Do you ever wonder how much load a climbing rope can hold?
The answer leads to some limiting factors when you look into it. When you buy a rope from a quality brand, you can roughly assume that it can bear your weight easily. To be fair, that’s quite a safe assumption.
The ropes manufactured by quality brands go through rigorous tests that ensure their strength to bear standard rock climbing weights. Moreover, these ropes can carry heavier loads than what you put on them.
But, since you won’t always be buying branded climbing ropes, you can’t work based only on these assumptions. As your lives will be hanging on the climbing rope, you need a better understanding of how much weight a climbing rope can hold.
Several key factors can influence the climbing rope working load. From the types (static climbing ropes and dynamic climbing ropes) to the weight being supported, there are several aspects that you need to consider.
In this article, we will have an indepth look at these influencing factors and also present you with the standard testing for determining the strength of your climbing rope.
Let’s get along with the details!
General Idea of Climbing Rope Weight
Do you know?
Climbing ropes tend to have a breaking strain of as much as 2,500kg, which is way more than a car or even an SUV!
That’s how much strength this little piece of the climbing tool can have. The overall strength of a climbing rope depends on its weight. Its diameter and length largely determine the weight of a climbing rope.
In general, a skinner rope will be lighter than a thicker one. However, the core construction is a factor that can make a skinny climbing rope heavier than a thick rope.
When we go by the types, the weight of a static rope is often given as weight per foot. Besides, the standard weight for a dynamic rope is listed as grams per meter. You can use the grams per meter number and the length of the climbing rope to calculate its overall weight.
Key Considerations to Determine the Strength of Your Climbing Rope
The following are some few considerations that help to determine the strength of your climbing rope:
Types of Climbing Ropes
Different climbing ropes come with varying weight capacities. When we talk about the types of climbing ropes, we mean,
- Static Ropes, and
- Dynamic Ropes
We have already mentioned above the standard weight calculation method of each of these types. But since the static ropes won’t stretch under the weight of any load, they are not suitable for rock climbing.
On the other hand, dynamic ropes possess stretching ability even under different loads, which makes them appropriate for rock climbing.
There are three different types of dynamic ropes. They are:
Single ropes are ideal for traditional climbing, sport climbing, big-wall climbing, and top climbing. These common types of ropes come in different lengths and diameters, which influences the overall weight capacity.
When using single ropes, the diameter is generally wider, as one rope is entitled to do all of the leg work. These ropes are suitable for a wide range of climbing disciplines and are easier to handle than the two-rope system.
Half ropes are comparatively thinner than single ropes. When using the half rope technique, the load gets distributed over two thinner ropes that are attached to different pieces of equipment.
Due to this, it is difficult to determine the weight load of one rope in isolation as the weight and forces get distributed across two thinner ropes. These are popular for traditional climbing on wandering multi-pitch rock routes, as well as for mountaineering and ice climbing.
Like half ropes, twin ropes are a two-rope system. The only difference is that in this technique, the two ropes used are attached to one piece of equipment and location.
This technique can shift how the weight is distributed. Both the ropes which are thinner than single ropes bear part of the load.
Difference Between Static and Dynamic Weight
To get the details about what can influence the weight-load capacity for your rope, you need to get acquainted with the difference between static and dynamic weight.
In general, static refers to idle weight. To take the best example of static weight, you can refer to the situation when you are hanging on the rope and not moving. Now you calculate the maximum static weight a rope can hold without breaking.
On the other hand, dynamic weight means the weight that is moving. If you fall while climbing, the combined force of the fall adds to the weight. For this reason, you must make sure that the dynamic weight can support you and your load in case of a fall.
When looking at the weight capacity that your rope can hold, it is essential to consider both the static and dynamic weights.
Factors that Influence Weight Capacity of the Climbing Rope
Here are some of the factors that can directly influence the weight-bearing capacity of your climbing rope:
The diameter of ropes varies based on the type. For instance, single ropes can vary in diameter from 9.4mm to about 11mm, with an average of 10.5mm.
Likewise, half ropes have a diameter of about 8mm to 9mm, while twin ropes are usually about 7mm to 8mm in thickness.
On the other hand, static ropes, commonly measured in inches, have a diameter of about 9mm to 13mm.
Ropes with a higher diameter typically bear greater loads. The bigger the diameter of the rope, the more weight it can hold. However, climbers prefer to invest in thinner ropes because it will be easier to handle on challenging climbs.
Length is another factor that impacts the weight-bearing capacity of your climbing rope. Generally, dynamic climbing ropes for rock climbing range in length from 30m to 80m. The standard length of a rope is 60m, which will meet your needs most of the time.
