Prusiking is going back up the rope, and is necessary in most vertical caves in Australia. There is the odd gem of a cave where you can do what’s known as a ’through-trip’, abseiling in a higher entrance and walking out a lower one after a series of abseils. These are to be savoured where you find them, as they are the exception rather than the norm. To go back up, we use mechanical ascenders rather than the prusik loops the technique is named after, as they’re far, far more efficient and easier to use. It still requires some stamina (as you’re fighting against gravity), but more important is technique, and we have weekly SRT sessions for members to refine that in.
Getting on rope for a prusik is more simple than for abseiling, as you’re usually standing up at the bottom of a pitch. The main safety concern is that once you start prusiking you maintain at least two points of contact with the rope at all times- your two ascenders. NEVER prusik with only one ascender, as not only is it inefficient, but you’re entirely reliant on that one device for your safety…
Anyway, the description below is for a frog system with two ascenders (hand and chest), which is the standard SRT setup for cavers in Australia. Europeans also use the frog system, but add an extra ascender on their foot; Americans use a completely different system called ropewalking.
- Approach the rope. You want to be as high up as you can get safely and easily to minimise the amount of prusiking you have to do, but don’t compromise safety to save a few metres. It’s NOT customary to shout “ON ROPE” when you start heading up, unless you think the people at the top of the pitch really need to know that you’re on your way up (for instance, if there was a lot of loose debris at the top of the pitch)
- Attach your chest ascender to the rope. You do this by pulling down then out on the tab of the cam on the chest ascender, slotting the rope into the channel, and pushing the cam closed.
- Pull the rope through the chest ascender from below several times or until the rope is taut. This ensures the ascender is attached, and removes any slack in the rope (which means less prusiking).
- Unclip your hand ascender from your harness , and unclip the D-ring securing the footloop so that it hangs free. Attach it to the rope in the same manner as the chest ascender slightly above head height
- Sit down in your harness, and your ascenders should take all your weight. Make sure that the rope falls straight down the pitch, not on an angle, as otherwise you’ll swing in towards the pitch (usually the wall) in a pendulum. Put both feet in the footloop, and the rope between your boots in in front of the foot loop. Also, read Notes 1, 2 and 3 at the end of this list!
- Grip onto the rope with your boots, and holding onto your hand ascender with both hands, stand up, putting all your weight into the footloop. Keep your posture straight, and your centre of gravity in close to the rope. Your chest ascender should move up the rope.
- Sit back down as much as you can, making sure that you take all pressure off the footloop, and let go of the rope with your feet. Slide the hand ascender up the rope as far as you can, but NEVER take it off the rope.
- Grip onto the rope with you boots, and holding onto your hand ascender with both hands, stand up, putting all your weight into the footloop like you did before. Continue with this sit-stand motion until you reach the top of the pitch.
- At the top of the pitch, DO NOT start climbing until you’ve put your long cowstail into a safety point at the top of the pitch. Because of the cam and the teeth on it, ascenders a comparatively weak devices and will either break or cut through the rope if subjected to a fall of any significance. That’s one of the reasons there’s two of them.
- Once you have a long cowstail attached to something above your ascenders, it’s safe to climb to a more comfortable spot where you can detach your ascenders from the rope. The chest ascender comes off first, followed by the hand ascender. If you’re having trouble getting off rope, check that the position of your body isn’t accidentally weighting one of your ascenders, as they can only be removed from the rope when unweighted. Alternatively, your hand ascender footloop might be snagged on something and being a menace.
- Shout “OFF ROPE” down to the people below you. They’ll probably shout something like “OK” back.
- Move away from the pitch and unclip your long cowstail when safe to do so, enjoying the sunshine (or savouring the fact that you’re one pitch closer to it!)
Note 1: to make going up easier, attach a weighted bag of stuff to the rope below you, and it will pull the rope tight. This will make each step more efficient, and also mean that you don’t need grip onto the rope with both feet in step 6. After about 10-15m there should be enough weight of rope beneath you that you won’t have to do this anyway. You can also have someone below you pull on the rope, as this provides much the same effect as a bag of caving tackle, but make sure that they’re not about take a rock to the face as you prusik up!
Note 2: there are several ways people attach their hand ascenders, but I am assuming yours is permanently tethered to your harness with a dynamic rope lanyard and a maillon connecting the lanyard to hand ascender. There is a second maillon attaching your footloop, and lightweight clip clipped into that which attaches the whole assembly to your harness storage loops when not in use
Note 3: when you put your harness on, you will have had to adjust the footloop so that it is the right length. Otherwise prusiking will be extremely difficult. You want the top of the hand ascender to be at about belly-button height when your feet are standing in the footloop