One person I regularly climb with uses a belay technique that I was taught to be unsafe, so I would like to know just how unsafe it really is. With a classic tube-style belay device, after taking in slack and bringing the brake hand back down, he simply slides his brake hand up the rope, opening it up just enough to allow the rope to stay in place.

Although it is obvious that PBUS (which is unfortunately not taught here at all) would be much safer, it is less obvious to me whether there is any real danger of him not catching a fall, given that he would probably hold tight as soon as he feels his other hand being pulled. So ideally I would like to know some hard facts such as:

  • Have any accidents been attributed to this belay technique? (Or a similar technique -- holding the brake hand above the device does not count as similar though.)
  • Does anyone know of any experiments to determine if people usually catch falls even if they were holding the rope loosely?
  • 3
    Is the unsafe method the slip-slap-slide technique?
    – StrongBad
    Jun 7, 2017 at 22:45
  • 2
    In this case the OP says "sliding brake hand up the rope" - I think he is describing the belayer with brake hand behind him (locked position) and sliding up, toward the belay device.
    – user5330
    Jun 8, 2017 at 1:26
  • 3
    @mattnz: Exactly. Basically PBUS without the U, maybe? I've edited the question to hopefully make it clearer. Jun 8, 2017 at 6:59
  • Slip slap slide may be safe when done correctly, but PBUS is clearly more foolproof and that makes it the preferred technique in my book.
    – Qudit
    Sep 13, 2018 at 4:23
  • 1
    you may want to check the recent video pushing the method "to the limits" in order to check at which point it might fail. youtube.com/watch?v=03ext7Dahxo Nov 17, 2022 at 16:43

4 Answers 4


It's not unsafe; really.

Gyms will enforce the most foolproof techniques they can, because they can't afford to have some idiot hurt themselves in their gym. Gyms see a lot of casual climbers, and fresh beginners, and they don't want them picking up any habits that could lead to complacency. Sure, the brake-under-slide (or PBUS) is the most redundant and reliable belay, but when you're standing on the 6th pitch of a rotten dolomite face trying to pull 70m of rope while dealing with rope drag so bad you can't tell if you're only taking up the slack or up-hauling your second, then you really don't care about your handwork.

Having slack in the rope is way more unsafe than how you're pulling it through your belay device; sometimes you gotta do what you gotta do, and just because there is a preferred, safer method, doesn't mean that all other methods are dangerous. The most dangerous aspect of rock climbing is the human condition. A competent climber could belay you without any device at all.

They used to train newbie climbers by tying an 80lb sand bag to the end of a hemp rope, handing the other end of the rope to a belayer, and dropping the weight over the branch of a big tree or over a beam. If the belayer could stop the weight using a hip belay, then he was considered good enough to climb with all the big boys (it was sort of an initiation, because no matter how good you were at it, it still hurt each time you did it).

Whatever technique you use, just make sure you're ready for when your climber needs you.

  • 2
    Pulling 70mm of rope shouldn't be that much work, regardless of where you are ;-)
    – anderas
    Jun 8, 2017 at 6:12
  • @andreas Are you kidding? The recommended rope length for the climbs I was doing over the weekend is 40m, because if you climb a pitch any longer than that then the rope drag gets too bad. They were easy climbs with lots of ledges, so the rope was dragging on the rock a lot. But seriously, I stopped and set up the next belay several times because it was getting too hard to pull the rope along with me. Sharp limestone can feel like velcro when you're pulling your rope over it.
    – ShemSeger
    Jun 8, 2017 at 16:51
  • 1
    @ShemSeger Wondering what a 70 millimeter pitch might be like. ;-) Anyway, it's hard to decide between four interesting answers. Thank you all. Jun 8, 2017 at 20:51
  • @SebastianReichelt We'll just pretend that stands for "Manly-Metres".
    – ShemSeger
    Jun 12, 2017 at 17:42
  • @anderas Call me slow, but I just barely got your joke today.
    – ShemSeger
    Feb 5, 2018 at 17:18

In Germany the DAV teaches the method I think you describe (video here) and calls it "tunneling". The hand above the device makes sure that the braking hand can stay below the braking plane. You have to close your hand in case of a fall, which is possible quickly enough.


Religious wars have been fought for less.

Is this safe? Depends on who you ask I'd say.

Dodging that bullet, basically this is down to you and your preferences. It's your safety the person is responsible for (presuming your climbing). There is a fair chance that this technique is perfectly safe, but you're right, it's not the up to date recommended technique (In the UK anyway, seems Germany might be different). So the question you should be asking yourself is Do YOU want this person to belay you like this?

If you're happy with their competency and you're happy that it seems safe then fine. If not you need to have a difficult conversation with them (Look, I don't mean to be funny but could you belay me this way please? I'm not happy with that technique).

Any belayer worth their salt should go, oh yeah, fine. You should always belay how the climber wants to be belayed, not how you want to belay. If they disagree, then maybe you need to find a different partner.

Why is this (potentially) unsafe?

The issue is without a hand holding the rope at all times (and I mean gripping it), if you have a fall there is a chance the rope can accelerate though the belay device. Have you ever tried to catch a moving rope? You won't.

Have there been any studies, etc.?

Not that I'm aware of. Rock and ice keep a log of accidents but these are not particularly collated. I'm not aware of any particular studies on this matter.

  • 6
    Personally I go the other way round on belaying: If the belayer uses a method different to the one I know, I ask them about it. If I get a reasonable reply as to how and why they do it, I won't press for a change (unless it is obviously dangerous, but then you don't get a reasonable answer :) ). My reasoning is, that they have trained and built reflexes for their method, so it is probably safer that way than making them use a new method.
    – imsodin
    Jun 8, 2017 at 11:16
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    Providing you've had "the conversation" I think it's fine. The goal is to be comfortable that your safe to whatever standard you deam that to be. This is why a good solid climbing partnership is a hard thing to find
    – user2766
    Jun 8, 2017 at 12:20
  • The American Alpine Club maintains accident reports and statistics going back to 1948. When searching for "belay" in their archive shows a list of 1200 accident reports that involve belay, most of these are anchors or rigging mistakes, OTH there are plenty of examples of people lowering past the end of the rope or simply forgeting to clip their belay device
    – crasic
    Sep 10, 2018 at 20:33

As knitti already answered, this is the standard method taught in Germany and Switzerland (and possibly others). To keep naming clear, I am going to refer to PBUS and european method. Here we have a discussion about another "phase" of belaying as being unsafe (hand up while pulling in slack).

ShemSeger already puts the hole thing nicely into perspective, so I will only try to convince you, that it is even equally safe:

As any (sane) belaying method, the main principle is to never let go of the braking strand. Now if you take that strictly, you could say loosening, but not removing, your hand from the braking strand equals letting go - but I would refute that, due to the second principle of the european method: Use the non-breaking hand as "sensor". In the phase where you slide your hand on the braking strand upwards, your other hand is holding the rope above the belay device. In case of a fall in that exact moment, you feel it there, giving you ample time to close your hand behind the belay device. I consider this even advantageous, as it facilitates dynamic belaying. You grip the rope before the device, building up tension in the rope and preparing yourself for the harder pull. Then you can let some rope through the belay device in a controlled fashion.

Mind you, I am not saying PBUS is bad. I can't, I have never done it. I am just making a case for a method which is widely and successfully used and at least according to the OP, is accused of being unsafe.


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