Fundamentals of Maritime Practice. Vegetable ropes Types of ropes and ropes on the ship
Performance of cables . Cables (ropes) are products made of vegetable and artificial fibers or steel wires. According to the material used for the manufacture, the cables are divided into vegetable, synthetic, steel and combined, and according to the method of manufacture - into twisted (twisted), non-twisted and braided.
When choosing a cable for work in specific conditions, they are guided by its performance, which are determined by the physical and mechanical characteristics of the cable. The most important of these are strength, flexibility and elasticity.
Rope strength- its ability to withstand tensile loads. It depends on the material, design, manufacturing method and thickness of the cable. The latter is measured in millimeters: vegetable and synthetic cables - along their circumference, steel - in diameter. Strength is the main criterion for evaluating any rope designed to work in a highly stressed state.
Distinguish between breaking and working strength of the rope.
The breaking strength of the rope is determined by the smallest load at which it begins to collapse. This load R called breaking force. Its numerical value in newtons is indicated in state standards and can be calculated approximately using the formulas.
For vegetable and synthetic ropes:
for steel cables:
where f- empirical coefficient; C - the length of the cable section circumference, mm; d,- cable diameter, mm.
The working strength of the cable is determined by the highest load at which it can operate under specific conditions for a long time without violating the integrity of individual elements and the entire cable. This load is called the allowable force. Its value in newtons is set with a certain margin of safety:
where R - breaking force, N; k- safety factor selected depending on the purpose and operating conditions of the cable.
For most ship ropes, the safety factor is taken equal to 6, and in devices for lifting people - at least 12.
Flexibility of the rope- its ability to bend without breaking the structure and losing strength. The more the rope is flexible, the more comfortable and safer it is to work with it.
Elasticity (elasticity) of the rope - its ability to elongate under tension and take on its original dimensions without residual deformations after removing the load. Elastic cables are optimal when dynamic loads are applied.
For proper maintenance of ropes, their correct storage and use on board, it is also important to know and take into account the resistance of ropes to the effects of external factors: water, temperature, solar radiation, chemicals, microorganisms, etc. Regulations and state standards define the quality requirements for raw materials and the main characteristics of the cables.
Plant ropes are made from specially processed durable long fibers of some plants. According to the method of twisting, they can be cable and cable work.
Rice. 1. Vegetable cables.
Making a plant cable (Fig. 1) begins with a twist of threads 1 in heels 2. A strand is twisted from several cables 3, and several strands twisted together form a cable cable work(fig. 1, a). Depending on the number of strands, there are three-, four- and multi-strand cables. A cable with a smaller number of strands is stronger than a cable of the same thickness, twisted from a larger number of strands, but inferior to it in flexibility. Cable cable work(fig. 1, b) is obtained by twisting several cables of cable work, which in the structure of such a cable are called strands 4. Wire rope is less strong than wire rope of the same thickness, but more flexible and resilient. To prevent the cable from unrolling and retain its shape, each subsequent element of the cable is folded in the direction opposite to the roll of the previous element. Typically, the fibers are twisted into bobbins from left to right. Then the bobbins are twisted into strands from right to left, and the strands into a cable - again from left to right. Such a rope is called a rope. straight descent, or right lay(fig. 1, v), and a cable with the opposite direction of twisting of elements - with a cable reverse descent, or left lay(fig. 1 , G).
On the ships of the marine fleet, hemp, Manila and Sisal plant cables are most widely used. Coconut, cotton and linen ropes are less commonly used.
Hemp ropes are made from hemp fibers - hemp. A significant disadvantage of these cables is their high hygroscopicity and susceptibility to decay. To prevent rotting, the strands of the rope are twisted from tarred cables. Such a cable is called resinous, and a cable made of non-resinous cables is called white. The strength of the resin rope is about 25% lower than the strength of the white rope of the same thickness, and the weight is 11 - 18% more. Hemp cables for cable work are made white and tarred, and cables for cable work are made only with tar. The latter, being more moisture resistant, are mainly used as mooring lines. White cables have a gray-greenish color, resinous ones - from light to dark brown. Hemp cables are lengthened without loss of strength by 8-10%.
Manila The ropes are made from the fibers of the tropical abaca banana - Manila hemp. Of all plant ropes, they have the best performance characteristics: great strength, flexibility and elasticity - they lengthen without loss of strength by 20 - 25%. The ropes slowly get wet and do not sink in water, under the influence of moisture they do not lose their elasticity and flexibility, they dry quickly and therefore are less susceptible to decay. The color of these cables ranges from light yellow to golden brown.
Sisal The cables are made from the fibers of the leaves of the tropical plant agave - Sisal hemp. They are elastic, like Manila cables, but they are inferior to them in strength, flexibility and moisture resistance, in a wet state they become fragile. The color of these cables is light yellow.
Coconut the ropes are made from the fibers that cover the coconuts. The ropes do not sink in water, are half the weight of resin hemp ropes, but are less durable. The cables are very elastic - when the tensile load is close to the breaking force, they lengthen by 30 - 35%.
