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KA

← Where the theory applies
Bend — two lines

Zeppelin Bend

Wrap stack · Constriction

DiagramsHow to tie it

Does not pick a knot

This page does not pick a knot for you. DNA, molecules, quantum braids and vortices stay off Decide.

Finished structure

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

Failure modes

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

Interlocking-bend family

Two interlocking overhands or a Carrick lattice — tails on the documented sides.

  • !Tails on the wrong sides of the bend
  • !Broken lattice or a reef-knot form in disguise
  • !Undressed so one overhand takes the whole load
Fails when
  • !A working end slides back through the shared hole during tightening, so the knot sets lopsided and has not locked
  • !The loops have the same handedness, which ties Hunter's bend. Animated Knots calls it less satisfactory and hard to tell apart.
  • !One working end goes through only its own loop instead of through both loops, which leaves the knot incomplete
Geometry

  • Both working ends on the same side

    Bend will not lock and spills under load

    The 6 and the 9 must have opposite working ends · step 02

  • One end missing the second loop

    Unfinished 6-and-9 — looks like a sheet bend and will slip

    Each working end must pass through the centre of both loops · step 03

  • Used on a large diameter mismatch

    Thinner rope walks out of the lock

    Similar diameters only; mismatch is a double sheet bend · step 01

If you saw this

  • Bend spills or will not dress into two loops

    Check

    • ?Opposite working ends
    • ?Two interlocked loops

    Then

    • →Retie the 6-and-9
    • →Step to double sheet bend on a mismatch

  • Both working ends on the same side

    Check

    • ?Bend will not lock and spills under load
    • ?Inspect step 02

    Then

    • →Retie. Do not dress a defective structure and call it seated.

  • One end missing the second loop

    Check

    • ?Unfinished 6-and-9 — looks like a sheet bend and will slip
    • ?Inspect step 03

    Then

    • →Retie. Do not dress a defective structure and call it seated.

  • Used on a large diameter mismatch

    Check

    • ?Thinner rope walks out of the lock
    • ?Inspect step 01

    Then

    • →Retie. Do not dress a defective structure and call it seated.
Same family

Same failure class, different geometry. Open the plates — Diagnose still starts from the symptom.

This failed — start Diagnose

What holds it

  • ·A bend captures two working ends. Holding is constriction and the seated wrap or barrel — not a closed-knot invariant.
  • ·Unequal diameters and slick pairs (braid to fluoro) are material problems. Crossing number does not rank FG against a Double Uni.

What topology does not predict

  • ·A Jones polynomial does not pick a braid-to-leader family.
  • ·Published retention bands stay as cited on the knot record. This page does not invent one.
  • ·Guide-click and tag-trim are field geometry, not topology.

Not for

  • ·Attaching a single line to a spar or cleat — that is a hitch
  • ·Reading this page as a recommendation from Decide
  • ·A 10-second join you will cut anyway (sheet bend is faster)
  • ·Extreme diameter mismatch (double sheet bend or splice)

Same pattern, different job

No sourced twin among these knots. Related knots stay on the Library card.

Sources