Bowline on a Bight

An excellent and reliable midline loop.

This is slower to tie than the alpine butterfly but harder to get wrong. We recommend it if you aren’t certain of your ability to correctly remember the alpine butterfly.

Step by step

A single strand of blue rope enters at the top of the image and exits at the bottom. In the middle of the frame, an eighteen inch long bight has been created. The bight extends out to the right and makes a counter-clockwise loop, crossing over itself and leaving a twelve inch tail.

1Make an 18" bight in the middle of the rope.

Make a twist at the beginning of the bight, with the standing part on the bottom of the twist.

The bight comes up through the loop it just created, running toward the top of the image.

2Bring the bight up through the twist.

Right where it teaches the center of the original loop, the bight has been opened up to make a loop. This loop has been flipped over so that it forms a circle around most of the original loop, including all of the rope crossings.

3Expand the bight and open it up, so it makes a large loop around the core of the knot.

The circle made by the bight has now been pulled under the original loop and the vertical parts of the rope, so the midpoint of the circle lies to the left of the vertical parts of the rope. The final effect is that the strand of rope that makes the bight comes out of the original loop, crosses under the top vertical rope, under the bottom vertical rope, and goes back into the original loop.

4Flip the bight underneath the core of the knot, so it goes around the neck of the knot, where it connects to the standing end.

Grasp the strands of rope right before the bight comes out of the original loop and pull on them, pulling most of the bight back out of the original loop and tightening it around the vertical lines. This will create a new loop facing toward the lower right of the image.

5Pull the rope just below the end of the bight, shrinking the bight and creating the final loop.

6Dress the knot.

Notes for nerds

References and naming

This knot is ABOK # 1080

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