Cotton The cables are used mainly for household needs. They are not strong enough, short-lived, very hygroscopic and highly elongated.
Depending on the manufacturing method and thickness, plant ropes have special names:
- lines - cables of cable work with a thickness of up to 25 mm and cables of cable work with a thickness of up to 35 mm;
- perlini - cables for cable work with a thickness of 101 - 150 mm;
- cable - cables for cable work with a thickness of 151 - 350 mm;
- ropes - cables for cable work with a thickness of more than 350 mm.
High-strength lines are twisted from several cables of high quality hemp. Tench twisted from low-grade hemp is called shkimushgar. It is used for the manufacture of mats, fenders and other products. Lines made by weaving linen threads are called cords. Braided cords are flexible and elastic, do not have large external changes and deformations as a result of twisting.
When calculating the breaking force for plant ropes, the following values of the empirical coefficient are taken:
- for Manila - 0.65;
- for hemp whitewash - 0.6;
- for resinous hemp - 0.5;
- for Sisal - 0.4.
Synthetic cables. Depending on the brand of polymer, these ropes are subdivided into polyamide, polyester and polypropylene. Polyamide ropes are made of nylon, nylon (nylon), perlon, silon and other polymers. Polyester ropes are made from lavsan, lanon, dacron, diolene, terylene and other polymers. The materials for the manufacture of polypropylene cables are films or monofilament of polypropylene, tiptolene, bustron, ulstron, etc.
Synthetic ropes have great advantages over plant ropes. They are much stronger and lighter than the latter, more flexible and elastic, moisture resistant, for the most part do not lose strength when wet and are not subject to decay. Such cables are resistant to solvents (gasoline, alcohol, acetone, turpentine). Polyamide and polyester ropes retain all their properties when the air temperature changes from -40 to + 60 ° C, which allows them to be used when the vessel is operating in various climatic conditions.
When operating synthetic ropes, it is necessary to take into account their features. Polyamide ropes are damaged by solar radiation, acids, drying oil, fuel oil, and polyester ropes - by contact with concentrated acids and alkalis. The breaking strength of polypropylene ropes decreases at temperatures above + 20 ° С, and at negative temperatures, their flexibility decreases. When rubbing against the surface of equipment parts and as a result of friction between strands, the cables can accumulate static electricity, which can cause sparking and damage to the cables. The outer fibers are not sufficiently abrasion resistant and can melt, especially when rubbed against rough surfaces.
Synthetic ropes are very flexible. So, with a load equal to half the breaking force, the relative elongation of braided eight-strand cables is as follows: polypropylene - 21 - 23%, polyester - 23 - 25%, polyamide - 35 - 37%. Such great elasticity makes a tightly stretched cable dangerous for workers, as if it breaks, the ends of it can injure them. Braided eight-strand cables are less dangerous than twisted three-strand ones. In addition, they are more resistant to abrasion, have better flexibility, retain their structure and shape even when two strands break, while withstanding a load of 75% of the breaking force. Lack of torque in a braided rope, which is in a stressed state, makes it more convenient to use.
The breaking strength of synthetic ropes depends on the grade of polymer (see table).
Table. Breaking forces (kN) for braided eight-strand cables, depending on the material of their manufacture.
| Rope type | Circumference of the cable section, mm | |||||||||||
| 80 | 90 | 100 | 105 | 115 | 125 | 140 | 150 | 165 | 175 | 190 | 200 | |
| Polyamide | 118 | 139 | 176 | 197 | 219 | 264 | 315 | 370 | 430 | 476 | 563 | 635 |
| Polyester | 94 | 108 | 138 | 155 | 190 | 210 | 251 | 296 | 345 | 394 | 439 | 511 |
| Polypropylene | 74 | 89 | 112 | 123 | 143 | 165 | 191 | 222 | 256 | 291 | 334 | 379 |
Braided and twisted nylon ropes of domestic production are common and of increased density. The breaking strength of the latter is higher than that of conventional ones. The breaking force values for conventional 8-strand braided ropes are as follows:
The breaking force values for high-density 8-strand braided ropes are as follows:
They are usually made of galvanized wire. According to the quality of galvanizing, the wire is divided into three groups with the indices LS (for light working conditions), SS (for medium working conditions) and ZhS (for severe working conditions).
Rice. 2. Steel cables.
By design, the cables are single, double and triple lay. Single lay rope, also called spiral (Fig. 2, a), consists of one strand, in which the wire is twisted in a spiral in one or more rows around the central wire. Several strands twisted around one core form double lay rope(fig. 2.6). This is a wire rope work. Triple lay rope(fig. 2, e) is obtained by twisting several double-lay cables. It is a wire rope for cable work.
