Ropes tourist - are the main technical means for insurance in camping trip and the movement of tourists on difficult terrain. They are made from synthetic strands that form the core of a complex structure, which is surrounded by a protective sheath, the so-called braided ropes, as in Figure 1.
For the insurance and movement of tourists on the route, ropes are used, called the main ones, having a diameter of 9-12 mm and a running weight of 50-90 g / m. The strength and quality of a 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 an ejected load weighing 80 kg. Rope with a diameter of 9-10 mm - 10 jerks with a load of 40 kg. In addition, the samples are brought to rupture under static load, as in Figure 2. The main technical data of the safety ropes are given in the table.
As a support during movement, as well as for hanging railings, it is better to use relatively rigid ropes that slightly elongate under load. For insurance - more elastic, capable of absorbing due to a 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, retain its qualities during long-term operation.
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 stall 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, ends of different colors are usually picked up.
The main rope of any diameter can be used for hanging the railing. When working with a rope, it must be taken into account that a significant decrease in the strength of the rope occurs in the knot. 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, called a "rope". For skiing, skiing, hiking and simple mountain trips, it is enough to have ends of a rope 25 - 30 meters long. In difficult mountain and speleological routes, ropes with a length of 45 - 80 m or more are used.
The service life of a safety rope, depending on the intensity and operating conditions, is from 2 to 6 years. The safety of the rope must be checked before the trip, as well as after passing each section of the route where it could be damaged. A rope with significant damage to the sheath or withstanding a large dynamic load cannot be used for belaying, as well as as a support when moving without an additional safety rope.
If wet, dry the rope in the shade, if heavily soiled, wash in warm soapy water with thorough rinsing, store in a cool, dry, closed from direct contact. sunlight place. To reduce wetting, the rope is impregnated with special compounds. The main ropes are carried coiled in single or double rings, as in Figure 3.
For chest harnesses and "arbors" in simple hikes, for self-insurance loops and loops attached to ledges and hooks when hanging railings, as well as together with the main rope during crossings and descents, as a rule, a braided nylon rope with a diameter of 6 - 8 mm is used, called auxiliary or cord. The cord withstands 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 a rope is not directly related to the safety of people, for example, securing backpacks and other items of equipment, lashing cargo and packs, building a stretcher, etc., you can use any ropes, including twisted ones, as well as sisal ropes and ribbons , hemp, cotton with a tensile strength of 100-150 kg.
Rope (cable) braking is used to regulate, up to a stop, movement when lowering people or cargo, as well as for dynamic insurance.
To brake the ropes, relief protrusions are used, as in Figure 4. A carabiner hung on ledges or arts, fulcrum (hooks, bookmarks, ice column, eye, snow anchor, ice ax) directly or using a loop, as in Figures 5 and 6.
Braking devices without the possibility of blocking the rope - "Shticht's washer", "frog", "eight", as in Figure 7. Braking devices that block the ropes - "petal", Munter's yoke, "insects" of Kashevnik, "slingshot", "lattice" , "wheelchair", as in Figure 8.
Automatically locking friction devices Petzl and Serafimov, as in Figure 9. Carabiner brakes, as in Figure 10. Carabiners in combination with brake assemblies, as in Figure 11, as well as the body and hands of a tourist.
Rope braking, in which only the body and hands take part, is used when belaying over the shoulder and lower back, as in Figure 4.6. Sometimes as an additional insurance when descending in the sports "Svan" way and the classic "rappel".
Rope braking through the body and hands in combination with braking devices is used for dynamic belay and various ways descent along the rope, as in Figure 12 and Figure 13. To brake the cable, as a rule, a block brake and friction devices are used: “tube”, “ladder”, Rogozhnikov’s “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 the rope or cable relative to the braking device or the braking device relative to the rope (cable) without applying the holding force of a person. Sometimes V.'s braking is carried out by means of shock-absorbers.
Number of impressions: 5716
Knitted from rope Æ 5 - 8 mm. Cord breaking force Æ 6 mm is equal to 400 kg, but taking into account factors that reduce the strength of nylon equipment (§ 5.8), maximum load it is customary to consider 100 kg, for a double, respectively, 200 kg.
For self-insurance, in addition to the grasping knot, you can use the "Bahmann" knot ("Austrian" grasping) or the carabiner "Bachmann". All of the following is true in the general case for all three nodes.
