Stopper (knot)

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An Ashley stopper knot at the end of a line

The term stopper knot (or simply stopper) has three distinct meanings in the context of knotting and cordage.

At the end of a line

A stopper knot is tied at the end of a rope to prevent the end from unraveling, slipping through another knot, or passing back through a hole, block, or belay/rappel device. Knots commonly used for this purpose are:

• Overhand knot
• Double overhand knot
• Figure-of-eight knot
• Stevedore knot
• Ashley's stopper knot

Around the standing part

A Flemish bend stopped (or "backed up") with a double overhand knot around each standing part

When a stopper knot is tied outside another knot and around the standing part it can also be called a backup knot. Tying the end around the standing part helps prevent the knot from unraveling by not allowing the end to slide back into the knot. Examples of this usage are often seen in climbing, rope rescue, and other safety-of-life situations. The most common knots used for this purpose are:

• Overhand knot
• Double overhand knot / Strangle knot

Nautical usage

In nautical settings a stopper may refer to a length of rope that is belayed on one end with the other end attached to a tensioned line with a friction hitch to prevent the tensioned line from slipping under load. For example if a sheet becomes jammed on a winch while under sail, a "stopper" can be used to temporarily take the strain off the winch while the riding turn is cleared. The knots commonly used for this are:

• Rolling hitch
• Other similar friction hitches