Rappelling with a carabiner brake.
Carabiner Brake Introduction
Rappelling typically makes use of specialized equipment, such as brake racks and other lowering devices, but in an emergency situation, you can make a rappelling rig using carabiners and rope. Called a “carabiner brake”, it offers the benefits of not twisting the rope and providing more even friction than other brake methods such as the Munter hitch method. If you make a carabiner brake rig, understand that it is dangerous and easy to rig incorrectly. You should practice making a carabiner rig and try it out in safe conditions before using this technique in the wild.
Also note that the system makes use of carabiners in pairs, with each carabiner placed opposite (ends are opposite) and with opposed gates (each gate opens in the opposite direction). The reason for setting the carabiners opposite and opposed is to add redundancy to the system. Using single carabiners in the rig is highly risky and dangerous.
Carabiner Brake Components
There are several carabiner brake methods but all require carabiners and rope. Oval shaped carabiners are best suited for the rig but D-shaped carabiners will work if that is all you have available. Gate carabiners are to be avoided if possible. Locking carabiners, either auto-locking or screw gate carabiners, are must safer. Again, all carabiners are attached in pairs in an opposite and opposed configuration.
When you rig the system, you should reverse the carabiner gates. This helps introduce a bit of a ‘”fail safe” in case one of the carabiner gates accidentally opens. Also don’t set up the carabiner brake directly on your harness belay loop. Always use two carabiners or a locking carabiner to rig the brake on, otherwise you risk abnormal wear and damage to the belay loop.
How to make a Carabiner Brake
Once the carabiner break is rigged, you will use one end of the rope as the “guide” and the other end of the rope as the “brake” (which you will pull towards your body to brake). Follow these steps to rig a carabiner brake.
Clip a large locking carabiner to your belay loop. If you have enough carabiners, to ensure safety, clip two carabiners to your harness belay loop. If you use two carabiners, make sure the carabiner gates are opposed (redundant safety).
Attach two more carabiners to the dual-carabiners that are clipped to the belay loop. As with the first pair, be sure the reverse the carabiner gates and carabiner ends in opposite directions. These two carabiners will form the frame of the braking system (which later will incorporate two carabiners slid over it to provide the needed friction).
Take a bight (i.e. form a bend or loop) of your rappel rope and push it through the second set of carabiners, the ones that form the frame of your carabiner brake system.
Clip two more carabiners below the bight of the rope. Make sure the carabiners face down and away from the rope and as with the other pairs of carabiners, reverse each one (end and gate).
Pull down on the bight of the rope and let it run across the top of the carabiners. The two carabiners should slide down and around the first set. This forms the brake system.
Add additional carabiners or another frame of two carabiners and two more brake carabiners on the end to create more friction in the system.
Here is a reversed view of the rig.
This generates a tremendous amount of heat when used.