The grasping knot is knitted on the main rope with a double cord or a ready-made "prusik" (a looped cord of a selected length with a double conductor at the end. After selecting the length, a figure-eight guide is knitted from the double cord. If necessary (no carabiners), the double cord can be tied into the bowline system. Threads double cord must be equal in length to prevent stress on the single cord.The knot must always be tight, a loose knot does not work well.An eraser with a hole can be used to keep the knot tight.
The length of the gripper, used for self-insurance when descending the railing, is selected so that when hovering, the participant can reach the knot with his hand. When descending, the knot must be held with the thumb and forefinger, while the double cord should go between them on top of the hand. This increases the likelihood of tightening the knot when jerking. In no case should you clamp the knot in your fist!
When using the grip as a self-insurance when climbing free climbing, the length is selected in the same way. When moving across the terrain, the knot must not remain on the railing below the participant's knee, as this creates the danger of a strong jerk in the event of a fall. The knot should not relax during the movement.
To organize self-insurance when climbing along the railing, the length of the cord is determined by the length of the jumar - if the cord is shorter than the jumar, this will significantly complicate the climb, because. grasping will be tightened. If the jumar has a secure lanyard or is included in the lanyard of the system, a short cord can be used. The grasper is also knitted in front of the jumar, and the conductor is included with a carabiner in the jumar itself or in the mustache of the self-insurance in which it is fixed. In both cases, when the self-insurance is triggered (breakage or slippage of the jumar), the participant will not be able to reach the knot, which is a disadvantage of this technique and complicates the way out of an emergency. When climbing with a jumar, it is recommended to use a top belay.
The catcher is not used for self-insurance on the horizontal sections of the railing. It is forbidden to use a double cord as a lanyard. It is forbidden to use a grasping knot for static self-insurance.
For self-belaying on slopes with a steepness of more than 50 - 60 ° and when moving with a heavy backpack, it is recommended to use a rope Æ 8 mm or cam clamps. In systems of increased load (chain hoist) grasping and "bakhman" are knitted from a cord Æ 6 mm in 4 strands or cord Æ 8 mm in two strands.
At the moment, it is the most affordable means of self-insurance, but in terms of reliability and technical specifications significantly inferior to special clamps. For knitting a grasping knot, it is possible to use a special Kevlar cord that does not melt during sudden slippage.
These recommendations are based on recommendations and tests conducted by the UIAA, Mountain Rescue Association, tests in the Vento laboratory and etc.
Grasping nodes are designed for climbing / descending on a rope, organizing chain hoists, organizing insurance during descent and ascent, organizing self-insurance, etc.
Applied materials.
In all cases, a certified cord must 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 dynima cords with a nylon sheath 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 knots 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 of such a cord meet all the requirements for strength and reliability.
Use for gripping knots of cords and tapes from Dyneema, Spectra and Kevlar NOT RECOMMENDED .
Dyneema and spectrum have a very low melting point of +147C, and Kevlar fibers (CBM) are subject to rapid aging under the action of UV radiation and kinks.
Consider the properties of these materials depending on temperature.
- Nylon / kapron - melting point 230 degrees.
- Dyneema / spectrum (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 determines the very low strength of the gripping knots made of dyneema.
But it's not even about the melting point, 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 strongly melted - itselfKevlar does not melt, but it heats up very much and, having a much lower thermal conductivity than nylon, keeps all the heat released in the knot, which can lead to damage to the rope.
This graph shows the strength degradation 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 assess this loss of strength externally.
Also, Kevlar does not tolerate abrasion and sharp bends very well; strength is also sharply lost in places of bends.
Cords with a nylon whip and a dyneema core perform much better (kevlal core cords are very stiff and not well suited for grasping knots). When jerking, it heats up and melts only outer part nylon sheath, which does not lead to significant loss of strength.
Conclusion - the use of ribbons and cords made of Dyneema and Kevlar materials without braiding - dangerous and not recommended.
Studies have shown that the cord diameter for the grappling knots should be approximately 2/3 of the thickness of the rope on which the grappling knot is to be operated. Those. when using ropes of 10-11 mm, the grasping knots should be tied from a cord 7 mm thick. The use of a 6 mm cord is possible on thin 8-9.5 mm ropes.
