Static rope is designed to have a low elongation rate, has limited elasticity and is primarily produced for speleological purposes, and is therefore called “speleological”. Such a rope can withstand a fall with a factor of less than 1.
Static safety and rescue rope is used in mountaineering, industrial mountaineering, speleology and tourism for a fixed hitch, tensioning crossings, installing handrails and for hanging wells. For belaying a partner, it is used only if belaying with a static rope is carried out from above.
The main indicator of a static rope is elongation (which should not exceed 5%, and for some - 0%). The lower the elasticity of the rope, the lower the permissible fall factor.
The second indicator of a static rope is its strength (can reach 44 kn, but not less than 22 kn).
When choosing when you are going to buy a static rope, you must take into account that the working load should be approximately 1/10 of that declared by the manufacturer. Two types: Type - A, - used for rescue and high-altitude work, and in speleology. Type – B, can only be used for rappelling, as it is designed for a lower load and has a smaller diameter than a type A rope.
Conditions of use: Speleo - ropes, specially designed for speleology and have great wear resistance. Canyon rope floats on the surface and does not get wet, however, due to the use of polypropylene, it has less strength and the number of jerks.
Store this rope in a dry, dark place. Preferably in a case.
You can choose and buy a static rope from the options presented that meet all the requirements you need.
Buying a rope in the AlpExtrim online store means buying it cheaper!
Ropes are divided, according to their purpose, into dynamic, intended for climbers, and static, intended for industrial work at height, for rescue work and in caving. Static ropes are ropes with low stretch. They are used for insurance when working at heights, for rescue work, in caving, etc. It is important that a static rope has minimal stretch and maximum strength. Climbing rope - dynamic - designed for belaying climbers during falls. Its task is to ensure minimal load on a person even with a deep breakdown due to elongation.Rope construction
Static ropes are braided textile ropes, the construction of which consists of a core (1) and a braid (2). The core has the main load-bearing function and consists of individual cores. The braid protects the core from various influences (mechanical, chemical, thermal, etc.).Diameter measurement
This value is measured with a rope load of 10 kg. Minimum diameter 8.5 mm, maximum 16 mm.Rope extension
Static elongation is tested at a test load of 150 kg (preliminary measurement at 50 kg). Should be no more than 5%.Static strength (breaking load)
In accordance with the requirements of European and Russian standards, static ropes have a static strength of at least 22 kN (2200 kgf).ATTENTION! The recommended working load of the rope is 1/10 of the rated strength indicated on the product label.
Requirements in terms of material
Static rope must be made from a material that has a melting point above 195°C. Polyethylene and polypropylene cannot be used for their manufacture. Ropes are an exception for canyoning, but their strength complies with static standards.Braid displacement relative to core
When repeatedly climbing the rope on jumars and when descending the rope, there is a risk of the braid becoming dislodged. The rope test measures the displacement of the braid relative to the core. It is required that the displacement does not exceed 40 mm when pulling a rope length of 1930 mm, i.e. approximately ±1%.Dynamic impact during jerks
The number of falls is a measure of the safety (strength) of the rope. No new rope in good condition, when properly used, can, in practice, break at the specified breaking load. In accordance with the requirements, the rope must withstand at least five falls with a fall factor of 1 with an 80-kilogram load. A test sample 2 m long is tied at the ends with figure-of-eight knots and tested with five jerks with a fall factor of 1. The rope must withstand all five falls. In practice, the pull test continues until the rope breaks. This parameter is indicated in the product passport.
The safety of the rope gradually decreases due to aging of the material and wear, and its strength decreases. Humidity affecting the polyamide fibers also reduces the strength of the rope.
Knotting coefficient (rope stiffness)
One of the most important requirements for climbing ropes is reliable knotting. Hard rope doesn’t fit well in carabiners and doesn’t tie well into knots; working with soft rope is much more pleasant. How can I check this? A simple knot is tied on the rope and loaded with a mass of 10 kg. Then the ratio of the diameters of the free rope and the rope in the knot is measured. This is the nodal coefficient. It should not be higher than 1.2. Climbing rope- a special rope with special dynamic and strength properties, .
Climbing ropes are made mainly of polyamide (nylon, nylon; strong, elastic, wear-resistant, quite resistant to moisture and chemicals, except acids). Sometimes polyester is also used (less elastic and the rope does not hold the knot well), rarely Kevlar (Kevlar ropes are the strongest, but the least durable and do not hold the knot well).
