Rep cord and paracord, safety cord and polyamide rope, nylon cord - how to distinguish and is it necessary?
First, let's understand the concepts.
False (from vallen - to fall, lower)- gear designed for raising and lowering sails (mainsail, staysail and others), individual parts of the spar (for example, yards, topmasts, gaffs), flags, pennants, etc.
The halyards used on ships and vessels are classified as running rigging. Depending on their purpose, halyards receive an additional name, for example, dirk-halyard, jib halyard, staysail halyard, signal halyard, anchor halyard, etc.
A water ski halyard is a floating rope made of synthetic fibers, equipped with a handle at one end and attached at the other end to a pylon on a boat. Serves for towing water skiers. Similarly used in hydrofoil, wakesurf, wakeskate and wakeboard.
A safety rope is often called a halyard (for example, a rope for attaching a parachute's exhaust device to an airplane, or an astronaut to a spacecraft during a spacewalk).
A towing halyard is a cable used in air towing of gliders, which connects the glider and the towing aircraft. In automotive practice, a halyard is also called a tow rope.
A cord is an auxiliary static rope with a diameter of 3-8 mm. This type of rope has a core and a braided braid. The number of strands in the braid may vary and this affects the elasticity and strength of the rope. It is used in mountaineering, rock climbing and speleology exclusively to perform auxiliary functions.
The rope is used as an auxiliary rope for solving various problems in mountain and water hikes, as well as at camping. Synthetic (nylon, polypropylene or combined) cord is designed for tying grasping knots.
Attention! The rope is not designed for dynamic load changes and is not intended for belaying as the main rope.
Paracord- a lightweight rope cable made of nylon (aka polyamide, also known as nylon), originally used in parachute lines. The shell (braid) of paracord is woven from many intertwined threads, making it quite elastic.
From the above, we conclude that synthetic (,) rope (nylon cord) is a rope that, depending on the task and diameter, can be called differently: Rep cord, Safety cord, Nylon halyard, Paracord, Rope rope, tow rope, etc. .d.
(cords, halyards) are widely used in industrial mountaineering, construction, speleology, rock climbing, sports, and tourism. Also, nylon cord (polyamide rope, polypropylene halyard) is used to provide auxiliary functions, pulling, pulling, securing loads, for attaching tools to a flexible suspension system or climbing platform, for installing and dismantling various structures and products, stretching awnings, securing banners, for installation of tents, as a leader rope for pulling electrical cables and communication lines, strapping submersible pumps and other auxiliary purposes.
Conventionally, a cord, cord and paracord are a rope with a diameter of 3-8mm made of synthetic materials, which has a core and an outer braid. But depending on the materials used, which affect the breaking loads, softness and other properties are called differently.
Cord
The cord has everyday household use. Made from inexpensive materials. For example, " " is made of polyester (core) and polypropylene (braid). It is inexpensive (up to 10 rubles per meter), but at the same time it has good tensile strength - 300 kgf. One of the most popular uses of 4mm hoztex cord is for banners.
Rep cord
The concept of "rep cord" is most often used in mountaineering circles.
Rep cord is a static rope with a diameter of 4-8 mm of round section with a protective braid. It is used in mountaineering, rock climbing and speleology exclusively to perform auxiliary functions - for grasping knots (eg Prusik, Bachmann knot, Austrian grasping knot) and for auxiliary purposes.
Typically, a nylon rope with a diameter of 3-8 mm is used, which, depending on the brand and year of production, has different strengths, from 250 kgf for 4 mm rope to 1200 kgf for 7 mm and 1550 kgf for 8 mm rope. For example, Tendon repshur has a breaking load of 340 kgf.
Cords 7-8 mm thick are used for knitting loops, improvised bottom and upper harness and other auxiliary purposes.
Cords 5-7 mm thick are best suited for tying self-tightening knots.
Cords 3-6 mm thick are used for making climbing ladders, tying various loads and tools to a flexible suspension system or climbing platform.
Important: You need to know that the cord is not designed for dynamic jerking.
Paracord
We got to the most interesting part. If everything is clear about the cord/cord, then “paracord” in Russia is used in speech simply as a fashionable word that is increasingly heard. As practice has shown, 90% of clients who ask us “Do you have paracord?” They mean a regular domestically produced cord.
The name Paracord is short for Parachute Cord - parachute cord. The name first appeared during World War II, when US Army paratroopers needed a light and durable cord for parachute cables.
When landing on the battlefields, soldiers cut off the feet of their parachutes and used them later. So, gradually, paracord acquired a great variety of uses: it helped in the construction of shelters, repairs and much more.
