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EN 1891 Standard for Static Ropes
EN 1891 Standard for Static Ropes
Image source: coloradozipline.net
Written in January 2024.
The relevance of information might change over time.
Written in January 2024.
The relevance of information might change over time.
While dynamic ropes, the certification of which we discussed in the previous article, cater to a highly specialized audience, including climbers, mountaineers, and rope jumpers, static ropes serve a much broader purpose. They find application not only among outdoor enthusiasts like the aforementioned climbers, cavers, and canyoneers but also among professionals in various fields. This includes rope access and construction workers, arborists, riggers, rescuers, military personnel, and even individuals undertaking DIY roof repairs. Static ropes serve purposes such as ascent, descent, raising, lowering, positioning, restraint, fall arrest, tensioning, and a multitude of other tasks. The range of applications is incredibly broad!
But what exactly are static ropes? Why are they often referred to as semi-static or low stretch kernmantel ropes? What characteristics make these ropes so versatile? What are the minimum certification requirements, and how are they verified? Throughout this article, we will explore and understand all these aspects, guided by the fundamental quality standard – EN 1891.
But what exactly are static ropes? Why are they often referred to as semi-static or low stretch kernmantel ropes? What characteristics make these ropes so versatile? What are the minimum certification requirements, and how are they verified? Throughout this article, we will explore and understand all these aspects, guided by the fundamental quality standard – EN 1891.
Contents:
- STATIC ROPE DEFINITION
- THE "STATIC" PROBLEM
- CLASSIFICATION
- MATERIAL
- SAMPLE CONDITIONING
- DIAMETER
- MASS
- SHEATH/CORE PERCENTAGE
- SHEATH SLIPPAGE
- KNOTABILITY
- SHRINKAGE
- ELONGATION
- STATIC STRENGTH WITHOUT TERMINATIONS
- STATIC STRENGTH WITH TERMINATIONS
- DYNAMIC TESTS
- FALL ARREST PEAK FORCE
- DYNAMIC PERFORMANCE
- MARKING
- SUMMARY OF EN 1891 REQUIREMENTS
Static Rope Definition
Interestingly, defining the concept of static ropes is not as straightforward as one might think. To begin, what most people are accustomed to calling static ropes is formally referred to as "low stretch kernmantle ropes." This term originated from the European standard EN 1891-1998 titled "Personal protective equipment for the prevention of falls from a height - Low stretch kernmantel ropes ". Here's the definition from the standard:
The International Climbing and Mountaineering Federation (UIAA), with its voluntary standard UIAA-107, which historically served as the basis for EN 1891, does not refer to these ropes as static either. There, they are listed as "Low Stretch Ropes."
However, this wasn't enough — some have taken to labeling these intricate ropes as "semi-static", adding another layer to the confusion.
"A textile rope consisting of a core enclosed by a sheath, designed for use by persons in rope access including all kinds of work positioning and restraint; for rescue and speleology.
The characteristics required are low extension during normal working procedure but with the capacity to withstand forces generated by a fall. Some energy absorption of these impact forces is also desirable, the amount usually a compromise with the acceptable extension during normal working practice."
The International Climbing and Mountaineering Federation (UIAA), with its voluntary standard UIAA-107, which historically served as the basis for EN 1891, does not refer to these ropes as static either. There, they are listed as "Low Stretch Ropes."
However, this wasn't enough — some have taken to labeling these intricate ropes as "semi-static", adding another layer to the confusion.
Static ropes, aka semi-static ropes, aka low stretch kernmantel ropes.
Image source: marlowropes.com
The "Static" Problem
So, what's wrong with the so-familiar term "static ropes"? The issue lies in the fact that most low stretch kernmantle ropes (LSKR) aren't truly static compared to some other types of ropes. Let's take a look.
According to the EN 1891 standard, LSKR must not stretch more than 5%. The current market average hovers around 3-4%. However, for example, yachting ropes, crafted from various aramids and ultra-high-molecular-weight polyethylenes, might have a stretch of sometimes less than 1%. Ropes with such low elongation qualities are often referred to as true static or super static. Nevertheless, most of these models do not comply with the EN 1891 standard and are not considered means of protection against falls from height.