There are currently two types of climbing ropes: twisted and braided, or cable type ropes. Usually, with the same material and the same thickness, a twisted rope, in comparison with a braided one, has better strength and dynamic characteristics. At the same time, due to the fact that a braided rope has a load-bearing core and a protective braid, it is better protected from mechanical damage and the adverse effects of solar ultraviolet radiation. A typical rope of this type has a core consisting of several tens of thousands of synthetic threads. They are distributed in two, three or more straight, braided or twisted strands, depending on the specific design and required performance characteristics.
There are two types of climbing ropes: twisted and braided, cable type ropes
According to the method of application, ropes are divided into dynamic ropes, static ropes and auxiliary ropes:
Dynamic ropes are used for belaying on a route (rocky or ice) when walking with a bottom belay. The main property of dynamic ropes is the ability to absorb dynamic shock arising.
Disadvantages of dynamic ropes:
- Dynamic ropes are soft and, as a rule, get very wet and frosty;
- Jumars hold worse on soft ropes;
- Strongly stretched out on the rappel;
- When contacting a rock, a dynamic rope rubs more than a static one;
- Dynamic ropes cannot be used under constant static loads (crossings, railings).
Dynamic rope production: MFH Int. Comp Germany
Dynamic ropes are divided into single rope, half rope and double rope (otherwise known as twisting rope).
Single rope (9 to 12 mm) - this type of dynamic rope, which by its design is intended for use for belaying during free climbing and has the necessary qualities for reliable fall arrest with a maximum factor of 2. Most suitable for sport ascents and ascents along simple “traditional” routes (where the route and work with a rope not very difficult).
A half-rope is a dynamic rope that must be doubled when belaying. A single half rope does not have the necessary qualities to withstand a factor 2 fall.
Half ropes have a thickness of 9 and 10 mm. When using a system of two half-ropes, they are fastened into different carabiners and different belay points, forming two parallel tracks. The half-ropes are snapped into the carabiners alternately, distributing one rope on the right in the direction of travel, the other on the left. Overlapping of ropes is not allowed. Usually half ropes of different colors are used. They are most suitable for more complex work with a rope, or when safety in the event of a fall is increased due to the reduced force of the jerk on divided ropes, or when it is necessary to organize.
Double rope - best for mountain routes (it is much lighter than two half ropes). It's easier to work with a single rope. As a rule, it is used more often than other types of ropes. It is also more versatile and a little cheaper than a twisting rope or 2 half ropes. A single rope is more stable in terms of susceptibility to mechanical damage. However, the advantages of using double ropes are quite significant and the choice is most often based on personal preferences and habits. From the point of view of safety in use, we can assume that they are equally safe.
UIAA and European requirements have been developed for ropes. If the rope satisfies them, then its use in mountaineering is possible.
UIAA and EN892 requirements for dynamic rope:
The jerk force should be no more than 12 kN at a jerk factor of 2 with a weight of 80 kg (55 kg for half rope or double rope).
The rope must withstand at least 5 jerks with a jerk factor of 2 and the weight specified above.
Elongation under load - should not be more than 8% under a load of 80 kg (for a half rope - elongation no more than 10% under a load of 80 kg).
Flexibility when tying knots - checked by measuring the diameter of the rope inside the knot under a load of 10 kg.
The displacement of the rope sheath relative to the core is 2 m. The ropes are pulled through a special device 5 times. The displacement of the rope sheath should be less than 40 mm.
The marking must indicate the type of rope (single, half rope or double rope), manufacturer and CE certificate.
Static rope is used for handrails in mountaineering and speleology, during rescue work and in industrial mountaineering. Their main difference from dynamic ropes is that a static rope should not stretch much (no more than 5% with a load of 150 kg).
There are 2 types of static ropes:
- Type A used for high-altitude and rescue work, as well as in speleology;
- Type B- rope of smaller diameter for less load than rope type A. Can only be used for rappelling.
EN 1891 requirements for static ropes:
- The jerk force must be less than 6 kN with a jerk factor of 0.3 and a weight of 100 kg.
Must be able to withstand at least 5 pulls with a fall factor of 1 and a weight of 100 kg, using a figure eight knot. - The elongation resulting from loads from 50 to 150 kg should not exceed 5%.
- Flexibility when tying knots - as above. The flexibility coefficient (factor K=rope diameter/rope diameter inside the knot) should be no more than 1.2.
