The Prusik Loop is not only a safety autoblock that could save your life while rappelling, but it’s also a great friction hitch for other purposes.
In addition to showcasing how to tie the knot using a Double Fisherman’s Knot to start, Bryan offers a look at how the knot will fit into our DIY Knot Board Display.
Prusik Loop » Hitches
(Strength: 4/Security: 4/Stability: 4/Difficulty: 4) See below for what these ratings mean.
With a Prusik Knot, it’s important to use the right diameter rope versus the main line you’re attaching it to. It can slip if your cordage is too small of a diameter and you never want to use paracord when using the Prusik Knot as an autoblock. The number of wraps around the main line will determine how tight the grip on the rope will be when loaded and more than three wraps is considered excessive, but you need at least two.
A pull from either direction on the Prusik Loop will cause it to bind, locking the knot. Another great use for the Prusik is ascending a rope, which can be done with two Prusiks. When Prusiking, one Prusik Loop is attached to a climbing harness and another longer Prusik Loop is attached below, that you place a foot into. The technique is to stand up in the foot loop, sliding the harness Prusik up the rope and then sitting down in it. Now just slide the foot Prusik up the rope and repeat.
Depending on the type, some traditional mechanical ascenders can damage a rope and using Prusiks can be a great way avoid that damage by always having a lightweight means of ascending the rope with you. Unlike mechanical ascenders that only grip when downward force is applied, the Prusik can be loaded from either direction to grip.
Ratings
Strength/Security/Stability/Difficulty
Each knot will be assigned a rating from 1-5 (1 representing the lowest score) based on the following four properties:
Strength – All knots will weaken the strength of a rope, however, there are knots that are stronger than others. The scale here will reflect how strong the rope remains with the specified knot.
Security – The security scale refers to how well the knot will stay tied, and resist coming loose under a normal load.
Stability – Stability refers to how easily the knot will come untied under an abnormal load (i.e. the knot being pulled in a direction it was not intended to) A lower score here represents instability.
Difficulty – The lower the number, the easier a knot is to tie.