According to the EN 1891 standard, LSKR must not stretch more than 5%. The current market average hovers around 3-4%. However, for example, yachting ropes, crafted from various aramids and ultra-high-molecular-weight polyethylenes, might have a stretch of sometimes less than 1%. Ropes with such low elongation qualities are often referred to as true static or super static. Nevertheless, most of these models do not comply with the EN 1891 standard and are not considered means of protection against falls from height.
The GPX yachting rope from the Samson brand boasts a static elongation of 0.45%, 0.71%, and 0.98% at loads of 10%, 20%, and 30% of the Minimum Breaking Strength (MBS), respectively. The MBS for the 10 mm model is an impressive 62 kN. Such an outstanding performance is attributed to a blend of Dyneema forming the rope's core and a sheath made of a combination of Polyester and Technora. This is the essence of a true static rope!
Image source: samsonrope.com
This is because the rope must exhibit some degree of stretch to mitigate the impact of falls, which, despite efforts, cannot be completely avoided. Even a slight stretch of a few percent plays a critical role in preventing catastrophic consequences. The EN 1891 standard requires that the maximum load during a fall with a fall factor of 0.3 must not exceed 6 kN. Additionally, a LSKR must withstand at least 5 falls with a factor of 1. We will delve into these requirements in detail later on.
This sets up a paradoxical situation: on one hand, the less a static rope stretches, the more it is valued in the vast majority of cases. This is because when ascending or hauling something, one expends less energy overcoming the stretch. Furthermore, low stretch ropes, unlike spring-like dynamic ropes, tend to rub less on potentially hazardous surfaces, reducing the risk of being cut. Not to mention the importance of low elongation in mechanical advantage systems and for tensioning tyrolean traverses and ziplines.
Therefore, manufacturers find themselves in a delicate balance, striving for extremely low stretch while ensuring compliance with the standard's requirements for sufficient impact force reduction.
This sets up a paradoxical situation: on one hand, the less a static rope stretches, the more it is valued in the vast majority of cases. This is because when ascending or hauling something, one expends less energy overcoming the stretch. Furthermore, low stretch ropes, unlike spring-like dynamic ropes, tend to rub less on potentially hazardous surfaces, reducing the risk of being cut. Not to mention the importance of low elongation in mechanical advantage systems and for tensioning tyrolean traverses and ziplines.
Therefore, manufacturers find themselves in a delicate balance, striving for extremely low stretch while ensuring compliance with the standard's requirements for sufficient impact force reduction.
A tyrolean traverse over a river tensioned with low stretch kernmantel ropes.
Image source: wikimedia.org
It's worth noting that although EN 1891 is the one most often related, it is not the only standard regulating low stretch ropes. Other standards, such as NFPA 2500 (1983), ANSI Z359.15, CI-1801, XF 494... might have different requirements and their own nuances.
Classification
The EN 1891 standard distinguishes between two types of static ropes:
- Type A: low stretch kernmantel ropes for general use.
- Type B: low stretch kernmantel ropes with a lower performance than type A, intended for specialized or auxiliary tasks, requiring greater care.
Example of a Tendon static rope end marking. "A 11.0" indicates a type A rope with a diameter of 11 mm.
Image source: lanex.cz
Material
The materials used in the manufacturing of low-stretch kernmantle ropes must be synthetic fibers with a melting point of not less than 195°C. Consequently, materials like Polyethylene (to which, e.g., Dyneema® belongs) and Polypropylene, with their low melting temperatures, cannot be employed for producing either the sheath or core of static ropes according to the EN 1891 standard.
Sample Conditioning
Before undergoing certification tests, all rope samples are conditioned for 24 hours at a humidity level of less than 10%. Following this, the samples are stored for a minimum of 72 hours at a temperature of 20 ± 2 °C and a humidity of 65 ± 5%. The subsequent tests are carried out at a temperature of 23 ± 5°C.
Sterling rope conditioning (enviro) chamber.
Image source: sterlingrope.com
Diameter
EN 1891 standard requirement: The rope diameter shall be a minimum of 8,5 mm and a maximum of 16 mm.
