EN 892 Requirements for Dynamic Mountaineering Ropes

Every mountaineer and climber knows what a dynamic rope is and uses one regularly. Far fewer can explain how dynamic ropes differ from one another, apart from length, diameter, and color. Fewer still know exactly what properties a rope must have in order to be considered dynamic under internationally recognized safety standards.

So let’s dive into the world of modern standards and look at the certification requirements for one of the most important pieces of climbing equipment.

A dynamic rope is a synthetic rope composed of a core enclosed in a sheath — a construction known as kernmantel — and used to arrest a user’s fall while limiting the maximum impact force.

The main quality benchmark for modern dynamic ropes is the European standard EN 892, officially titled “Mountaineering equipment — Dynamic mountaineering ropes — Safety requirements and test methods.”

In the European Union, no dynamic rope can be sold without certification to this standard. By certification, we mean an independent assessment of equipment against the requirements set out in the relevant standard. By contrast, in Russia and the United States, dynamic ropes are not subject to mandatory certification, so, formally, all kinds of products may appear on the market.

At the time of writing, the current version of the European standard is EN 892:2012+A3:2023, but for simplicity we will refer to it as EN 892.

Now let’s look at how the standard classifies dynamic ropes and what requirements they have to meet.

EN 892 classifies dynamic ropes into three types:

• Single ropes
• Half ropes
• Twin ropes

Before the tests described below, all rope test samples are dried for at least 24 hours at a temperature of 50 ± 5 °C and a relative humidity of less than 20%. The samples are then conditioned for at least 72 hours at 23 ± 2 °C and 50 ± 2% relative humidity. The tests themselves are carried out at 23 ± 5 °C and must begin within 10 minutes after the samples are removed from the conditioning chamber.

Since moisture is known to affect the properties of polyamide ropes, standardizing the samples in this way helps ensure that the test results are consistent and comparable.

To determine the diameter, one end of the rope is clamped, and a load is applied gradually and without shock to the other end:

• 10 kg for single ropes;
• 6 kg for half ropes;
• 5 kg for twin ropes.

The load is applied for 1 minute at a distance of at least 1.2 m from the clamp. Then, without removing the load, a 1 m reference length is marked within the next 10 seconds. The distance from the clamp or attachment point to the reference-length marking must be at least 50 mm.

Without removing the load from the test sample, the diameter is then measured within the next 3 minutes at three different cross-sections, each perpendicular to the rope axis and approximately 100 mm apart. In each cross-section, two measurements are taken at 90° to each other. The contact areas of the measuring instrument must be 50 ± 1 mm long, and the rope must not be compressed during measurement.

The result is calculated as the arithmetic mean of the six measurements and expressed to the nearest 0.1 mm.

The standard does not set any specific minimum or maximum diameter for dynamic ropes. Interestingly, however, the sheath slippage test apparatus, which we will look at later, has 12 mm openings. This makes it effectively impossible to test ropes of larger diameter using the prescribed apparatus — although, in practice, this is hardly a problem for modern dynamic climbing ropes.

To determine rope weight, the marked 1 m portion of the same test sample used for the diameter measurement is cut out and weighed. The result is then expressed as the rope’s mass per unit length, usually in grams per metre (g/m).

EN 892 does not set any minimum or maximum weight for dynamic ropes, but it does require the rope’s mass per unit length to be stated in the product information.

To determine sheath slippage, a rope sample is pulled through a special apparatus where radial forces restrict its movement. The resulting friction on the sheath causes it to slip relative to the core.

The test is carried out on two new rope samples.

One end of each sample is fused so that the sheath and core are joined together. Before the other end is cut to the required length of 2,250 mm, adhesive tape is applied to the cutting point in a prescribed way. The rope is then cut so that the piece of tape remaining on the test sample is about 10 mm wide. The tape and the way it is applied should reduce the amount of fibre unraveling at the cut end, but must not interfere with slippage between the sheath and the core.

The sheath-slippage apparatus consists of a frame made from steel plates: four fixed plates and three moving plates that can slide along a defined path. The moving plates are arranged at 120° to one another. Each of the seven plates has a 12 mm opening. The moving plates can also be locked so that all the openings are aligned along the central axis of the apparatus.

When released from the locked position, each moving plate applies a force of 50 N — roughly equivalent to the weight of a 5 kg mass — to the test sample in its own direction. The sheath-slippage apparatus is mounted horizontally, and the rope sample must lie in the same plane as the central axis of the apparatus.

At the start of the test, the moving plates are locked, with all openings aligned along the central axis of the apparatus.

The fused end of the 2,250 mm rope sample is inserted into the apparatus and pulled through by 200 mm. The remaining length of the rope must lie horizontally and in line with the central axis of the apparatus, without being loaded or bent. The moving plates are then released, and each of them applies a force of 50 N to the test sample. The rope sample is pulled through the apparatus at a speed of 0.5 ± 0.2 m/s for a distance of 1,930 mm. The load is then removed by locking the plates, and the sample is carefully pulled back through the apparatus to its starting position.

This procedure is repeated three times. It is then carried out once more, but this time the load is not removed from the moving plates at the end of the pull. While the sample is still in the apparatus and still under load, the sheath slippage relative to the core is measured at the open end of the rope sample.

Sheath slippage is calculated as a percentage of the 2,000 mm sample length. The result is recorded for each of the two test samples to the nearest 0.1%.

To pass certification, the displacement of the sheath relative to the core must not exceed 1%, or 20 mm.

The test is carried out on:

• a single strand for single ropes;
• a single strand for half ropes;
• a double strand for twin ropes.

