Figure 1. Detail of the Alpine Butterfly and Figure-of-8 knot combination.
The Alpine Butterfly — the Better Way to join free-hanging fixed ropes
You’ve just knocked off the first four pitches of Tangerine Trip, a popular A2+ trade route on El Cap’s relentlessly overhanging southeast face. Nothin’ left but to enjoy the 350-foot-plus free-hanging rappel back to the talus. With any luck you’ll be at Degnan’s Deli before closing, then back at first light to jug your fixed lines and haul your stuff. Tomorrow you blast off! You tie your fixed ropes together with a standard Figure-of-8 knot and cruise down. You can almost taste the beer as the ground draws closer, but 200 feet off the deck, when it’s time to pass your knot (perhaps the trickiest rope maneuver you’ll ever perform), you realize that you’ve created a monster! Not only is your knot needlessly tough to pass, it’s also going to be a bugger to untie after you’ve welded it by hauling up your pigs up the next morning. The “Better Way” would be a knot that is both easy to undo, and provides the convenience and safety of a separate point of attachment to clip into when passing the knot on free-hanging fixed ropes. What knot is that? It’s the Alpine Butterfly Knot, the same one you use to attach the suspension-point locker atop your haul bag to your haul line. To join your fixed ropes using the Alpine Butterfly, first tie them together with a threaded Figure-of-8. Leave long enough tails so that you can secure the knot by threading the free ends back through the 8. Now take the whole assembly and put it in the middle of the Alpine Butterfly. (See page 138 of Climbing No. 176 for a step-by-step illustration.) The easiest way is to lay the joined ropes on a flat surface (like your partner’s outstretched palms) and put two twists into them to form a “sideways eight.” The secured Figure-of-8 is on one side of the sideways eight, while the two free ends of the ropes are on the other side. Pass the secured 8 around the top of the free ends, then back underneath and up through the hole in the middle (figure 1). Voila! You have now joined your two fixed lines with a knot that is both easy to untie and safe, plus you’ve left a clip-in loop in the middle of the knot with which to back yourself up as you pass your rap device across the knot (Figure 2).
Figure 2. Passing the knot (and untying it later) is a breeze with the Alpine Butterfly.