What Does ATC Stand For In Rock Climbing?

If you have just entered the world of sports climbing and have slowly begun acquiring your climbing gear, the first things experienced climbers tend to recommend buying are: a harness, shoes, and an ATC. 

The harness and the shoes are an obvious purchase, but what is this ATC?

What is ATC Climbing Anyway?

The ATC is one of the most common belay devices used in rock climbing. It secures  a climber as they are going up or down the wall. 

ATC stands for “Air Traffic Controller”, which is a tube-like belay device manufactured by Black Diamond. However, BD’s ATC was so popular that it had the “Kleenex effect.” 

Every tube-like belay device produced after the ATC by other brands was also called an ATC, just like every tissue paper is called Kleenex by most people.

The ATC has two main uses: belaying a climber to safely stop any potential fall, and abseiling or doing a rappel down the route.

Types of ATC Devices

There are different variations of the ATC device, and while at their core they all serve the same purpose, we will cover the unique benefits each of them brings to the table.

Basic ATC

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The basic ATC is a tube-like belay device that consists of an aluminum tube split down the middle which divides it into two identical orifices and is attached to a plastic loop on one side. 

This simple design, which is probably around $15 USD, is one of the most widely used pieces of equipment in adventure sports, and specifically in climbing. 

It is perhaps one of the most inexpensive items in a climber’s bag, and it is one of the key components keeping you from hitting the ground. 

In fact, it is considered one of the best investments a rock climber will ever make.


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Another variant of the basic ATC is the ATC-XP. It Is basically the same piece of equipment, but instead of being a symmetric tube, it has a teethed indentation to increase rope friction. 

It serves the same purpose as the ATC device, but it is also recommended for ice climbing, where the increased friction can be very important due to the pieces of ice or water that can come along with the rope as you climb.

ATC Guide Devices

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After the two basic ATC devices, comes the ATC guide device. It is very similar to the ATC-XP, but with the addition of a metal loop on the opposite side of the toothed indentations. 

When belaying someone else from the base of a route, as in normal single pitch climbing, the ATC-guide is used just as if you were belaying with a regular belay device. 

The benefit of the ATC-guide comes when you are top-rope belaying someone from the top of a climb as he follows your lead on a multi-pitch scenario. 

The ATC-guide can be set up so that it gains automatic lock capabilities if a climber falls. You do this by attaching the ATC-guide device to the anchor with the additional metal loop and a carabiner.

how to use the guide mode function on an ATC device multi pitch rock climbing
A Typical Set Up When Belaying From Above With an ATC in Guide Mode

With this setup, you can belay a climber as he follows in top-rope, and in case of a fall, the rope and the weight of the climber itself will create the friction that stops the fall automatically. 


The ATC is the basic form of a belay device, however, there are other types of devices out there that are widely used by climbers. 

The most common alternative to the ATC is an auto-locking belay device. Needless to say, that there are several brands and models out there, but they are all essentially, all the same. 

rock climbing team

One  such model is Petzel’s Gri-Gri family, where the rope is fed through a mechanical system made for automatic breaking in case of a fall. 

While it is arguably safer to use an auto-locking device, since it will stop a fall even if the belay went unconscious, one must learn to use these kinds of devices since they require additional technique as compared with the ATC. 

Even though an automatic device will stop a fall, whether the belay reacts accordingly or not, one should still keep all safety measures normally taken when belaying with an ATC, like never letting go of the lower end of the rope.

How to Use an ATC Belay Device

For Belaying:

One can safely and easily use the ATC device for belaying a partner by following these simple steps:

  1. Grab the rope close from the end that is attached to the climber, and make a small bend on it.
  2. Grab the small bend and insert it into one of the dents in the belay device from the side that does not have the plastic loop. Most devices have an image showing where each of the rope ends should go, the climber or the rest of the rope. Make sure to verify correct orientation.
  3. Once the bend of the rope goes through the ATC, use a locking carabiner to grab both the rope and the plastic loop, and attach it to your harness’s belaying loop.
  4. The system should look like the image above, where one rope goes towards the climber, and the other goes to the rest of the rope.
  5. With this system set up, you can safely belay your climber by following the proper belaying technique. Make sure you adequately learn belaying techniques before attempting to belay someone else, as it is critical for the climber’s safety. The wrong technique can lead to fatal consequences.

For Rappelling or Abseiling

One can safely and easily use the ATC device for abseiling with a double rope by following these simple steps:

  1. Set up the anchor.
  2. Using both ends of the rope, make a small bend on each of the rope ends by pinching it.
  3. Insert the small bends of the rope each into one of the two slots of the ATC on the side that does not have the plastic loop.
  4. Once the bends of the rope are inserted, and they go through the ATC, use a locking carabiner to grab both the ropes and the plastic loop, and attach it to your harness’s belaying loop. 
  5. The system should look like the video above, where two ropes go up towards the anchor, and the two rope ends go down to the floor.
  6. With this system set up, you stop yourself by pulling the lower ropes down, and you can bring yourself down by reducing the strength you use to pull the ropes down. You must never let go of the rope. Make sure you adequately learn abseiling techniques before attempting them, as poor, or wrong techniques can prove fatal.

Why Use An ATC

rock climbing team

The ATC is just one of several belay devices out in the market, so you could be using an ATC or one of the alternatives. Why should you be using an ATC?

ATC Main Benefits

  • It is the primary device, so learning ATC techniques translates to other belay devices.
  • It is the cheapest, so it is also the most common device out there. Therefore, it could be wise to learn how to use it in case it is the only option at some point, which can happen more often than with the other devices.
  • It is quite versatile, and can be used for several functions with ease.
  • It is lightweight.
  • It can do double-roped rappels. 

ATC Main Drawbacks

  • It does not have auto-locking capabilities, so if the belayer loses focus, consciousness, or the ability to grab the climbing rope, the climber will fall.
  • It can be more tiresome for the belayer in some circumstances. 

Other Common Belay Devices

Though ATCs are still common, many modern climbers have made the switch over to one of the many new design options for belay devices. For more information, check out our article on the best belay devices.

Published by Alex "Don Loro" Casar

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