- The displacement of the rope sheath relative to the core is 2 m. The ropes are pulled through a special device 5 times. The displacement of the rope braid should be no more than 15 mm.
- The weight of the rope braid should not exceed a certain proportion of the total weight of the rope.
- Static breaking force - the rope must withstand at least 22 kN (for ropes with a diameter of 10 mm or more) or 18 kN (for 9 mm ropes), with a figure-of-eight knot - 15 kN.
- Marking - the ends of the rope indicate the type of rope (A or B), diameter, manufacturer and EN to which the rope corresponds. The center stripe should indicate the type of rope (A or B), model, manufacturer, number and year of manufacture.
— The main indicator of a static rope is elongation (which should not exceed 5%, and for some - 0%). The lower the elasticity of the rope, the lower the permissible fall factor. — The second indicator of a static rope is its strength (can reach 44 kn, but not less than 22 kn).
When choosing when you are going to buy a static rope, you must take into account that the working load should be approximately 1/10 of that declared by the manufacturer. Two types: Type - A, - used for rescue and high-altitude work, and in speleology. Type – B, can only be used for rappelling, as it is designed for a lower load and has a smaller diameter than a type A rope.
In an effort to combine the properties of dynamic and static ropes in one rope, designers from several companies developed a version of it - the so-called static-dynamic rope.
Static-dynamic rope also has a cable structure, but consists of three structural elements: two load-bearing cores that are different in their dynamic qualities and a protective braid. The central core of static-dynamic ropes consists of polyester or Kevlar fibers. It is pre-tensioned to a certain limit to reduce its ability to elongate under load. The second core, braided around the central one, is made of polyamide fibers, which are more elastic than polyester or Kevlar. The protective braiding fibers are also polyamide
The idea behind this design is this: during normal use, i.e. during descent and ascent, the load is taken entirely by the less elastic core, and the behavior of the rope up to a load of 650-700 kg is static. With a load of over 700 kg, this core breaks and at the same time absorbs part of the fall energy. The remaining part of it is absorbed by the much more elastic polyamide core that comes into action.
Auxiliary rope used for various other purposes, where the possible loads are significantly lower in magnitude than in the cases listed above.
Rope storage is quite an important issue. How it is stored depends on how long it can be used.
- Rope should be stored in a dry, dark, cool place. Preferably in a case.
- It cannot be kept in a stretched state, as its elastic properties are lost.
- If the rope becomes dirty, you need to wash it with shampoo (preferably baby shampoo) or a special detergent for washing ropes, then rinse it well to remove the detergent.
- You need to dry the rope in a spread out position ( not suspended! ) condition.
- If the rope is dirty, firstly, its elastic properties deteriorate faster, and secondly, during loading, the tense internal fibers of the rope can be damaged by dirt particles, such as grains of sand.
Do not expose the rope to chemicals or heat.
Carefully inspect the rope for damage to the braid or internal damage, especially before use. If there is damage, replace the rope or cut off the damaged area.
After strong jerks, it is advisable to replace the rope (depending on what kind of jerk and how many there were).
The rope can be used for 2 years, but no more than 5 years from the date of release. In this case, aging of the fibers and their depolymerization occurs. After 5 years, its properties may change such that it is no longer suitable for use (i.e. does not meet UIAA standards).
G. Huber’s book “Mountaineering Today” provides the following criterion for the duration of rope use - use an 11 mm rope for no more than 300 climbing lengths.
Route leader insurance
ROPE LENGTH
When buying rope, the obvious question is: “how long should I buy rope? 50, 60, 70 or 80 m? I even know a man who bought a 100-meter rope! It is not loose, but wound on a bobbin. A 50 meter rope will do the trick in Yosemite or Toulumni, but many other places require a longer rope. 60 meters was once the standard, but now new routes are planned on the assumption that climbers have a 70 m rope. I know people who climb with 80 m rope, and they have no problem walking the latest “multipitches”. But if you plan to walk shorter sections of the routes, then the extra length of rope will be a hindrance. In general, the choice is yours, but do not forget to take into account such a moment as the length of the rope.
TWO-COLOR BRAID, ROPE MIDDLE MARKER
If you have to rappel a lot, it is better to buy a rope with a two-color braid, or a rope with a middle mark. If you choose a rope without a middle marker, you can mark the middle with a special marker. This will make the descent easier and safer. It will also help the belayer calculate the amount of rope remaining and inform the leader. Ropes with two-color braiding are more expensive.