Testing procedure: A single unused rope sample with a minimum length of 3000 mm is employed for the test. After one end of the sample is secured, a 10 kg load is applied without shock at a distance of at least 1300 mm from the attachment point (clamp or inner end a figure of eight knot) for 60-75 seconds. Then, without removing the load, the rope is measured "in two directions around the diameter, starting at points 90° apart, at each of three levels approximately 300 mm apart" (blink if you understood that from the first time). The measuring instrument's contact length must be 50 mm. Throughout the measurement process, the sample should not be compressed. The results are expressed as the arithmetic mean of six measurements with an accuracy of 0.1 mm.
Testing procedure: A single unused rope sample with a minimum length of 3000 mm is employed for the test. After one end of the sample is secured, a 10 kg load is applied without shock at a distance of at least 1300 mm from the attachment point (clamp or inner end a figure of eight knot) for 60-75 seconds. Then, without removing the load, the rope is measured "in two directions around the diameter, starting at points 90° apart, at each of three levels approximately 300 mm apart" (blink if you understood that from the first time). The measuring instrument's contact length must be 50 mm. Throughout the measurement process, the sample should not be compressed. The results are expressed as the arithmetic mean of six measurements with an accuracy of 0.1 mm.
Measuring rope diameter according to the EN 1891 standard.
Image source: Edelrid Static Rope Handbook
Mass
Standard requirement: To determine the mass of the rope per meter (g/m).
Testing procedure: A single unused rope sample with a minimum length of 3000 mm is utilized for the test. After one end of the sample is secured, a 10 kg load is applied without shock at a distance of at least 1300 mm from the attachment point for 60-75 seconds. Then, with the load still applied, two marks are made on the rope sample 1000 mm apart and at least 100 m away from the attachment point. Subsequently, the load is removed, and the marked segment of the sample is cut off and its mass is measured to the nearest 0.1 g.
Testing procedure: A single unused rope sample with a minimum length of 3000 mm is utilized for the test. After one end of the sample is secured, a 10 kg load is applied without shock at a distance of at least 1300 mm from the attachment point for 60-75 seconds. Then, with the load still applied, two marks are made on the rope sample 1000 mm apart and at least 100 m away from the attachment point. Subsequently, the load is removed, and the marked segment of the sample is cut off and its mass is measured to the nearest 0.1 g.
Rope mass per unit length testing according to the EN 1891 standard.
Image source: Edelrid Static Rope Handbook
Sheath Percentage / Core Percentage
Static ropes feature a Kernmantel construction, comprising a core responsible for carrying the main load and a sheath that protects it against external factors. In general, a higher sheath percentage enhances the rope's resistance to abrasion, while a higher percentage of core contributes to greater breaking load.
Standard requirement: The percentage of sheath and the percentage of core, relative to the total mass of the rope must not be less than the minimum calculated by a individual formula for each diameter and type of rope.
Testing procedure: After measuring the total mass of the test sample (see the previous point), the sheath is separated from the core, and its mass is determined with an accuracy of 0.1 g. Then, the mass of the sheath and the mass of the core are calculated as a percentage of the total mass of the sample. The obtained values are expressed to the nearest whole number.
The minimum sheath percentage (Smin) for a particular rope is calculated using one of the following formulas:
Standard requirement: The percentage of sheath and the percentage of core, relative to the total mass of the rope must not be less than the minimum calculated by a individual formula for each diameter and type of rope.
Testing procedure: After measuring the total mass of the test sample (see the previous point), the sheath is separated from the core, and its mass is determined with an accuracy of 0.1 g. Then, the mass of the sheath and the mass of the core are calculated as a percentage of the total mass of the sample. The obtained values are expressed to the nearest whole number.
The minimum sheath percentage (Smin) for a particular rope is calculated using one of the following formulas:
Where S = sheath and D = rope diameter.
For example: The minimum sheath percentage for a type A static rope with a diameter of 11 mm is calculated as (4 x 11 - 4) : 11² x 100 = 33.06. Rounding to the nearest whole number, we get 33%.
The minimum core percentage (Cmin) is calculated based on the type of rope using one of the following formulas:
The minimum core percentage (Cmin) is calculated based on the type of rope using one of the following formulas:
- For type A ropes:
- For type B ropes:
Sheath Slippage
Sheath slippage occurs when the sheath and core of a rope shift relative to each other. This might happen when the same section of rope experiences multiple identical loads, such as during regular top-roping in a climbing gym or numerous descents on a fixed line.