Over time, for lack of analogues, paracord became popular throughout the world and today is used as a common multi-functional rope by both military and civilians.
It was even used by astronauts (as a multi-purpose tether during the STS-82 mission of the second shuttle flight to repair the Hubble telescope)
WHAT IS PARACORD MADE FROM?
Paracord is a lightweight nylon cord with a core woven from numerous nylon strands. It can be divided into two parts: the “shell” - the outer covering consisting of large quantity intertwined fibers and the so-called “offal” - an internal cable woven from several single cords, each of which in turn consists of many intertwined threads.
TYPES OF PARACORD:
Paracord is divided into 2 types: MILITARY AND CIVIL.
MILITARY paracord is called Mil-Spec Paracord, or MIL-C-5040 Type III (Military Specification) - mil-spec that meets military specifications.
It is manufactured by only a few companies in the United States and mostly goes to government needs - for example, to equip army units, law enforcement etc.
The production of military paracord is under the control of the US Department of Defense and certified by the US Department of Defense Industrial Supply Center. All military paracord meets quality standards and regularly undergoes laboratory testing and a series of field tests.
- CIVIL paracord is called civilian or commercial - civil or commercial.
With the increasing popularity of paracord, the demand also increased - many people wanted to have such an “indestructible rope”.
The US government, responding to the demand for paracord, allowed it to be released to civilians, creating the so-called “commercial” version.
It is produced by many companies everywhere. Commercial paracord, like military paracord, has a tensile strength of 550 lbs (249+ kg) and almost identical characteristics, however, it has a rougher texture and a slightly larger diameter.
It is slightly thicker due to the fact that it is not always produced to military quality standards. In all other respects, the difference is almost minimal.
There is one marking feature associated with this. For a cord, the main indicator, which is indicated in the name, is the diameter (Cord 3mm, Cord 4mm, etc.). For paracord, the main indicator is strength, so the name indicates Paracord 550, which usually corresponds to a diameter of 4mm.
The range of uses of paracord in Everyday life extremely wide - it can be used for making lanyards for knives, bracelets, both decorative and intended for use as NAZ (wearable emergency supply), watch straps, key rings, zippers, buttons, for braiding various items (lighters , flashlights, knife handles, tools)
Nike used paracord in their Special Field Air Force
Paracord products can even serve as self-defense weapons (for example, a monkey’s fist).
Nylon sheath is often used alone without a core when there is a need for a thinner or less elastic rope. The ends of the cable are almost always melted and crimped to prevent it from unraveling. The core can also be used.
The core (in the American army it is called “giblets”) can be removed when a thinner thread is needed, for example, for repairing clothing or as a fishing line for fishing if one is not available in an extreme situation.
Unlike cords, paracord is softer, more elastic and pleasant to the touch. It is very easy to weave with.
To summarize, we can say that paracord is not entirely suitable for mountaineering and is a bit expensive for a cord for household needs. But it is very relevant for “survivalists” and as a material for functional accessories. Finding yourself in nature, dacha, hunting, fishing, etc. It's nice to know that in case of emergency you have 5-10 meters of rope.
And speleology exclusively for performing auxiliary functions - for knitting loops with grasping knots (for example, Prusik, Bachmann knot, Austrian grasping knot), making climbing ladders, etc.
Usually a nylon rope with a diameter of 3-8 mm is used, which, depending on the brand and year of production, has different strengths, from 230 kgf for a 4 mm rope to 1200 kgf for a 7 mm rope and 1550 kgf for an 8 mm rope (data from 1983) . Kevlar ropes are stronger, but they are slipperier and stiffer and are difficult for gripping knots. Ropes with particularly slippery braiding (fluoroplastics, polyethylene, etc.) are also not used, even if their strength corresponds to the standard one, as well as twisted ropes without braiding.
- Cords 7-8 mm thick are used for knitting loops, improvised lower and upper harnesses and for other auxiliary purposes.
- Cords 5-7 mm thick are best suited for tying self-tightening knots.
- Cords 3-6 mm thick are used for making climbing ladders, tying various loads and tools to a flexible suspension system or climbing platform.
Important: You need to know that the cord is not designed for dynamic jerking.
see also
Write a review about the article "Rep Cord"
Links
|
||||||||||||||||||||||||||||||||||
An excerpt characterizing Repshnur
After everything that Napoleon said to him, after these outbursts of anger and after the last dryly spoken words:
“Je ne vous retiens plus, general, vous recevrez ma lettre,” Balashev was sure that Napoleon not only would not want to see him, but would try not to see him - the offended ambassador and, most importantly, a witness to his obscene fervor. But, to his surprise, Balashev, through Duroc, received an invitation to the emperor’s table that day.