WATER REPELLENT COATING OF ROPE
This property of the rope is useful for ice climbing and mountaineering on snow and ice routes. If a rope gets wet, it becomes heavier, thicker, more difficult to handle, and according to research, the rope loses 30% of its strength. Dry rope will make your climbing (or rappelling) easier if the weather is unfavorable. Dry coating protects the rope and extends its service life. But even if you buy such a rope, the protective coating will not last forever. A rope with such a coating is more expensive, but it will pay off if you have to climb in high humidity conditions.
Use of this material on other resources is prohibited!
· Static rope is used for fixed mounting, that is, for hanging wells and installing railings;
· Due to its lower elongation, its energy absorption capacity is lower and peak dynamic loads are greater. They exceed 1000 kgf for a fall of 80 kg with a factor of only 1, while for a dynamic rope this value is rarely exceeded even in a fall with the highest factor of 2.
· The lower the elasticity of the rope, the lower the permissible fall factor;
· A static rope can be used to belay a partner only if the belay is from above.
PrEN 1891 (European requirements) requirements for static ropes:
· The jerk force must be less than 6 kN with a jerk factor of 0.3 and a weight of 100 kg;
· The rope must withstand at least 5 jerks with a fall factor of 1 and a weight of 100 kg, with a figure eight knot;
· Elongation occurring under loads from 50 to 150 kg should not exceed 5%;
· The flexibility coefficient when tying knots (diameter of rope/diameter of rope inside a knot with a load of 10 kg) should be no more than 1.2;
· Displacement of the rope sheath relative to the core - 2 meters of rope are pulled through a special device 5 times. The displacement of the rope braid relative to the core should be no more than 15 mm;
· The weight of the rope braid should not exceed a certain proportion of the total weight of the rope;
· Static breaking force - the rope must withstand at least 22 kN (for ropes with a diameter of 10 mm or more) or 18 kN (for 9 mm ropes), with a figure eight knot - 15 kN.
· Marking - at the ends of the rope the type of rope (A or B), diameter, manufacturer is indicated.
There are 2 types of static ropes:
Type A
Type A - used for high-altitude and rescue work, as well as for speleology.
Type B
Type B is a rope of smaller diameter with a lower load than a type A rope. It can only be used for rappelling.
Static-dynamic rope
In an effort to combine the properties of dynamic and static ropes in one rope, designers from several companies developed a version of it - the so-called static-dynamic rope.
Static-dynamic rope also has a cable structure, but consists of three structural elements: two load-bearing cores that are different in their dynamic qualities and a protective braid. The central core of static-dynamic ropes consists of polyester or Kevlar fibers. It is pre-tensioned to a certain limit to reduce its ability to elongate under load. The second core, braided around the central one, is made of polyamide fibers, which are more elastic than polyester or Kevlar. The protective braiding fibers are also polyamide.
The idea behind this design is this: during normal use, that is, during descent and ascent, the load is taken entirely by the less elastic core, and the behavior of the rope up to a load of 650-700 kg is static. With a load of over 700 kg, this core breaks and at the same time absorbs part of the fall energy. The remaining part of it is absorbed by the much more elastic polyamide core that comes into action.
Miscellaneous
Strength of ropes
The declared tensile strength values guaranteed by manufacturers are very impressive - from 1700 kg for a 9 mm rope to 3500 kg for a 14 mm rope and more. However, many factors reduce the strength of ropes and you should not rely on these numbers:
Any knot weakens the rope to one degree or another. By choosing the right nodes you can significantly reduce the attenuation.
· Bending in knots - depending on the knot, the strength of the rope weakens by 30-60% (from 30% for a nine knot to 59% for a counter conductor knot). The forces acting on a loaded rope without knots are distributed evenly over its entire cross-section. If the rope bends, the forces under loading are distributed unevenly. Some of the threads located on the outside of the arc are stretched quite strongly. In the bending zone, transverse forces also arise, which are added to the longitudinal ones and additionally load the rope threads. The more it is bent, the more its strength decreases;
· Effect of water and humidity - The absorption of water by the polyamide fibers that make up the rope is significant. Knot tests have shown that wet rope is 4-7% weaker than dry rope. When a wet rope freezes, its strength decreases even more, to 18-22%. Wet Kevlar ropes are up to 40% weaker;
· Aging - under the influence of photochemical and thermal processes, as well as due to the oxidative effects of air, polymers are subject to a continuous progressive irreversible process - depolymerization or aging. Depolymerization occurs especially quickly in the first months after production, then the process slows down. Aging processes occur regardless of whether the rope is in use or not. The process is especially intense under the influence of heat and light.
