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Stopper

Figure-8 Stopper

Jam · Climbing

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.

Figure-8 Stopper, finishedFigure-8 Stopper, finished

Finished structure

Drawn from a rope model of this knot: which strand passes over which comes from where the rope actually lies.

Failure modes

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

Stopper family

Bulk at the tail, larger than the opening — not a join.

  • !Body smaller than the block or fairlead after dress
  • !Asked to join two ropes
  • !Figure-8 used in HMPE where Estar extra turns were the stopper, or Ashley left as a two-lobe overhand
Fails when
  • !The set knot is smaller than the opening in the block or fairlead, so it pulls through under load
  • !It is set loosely enough to squeeze into the opening
  • !The tail is shorter than a hand's length, so the knot capsizes or shakes out on a flogging line
  • !It is left unchecked on a working line. Animated Knots notes a figure-eight can occasionally come undone.
Geometry

  • Overhand instead of a figure-eight

    Jammier stopper, harder to inspect

    The eight is the hitch · step 01

  • Undersized or loose eight

    Pulls through the block

    Size after dress is the job · step 03

  • Asked to join two ropes

    A stopper is not a bend

    Pick a sheet bend or Zeppelin if you needed a join · step 04

If you saw this

  • Stopper pulls through the block

    Check

    • ?Compact eight larger than the opening

    Then

    • →Retie larger
    • →Do not substitute an unfinished overhand on a running sheet

  • Overhand instead of a figure-eight

    Check

    • ?Jammier stopper, harder to inspect
    • ?Inspect step 01

    Then

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

  • Undersized or loose eight

    Check

    • ?Pulls through the block
    • ?Inspect step 03

    Then

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

  • Asked to join two ropes

    Check

    • ?A stopper is not a bend
    • ?Inspect step 04

    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 stopper is a bulk knot. It bears on a hole, a device, or the hand (heaving line).
  • ·Figure-eight stopper and figure-eight loop share a body and split a job. That is a family identity, not a rating.

What topology does not predict

  • ·Bulk vs security on HMPE is material. EStar exists because figure-eight can walk on slick line — that is cited practice, not an invariant.
  • ·Heaving-line mass is a throwing job, not a topological one.
  • ·No strength retention is computed here.

Not for

  • ·Joining two ropes
  • ·A load-bearing eye
  • ·Any load-bearing join
  • ·A stopper that must be tiny (use an overhand, knowing it jams harder)

Same pattern, different job

Sources