Currently, the descenders and protectors we use mainly fall into three categories: figure-eight, ATC, and mechanical braking types.
1. Figure-Eight Type Protectors
Figure-eight type protectors are the most common type of protector-descenders. Their characteristic is the absence of complex mechanical mechanisms, so they don’t experience mechanical failures during use. The method of using a figure-eight is relatively simple—it is a symmetrical closed metal ring with no distinct braking end or climbing end. When setting up the rope, you just follow the usual method of operation. Its various shapes, such as C-type and D-type, are designed to adjust the angle of rope deformation and increase friction.
In terms of usage: the figure-eight type does not have particularly strict requirements for rope diameter, making it suitable for a relatively wide range. For example, the larger ring of an A-type figure-eight can accommodate ropes over 8.3mm, while conversely, the smaller ring of the A-type is suitable for ropes under 8.3mm.
2. ATC Type Protector-Descenders
The ATC is one of the most widely used types of protector-descenders in recent years, second only to the figure-eight. Compared to mechanical protectors, its structure is much simpler, and it is just as easy to operate as a figure-eight. However, its biggest advantage over the figure-eight is that the rope is less likely to deform after passing through the carabiner, which prevents kinking. Additionally, the ATC relies on pressing down on the braking end to create rope deformation and increase friction, so ATCs generally have distinct braking and climbing ends. When setting up the rope, pay attention to the rope direction indicated in the diagrams on the device.
In terms of usage: the ATC has stricter requirements for rope diameter compared to the figure-eight, typically between 8.3mm and 12mm—for example, E/F/H types. But if the ATC needs to be paired with a smaller diameter rope, then a smaller bore ATC should be chosen. For example, G and H: G has a bore of 7.5mm–8.2mm, and H has a bore of 8.1mm–11mm.
3. Mechanical Braking Type Descenders
Compared to figure-eight and ATC type protectors, the operation of mechanical braking type protectors is much more complex. Especially when it comes to rope setup, there are very strict regulations—if done incorrectly, it can lead to fatal danger.
In terms of usage, mechanical braking type protectors also differ significantly from figure-eight and ATC types. They are generally used only for descent (single rope) and top-rope protection (single rope). Their most prominent advantage is that they can self-lock and allow control of descent speed by manipulating the free end of the rope, similar to a Stop device.
Adventure sports carry inherent risks. Proper use of equipment and reasonable application of techniques are the responsibility of every adventurer. Any consequences resulting from improper use of equipment are not related to this article.
Even with extensive adventure experience and strict adherence to correct operating procedures, potential accidents caused by natural environments or human factors cannot be completely avoided—this is something every adventurer should understand before engaging in the sport.
A word of advice to every adventurer: cherish life.