· Wear during use - as a result of the mechanical influences to which the rope is subjected during operation, simultaneously with aging, it wears out physically. The abrasive effect due to friction makes a particularly large contribution to the reduction in strength. A descender littered with clay, dirt, etc. has a particularly unfavorable effect, which contributes to intensive wear of the rope. Even with slight contamination by clay, the strength decreases by about 10% in a short time.
All the above facts lead to the fact that practical The strength of a used rope may be significantly less than the declared values. For example, the Edelrid-Superstatic caving rope produced in 1981-82 has a declared strength of 2500 kgf. After 5 years of operation, its practical strength was less than 700 kgf.
Rope mass
The weight of the rope depends on its thickness. Its value is measured under standard conditions (air humidity 65%, temperature 20 °C) and is indicated by the manufacturer in the rope passport (in grams per meter). Typically the weight ranges from 52 to 77 g/m depending on thickness and design. Wet rope is heavier by up to 40% of its original mass. Nowadays, impregnated ropes are used for caving, which get less wet (“Drylonglife”, “Everdry”, “Superdry”).
Storage
· The rope should be stored in a dry, dark, cool place, preferably in a case.
· It cannot be kept in a stretched state, as its elastic properties are lost.
· If the rope becomes dirty, it must be washed with powder, then rinsed well from the detergent and dried in an unfolded (not stretched) state (According to some sources, it is recommended to wash the rope in warm fresh water WITHOUT the use of detergents).
· Do not expose the rope to chemical or thermal influences. You need to know that ultraviolet radiation has little effect on the strength of a good rope, but any source of heat spoils and destroys synthetic fibers. Do not dry the rope near heating appliances or under the hot sun.
· Carefully inspect the rope for damage to the braid or internal damage, especially before use. If there is damage, replace the rope or cut off the damaged area.
· After strong jerks, it is advisable to replace the rope (the passport indicates how many jerks the rope is designed for).
· The rope can be used for 2 years, but no more than 5 years from the date of issue. In this case, aging of the fibers and their depolymerization occurs. After 5 years, its properties may change and it will not meet UIAA standards. According to some authors, the rope should be replaced after 300 climbing lengths.
Rope length
In mountaineering, there is a unit for measuring the length of a complex slope - a rope. Classically, it is equal to 40 meters, this is a distance of comfortable audibility, and often visibility, of the members of the team, however, this length of ropes has almost completely lost its relevance, giving way to ropes of 50 m each. Recent trends in Mountaineering, the development of belay devices, communications, increasing the complexity of routes , lead to the spread of 60 meter ropes, and the European standard for new routes is 70 meter ropes.
The main distinguishing feature that determines the type of rope is its dynamic qualities - the ability to lengthen under load. Even when constructing a rope, depending on the desired performance properties, the ability to elongate is set both during normal use and when absorbing a dynamic shock. In accordance with the degree of elongation under load, as well as the purposes for which it is produced, rope is divided into several types:
The diameter of dynamic and static ropes most often ranges from 9 to 11 mm. Ropes with a diameter below 8 mm are called cords and are used as auxiliary ropes. In practical work, the thickness of the rope relates only to the overall weight, flexibility, ease of handling and is not an indicator of the reliability of the rope.
Structurally, all ropes consist of two components: a core, which bears the main load and consists of threads and braid, the main function of which is to protect the core and give the rope its usual round appearance. Depending on the number of threads in the braid, it can be 48, 32 or 40 strands. The most common versions are 48 and 32. 32-strand braid is more durable due to the thicker braid, but is rougher to the touch and slightly stiffer than 48-strand.
As a rule, the braid and the core are not connected to each other in any way, so the effect of shearing of the braid occurs. This is especially evident if the rope is often used for descents. This also manifests itself when cutting the braid of a loaded rope with a sharp edge or biting it with a jumar - the braid slips. There are technologies for “gluing” the braid to the core. This increases the safety of the rope: even if you slash the braiding with a knife, it does not slip. Of course, the price of such ropes is much higher.
Static rope
Low stretch ropes are usually referred to as static ropes. They are used for work at heights, for rescue work, in caving, etc. It is important that a static rope has minimal stretch and maximum strength. After the rope became the main means of not only belaying, but also climbing, its great elasticity, useful for belaying, immediately turned into its main drawback. All this required the creation of a rope with a low degree of elongation, which was called static.