Sheath slippage poses a potentially dangerous issue. One scenario involves the sheath bunching up, exposing the white strands of the core at the end of the rope. A less obvious and therefore more hazardous situation arises when there is no core left under the sheath. In this case, the end of the rope resembles a soft and hollow "stocking", incapable of withstanding significant loads and likely to slip through a belay or rappel device.
Though sheath slippage is a rare issue for modern ropes, especially as manufacturers increasingly employ various technologies like Beal "Unicore" and Tendon "TeFix" to bond the core with the sheath, it remains important to be aware of its possibility. Now, let's explore what the EN 1891 standard has to say about this.
Sheath slippage poses a potentially dangerous issue. One scenario involves the sheath bunching up, exposing the white strands of the core at the end of the rope. A less obvious and therefore more hazardous situation arises when there is no core left under the sheath. In this case, the end of the rope resembles a soft and hollow "stocking", incapable of withstanding significant loads and likely to slip through a belay or rappel device.
Though sheath slippage is a rare issue for modern ropes, especially as manufacturers increasingly employ various technologies like Beal "Unicore" and Tendon "TeFix" to bond the core with the sheath, it remains important to be aware of its possibility. Now, let's explore what the EN 1891 standard has to say about this.
Sheath slippage illustration.
Image source: Tendon dynamic and static ropes manual
Standard Requirement: On a 1930 mm rope segment sheath slippage shall:
For example: The sheath slippage for an 11 mm type A static rope must not exceed 20 + 10 × (11 - 9) = 40 mm or 2%. Accordingly, if the total length of rope is 50 meters, the maximum sheath slippage shall not exceed 1 meter.
Testing Procedure:
To determine sheath slippage, the low-stretch kernmantel rope is drawn through a special device where its movement is restricted by radial forces that cause the sheath to slip relative to the core.
- Not exceed 20 mm + 10 (D - 9 mm) for type A ropes with a diameter up to 12 mm.
- Not exceed 20 mm + 5 (D - 12 mm) for type A ropes with a diameter from 12.1 to 16 mm.
- Not exceed 15 mm for type B ropes.
Where D is the rope diameter.
For example: The sheath slippage for an 11 mm type A static rope must not exceed 20 + 10 × (11 - 9) = 40 mm or 2%. Accordingly, if the total length of rope is 50 meters, the maximum sheath slippage shall not exceed 1 meter.
Testing Procedure:
To determine sheath slippage, the low-stretch kernmantel rope is drawn through a special device where its movement is restricted by radial forces that cause the sheath to slip relative to the core.
Apparatus for sheath slippage test.
Image source: edelrid.com
As a test sample, a segment of unused 2250 mm rope is utilized. On one end, the sheath and core of the specimen are fused together (heat sealed). The other end is cut at right angles to the axis of the sample rope.
The device for measuring sheath slippage consists of a frame made of steel plates —four fixed and three movable plates capable of sliding radially. Each movable plate is capable of applying a radial force of 50 N (~5 kg) on the test sample. The axes of the movable plates are arranged in a single plane, 120° apart from each other. Each of the seven plates has a opening with a diameter of 12-13 mm for testing ropes up to 12 mm and with a diameter of 16-17 mm for testing ropes from 12.1 to 16 mm. The movable plates incorporate a locking function, that, when activated, aligns the openings of all plates along a central axis.
The device for measuring sheath slippage consists of a frame made of steel plates —four fixed and three movable plates capable of sliding radially. Each movable plate is capable of applying a radial force of 50 N (~5 kg) on the test sample. The axes of the movable plates are arranged in a single plane, 120° apart from each other. Each of the seven plates has a opening with a diameter of 12-13 mm for testing ropes up to 12 mm and with a diameter of 16-17 mm for testing ropes from 12.1 to 16 mm. The movable plates incorporate a locking function, that, when activated, aligns the openings of all plates along a central axis.
Apparatus for sheath slippage test, where 1 – Moving plates, 2 – Spaces, 3 – Fixed plates.