You should be very careful in the selection and rejection of cords for grasping knots. Too stiff or overused cord - not suitable for grabbing knots.
Test to verify. A cord suitable for softness should not pass into a ring formed from it and compressed by fingers with little effort.
Suitable - soft.
Not suitable - very hard.
Tying knots.
Cord loops for grasping knots are tied with 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
Dangerously!!!
Correctly.
Also for the purposes of self-belaying when descending a rope, securing pulley systems (only when working with light - up to 100 kg load) 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 diameters of the cord, i.e. 60-70 mm for 6 and 7 mm cord.
Abseiling system with 3 turns prusik safety net.
Abseiling system with safety net with autoblock knot.
Tying on a loop for a grasping knot of additional knots - conductor, figure eight, hare ears, stirrup, etc. - NOT RECOMMENDED! Tying these knots leads to a significant decrease 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 load balancing - and in reality only one branch of the loop and half of the grasping knot bears 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 grasping knot may not work - and the load will fall to the ground. When descending with an rappel along a double rope, a grasping knot is tied on a double rope to secure the descender.
Prussian in 3 turns.
With a slight increase in labor intensity when tying, a 3-turn prusik has an almost twofold superiority in slip force before a 2-turn knot. It is used in all cases when a grasping knot is required, it is especially convenient when organizing chain hoists.
During the studies of an ideal system that meets the requirements for COMPETENT INSURANCE (studies on the organization of insurance of a heavy 200 kg load for RPS), many different grasping knots were investigated. But no option has shown better results than a 3-turn prusik.
The classic three-turn prusiks showed the best repeatability of the results and the stability of the pickling force. It is not the maximum possible strength of the system that is important, but the prevention of excessive loads in the system, and it is the slippage of the prusiks that ensures smoothing and reducing peak loads during jerks.
A single prusik in three turns of 7 mm cord, tied on a rope with a diameter of 11 mm, begins to slip at a force of 7-9 kN. And at the same time moderately damages the rope.
French grasping (autoblock, winding).
The number of turns in a 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 a mandatory check 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-insurance when descending a rope. The self-insurance option is knitted below the descender. With this option, it provides easy etching and no danger of falling when the knot is held in the hand - “panic refrex”.
It is also often used for RPS in a small group, as it allows you to move the node under load.
Marshard's knot (Austrian, Claimhest).
A variant of the wrapping grappling knot, characterized by stable and reliable performance 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 grasping. It is recommended, if necessary, to organize a grasping knot on a wet, dirty or icy rope.
Parcel prusik system.
This is a convenient and very reliable system for organizing a self-belay, adjustable harness for a rescuer and a victim, adjustable harness for a stretcher, and much more.
In tests, the Parcel Prusik lanyard showed the best results in terms of reliability and minimum jerk 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 the rope, they provide a reliable hold on the “rescue load” in the event of a failure of the cargo rope. The tandem prusik system withstands loads of more than 10 kN. This system is indispensable when organizing insurance in case of RPS.
Working with the Tandem Prusik system when belaying cargo on the descent.
Working with the Tandem Prusik system when belaying a load on the rise.
System tandem Prusik begin to slip at a force of 7.5-9.5 kN. The difference in force compared to a single prusik of 3 turns is not very large, 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 tensioned grasping knots in the tandem prusik system is no more than 7-10 cm - approximately equal to the width of the palm.
During the tests, the tandem prusik system from a 7 mm cord withstood the fall of a rescue load (200 kg) from a height of 1.75 meters - a jerk factor of 0.6, and the system with prusiks from 8 mm cord withstood a fall of a load from a height of 2.5 meters, jerk factor 0.8.
Sergey Vedenin 2014
Cord and paracord, safety cord and polyamide rope, nylon cord - how to distinguish and is it necessary?
First, let's understand the concepts.
Fal (from vallen - to fall, to lower)- tackle designed for raising and lowering sails (mainsail, staysail and others), individual parts of the spars (for example, yards, topmasts, gaffs), flags, pennants, etc.
The halyards used on ships and ships are running rigging. Depending on the purpose, the halyards receive an additional name, for example, dirik halyard, jib halyard, staysail halyard, signal halyard, anchor halyard, etc.