The test samples are clamped so that the free test length of the rope (or ropes) is 1,500 mm, excluding the clamps and knots. After that:

1. A load of 80 kg is applied gradually and without shock to the end of the sample and held for 3 minutes.
2. The load is then removed, and the rope is left to rest for 10 minutes.
3. Next, a load of 5 kg is applied to the sample and held for 1 minute. A 1,000 mm reference length is then marked on the rope.
4. Finally, the load is increased again to 80 kg and held for 1 minute. Without removing the load, the new distance between the reference marks is measured. This value is recorded as L1.

Static elongation (E) is calculated to the nearest 0.1% using the formula:

E = (L1 − 1,000) / 10
where L1 is the length after the load has been applied.

To comply with the standard, static elongation must not exceed:

• 10% for single ropes;
• 12% for half ropes;
• 10% for twin ropes.

The drop-test apparatus is a combination of several devices and structural elements. It includes:

• a bollard and clamps for the rope ends;
• an orifice plate;
• a metal falling mass guided by vertical rails;
• a sensor for measuring the peak force during fall arrest;
• equipment for measuring the peak extension of the rope during the drop.

The apparatus must be sufficiently precise and rigid to ensure the required accuracy and reproducibility of the results. Its rigidity is checked by applying a static load of 16 kN to the rope: under this load, the orifice plate must not move by more than 1 mm from its initial position. The apparatus must also include a system for timing the descent of the falling mass. This is used to check that the guidance system does not interfere with the mass’s free fall.

The mass of the test weight, including attachment points, bearings, and other structural elements, must be:

• 80 kg for single ropes;
• 55 kg for half ropes;
• 80 kg for twin ropes.

The falling mass must be made of metal and must fall strictly along the guide rails.

The test is carried out on three new rope samples: 5 m long for single and half ropes, and 10 m long for twin ropes.

For single and half ropes, the sample is attached to the falling mass with a figure-eight knot with an internal loop length of 50 mm. The knot must be tied without crossed strands and tightened by hand, pulling each strand alternately. For twin ropes, the mass is attached with a figure-eight knot tied in the middle of the rope.

The test sample is then passed through the orifice plate, wound three times around the bollard, and secured in the clamp. The rope is marked at the clamp to detect any slippage during the test.

The falling mass is then used to apply a static load to the rope sample for 60 seconds. The sample is adjusted so that the length of rope from the lower edge of the orifice to the attachment point on the falling mass is 2,500 mm. When twin ropes are tested, the tension in both strands must be similar.

Before each drop, the falling mass is raised so that the attachment point is 2,300 mm above the lower edge of the orifice. This gives a fall factor of approximately 1.7.

The falling mass is released by a quick-release device and falls freely with no initial velocity. There must be no external influence on the free fall of the mass onto the rope.

During the first drop, two values are recorded:

• the peak force during fall arrest, expressed to the nearest 0.1 kN;
• the maximum dynamic elongation calculated as the peak extension of the rope during the first drop, expressed as a percentage of 2,800 mm, to the nearest 1%.

The test is then repeated until the sample breaks completely. The test sample must not break at the knot. If it does, the test is declared invalid and repeated with a new sample. If another sample also breaks at the knot, this fact is recorded separately, but the results are accepted. Only one repeat test due to knot breakage is allowed.

For every drop, the time interval in which the falling mass travels from the upper timing point to the lower timing point is recorded. This interval must be between 120.6 and 122.9 ms. If it falls outside this range, the fall energy is incorrect and the test is invalid. In that case, the test must be repeated with a new sample.

After each drop, the load is removed from the sample within 60 seconds. The interval between consecutive drops on the same sample must be 300 ± 15 seconds, measured from release to release.

The rope ends must be secured in the clamp so that the sample cannot slip. If the rope slips in the clamp by more than 5 mm, the result is not accepted and the test is repeated with a new sample.

Finally, the number of drops sustained by each sample without breaking is recorded. Any breakage at the knot is also recorded.

To meet the requirements of EN 892:

• Dynamic elongation during the first drop must not exceed 40%.
• The peak force during the first drop must not exceed:

- 12 kN for single ropes;
- 8 kN for half ropes;
- 12 kN for twin ropes.

• The rope must withstand:

- at least 5 drops for single and half ropes;
- at least 12 drops for twin ropes.

Both ends of the rope must have durable bands, no more than 30 mm wide measured along the length of the rope. These bands must be marked clearly, indelibly, and permanently with at least the following information:
a) the name or trademark of the manufacturer, or the manufacturer’s authorized representative;
b) the graphical symbol indicating the rope type;
c) the rope diameter;
d) the year of manufacture;
e) the rope length.

For ropes sold as PPE in the European market, the product also carries the CE mark with the four-digit identification number of the notified body involved in the standard conformity assessment.

These are the main certification tests and requirements set out in EN 892.

Of course, this overview does not cover every detail of the standard. If you want, for example, detailed descriptions of all the test apparatuses and setups, you should consult the full text of the standard.

It is also worth noting that EN 892:2012 does not include tests or requirements for parameters such as knotability and sheath/core mass percentage. Nevertheless, both values still sometimes appear in the specifications of modern dynamic ropes, which can be a bit confusing.

Perhaps some manufacturers still carry out these measurements out of habit, remembering EN 892:1997, where requirements for knotability and the mass ratio between the sheath and the core were indeed present. Or perhaps it is simply easy for them — and useful for customers — to run a couple of additional tests, since manufacturers are already used to performing similar measurements when testing low-stretch kernmantel ropes under EN 1891:1998, where these requirements are also included.

In any case, we will look at this in future articles — along with the voluntary UIAA 110 standard for static ropes and UIAA 101 for dynamic mountaineering ropes. The latter, by the way, includes a fairly strict requirement for water-repellent performance. But that is a different certification story... So, see you soon!