Image source: EN 1891-1998
Before the test begins, the moving plates must be locked to ensure that the openings of all the plates are coaxial. The sealed end of the 2250 mm rope sample is passed through the apparatus for a length of 200 mm. The open end of the rope sample must lie in the horizontal position in a straight line and shall not be subjected to any loads. Subsequently, the moving plates are unlocked, causing each of them to apply a force of 50 N to the rope. The rope sample is then pulled through the device at a speed of 0.5 ± 0.2 m/s for a distance of 1930 mm. After that, the load is removed, the sliding plates are locked and the test sample is passed back through the device to its original position. The test is repeated four more times (five in total) in the aforementioned order. After the last test, the rope sample is removed from the test apparatus, and the relative slippage of the sheath along the core (V) is measured at the open end and expressed to the nearest millimeter. Then, the percentage slippage (Ss) is calculated with an accuracy of 0.1% using the formula:
Apparatus for testing sheath slippage according to the EN 1891 standard.
Image source: Edelrid Static Rope Handbook
Knotability
The knotability ratio determines the flexibility of a new rope and, consequently, the ease of tying knots on it. Although all ropes tend to stiffen with time, depending on their condition and history of use, knotability is a useful parameter for initial differentiation of various models.
Standard requirement: Knotability shall be less than 1.2.
Testing procedure: An unused rope sample with a minimum length of 3000 mm is utilized for the test. Two single overhand knots are tied on the rope, spaced 250 ± 50 mm apart, with loops running in opposite directions. After securing one end of the sample, a 10 kg load is applied without shock for 60-75 seconds, ensuring that the load affects both knots. Then, the load is reduced to 1 kg and maintained, while the internal diameter of the knots is measured to the nearest 0.5 mm, using a tapered plug gauge. Care is taken to prevent any alteration of the free width of the knot under the pressure of the measuring device.
Standard requirement: Knotability shall be less than 1.2.
Testing procedure: An unused rope sample with a minimum length of 3000 mm is utilized for the test. Two single overhand knots are tied on the rope, spaced 250 ± 50 mm apart, with loops running in opposite directions. After securing one end of the sample, a 10 kg load is applied without shock for 60-75 seconds, ensuring that the load affects both knots. Then, the load is reduced to 1 kg and maintained, while the internal diameter of the knots is measured to the nearest 0.5 mm, using a tapered plug gauge. Care is taken to prevent any alteration of the free width of the knot under the pressure of the measuring device.
Knotability (K) is calculated as the average value of the internal diameters of both knots, divided by the diameter of the rope sample. In other words, the knot should be tight enough so that the width of its internal opening is less than the diameter of the rope multiplied by 1.2. Much clearer, isn't it?
Image source: EN 1891-1998
Shrinkage
Shrinkage refers to the irreversible shortening of a rope, primarily induced by exposure to water. In the EN 1891 standard, shrinkage is quantified as the percentage of shortening of the rope after a 24-hour immersion in water.
Shrinkage may occur asymmetrically on each end of the rope, posing a particular concern when the rope features a middle mark.
Image source: petzl.com
Standard requirement: To determine the rope shrinkage.
Testing procedure: A single unused rope sample with a minimum length of 3000 mm is utilized for the test. After securing one end of the rope, a 10 kg load is applied without shock at a distance of at least 1300 mm from the attachment point for 60-75 seconds. Subsequently, with the load still applied, two marks are made on the rope sample 1000 mm apart (LA) and at least 100 mm away from the attachment point. The load is then removed. After first ensuring that the ends of the rope sample are fused, it is submerged in clean water within a temperature range of 15 ± 5 °C and a pH range of 5.5 - 8.0 for a period of 24 hours. Within 15 minutes of removal the sample from the water, the load of 10 kg is reapplied for a period of 60 seconds. Without removing the load, the new distance between the two previously applied marks (LB) is measured and expressed with an accuracy to the nearest millimeter.
Shrinkage is calculated using the following formula and expressed as a percentage to the nearest 0.1%.
