Rappelling, also known as abseiling, is the act of descending a rope or pair of ropes in a controlled way.
- 1 Mechanism
- 2 Hand placement
- 3 Device placement
- 4 Adding friction
- 5 Locking off
- 6 Reducing friction
- 7 Dangers
Rappel descent is controlled by the use of a descent device. There are many devices, but the most common devices in canyoneering are figure 8, ATC, Pirana, and ATS (device). In caving, racks and similar devices are more common. On most devices, descent speed is controlled by varying the angle of and force applied to the rope after it exits the device going downward (the "brake side").
Primary brake hand
In most rappel configurations, one hand is usually the main brake hand and must remain on the rope at all times to control the descent. Most people delegate this important task to their dominant hand, but others prefer to have their dominant hand available for maneuvering around rocks, taking pictures, and other on-rope tasks.
In most rappel configurations, the most critical instruction is to never let go of the rope.
The hand not being used for primary control of the brake can be used for other things during the descent. Catching oneself during a fall, maneuvering around rocks or other features of the rappel, and adjusting the rigging or rope are generally accepted as appropriate uses of the secondary hand. The use of an Autoblock requires the secondary hand for operation of the Autoblock. When the secondary hand is not being used for any of these purposes, the canyoneering community has varying opinions on what it should be doing.
Second brake hand
Placing the secondary hand on the brake strand (below the rappel device) adds redundancy to a rappeller's braking ability and increases the maximum amount of brake force the rappeller can apply. It also allows the rappeller to maneuver with either hand because one hand will always remain on the brake strand. Because two hands are used on the brake strand, it is less likely the rappeller will start falling because he removed one hand from the brake strand to catch himself during a slip. Rappellers should take care to ensure that the second brake hand is not close enough to the rappel device to be sucked into the device during descent.
Because there is no recognized advantage for a different hand position on free-hanging rappels where the rappeller's feet do not touch anything, this hand position is generally considered best for free-hanging sections of rappels. If a rappeller feels the need to steady himself by holding onto the rope above the rappel device on a free-hanging rappel, it is likely his pack or weight configuration is attempting to invert him and much better solutions include lowering his center of gravity by hanging his pack below him, or creating a chest harness to prevent inversion.
On the rope above the rappel device
Placing the secondary hand on the rappel rope above the rappel device improves the rappeller's stability under many circumstances and feels most natural for many beginner rappellers. Rappellers should recognize that the natural reaction to grab this portion of the rope during a slip is usually ineffective at preventing the rappeller from falling, so it is important for rappellers to understand that holding onto this part of the rope will not do anything to stop or control their descent.
On the rappel device
Placing the secondary hand on the rappel device is similar to placing it on the rope above the rappel device; doing so aids stability but cannot control descent. By holding onto the device rather than the rope above the device, the rappeller can avoid rope abrasion on their secondary hand, but must also be careful not to allow their hand to be sucked into the rappel device.
Keeping the secondary hand completely free without holding onto anything may reduce the time required to react to a slip.
Most canyoneers generally attach their rappel device directly to their harness, but this is not the only place the device may be attached.
Extending the rappel device
By placing a tether between a rappeller's harness and their rappel device, the rappel device can be extended away from their harness. This tether is often a Spelegyca or other fiber lanyard, but it may also be a carabiner or string of carabiners.
- The rope directly in front of the rappeller is the brake side rather than the non-brake side. This means a rappeller who panics and grabs the rope in front of them will likely be successful in arresting their fall while they would likely be unsuccessful if they grabbed the rope above their device instead.
- Because the rappel device is higher above the rappeller, the natural angle at which the rope exits the rappel device will be steeper, so it will be easier for the rappeller to apply braking force.
- If the brake strand is tensioned across the tether, it could saw through a fiber tether which would cause the rappeller to free-fall.
- It is more likely for the extended rappel device to be caught in cracks or going over an edge.
- If the rappel device is extended too far, it may be hard to reach to clear a jam or free it from a crack.
- Extending the rappel device puts it closer to hair, which may become caught in the rappel device.
Letting go of the brake
A common mistake on rappel is to lose footing, slip, swing toward the rock, and take the primary brake hand off the brake to absorb the impact with the rock. The slip against the rock is relatively minor and will often cause bruising, but removing both hands from the brake is a critical mistake and can result in an uncontrolled descent as shown in this video:
Too little friction
The rappelling mistake that likely causes the most injuries and fatalities is configuring or rigging the rappel device with too little friction, or failing to add additional friction before it is needed. This mistake is especially common on long rappels because the amount of friction or brake force that the rappeller must provide increases as the rappeller descends. This is because the extra brake force the weight of the rope provides decreases as the amount of rope hanging below the rappeller decreases.