What is an Auto Belay?

by | Sep 23, 2019 | Auto Belay

You may have seen them in climbing gyms or heard about them, or may even use them - but may not really know what is going on inside these belay systems. Well, we breakdown and break apart the inner workings of an inner belay is this blog post.

What you’ll learn from this post:

  1. What is an auto belay?
  2. What is it made of?How does it help with ascent?
  3. How does it help with descent?
  4. How does the braking work?
  5. How do you climb using an auto belay?
  6. What does an auto belay allow you to do?

1. What is an auto belay?

An auto belay is an automatic electro-mechanical or mechanical climbing belay system. It replaces the need for a human belayer as the auto-belay automatically retracts the climbing rope, taking up the slack as you climb. Once a climber has reached the top of the wall, the auto belay braking system ensures a smooth descent back to the ground. If you should fall the auto belay slows your descent safely to take you safely to the ground.

An auto belay system has the following functions:

  • Removes the need for a human belayer
  • Retracts rope during ascent
  • Controls descent
  • Protects against falls

2. What is it made of?

The auto belay is usually a metal shell housing the internal mechanisms. The shell is usually of a lightweight metal like aluminium.

There will also be a handle that allows it to be anchored safely to a climbing wall or mobile climbing wall. Some auto belays come with a backup anchor.

3. How does an auto belay help with ascent?

Inside is a lanyard which is wound around a spring-loaded central spool. This is similar to a tape measure or seat belt mechanism. When the climber is on the ground the coil is stretched, so when they ascend, the slack is pulled in by the tightly wound coil.

4. How does an auto belay help with descent?

When climbing a wall you usually need another person, a belayer, to take up the slack of your rope. With an auto-belay, this slack is automatically pulled up (or retracted) as you climb.

Most auto belays have a fast retraction mechanism which makes them ideal for speed climbing.

The descent mechanism which acts as a brake on the rope can differ in auto belays. This can be either hydraulic, magnetic or friction-based technology.

5. How does braking work?

Hydraulic Auto Belays

Hydraulic auto belays systems were one of the first mechanisms. They basically work by using a hydraulic cylinder attached behind a climbing wall. The cable would come up and over the wall clipping on to the climber.

The cylinders contain a combination of air and oil. Oil cannot be compressed. If a climber falls, the rope pulls on the chambers forcing the oil to compress through a small gap. The small amount of pressurised air in the chamber allows some movement, but it is very slow. This slow movement in the chambers slows the climber’s rope and lowers them safely to the ground. The pressure in the hydraulic cylinder is also responsible for pulling up the slack on ascension. However, this gives an added ‘assistance’ to a climber. This is something that is helpful for young children climbing, but not great for experienced climbers.

Hydraulic auto belays are very heavy and cannot be moved easily.

Magnetic Braking Auto Belays

Magnetic braking works in a similar way to the brakes on a roller coaster. Instead of using friction - they use an electromagnetic field to control and slow down speed. Its all due to ‘eddy currents’. Basically, if you were to drop a magnet through a plastic tube, it would drop quickly. But drop it through a copper tube, it falls very slowly. That’s because an electromagnetic field has been created around the magnet.

The climbing rope is attached to a retraction spring. When the rope suddenly spins, due to a fall, the magnets kick in and stop the flow.

Friction Braking Auto Belays

With friction braking auto belays, the device attaches to the top of a wall. They work in a similar fashion to car brakes.  Basically, it’s a drum and inside are a number of plates or ‘shoes’ as they are called. These shoes press against the inner side of the drum creating friction from the centrifugal force generated during descent, thereby lowering the climber at a safe and controlled speed.

The benefit of friction devices is that they engage their brakes almost instantaneously. This means that there is no free fall during initial descent from the climbing surface.

The Safedown Auto Belay uses a tried and tested centrifugal braking system that has been utilised by the industrial & leisure height safety markets for over twenty years. Combined with newly developed long-life friction surfaces, the Safedown offers a reliable braking system without the dust and frequent change of parts associated with older brake designs.

Another benefit of a friction auto belay is that they can be serviced on-site. This ensures limited downtime for your business and your customers.

6. How do you climb using an auto belay?

Simply clip the carabiner from the auto belay onto your belay loop or ‘anchor attachment’ point on your harness.

7. What does an auto belay allow you to do?

Auto belays allow climbers to climb on their own. This means that they can do laps, speed climb or do solo training.

But there are even more benefits. An auto belay can help get novice climbers climbing quickly with minimal training and supervision.

They can also enable climbing gyms to introduce more programmes and events like birthday parties and corporate events, where time is limited. Everyone, young and old, can quickly get a climbing experience with minimal supervisor input and training time.

Auto belays provide confidence to climb, and reassurance in case of a fall.

Find out more about the benefits of auto belays for your climbing facility or gym in our blog “Why do you need an auto belay?

We love climbing and are passionate about safety. We can help you find the right climbing wall for your facility and provide auto belays and all other climbing equipment through www.safeclimb.co.uk.

For more information about the Safedown Auto Belay, contact Liza or Scott on +44 (0)333 200 2602 to find out how our SafeClimb can become your climbing partner.