| Mechanism | Helps lock the rope in a fall |
| Best-known | Petzl GriGri |
| Still needs | A hand on the brake |
| Difficulty | Beginner (requires instruction) |
An assisted-braking device (ABD) is a belay device with a mechanism — usually a camming lever — that helps pinch and lock the rope when it’s loaded suddenly, adding a margin of safety in a fall. The GriGri is the best-known example. Crucially, ABDs still require a hand on the brake at all times; they are not hands-free.
How it works
A cam engages under sudden load to help clamp the rope, supplementing the belayer’s brake hand — unlike a plain tube ATC.
The key rule
Keep your brake hand on the rope; ‘assisted’ is not ‘automatic’. The GriGri is the classic example. See GriGri vs ATC. Educational only; not a substitute for instruction.
Frequently asked questions
What is an assisted-braking device?
It's a belay device with a built-in mechanism — typically a cam — that engages and helps clamp the rope when a fall suddenly loads it. This gives an extra margin over a plain tube device, which relies entirely on the belayer's brake hand for friction.
Are assisted-braking devices safer than tube devices?
They add a helpful backup that can catch a fall even if the belayer is briefly distracted, which is why they're popular for sport climbing. But they can be misused, and a moment of bad technique can defeat the assist, so they're a supplement to good belaying, not a replacement.
Can you let go of the rope with an ABD?
No. Despite the name, assisted-braking devices are not hands-free or auto-locking — you must keep your brake hand on the rope at all times. Letting go relies on luck that the mechanism engages, which is a dangerous habit.
Sources
- Belay device technical notice — Petzl