Petzl Huit Figure 8 Descender

The Petzl Huit is a classic figure 8 descender for controlled rappels and lowering. Its simple aluminum design is easy to rig, easy to inspect, and gives smooth friction on a range of single rope diameters.

How a figure 8 descender works

The rope passes through the large eye and around the neck of the 8, creating friction as it slides. The user controls speed with a brake hand on the rope below the device. It is a simple tool with no moving parts, so there is little to go wrong and inspection takes seconds.

Climbing figure 8 descenders like the Huit are common in rescue, caving, and training kits because they rig quickly and work with gloves on.

The Huit is simple and inexpensive, so many crews keep one in the rescue bag. It does not need special rope or a complex setup, which can make a difference when every minute counts.

Where it fits for tree workers

Modern arborists usually descend on hitches, mechanical friction devices, or SRS devices designed for tree work. A figure 8 still has a place in a rescue kit for lowering or rappelling on a dedicated rescue line, and in training where students learn basic friction principles.

A figure 8 does not lock by itself. If you let go of the brake strand, it does not hold you. Anyone using it should be trained in tie-offs and have a backup where required. Compare devices built for tree work in our ascent and descent section.

Figure 8 descenders also have uses on the ground. For example, they can be used to add friction to a lowering line in light rigging, though dedicated rigging devices are better for regular use.

It is also a common first device for teaching how rope friction, wraps, and brake-hand position control speed on a descent.

Rope twist and heat

Figure 8s are known for putting twist in a rope, especially on long descents. Keep the rope running straight into the device and shake out twists between uses. On long or fast lowers the aluminum can get hot enough to glaze nylon and polyester ropes, so control speed and let the device cool.

Pair the Huit with rope in the diameter range Petzl lists, and keep a locking carabiner dedicated to it.

For extra friction, the rope can be rigged in a different way through the device, but only use configurations shown in Petzl's instructions. Practice them on the ground before you need them.

Keep a dedicated rope for rescue, matched to the device, rather than relying on whatever climbing line happens to be on the truck.

Inspection

Look for grooves worn by the rope, sharp edges, cracks, and corrosion. Retire it if a groove becomes deep or sharp enough to damage rope. Life-support gear must meet the applicable standard (ANSI Z133 and the manufacturer's instructions), be inspected before every climb, and be used only by trained climbers.

Keep the Huit clean and dry. Wash it with fresh water if it has been exposed to salt or dirt, and let it dry before storage.