Bessieres, Caulaincourt and Berthier were at dinner. Napoleon met Balashev with a cheerful and affectionate look. Not only did he not show any expression of shyness or self-reproach for the morning outburst, but, on the contrary, he tried to encourage Balashev. It was clear that for a long time now the possibility of mistakes did not exist for Napoleon in his belief and that in his concept everything that he did was good, not because it coincided with the idea of what is good and bad, but because he did This.
The Emperor was very cheerful after his horseback ride through Vilna, in which crowds of people enthusiastically greeted and saw him off. In all the windows of the streets along which he passed, his carpets, banners, and monograms were displayed, and the Polish ladies, welcoming him, waved their scarves at him.
At dinner, having seated Balashev next to him, he treated him not only kindly, but treated him as if he considered Balashev among his courtiers, among those people who sympathized with his plans and should have rejoiced at his successes. Among other things, he started talking about Moscow and began asking Balashev about the Russian capital, not only as an inquisitive traveler asks about a new place that he intends to visit, but as if with the conviction that Balashev, as a Russian, should be flattered by this curiosity.
These recommendations are prepared based on recommendations and tests carried out by the UIAA, Mountain Rescue Association, testing in the Vento laboratory and etc.
Grasping units are designed for climbing/descending on a rope, organizing pulleys, organizing belay during descent and ascent, organizing self-belaying, etc.
Materials used.
In all cases, a certified cord should be used (breaking load for 6 mm from 7 kN and for 7 mm from 9.8 kN). The best modern nylon cords have a strength of up to 15 kN, and dyneema cords with nylon braid have a strength of more than 20 kN.
Use of “unknown” cords without certification and testing NOT RECOMMENDED
, their strength can be only 3-4 kN, which, taking into account the loss of strength in the nodes and the natural aging of nylon, does not provide the necessary reliability.
The use of a cord with a diameter of 7 mm makes it more versatile - station loops made from such a cord meet all the requirements for strength and reliability.
Use for gripping knots of cords and tapes made of Dyneema, Spectra and Kevlar NOT RECOMMENDED .
Dainima and Spectrum have a very low melting point of +147C, and Kevlar fibers (KVM) are subject to rapid aging under the influence of UV radiation and kinks.
Let us consider the properties of these materials depending on temperature.
- Nylon/nylon - melting point 230 degrees.
- Dainima/spectra (high molecular weight polyethylene) - melting point 147 degrees.
- Kevlar/SVM/aramid - up to a temperature of 450 degrees practically does not lose strength.
It is the difference in melting temperature that causes the very low strength of Dyneema gripping units.
But it’s not even a matter of melting temperature; at a temperature of +67 degrees, dyneema loses 30% of its strength.
Kevlar practically does not lose strength with moderate heating, but the nylon rope under the knot can be severely melted - theKevlar does not melt, but it heats up very much and, having a much lower thermal conductivity than nylon, retains all the released heat in the knot, which can lead to damage to the rope.
This graph shows the reduction in strength of Kevlar when exposed to sunlight at sea level.
Kevlar fibers are very damaged by ultraviolet radiation. Within 30 days of exposure to the sun in the mountains, strength can drop by 70%. Unfortunately, it is impossible to externally assess this loss of strength.
Kevlar also does not tolerate abrasion and sharp bends very well; strength is also sharply lost in places where there are bends.
Cords with a nylon braid and a dyneema core perform much better (cords with a kevlal core are very stiff and are not suitable for gripping knots). When jerking, it heats up and melts only outer part nylon braid, which does not lead to a significant loss of strength.
Conclusion - the use of tapes and cords made of Dyneema and Kevlar materials without braiding - dangerous and cannot be recommended.
Research has shown that the diameter of the cord for gripping knots should be approximately 2/3 of the thickness of the rope on which the gripping knot is supposed to work. Those. When using 10-11 mm ropes, the gripping knots should be tied from a cord 7 mm thick. Using a 6 mm cord is possible on thin 8-9.5 mm ropes.
You should be very careful when selecting and rejecting cords for grasping units. A cord that is too stiff or has been used a lot is not suitable for gripping knots.
Test to check. A cord that is suitable in terms of softness should not pass into a ring formed from the same fingered with little effort.
Suitable - soft.
Doesn't fit - very hard.
Tying knots.
The loops from the cord for the grasping knots are tied using a grapevine knot (double fisherman). The free ends in the grapevine knot should have a length equal to 10 cord diameters, i.e. 60-70 mm for 6 and 7 mm cord
Dangerous!!!
Right.
