along the line. The butterfly’s symmetric body locks against itself and keeps its shape. End-of-line loops such as the bowline aren’t made for this, and can capsize.
Tray 05Under the loupe
Drag to turn the knot, pinch in on the body, scrub back to any step, or glow the loop to follow the stretch of rope that becomes it through every move.
· Drag to turn · pinch to zoom
Tray 06Habitat
Tie in the middle climber of a three-person rope team, or on a glacier, clipped to the harness with a locking carabiner.
A strong clip-in point anywhere along a line, for gear, a sack or a person, without touching the ends.
A loop in the haul line to clip a pulley, a rope grab or the load to, in a simple hauling system.
Several butterflies along a ridgeline or a fixed line give evenly spaced points to hang gear or clip in to.
Tray 07Take a card
All five steps on one card. Pin it, or keep it with your rope bag for the next time you need a loop in the middle of a line.