A water ski halyard is a floating cable made of synthetic fibers, equipped with a handle at one end and attached at the other end to a pylon on a boat. Used to tow water skiers. It is similarly used in hydrofoil, wakesurf, wakeskate and wakeboard.
A safety cable is often called a halyard (for example, a cable for attaching a parachute exhaust device to an aircraft, an astronaut to a spacecraft during a spacewalk).
A towing rope is a cable used in the air towing of gliders, which connects the glider and the towing aircraft. Also called a halyard in automotive practice - a tow rope.
Cord is an auxiliary static rope with a diameter of 3-8 mm. This rope has a core and a braided sheath. The number of strands in the sheath may vary and this affects the elasticity and strength of the rope. It is used in mountaineering, rock climbing and speleology exclusively for auxiliary functions.
The cord is used as an auxiliary rope for solving various problems in mountain and water trips, as well as in camping. Synthetic (kapron, polypropylene or combined) cord is designed for knitting grasping knots.
Attention! The cord is not designed for dynamic load changes and is not intended for belaying as a main rope.
Parachute cord- a lightweight rope cable made of nylon (aka polyamide, aka kapron), originally used in parachute lines. The shell (braid) of the paracord is woven from many intertwined threads, due to which it is quite elastic.
From the foregoing, we conclude that a synthetic (, ) rope (nylon cord) is a rope that, depending on the task and diameter, can be called differently: Cord, Safety cord, Nylon halyard, Paracord, Rope rope, towing rope, etc. .d.
(cords, halyards) are widely used in industrial mountaineering, construction, speleology, rock climbing, sports, and tourism. Also, a nylon cord (polyamide rope, polypropylene halyard) is used to provide auxiliary functions, pulling up, pulling out, securing loads, for attaching tools to a flexible suspension system or climbing platform, for mounting and dismantling various structures and products, stretching awnings, fixing banners, for setting up tents, as a leader cable for pulling electric cables and communication lines, tying submersible pumps and other auxiliary purposes.
And speleology solely to perform auxiliary functions - for knitting loops with grasping knots (for example, prusik, Bachmann knot, Austrian grasping knot), making climbing stairs, etc.
A nylon rope with a diameter of 3-8 mm is usually used, which, depending on the brand and year of production, have different strengths, from 230 kgf for a 4 mm rope to 1200 kgf for a 7 mm and 1550 kgf for an 8 mm rope (data from 1983) . Kevlar ropes are stronger, but they are more slippery and stiff and inconvenient for grasping knots. Ropes with a particularly slippery sheath (fluorine plastics, polyethylene, etc.) are also not used, even if they correspond to the standard in strength, as well as twisted ropes without a sheath.
- Cords with a thickness of 7-8 mm are used for knitting loops, improvised lower and upper harnesses and for other auxiliary purposes.
- Cords with a thickness of 5-7 mm are best suited for knitting self-tightening knots.
- Cords with a thickness of 3-6 mm are used for the manufacture of climbing ladders, tying various loads and tools to a flexible suspension system or a climbing platform.
Important: You need to know that the cord is not designed for dynamic jerk.
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An excerpt characterizing Repshnur
After all that Napoleon had said to him, after these outbursts of anger, and after the last dry words:
“Je ne vous retiens plus, general, vous recevrez ma lettre”, Balashev was sure that Napoleon would not only not want to see him, but would try not to see him - the insulted ambassador and, most importantly, a witness to his obscene ardor. But, to his surprise, Balashev, through Duroc, received that day an invitation to the emperor's table.
At dinner were Bessières, Caulaincourt and Berthier. Napoleon met Balashev with a cheerful and affectionate air. Not only was there no expression of shyness in him or reproach to himself for his morning outburst, but, on the contrary, he tried to encourage Balashev. It was evident that for a long time for Napoleon there had been no possibility of error in his conviction, and that in his conception everything he did was good, not because it agreed with the idea of what was 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 met and saw him off. In all the windows of the streets along which he passed, carpets, banners, his monograms were displayed, and Polish ladies, greeting him, waved their handkerchiefs at him.
At dinner, having seated Balashev next to him, he treated him not only affectionately, 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 spoke about Moscow and began to ask Balashev about the Russian capital, not only as an inquisitive traveler asks about a new place he intends to visit, but as if with the conviction that Balashev, as a Russian, should be flattered by this curiosity.