Testing procedure: A single unused rope sample with a minimum length of 3000 mm is utilized for the test. After securing one end of the rope, a 10 kg load is applied without shock at a distance of at least 1300 mm from the attachment point for 60-75 seconds. Subsequently, with the load still applied, two marks are made on the rope sample 1000 mm apart (LA) and at least 100 mm away from the attachment point. The load is then removed. After first ensuring that the ends of the rope sample are fused, it is submerged in clean water within a temperature range of 15 ± 5 °C and a pH range of 5.5 - 8.0 for a period of 24 hours. Within 15 minutes of removal the sample from the water, the load of 10 kg is reapplied for a period of 60 seconds. Without removing the load, the new distance between the two previously applied marks (LB) is measured and expressed with an accuracy to the nearest millimeter.
Shrinkage is calculated using the following formula and expressed as a percentage to the nearest 0.1%.
Rope sample immersed in water during the shrinkage test according to the EN 1891-1998 standard.
Image source: Edelrid Static Rope Handbook
Elongation
Elongation, as per the EN 1891-1998 standard, indicates the extent of rope stretch under a 150 kg static load. This parameter aims to illustrate the rope's behavior in practical scenarios, simulating the weight of a user on the rope or a lowered load. It's important to note that 150 kg is not a universal figure, and real life loads, and consequently elongation, may vary significantly depending on the application. That is why manufacturers who surpass standard requirements by measuring elongation for various loads are particularly commendable, as they provide a much better understanding of a specific rope's performance.
In accordance with the EN 1891-1998 standard, the elongation of the rope shall not exceed 5% under a 150 kg load.
Image source: Edelrid.com (left) Tendon dynamic and static ropes manual (right)
Standard requirement: Elongation under a 150 kg load shall not exceed 5%.
Testing procedure: A single unused rope sample with a minimum length of 3000 mm is employed for the test. After one end of the sample is secured, a 50 kg load is applied without shock and maintained for 5 ± 0.5 minutes. With the load still applied, two marks are made on the rope sample 1000 mm apart (LA). The load is then increased to 150 kg and maintained for an additional 5 ± 0.5 minutes. Without removing the load, the new distance between the two previously placed markings (LB) is measured with an accuracy to the nearest millimeter.
Elongation is calculated using the following formula and expressed as a percentage to the nearest 0.1%.
Testing procedure: A single unused rope sample with a minimum length of 3000 mm is employed for the test. After one end of the sample is secured, a 50 kg load is applied without shock and maintained for 5 ± 0.5 minutes. With the load still applied, two marks are made on the rope sample 1000 mm apart (LA). The load is then increased to 150 kg and maintained for an additional 5 ± 0.5 minutes. Without removing the load, the new distance between the two previously placed markings (LB) is measured with an accuracy to the nearest millimeter.
Elongation is calculated using the following formula and expressed as a percentage to the nearest 0.1%.
Static Strength without Terminations
Static strength characterizes the maximum load a rope can withstand before breaking. Generally, meeting the standard requires the rope to endure the specified minimum load. However, manufacturers often conduct tests to complete failure to indicate the actual load at which the rope breaks. The wording "without terminations" implies testing the rope without end knots, sewn loops, and other elements that can affect the strength of the rope.
Standard requirement: A rope without terminations must sustain:
Standard requirement: A rope without terminations must sustain:
- Not less than 22 kN for type A ropes.
- Not less than 18 kN for type B ropes.
EN 1891-1998 standard requirements for the static strength of ropes without terminations.
Image source: edelrid.com
The testing procedure involves referring to another standard – EN 919:1995, titled "Fibre ropes for general service". However, this standard goes beyond the scope of our current discussion. So, maybe next time :)
Testing the static strength of ropes without terminations according to the EN 1891-1998 standard.
Image source: Edelrid Static Rope Handbook
Static Strength with Terminations
Standard requirement: low stretch kernrnantel ropes with terminations shall sustain the following loads for a period of 3 minutes:
Testing procedure: A single unused rope sample, with a minimum length of 3000 mm and terminations at both ends in loops (at least one formed by a figure-eight knot), is employed for the test. The two rigid attachment points shall be in the form of a ring with a 20 mm bore and a 15 mm diameter cross-section, or a rod of the same diameter cross-section. The minimum rope length between the attachment points of the test machine, excluding terminations, must be 300 mm before applying any load. The knots must be symmetrical and hand-tightened equally, with strands lying parallel. The sample is installed in the test machine and subjected to the specified load: 15 kN for type A and 12 kN for type B for a period of 3 minutes. Requirements for force measurement and the rate of stressing are specified in standard EN 364 "Personal protective equipment against falls from a height. Test methods."
