Protect Your Posterior with a Prusik

Today we’re talking about how two loops of accessory cord and a locking biner could save your bacon and make you really glad you read this blog; today we're talking about prusiks.

While most sport climbers have got a firm hold of the fundamentals (proper belaying, communication, route cleaning, etc.), many venture out into the mountains without any emergency gear. And we’re not talking space blankets and storm shelters… although those are super useful and you should probably pick them up from your favourite adventure store wink wink. Nope, today we’re talking about how two loops of accessory cord and a locking biner could save your bacon and make you really glad you read this blog.

Let’s get to it.

What is a prusik?

A prusik – named for its inventor, Karl Prusik – is a knot that can be used in a variety of mountaineering applications, particularly those involving self-rescue. In simple terms, a prusik is a friction hitch, i.e. a loop of cord is wrapped around a rope in such a way that it can be ‘locked’ on the rope and adjusted. Thus, the prusik can be used both as protection while rappelling and as an ascension device in the case of a pickle.

Karl Prusik

Fun fact! There are pieces of gear that can function like a prusik, such as the Petzl Tibloc and the Wild Country Ropemans However, it is not recommended that you use these devices as an abseil back-up as this is not what they are designed for and things could easily go wrong.

How do I use a prusik?

Before we go any further, we’ve got to add a very important disclaimer: 

Do not attempt self-rescue or advanced mountaineering techniques without expert, hands-on guidance and thorough practice in a safe environment.

We believe it’s very important to share safety / self-rescue skills and knowledge with the community, because everyone should know how to protect themselves. However, we don’t want anyone to get hurt because they attempt a self-rescue that goes wrong due to lack of proper training and preparation. 

Okay, now that the serious stuff is out of the way – let’s get you radically self-reliant! We’re going to be unpacking one of the above-mentioned prusik applications – abseil safety.

Creating your prusik:

Using a prusik when you’re abseiling is the equivalent of wearing a helmet when sport/trad climbing or using a crash pad while bouldering – i.e. it’s an essential. If you let go of the rope for whatever reason while rappelling (who amongst us hath not tasted the fiery lashings of rope burn?), the prusik will lock on the rope and save you from a potentially fatal fall.

And, once again, all you need is a piece of accessory cord and a locking biner. To create the prusik loop:

  • – Take a piece of rated accessory cord and tie a double fisherman’s knot to create a secure loop.
  • – Create the prusik knot by looping the accessory cord around the rope (both strands) and tying a girth hitch (also known as a lark’s foot)
  • – Then, thread the loop (the side with the fisherman’s knots) through the centre of the girth. Repeat this step another two times to create a three-wrap prusik.
  • – Finally, clip a locking carabiner through the loop of the prusik and attach it to your leg loop (to keep a sufficient distance between your prusik and your belay device). Alternatively, you can use a multi-point personal anchor system to extend the belay device, which enables you to clip the Prusik to your belay loop, as demonstrated by Brigitte in the video.

Now that your backup is set up, you’re ready to ‘seil!

Note: you should only tie and attach your prusik after you have correctly clipped into your abseiling device.

Double fisherman’s knot
How to tie a classic prusik

Abseiling with your prusik:

The core idea of abseiling with a  prusik is to ‘mind’ the knot while you are descending, i.e. you will be moving the knot down the rope with you as you rappel. Although simple, it can take some time to get into the groove of minding your knot – be patient, and practice in a safe environment. 

To mind your knot:

  • – Keep one hand on your ropes and the other on your prusik. 
  • – As you descend, use your hand to gently slide the knot down with you.

This is definitely a ‘show, don’t tell’ kind of thing, so make sure to check out our video for a demonstration and don’t be shy to ask an experienced climber or gear shop assistant to guide you through the process until you feel confident. 

Be patient, ask for help, practice until you can do it in your sleep, take your time out on the rocks… and happy ‘seiling!

To learn how to safely ascend a rope using prusik knots, take a look at pages 79–81of our 2020 How to Climb magazine (available for purchase at the front desk) for detailed instructions and diagrams.

For more safety and self-rescue skills, check out our 2020 Self-Rescue September series: 

The Basics of Self-Rescue

The Basics of Self-Rescue 2

VIDEO: Knots and Prusiks

VIDEO: Up and Down

VIDEO: At the Belay



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