Essential Skills: Auto-Blocking Belay Devices
Belay transitions can be the real time-suck of multi-pitch climbing. Exchanging gear, restacking the rope, eating, drinking, and whatever else you might need to handle at the belay stance can really burn away those precious daylight hours, so it’s crucial to be as efficient as possible. Belaying your follower (or followers) with an auto-blocking device set up directly on the anchor allows the leader to go almost hands-free while safely bringing the follower up to his stance. This setup, which is also called “guide mode,” automatically stops the rope from moving through the device—or “catches” the follower—if he falls. It’s a must-have tool and technique for anyone who wants to tackle multi-pitch climbs.
The leader reaches the belay stance and builds an anchor with a master point. To set up the auto-blocking device, she just needs two locking biners and the belay device; at least one of the biners needs to have a smooth and rounded shape with no edges. Clip a rounded or non-rounded biner through the master point and then the large loop, called the anchor attachment point, on the device (A), which will be oriented with the friction grooves down (B). This will be where the brake strand comes out, while the climber’s strand goes into the top (C). Lock the biner. Pull up all the slack from the follower, then push a bight of rope through the device (making sure the climber’s side is in the top, brake side on bottom), and clip the rounded biner through the cable on the device and the bight of rope (D). Lock that biner. Double-check that the anchor is good, biners are locked, and belay device is oriented correctly. Now your follower is on belay.
As the follower moves up, use one hand to pull slack in, and the other to pull it through the device. This can be hard if there’s a lot of rope drag or it’s a long pitch, so get in a solid stance. The gripping power of the auto-blocking device is strong and more or less instantaneous. Should your follower fall, it will feel like a normal toprope fall for him—mostly just rope stretch. An attentive belayer should always keep her brake hand on the rope, but the braking action from the device is so reliable that it’s easy to switch hands and grab a snack or organize gear. The drawback to this technique is that the auto-block makes it difficult to lower a climber. It is possible but physically challenging; you must change the angle of the device when it’s under weight. Most devices come with a built-in release hole. Simply put the nose of a biner in this, and it will give you the leverage to rotate the device away from the anchor and reduce friction enough to lower the climber.
Also, when you release an autoblock device that's locked up with a second's weight, either with a carabiner as we describe or with a sling threaded through the release hole, the device generally goes from fully locked to fully open. There's no halfway or gradation to it, unless you are extremely skilled and careful. Therefore, we recommend:
1. The brake strand should be redirected up through the anchor (just clip it to another biner clipped to the anchor), which will give much more control.
2. The brake strand should be backed up with a friction hitch clipped to the belayer's harness (like a rappel backup).
As lowering is a complicated technique, we highly recommend practicing in a low-risk setting (and/or getting professional instruction) before heading into the hills. For a more in-depth explanation of safe, proper lowering, check out the American Alpine Club's Know The Ropes: Lowering.
One real upside to this device is that you can have two followers climb at the same time. Your setup should look like fig. 1. This is best done when there’s less rockfall potential and the route isn’t a perfectly straight line, which can cause the third climber’s rope to get in the second’s way. The slower climber needs to be the first follower. When he approaches a piece of gear, he should unclip his rope and leave the other follower’s rope clipped. The last climber needs to be faster because she will need to deal with cleaning gear, climbing the pitch quickly, and paying attention to where the climber in front of her is. The belayer will be pulling in both ropes, and the followers should be communicating if they need more slack (“slack”) or if they need slack taken out (“uprope”); make sure everyone agrees on commands before leaving the ground. One very important thing to keep in mind is that if one follower falls and locks the device, it will not catch the other follower’s fall. When belaying two followers, you need to tend each rope closely; that means you probably won’t be doing much else, but two followers simul-climbing is still faster than three people climbing each pitch separately. Here are a few more tips for climbing in a party of three:
>>Make sure followers pay attention and keep ropes untangled.
>>They should also be aware of where they are in relation to each other, making a point to spend as little time as possible directly above or below the other person.
>>Use two different-colored ropes so communication is easier and more clear: “Uprope on blue!” or “Slack on green!”
>>The followers should stay at least 20 feet apart.
>>You can use half ropes to save weight, instead of two singles. The leader should be tied into both; each follower tied into one.
>>This shouldn’t be done on difficult routes where many falls are possible.