Also for the purpose of self-insurance when rappelling, securing pulley systems (only when working with light loads up to 100 kg) and other applications in which continuous loads of more than 4 kN are not expected - it is possible to use oak knot(conductor, simple node).
Important! The free ends in the knot must be at least 10 cord diameters, i.e. 60-70 mm for 6 and 7 mm cords.
Rope descent system with 3-turn prusik belay.
System for rappelling with safety net using awobloc knot.
Tying additional knots on a loop for a grasping knot - conductor, figure eight, hare's ears, stirrup, etc. - NOT RECOMMENDED! Tying these knots leads to a significant reduction in the strength of the grasping knot.
This is due to the fact that the length of the branches going to the carabiner is not the same and the knot prevents the load from equalizing - and in reality only one branch of the loop and half of the grasping knot bear the entire load.
It is not recommended to tie any type of grasping knot on two ropes at once.(two separate ropes) -If one of the ropes breaks/fails, the gripping knot may not work - and the load will fall to the ground. When rappelling down a double rope, a catching knot is tied on a double rope to secure the person descending.
Prussian 3 turns.
With a slight increase in labor intensity when tying, a 3-turn prusik has an almost twofold superiority in the slipping force before a 2-turn knot. It is used in all cases where a gripping unit is required, it is especially convenient when organizing chain hoists.
During research into an ideal system that meets the requirements for COMPETENT INSURANCE (research on organizing insurance for a heavy 200 kg load during PSR), many different gripping units were investigated. But not a single option showed better results than the 3-turn Prusik.
Classic three-turn Prusiks showed better repeatability of results and stability of the etching force. What is important is not the maximum possible strength of the system, but the avoidance of excessive loads in the system, and it is the slipping of the prusiks that ensures smoothing and reduction of peak loads during jerks.
A single prusik made of three turns from a 7 mm cord, tied on a rope with a diameter of 11 mm, begins to slip with a force of 7-9 kN. And at the same time it moderately damages the rope.
French gripper (autoblock, winding).
The number of turns in the knot depends on the quality of the cord, the thickness of the cord, the rope and their condition. Usually knitted in 4-5 turns. Requires mandatory checking after tying; if the knot “does not hold,” add another 1-2 turns.
Provides high holding force, stable operation and the ability to loosen the knot even under load. Recommended for use for self-belaying when rappelling. The self-belay option is knitted below the descender. This option ensures easy etching and no danger of falling when squeezing the knot in the hand - “panic reflex”.
It is also often used for PSR in a small group as it allows the unit to move under load.
Marchard's knot (Austrian, kleimhest).
A variant of the winding gripping unit, it is characterized by stable and reliable operation on dirty, wet and icy ropes. But due to the effect of “clamping” the rope, its strength is lower than the strength of the French gripper. It is recommended, if necessary, to organize a gripping knot on a wet, dirty or icy rope.
Parcel Prusik system.
This is a convenient and very reliable system for organizing self-insurance, adjustable suspension of the rescuer and the victim, adjustable suspension of the stretcher and much more.
During testing, the Parcel Prusik lanyard showed the best results in terms of reliability and minimal breaking force.
Tandem Prusik system.
The system consists of 2 Prussians in 3 turns, the length of which differs by 7-10 cm. Installed in tandem on a rope, they ensure reliable retention of the “rescue cargo” in conditions of failure of the cargo rope. The Prusik tandem system can withstand loads of more than 10 kN. This system is indispensable when organizing insurance for RPS.
Working with the Tandem Prusik system when securing a load on a descent.
Working with the Tandem Prusik system when insuring cargo on an incline.
System Prusik tandems begin to slip at a force of 7.5-9.5 kN. The difference in force, compared to a single prisik of 3 turns, is not very great, but the main thing is that with a dynamic jerk, two prusiks contain twice as much material and twice as much energy is required to melt them. It is very important that the distance between the tense gripping units in the Prussian tandem system is no more than 7-10 cm - approximately equal to the width of the palm.
During testing, a tandem Prusik system made from a 7 mm cord withstood a fall of a rescue load (200 kg) from a height of 1.75 meters - a jerk factor of 0.6, and a system with a Prusik cord made of 8 mm withstood a drop of a load from a height of 2.5 meters, jerk factor 0.8.
Sergey Vedenin 2014
Ropes tourist - are the main technical means for insurance in tourist trip and the movement of tourists on difficult terrain. Made from synthetic strands that form the core complex design, which is surrounded by a protective braid, the so-called braided ropes, as in Figure 1.
