How to Use an ATC for Rappelling

The ATC (for Air Traffic Controller) is probably the most common device used today for both belaying and rappelling---it doesn't kink the rope, has no moving parts, is easier on the skin than a hip belay, it's light, inexpensive, and relatively safe if used properly. That said, rock climbing is a dangerous sport and no amount of reading can substitute professional instruction and practice to properly use an ATC. Remember also that far more accidents happen during the rappel than during the ascent.
As a "passive" camming device, the ATC brakes, and controls the speed of descent in a rappel, by "locking off" the rope at the carabiner with the brake hand. They come in many shapes; some have grooves for more control, but they all basically work the same way.

Things You'll Need

• ATC
• 2 locking carabiners
• Daisy chain, sling, or personal anchor system
• Harness
• Rope
• Safe anchor point
• Backup prussic and an additional locking carabiner (optional)
• Helmet (optional)
• Rappel gloves (optional)

Instructions

1. Make sure you are securely attached, with your anchor system or sling and a locked carabiner, to an anchor, not the rope. Put your rope through the anchor and pull it through until you have its middle. Make sure you will be able to later pull the rope down from the bottom.

2. Check your equipment: harness, carabiner, ATC, rope and anchor. Coil the rope. Tie a fat knot with the two ends of the rope so you don't accidentally slide right off the rope.

3. Yell "Rope!," wait, and throw the rope down. Make sure it goes all the way to your next station or to the bottom. If not, pull it back up and try again. If it's getting stuck or you can't see the end of the rope, you may have to find an alternate descent route. Use common sense.

4. Take the top part of the rope and push each end through the two slots in the ATC. Pull these loops through and attach them to the carabiner. Attach the carabiner to the belay loop on your harness so that the "brake" ends of the rope come out of the side of the ATC furthest from you. Lock the carabiner.

5. Check your equipment again.

6. Take the brake ends of the rope and lock off into the brake position by pulling the rope out and down. Test that you're able to hold your weight in the locked off position. From now on, do not let go of the brake ends until you are safely down.

7. Take yourself off anchor in the locked-off position. Start lowering yourself by gently feeding the rope through. Clear all edges and perform all maneuvers without letting go of the brake ends.

8. Rappel down. Don't let go of the brake ends.

9. Anchor yourself in once you reach your next rappel station. Check the anchor. If you are secured, take yourself off rappel by pulling the rope out of the ATC. Undo all knots on the rope and pull the rope out. Watch your face as it comes down.

10. Repeat Steps 1-9 as necessary until you're on the ground.

Tips & Warnings

• A prussic knot, if tied properly, will lock on the rope if you accidentally let go of the brake ends. To rappel with a prussic, use a piece of webbing, a sling or a cord that's thinner than your climbing rope. Tie a prussic knot on the rope above your ATC, and attach the prussic to your belay loop with a locking biner. As you rappel, slide the prussic down with your hand. If you get stuck on a prussic, or if you need to climb back up because you are too far away from the rock face, make a clove hitch loop on the rope at hip level, step into it, stand up, and repeat as necessary. Using just a prussic and clove hitching steps for your feet is all you need to ascend back up the rope.

• Rock climbing is a dangerous activity that can, and does, result in injuries and fatalities.

References

• The most common ATC
• More information