As the name suggests, static rope has limited elasticity and is not designed to absorb large dynamic loads. A static rope can withstand a fall with a jerk factor of less than 1. This means that anyone working on a static rope is strictly prohibited from going above the rope's anchorage point! Static ropes are of type A or B. The main difference is the minimum static strength. Type A ropes according to the standard must have a minimum static strength of 22 kN. Type B 18 kN, usually a rope of smaller diameter and designed for less load.
Main characteristics:
- rope type A or B;
- diameter 9-11 mm;
- number of strands 32, 40, 48;
- static strength.
Advantages:
- Jumars hold well on static ropes;
- Can be used for constant static loads.
Flaws:
- Can withstand falls with a dash factor of only less than 1;
- Has limited elasticity.
Dynamic rope
Dynamic rope – designed for insurance in case of falls. Its task is to ensure minimal load on a person even with a deep breakdown due to elongation. The main property of dynamic ropes is the ability to absorb the dynamic shock that occurs during a fall with a fall factor greater than 1. With each fall, the rope deteriorates. Dynamic ropes are of the following types: 
Single dynamic rope or main rope is a type of dynamic rope, which by its design is intended to be used for belaying during free climbing and has the necessary qualities for reliable fall arrest with a maximum factor of 2. The thickness of the main rope is most often from 10.5 to 11.5 mm . Single rope is the most durable to use and easier to work with. It is lighter than two half ropes (but heavier than a double rope).
A half-rope is a dynamic rope that must be doubled when belaying. A single half rope does not have the necessary qualities to withstand a factor 2 fall. Half ropes are 8.5-10mm thick. When using a system of two half-ropes, they are alternately fastened into different carabiners and different belay points, forming two parallel tracks. Half rope is less durable.
Double (double or twisting) rope - used as a single rope, both ropes are snapped simultaneously into each carabiner. The diameter of the double rope is 7.8-9 mm. It is convenient to use when rappelling. Lighter than single and double rope. It is thinner and more easily damaged. It cannot be used for railings.
Main characteristics:
- type of rope;
- diameter 9-11 mm;
- number of strands 32, 40, 48;
- weight - the larger the diameter, the greater the weight;
- number of jerks;
- maximum jerk force (for example, 8 kN = 800 kg is what affects a person; the rope will absorb everything above it).
Advantages:
- Withstands falls with factor 2;
- Convenient to use when rappelling;
Flaws:
- on soft ropes the jumars do not hold well, when starting to climb on the jumars you need to mark time until you climb up to 5-6 meters;
- dynamic ropes cannot be used under constant static loads.
Rep cord
Cords are used only for auxiliary purposes (Prussian loops, etc.). The cord should not be used as a rappel rope or belay rope.
Main characteristics:
- diameter 4-8 mm;
- weight - the larger the diameter, the greater the weight;
- tensile strength (breaking load, kgf);
Strength of ropes.
Manufacturers indicate a very impressive tensile strength value.
However, many factors reduce the strength of ropes:
- Influence of water and humidity - The absorption of water by the polyamide fibers that make up the rope is significant. Tests with knots have shown that wet rope is 4-7% weaker than dry rope. When a wet rope freezes, its strength decreases even more, to 18-22%. Wet Kevlar ropes are up to 40% weaker.
- Aging - under the influence of photochemical and thermal processes, as well as due to the oxidative effects of air, polymers are subject to a continuous progressive irreversible process - depolymerization or aging. Depolymerization occurs especially quickly in the first months after production, then the process slows down. Aging processes occur regardless of whether the rope is in use or not. The process is especially intense under the influence of heat and light.
- Wear during use - as a result of the mechanical influences to which the rope is subjected during operation, simultaneously with aging, it wears out physically. The abrasive effect due to friction makes a particularly large contribution to the reduction in strength. A descender littered with clay, dirt, etc. has a particularly unfavorable effect, which contributes to intensive wear of the rope. Even with slight contamination by clay, the strength decreases by about 10% over a short period of time.
- Any knot weakens the rope. Bending in knots - depending on the knot, weakens the strength of the rope by 30-60%. The forces acting on a loaded rope without knots are distributed evenly over its entire cross-section. If the rope bends, the forces under loading are distributed unevenly. Some of the threads located on the outside of the arc are stretched quite strongly. In the bending zone, transverse forces also arise, which are added to the longitudinal ones and additionally load the rope threads. The more it is bent, the more its strength decreases.
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