Diagram

Alpine Butterfly

Butterfly loop · Lineman's loop

A fixed loop in the middle of a line that can take load on the loop or along the rope from either end. It can also isolate a damaged section of rope inside the loop.

Loop · Intermediate · Polyester / Nylon rope / Polypropylene / Natural fibre / Dyneema / HMPE · 4 steps

Applications How to tie it

Diagram in reviewA drawing of the Alpine Butterfly itself is being made. Until then, follow the written steps.

Finished structure

No drawing of this exact knot yet. The written steps are the reference.

Diagram in reviewA drawing of the Alpine Butterfly itself is being made. Until then, follow the written steps.
Step 01
Wrap the rope twice around your open hand at the spot in the middle of the line where you want the loop. Lay the first turn near your fingertips and the second back near your thumb.
No drawing of this exact knot yet. The written steps are the reference.
You should now see
Two turns around the hand, one lying near the fingertips and one nearer the thumb, with a length of rope hanging off each side of the hand.
If it goes wrong
Wrapping near the end of the line to make an end loop. You will see only a short tail hanging off one side of the hand, where this knot needs rope running out on both sides.
Fix: For a loop at the end of a line, tie a bowline. For a butterfly, move the wraps to the point where the loop is needed so rope runs out on both sides.
Why: The loop can take load along the rope in either direction or at right angles to it, which is why it belongs in the middle of a line. It is also used to isolate a damaged section of rope inside the loop.
Diagram in reviewA drawing of the Alpine Butterfly itself is being made. Until then, follow the written steps.
Step 02
Pick up the turn nearest your fingertips, lift it back over the other two turns toward your wrist, then tuck it under both turns so it comes out past your fingertips.
No drawing of this exact knot yet. The written steps are the reference.
You should now see
The picked-up turn passes over both other turns and back under them, and stands out past your fingertips as a loop.
If it goes wrong
Picking up the turn near the thumb, or laying the lifted turn over the others without tucking it under them. An untucked turn slides straight out when you take the knot off your hand.
Fix: Put the turns back as they were in step 1, pick up the one nearest your fingertips, and take it over both turns and then under both.
Why: The turn you pick up becomes the finished loop. Taking it over and then under the other turns is what binds the wraps into a knot rather than loose coils. Draw it out to roughly the loop size you want.
Diagram in reviewA drawing of the Alpine Butterfly itself is being made. Until then, follow the written steps.
Step 03
Grip the new loop and the turns together with your free hand, then slide everything off the wrapped hand without letting the turns separate.
No drawing of this exact knot yet. The written steps are the reference.
You should now see
A loose but compact knot in your free hand, with the loop sticking out of it and a standing part leaving from each side.
If it goes wrong
Letting the turns spring apart as they come off your fingers, so the tuck slips out of place. You will see loose coils instead of a compact knot.
Fix: If the tuck has come out, rewrap the rope on your hand and repeat steps 1 and 2 rather than trying to rearrange the coils.
Why: Nothing holds the shape yet except the order of the turns. Moving the whole bundle off in one go keeps that order until the knot is pulled tight.
Diagram in reviewA drawing of the Alpine Butterfly itself is being made. Until then, follow the written steps.
Step 04
Hold the loop firmly, over a cleat or in your teeth, and pull the two standing parts hard in opposite directions, then pull the loop again until the knot draws down.
No drawing of this exact knot yet. The written steps are the reference.
You should now see
A compact knot with the loop standing out to one side, the two standing parts leaving in opposite directions, and no movement when you pull all three again.
If it goes wrong
Pulling only the standing parts, or only the loop, so the knot sets twisted with one standing part leaving at an angle. A knot not set on all three parts can change shape under its first real load.
Fix: Loosen the knot, straighten the turns, and pull again on the loop and on both standing parts until it sits square.
Why: Setting the knot on all three parts pulls it into the shape it will hold under load. It stays reasonably easy to undo even after heavy loading.

Failure modes

When this family fails, it fails as these. The recovered end still outranks the name.

Alpine-butterfly family

A mid-line eye that can take load in three directions.

!Twists not nested — the eye distorts under side load
!Tied as an overhand on a bight, which will not take three-way load
!Eye sized after it was already loaded

Fails when

!The lifted turn was laid over the other turns but not tucked under them, so it slides straight out as the knot comes off the hand.
!The turns separated while sliding off the hand and the tuck came out of place, leaving loose coils instead of a knot.
!It was set on only the loop or only the standing parts, so it sits twisted and can change shape under its first real load.

Geometry

Wrong wrap order
Body inverts into a slip loop
Fingertip turn must wrap around the other two before it leaves the hand · step 02
Twisted body never loaded on all three parts
One standing part slips through under load
Dress by pulling the loop and both standings · step 04
Used as an end-loop
Wrong job — a bowline or figure-8 would untie easier
This is a mid-line loop, not an end-eye · step 01

If you saw this

Loop distorts or one standing part slips through
Check
- ?Square body
- ?Loop standing perpendicular
- ?Both standings leaving opposite sides
Then
- →Untie and retie the hand wraps
- →Load all three parts to dress
Wrong wrap order
Check
- ?Body inverts into a slip loop
- ?Inspect step 02
Then
- →Retie. Do not dress a defective structure and call it seated.
Twisted body never loaded on all three parts
Check
- ?One standing part slips through under load
- ?Inspect step 04
Then
- →Retie. Do not dress a defective structure and call it seated.
Used as an end-loop
Check
- ?Wrong job — a bowline or figure-8 would untie easier
- ?Inspect step 01
Then
- →Retie. Do not dress a defective structure and call it seated.

This failed — start Diagnose

Not ideal for

×An end-loop (use bowline / figure-8)
×A loop you will tie and untie every five minutes in stiff hawser

Alpine Butterfly

Not ideal for

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