- Not less than 15 kN for type A ropes.
- Not less than 12 kN for type B ropes.
Testing procedure: A single unused rope sample, with a minimum length of 3000 mm and terminations at both ends in loops (at least one formed by a figure-eight knot), is employed for the test. The two rigid attachment points shall be in the form of a ring with a 20 mm bore and a 15 mm diameter cross-section, or a rod of the same diameter cross-section. The minimum rope length between the attachment points of the test machine, excluding terminations, must be 300 mm before applying any load. The knots must be symmetrical and hand-tightened equally, with strands lying parallel. The sample is installed in the test machine and subjected to the specified load: 15 kN for type A and 12 kN for type B for a period of 3 minutes. Requirements for force measurement and the rate of stressing are specified in standard EN 364 "Personal protective equipment against falls from a height. Test methods."
Testing the static strength of ropes with terminations in accordance with the EN 1891-1998 standard.
Image source: Edelrid.com (left), Edelrid Static Rope Handbook (right)
Dynamic Tests
As mentioned at the beginning of the article, low stretch kernmantel core ropes must possess some shock absorbing capabilities. While no one anticipates free-falling on a static rope with a factor of 2, especially without a shock absorber, breaking one's spine by a mere slip shouldn't occur either. Therefore, the EN 1891-1998 standard requires two dynamic tests to be conducted sequentially on the same rope sample:
Equipment: The apparatus for testing dynamic performance must meet the requirements of EN 364 standard on "Personal protective equipment against falls from a height. Test methods". The falling mass shall be made of metal and weigh 100 kg for type A ropes and 80 kg for type B ropes, including the fixing bracket and, if applicable, the measuring device. The shape of the mass is not specified, except that the distance between the point of attachment of the rope on the rigid structure and the point of attachment on the falling mass shall not exceed 100 mm. If the falling mass is guided, its speed, measured over a section of 100 mm in the range of 4.95 - 5.05 m beneath the release point, shall be 9.9 m/s. This ensures control over the friction allowed in a guiding device during the mass fall.
- The fall arrest peak force test, and
- The dynamic performance test, which involves measuring the number of falls until the rope breaks.
Equipment: The apparatus for testing dynamic performance must meet the requirements of EN 364 standard on "Personal protective equipment against falls from a height. Test methods". The falling mass shall be made of metal and weigh 100 kg for type A ropes and 80 kg for type B ropes, including the fixing bracket and, if applicable, the measuring device. The shape of the mass is not specified, except that the distance between the point of attachment of the rope on the rigid structure and the point of attachment on the falling mass shall not exceed 100 mm. If the falling mass is guided, its speed, measured over a section of 100 mm in the range of 4.95 - 5.05 m beneath the release point, shall be 9.9 m/s. This ensures control over the friction allowed in a guiding device during the mass fall.
100 kg falling mass for the dynamic tests of low stretch kernmantel ropes according to the EN 1891-1998 standard.
Image source: Edelrid Static Rope Handbook
Sample: A single unused rope sample with a minimum length of 4000 mm and terminations at both ends in loops (at least one formed by a figure-eight knot), is utilized for the test. The length of the termination loops from the inner end of the termination (including the knot or any other fastening arrangement except splicing) to the outer edge of the loop shall be 175 ± 25 mm while under a load of 100 kg for type A ropes and 80 kg for type B ropes. Knots must be symmetrical and hand-tightened equally, with strands lying parallel. The length of the test sample when suspended by the above mentioned mass shall be 2000-2100 mm when measured between the attachment points of the rigid structure and the suspended mass.
Rope sample length for the dynamic tests: 1 – Figure of eight knot, 2 – Termination loop
Image source: EN 1891-1998
Fall Arrest Peak Force
Standard requirement: The peak force after a fall of a 100 kg mass for type A ropes and an 80 kg mass for type B ropes, with a factor of 0.3, shall not exceed 6 kN.
