When rappelling, tying a stopper knot is one of the most important steps. I was surprised at the lack of information available online, so I wrote the following guide.

Rappelling stopper knots are knots at the end of your rope that prevent you from falling off once you reach the bottom of your rope. When you’re rappelling, it’s sometimes easy to lose concentration and forget where you are on the rope. If you forget to tie your stopper, you risk having the ends of the rope pass through your device, which will detach you from the rope and send you on a pretty unpleasant journey.

Stopper knots are super easy to tie and honestly take less than five seconds to create. The knot protects the end of your rope from passing fully through the belay device and sending you into free fall. It does so because, the opening in your rappel device. Instead of passing through whatever device you’re using, it jams in place and prevents the rope from moving any further. This stops you in your descent and keeps you attached to the rope.

Stopper Knots: Why You Need Them

I said once in a different article that backing up a rappel was maybe the easiest way to ensure your safety. I actually think I’m going to go back on that statement, because tying a stopper knot is so simple and so important that it’s almost inexcusable to not do it.

Tying a stopper knot isn’t even part of your safety routine. It’s more similar to tying a figure 8 or connecting your belay device to your harness; it’s an essential step in the process of preparing yourself to repair. Anyone who tells you that a stopper knot isn’t important is wrong. I don’t care if they’re a newcomer who only boulders indoors or the most grizzled trad climber at the crag; people who don’t tie stopper knots are fools.

So, now that I’ve got that out of my system, why are these knots so important? Not rappelling off the end of the rope should be pretty easy, right?

Intuition would tell you that yes, this is a fairly preventable problem. After all, how hard can it be to simply glance down, see how much rope you have beneath you, and ensure you don’t let it pass through your device?

This philosophy ignores the fact that, at the end of the day, we’re all human. People get distracted, tired, and lazy. They forget where they are, they misjudge distances, or they simply are just too occupied by taking in the view or talking to their climbing partner to even pay attention.

The other thing is that, when rappelling, a lot of people like to hold their ropes down and out of sight, because it makes it easier to brake. The problem here is that you can’t see the end of the rope until you feel it pass through your hand. As soon as that happens you lose all friction in the system: the rope goes slack, gravity takes a hold, and then you’re in freefall. If you were smart enough to tie a backup knot, there’s a change it will bite. If not, you’ll have a second or two to realize your mistake before the now un-checked rope gets pulled full through your belay device and you become detached from the rappel.

Now, as I mentioned, there are going to be people out there who think they’re too good for this to ever happen. In short, these people are wrong, and there’s a verifiable mountain of evidence out there to prove what I’m saying— all you need to do is listen to what professional climbers say.

Tommy Caldwell once had to stop his partner (who forgot to tie a stopper knot) from rappelling off their rope while 2,000 feet up El Cap. Let me write that again: Tommy Caldwell had to stop their partner. If you’re good enough to be climbing with Tommy Caldwell, you’re in the tope 0.005% of climbers in the world.

More recently, California dirtbag-turned-icon Brad Gobright died because his climbing partner forgot to tie a stopper knot while the two of them were simul-rappelling. The man who pushed the limits of trad climbing and did perhaps the most daring ascent of The Nose died because of a forgotten knot.

Stopper knots are important because, just like the best climbers in the world, you too are human. There’s going to be a time when you’re distracted while rappelling, or you’re too busy looking for the anchors to pay attention, and you’re going to be glad that you tied your stopper knot.

How to Tie a Stopper Knot

I’ve done so much talking about how simple it is to tie a stopper knot, so now let’s get into it.

The thing about a stopper knot is that the actual type of knot you tie isn’t super important. The most common one is a standard double-barrel overhand knot, the same type that people will tie over their figure 8 to keep the tail out of the way. To tie this kind of knot:

1. Take about 2 feet on the end of your rope and fold it in half
2. Loop the loose end of the rope around the other half twice
3. Pass the extra slack through the loops in a downwards direction and pull to tighten.

It’s that simple!

The more loops you do, the more solid the knot will feel and the less chance there is that it gets ‘pushed’ down once you apply weight to it. Some people will do three to four loops, while others will simply use an overhand knot if they’re in a hurry.

The next question that needs to be addressed is where you should tie your stopper knots. There’s no tried-and-true rule for this, but I would recommend leaving at least a foot of slack below your stopper knot. This gives you a little bit of a buffer and prevents the knot from coming undone if it slides to the end of the rope.

I Have an Auto-Locking Device. Do I Need to Tie a Stopper Knot?

Yes, yes, and yes.

Not many rappel devices have auto-locking features, but they’ve started to get introduced as equipment companies look for more and more innovation. Now, at first glance, this idea has more merit to it. Your gri-gri will automatically stop the rope if you let go of the handle, right? If the rope starts to slip, the camming device will not it in place, won’t it?

Technically yes, but there are a few issues with relying on your device in lieu of a stopper knot. Any auto-locking device is going to have a lever that you need to activate to allow rope to pass through it (think of the little plastic thingy on your gri-gri). When rappelling, you’re already going to have this lever activated so that you can get down the rope.

If you forget to tie a stopper knot and you’re holding your device in ‘open’ mode— that is, where the camming feature is disengaged— it’s no better than your standard ATC in terms of catching the rope. There’s a slight chance that you are able to see what’s happening and let go, but this goes against normal human instinct. If you’re holding on to something and you suddenly think that your life might be in danger, odds are you’re simply going to hold on tighter. This will open up your device further and prevent it from being able to catch the rope.

Using your auto-locking device as an excuse to not tie a backup knot is a questionable decision, but I can understand the justification. Using it to knot tie a stopper knot, however, is simply asking for a disaster.

Conclusion

So, there we go! That’s everything I have on stopper knots, why they’re important, and how to tie them. I hope you enjoyed the article. As always, do your own research and consult expert advice before staking your life on a knot that you’ve tied.

Stay safe and have fun!