For insurance and movement of tourists along the route, ropes are used, called main ones, having a diameter of 9-12 mm and a linear weight of 50-90 g/m. The strength and quality of the new rope is tested on samples cut from a coil 150–500 m long. A rope with a diameter of 11–12 mm is subjected to 4 jerks of a thrown load weighing 80 kg. Rope with a diameter of 9-10 mm - 10 jerks with a load weight of 40 kg. In addition, the samples are brought to breaking under a static load, as in Figure 2. The main technical data of safety ropes are given in the table.
As a support when moving, as well as for hanging railings, it is better to use relatively rigid ropes that slightly elongate under load. For insurance, they are more elastic, capable of absorbing, due to significant elongation (up to 30%), part of the jerk energy in the event of a tourist falling. The rope should glide well and tie into knots, be light and easy to use, and maintain its quality over long-term use.
When organizing insurance, one so-called single rope with a diameter of at least 11 mm is usually used. On difficult sections of the route, where a free fall is possible, a double rope is used - two ropes of the same diameter, usually 9-10 mm, or different, for example, 11 and 9 mm in diameter. When working with a double rope, you usually select ends of different colors.
The main rope of any diameter can be used to hang the railings. When working with rope, it is necessary to take into account that in the knot there is a significant decrease in the strength of the rope. For example, in the stirrup knot by 40%, in the bowline and figure eight knots by 25%. The strength of the rope at the bend in the carabiner is reduced by 30%.
The usual length of one rope or, as they say, the end of a rope is 40 m - a conventional unit of length is called a “rope”. For skiing, downhill skiing, hiking and simple mountain hikes, it is enough to have rope ends 25 - 30 meters long. In complex mountain and caving routes, ropes with a length of 45 - 80 m or more are used.
Life time safety rope depending on the intensity and operating conditions from 2 to 6 years. The safety of the rope must be checked before the hike, as well as after passing each section of the route where it could be damaged. A rope with significant damage to the braid or that has withstood a large dynamic load cannot be used for belaying, or as a support when moving without an additional safety rope.
If the rope gets wet, dry it in the shade; if it is heavily soiled, wash it in warm soapy water and rinse thoroughly, and store it in a cool, dry place, away from direct sunlight. To reduce wetting, the rope is impregnated with special compounds. The main ropes are carried wound into single or double rings, as in Figure 3.
For chest harnesses and “arbors” on simple hikes, for self-belay loops and loops attached to ledges and hooks when hanging railings, as well as together with the main rope for crossings and descents, as a rule, a braided nylon rope with a diameter of 6 - 8 mm, called auxiliary or cord. The cord can withstand at least 500 kg of static load before breaking. For the same purpose, a woven nylon tape with a diameter of 20-30 mm of the same strength is used.
In situations where the use of rope is not directly related to the safety of people, for example, securing backpacks and other items of equipment, tying loads and packs, constructing stretchers, etc., you can use any ropes, including twisted ones, as well as sisal ropes and tapes , hemp, cotton with a tensile strength of 100-150 kg.
Rope (cable) braking is used to regulate, even stopping, movement when lowering people or cargo, as well as for dynamic belaying.
To slow down the rope, relief protrusions are used, as in Figure 4. A carabiner is hung on protrusions or artefacts, support points (hooks, bookmarks, ice column, eyelet, snow anchor, ice axe) directly or using a loop, as in Figures 5 and 6.
Braking devices without the possibility of blocking the rope - “Sticht washer”, “frog”, “eight”, as in Figure 7. Braking devices that block ropes - “petal”, Munter’s yoke, Kashevnik’s “insects”, “slingshot”, “lattice” , “gurney”, as in Figure 8.
Automatically locking friction devices by Petzl and Serafimov, as in Figure 9. Carabiner brakes, as in Figure 10. Carabiners in combination with brake units, as in Figure 11, as well as the body and hands of the tourist.
Rope braking, in which only the body and arms take part, is used when belaying over the shoulder and lower back, as in Figure 4.6. Sometimes, as additional insurance when descending, use the sports “Svan” method and the classic “rappel”.
Rope braking through the body and hands in combination with braking devices is used for dynamic belaying and in various ways descent along a rope, as in Figure 12 and Figure 13. To brake the rope, as a rule, a block brake and friction devices are used: a “tube”, a “ladder”, a Rogozhnikov “cassette”, as in Figure 14.
The degree of braking depends on the friction developed in the places where the rope (cable) is supported and in the braking devices, as well as on the effort of the tourist holding (“etching”) the unloaded free end of the rope. Blocking means ensuring the immobility of a rope or cable relative to a braking device or a braking device relative to a rope (cable) without the application of a holding force by a person. Sometimes V. braking is carried out using shock absorbers.
Number of impressions: 5716