The formula is simple if the strength of the rope is related to the energy required to break it. A longer rope is considered more durable than shorter ones.
If you are opting for outdoor climbing, you need a rope that is about 60m or more in length. On the other hand, for indoor gym climbing, a shorter rope about 35m long should do the job nicely.
You may be adding knots for your safety, but you should be aware that different knots can influence the weight capacity of your rope.
Though knots tend to decrease the overall weight that your rope can support, the strength of the rope can outweigh any knot that you can tie into it.
As per the study conducted by Lyon Equipment Limited on the impacts of different kinds of knots on rock climbing ropes, these are the results:
- Double Figure-of Eight Knots, which are common in rock climbing, was found to retain between 66% to 77% of a rope’s full strength.
- Barrel Knots, which are used to tie to the carabiner, were found to keep 67% to 77% of a rope’s strength.
- Double Overhand Knots were found to retain only 58% to 68% of a rope’s strength.
No matter which knot you use, you will weaken your rope. Moreover, depending on which one you prefer, you could be reducing the weight even more.
Estimated Weight Capacity of Climbing Rope
The actual strength of a rope differs between different types. If we take the example of Lyon Equipment Limited’s comprehensive study on a specific set of tested ropes, we can get some rough estimations.
Note: the testes ropes all are of a diameter of 10.5mm.
Now let’s have a look at the standard ultimate strength of some common 10.5mm climbing ropes:
The new Edelrid ropes of 10.5mm diameter can be expected to support a weight of up to a 28.4kN to 28.9kN. Besides, the ropes that have undergone light glazing can withstand a force of 38kN to 30kN. Finally, the Edelrid ropes with minimal damage can bear the force up to 27kN.
When talking about Beal ropes, the ones with 10.5mm diameter and only minimal damage can withstand forces up to 24.5kN.
Marlow ropes that come with a diameter of 10.5mm and some light glazing can withstand forces up to 31kN, which is better than that of Edelrid and Beal ropes.
When testing the rope’s ability to withstand dynamic forces, the major factor that comes into play is an impact force. The dynamic ropes with wider diameter can do more to combat impact forces.
The length of a rope affects the impact force of a fall. Shorter ropes have less ability to absorb the shock of a fall, meaning that the impact force will be greater.
We will talk more about the impact force in our standard testing technique.
Some Standard Testing
These standard tests are carried out by the manufacturers under specific fall conditions where the impact force test is the most crucial.
The impact force is used to measure the energy that can act on the drop weight during a standard fall. If the climbing rope is more elastic, it takes sooner for this energy to be partially captured and dissipated.
When the impact is usually high, you perceive the fall as severely violent. It also increases the release of energy that acts on the climbing rope.
For instance, both single and twin rope types must have an impact force of 12kN. It means that you can carry a maximum weight of 2,646 pounds (1,200 kilograms). On the other hand, half ropes must come with a maximum impact force of 8kN for a maximum payload of 1,764 pounds (800 kilograms).
Few Important Tips to Consider
Besides the key considerations mentioned above, you need to keep these few tips on mind for determining the weight-bearing strength of your climbing rope:
- Newer ropes have a higher static and dynamic weight capacity. As they get used more, they start to become weaker.
- The more impact force the ropes absorb, the weaker they will become. It means that if you had multiple falls, your rope would likely bear less weight than the standard.
- You should always check on your ropes to make sure they are in the best condition. If you notice any wear, replace it with the new ones.
Table of Content
- General Idea of Climbing Rope Weight
- Key Considerations to Determine the Strength of Your Climbing Rope
- Factors that Influence Weight Capacity of the Climbing Rope
- Estimated Weight Capacity of Climbing Rope
- Some Standard Testing
- Few Important Tips to Consider
Frequently Asked Questions (FAQs)
The force rating of the climbing rope indicates the maximum amount of force it can deliver to a falling climber, which is measured in kilonewtons (kN), under test conditions designed to simulate a hard or violent fall. Usually, climbing ropes range from 9kN up to 24kN.
Well, this depends on your climbing route. If the route is 30m long, you need at least a 60m climbing rope to be able to climb up and be lowered back down off of an anchor. On the other hand, the new sport-climbing routes require a 70m rope to lower to the ground.
We hope you had a clear idea of what factors affect the strength of your climbing rope. To be precise, to get the most out of your climbing rope, you need to make sure the rope is always in tip-top condition. Not to forget, you will have great peace of mind as you start to take on the climbs.