Is rope strong enough to climb on?

All ropes that are made, tested, and certified (by the UIAA/CE) for recreational climbing are plenty strong for any reasonable climbing situations, for a human climber of any size.

Whether you trust that blanket statement or not (yet!), we’re here to break down why by adding context into what climbing ropes are designed to do and how climbing ropes are tested. By the end of this post you’ll understand falling (what generates the most force on a rope) and rope certification. And hopefully you’ll agree, climbing ropes are so overbuilt that they won’t break while we’re climbing (or falling) on them.

Falling

When climbers think of ‘falling’, we are usually thinking about what happens when we let go of the wall and give ourselves over to gravity. But depending on the type of climbing we’re doing, the amount of actual fall that we experience is different, so the weight the rope feels (or more accurately, the force it feels) can be very different.

True ‘falling’ usually only happens in climbing when leading a climbing route. A lead fall involves climbing above a bolt or piece of protection (like a bolt, a cam, a nut, or ice screw) and free-falling a distance (usually several feet) before the rope literally brings the climber to a stop, now hanging from that protection. A falling lead climber can generate a lot of potential energy and a lot of force on the system, no matter how much they weigh.

To be technically correct, these forces can also be affected by several other factors, including the amount of rope in the system, how much drag there is, and the weight of the belayer. To get real nerdy, you can check out this post where we dig into the forces and factors of falling in super detail.

Because no two climbing scenarios are the same, it can be tough to pin down exactly how much force we put on ropes when we take a lead fall, but the general consensus in the industry seems to be in the 2-5 kN range. In real world terms, that’s about the force that 450-1100 lbs (roughly 200-500 kg) would exert if it were hanging at the end of the rope, and that is quite a bit!

It is important to know that these forces are different from top-rope climbing, where the rope is run through an anchor at the top of the route and the climber can let go and hang at the end of the rope any time. Though it may feel like we are falling when we let go, our belayer is taking up the slack and keeping up with us as we go, so there is usually very little fall (often less than a foot) and very little extra force to absorb except our weight. Forces felt by the rope and anchor in a top rope scenario are typically less than 2kN.

So this begs the next question: How strong are ropes actually? Or more specifically, how much weight can a rope handle?

Rope Testing and Certification

This one is tough not to get too far in the weeds, but we feel it’s important to know a little bit about the testing process to understand how we know what ropes can actually handle.

Contrary to popular belief, the UIAA and EN certification of climbing ropes doesn’t actually involve pulling the rope until it breaks. While this might seem like an obvious test to see how much weight a rope can handle, it actually highlights a really important thing about how the test is designed; to simulate worse-case climbing scenarios and make sure the rope can handle them.

Because climbers are never going to weight a rope until failure, it actually doesn’t make a lot of sense for a test to determine when and if that break happens (outside of curiosity of course.) So to be more in line with real world situations, ropes are certified by how well they absorb the weight of a falling mass.

When it comes to strength, a rope that has passed certification must catch an 80kg weight falling 2.5m statically (7.5ft) at least 5 times without breaking and absorb enough force keep the system at or below 12kN. (These numbers are different for half and twin rope setups, but most climbing in the US happens on a single rope. You can head to this post to learn more about rope types.)

Something important to point out is that this falling mass isn’t being belayed like a climber, but instead is tied-off tightly to the drop apparatus, so the weight is coming to a stop very suddenly with nearly zero slippage. A climber that weighs 80kg would generate even less force thanks to natural rope slip through a belay device, in addition to movement by the belayer.

Knowing what we know about the force climbers can generate while falling (that 2-5kN we talked about earlier) this test actually makes a lot of sense. If we know that a rope can handle several static drops of an 80kg (about 175lbs) weight without breaking and can ALSO absorb as much as 12kN (about 2700lbs) of force, then we can say pretty definitively that it can handle the falls taken by climbers of any weight.

How much weight can a climbing rope hold before breaking?

As described above, there are no certification tests that answer this question exactly. But we can ask: How much can a rope handle while catching a fall and holding that weight? And the answer is: Ropes can catch and dissipate forces that are many times more than any falling climber could possibly generate, at least 5 times without breaking. These numbers easily say a climber under 1100 pounds won’t be threatening the rope.

Conclusion

Often, the rope is the only piece of equipment we use that isn’t redundant or backed up by another piece of gear, so knowing that it won’t fail while we flail is absolutely necessary. No matter what type of climbing you do, ropes that are certified for climbing are strong enough to handle all of the climbing situations we might find ourselves in.