Testing procedure: The first test is conducted on a sample prepared according to the previously outlined requirements within 10 minutes after removing the rope from the conditioning chamber. Initially, a mass of 100 kg for type A ropes or 80 kg for type B ropes is suspended for 1 minute. Then, it is raised by 600 mm at a maximum of 100 mm horizontally from the rigid anchor point. Subsequently, the mass is dropped using a quick-release device, and the peak force is measured with an accuracy of 0.1 kN.
Testing procedure: The first test is conducted on a sample prepared according to the previously outlined requirements within 10 minutes after removing the rope from the conditioning chamber. Initially, a mass of 100 kg for type A ropes or 80 kg for type B ropes is suspended for 1 minute. Then, it is raised by 600 mm at a maximum of 100 mm horizontally from the rigid anchor point. Subsequently, the mass is dropped using a quick-release device, and the peak force is measured with an accuracy of 0.1 kN.
The fall arrest peak force test according to the EN 1891-1998 standard involves dropping a rigid mass of 100 kg for type A ropes or 80 kg for type B ropes with a fall factor of 0.3.
Image source: Edelrid.com (left), EN 1891-1998 (right)
Within 1 minute after the drop, the load is released from the sample. Then, without removing the sample from the test rig, the first dynamic performance test is carried out in less than 3 minutes.
Dynamic Performance (Number of Falls)
Standard requirement: low stretch kernmantel ropes must withstand at least 5 falls with a fall factor of 1 without releasing the:
Testing procedure: The 100 kg mass for type A or 80 kg mass for type B is raised so that the attachment point of the mass is at the same height as the anchor point on the rigid structure and at a maximum of 100 mm horizontally from it. The load is then released by activating the quick-release device. After the fall, the load is removed from the rope sample within 1 minute, and the mass is lifted back to the initial height and position. The interval between the consecutive tests on the sample shall be 3 minutes. The test is conducted five times or until the rope breaks.
- 100 kg mass for type A ropes.
- 80 kg mass for type B ropes.
Testing procedure: The 100 kg mass for type A or 80 kg mass for type B is raised so that the attachment point of the mass is at the same height as the anchor point on the rigid structure and at a maximum of 100 mm horizontally from it. The load is then released by activating the quick-release device. After the fall, the load is removed from the rope sample within 1 minute, and the mass is lifted back to the initial height and position. The interval between the consecutive tests on the sample shall be 3 minutes. The test is conducted five times or until the rope breaks.
Dynamic performance test according to the EN 1891-1998 standard involves dropping a rigid mass of 100 kg for type A ropes or 80 kg for type B ropes with a fall factor of 1. The sample rope must withstand at least 5 falls.
Image source: Edelrid.com (left), Tendon dynamic and static ropes manual (right)
Unfortunately, no videos of dynamic tests by a certified laboratory were found. However, here are tests of old static ropes by Walter Siebert, which are enough for visualization and a better understanding of the process.
Marking
Low stretch kernmantel rope shall have external bands at both ends with the following permanent markings:
Additionally, low stretch kernmantel core ropes must have an internal identification tape along the entire length of the rope with markings repeated at least every 1000 mm, containing the following information:
- Rope type: "A" or "B".
- Diameter in millimeters.
- Standard number: "EN 1891".
Additionally, low stretch kernmantel core ropes must have an internal identification tape along the entire length of the rope with markings repeated at least every 1000 mm, containing the following information:
- The name or trade mark of the manufacturer, importer or supplier.
- The European Standard number (EN 1891) and the type of rope (A or B);
- The year of manufacture;
- The name of the material(s) from which the rope is made.
Illustration of the low stretch kernmantel rope identification tape and its markings.
Image source: petzl.com
And that's basically all the most important requirements of the EN 1891 standard!
Now, let's take a deep breath and summarize the info.
Now, let's take a deep breath and summarize the info.
Summary of EN 1891 Requirements
15.01.2024
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For more articles please visit the knowledge section
- Static Rope Definition
- Classification, Material, Sample Conditioning
- Diameter
- Mass
- Sheath Percentage / Core Percentage
- Sheath Slippage
- Knotability
- Shrinkage
- Elongation
- Static Strength without Terminations
- Static Strength with Terminations
- Dynamic Tests
- Fall Arrest Peak Force
- Dynamic Performance
- Marking
- Summary of EN 1891 Requirements
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