The double overhand noose is a very secure hitch knot. It might be used by cavers and canyoneers to bind a cow tail or a foot loop to a carabiner.Les longes en spéléologie et descente de canyon
Details
A heavily tightened double overhand noose will jam. The bound object has to be removed before untying.
As the double overhand knot, it neither slips nor turns around. However, a third round turn might be useful with some highly lubricious spectra/nylon ropes.Tom Moyer, Paul Tusting, Chris Harmston,(2000) Comparative Testing of High Strength Cord
See also List of hitch knots List of knots
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