Depending on the method of stranding wires in a multi-strand strand, cables with linear and point contact with the wires are distinguished. V cable with linear touch the wires of each subsequent row are twisted around the central core in the same direction as the wires of the previous row. In this case, the rows of wires touch along the entire length of the wire. This type of cable is designated by the letters LC. The breaking force values for cables of the LK type of construction 6X30 (0 + 15 + 15) + 10С are as follows:
| Rope diameter, mm | 19 | 21 | 23 | 26,5 | 28,5 | 30,5 | 32,5 | 34,5 | |
| Breaking force. kN | 143 | 177,5 | 215,5 | 284 | 332 | 373 | 416 | 473 | |
| Rope diameter, mm | 38 | 42 | 46 | 48 | 50 | 53,5 | 57 | 61 | 65 |
| Breaking force, kN | 572,5 | 711 | 831 | 909,5 | 994,5 | 1130 | 1330 | 1490 | 1660 |
When twisting the wires of each subsequent row in the direction opposite to the twisting of the wires of the previous row, it turns out point-touch rope wire, designated by the letters TK.
The breaking force values for cables of the TK type of construction 6X37 (1 + 6 + 12 + 18) + 10С are as follows:
In the direction of stranding wires in strands and strands in a cable, one-sided, cross and combined cables are distinguished.
One-way lay rope(right or left) is obtained by stranding the strands in the same direction as the strands of wire in strands. When stranding the strands into the cable in the direction opposite to the lay of the wires into strands, it turns out cross-lay rope. If the first half of the strands has a lay in one direction, and the second half in the opposite direction, such a cable is called with a combined lay rope.
Steel wire, oiled hemp and other vegetable cables of cable work, synthetic and asbestos materials are used as cores for the cables. The core ensures the tightness of the rope and maintains its shape on bends at high tension, makes the rope softer and more flexible. Oiled cores, in addition, protect inner wires from rusting, and asbestos - from premature wear of cables used in high-temperature conditions. In addition to the central core of various materials Many types of ropes have organic cores within each strand.
According to the degree of flexibility, the cables are divided into rigid and flexible. Tough called single-lay cables made of wires with high tensile strength, twisted in several rows around a wire core, as well as cable-work cables with a single core made of organic material. Flexible called cables of cable work, each strand of which is twisted from thin wires and has a core of organic material, as well as cables of cable work twisted from such cables.
Combined cables. They are used as towing and mooring lines. For their manufacture, various polymers (in combination) are used, as well as synthetic and steel cables with plant fibers. The factors that determine the choice of materials for the manufacture of combined cables are the performance characteristics to which they must correspond.
For the symbolic designation of the design, structure and characteristics of steel cables, an alphabetic and numeric system is used. The number of strands in the cable is indicated by a number, and the design of the strand is the sum of the numbers, of which the first characterizes the core, the second indicates the number of wires in the first row, the third indicates the number of wires in the second row, etc. For example, an entry for a two-row strand (1 + 6 +12) means that the strand has a core of one (central) wire, there are 6 strands in the first row, and 12 in the second. the cable has a common organic core. So, for a multi-strand cable, the entry 6X24 (0 + 9 + 15) + 1ОС means: a six-strand cable, each strand has 24 wires twisted around an organic core in 2 rows of 9 and 15 wires, respectively, and the strands are twisted around a common organic core.
Cables (ropes) are products that are twisted from steel wires or twisted from plant and artificial fibers. By material, ropes are divided into vegetable, steel (wire), combined and synthetic.
Made from appropriately processed plant fiber. Depending on the source material, plant cables are hemp, Manila and Sisal.
Hemp ropes made from hemp fibers - hemp. Hemp can be used neat (white ropes) and tarred (resinous ropes). Resin hemp protects the rope from moisture and rapid decay, but its strength is somewhat reduced. Hemp ropes are strong and elastic, but they strongly absorb moisture, so they sink in water, and in cold and damp weather they become heavy and tough.
Manila cables, made from the fibers of the stems and leaves of the bana-new tree, very convenient for use on ships. The peculiarity of these ropes is low hygroscopicity, due to which they do not sink in water. These ropes are the strongest of all vegetable ropes and are distinguished by their flexibility and considerable elasticity.
Sisal cables made from the fibers of the leaves of the tropical agave plant. These cables are inferior in strength to hemp cables. They have great rigidity, as a result of which they wear out quickly.
Vegetable cables are made as follows. First, the wrap-on is twisted into bobbins. Then a strand is obtained from several cables. Three to four strands, twisted together, form a cable, which is called a cable work cable (Fig. 1, a). Several cables (three to four) of cable-work, twisted together, form a cable-work cable (from-winch cable). The cables of cable work used in this case are called strands (Fig. 1, b)
Rice. 1 Vegetable cables a - cable work, b - cable work, c - direct descent, d - reverse descent, 1 - heels, 2 - strands, 3 - strands
In order for the cable not to unwind and maintain a constant shape, the constituent elements (strand heels, strands and cables as a whole) are twisted in different directions. Usually, the fibers are twisted into heels in a clockwise reverse side, and the strand into the rope again clockwise. With this direction, the lay is a straight descent rope (Z-shaped) (Fig. 1, v). In some cases, the reverse direction of the lay is used. Such cables are called return cables (S-shaped) (Fig. 1, G).
Braided cables, which consist of one weakly twisted strand, covered with a braid of linen threads, have also found application on ships. These cables stretch little and do not twist, therefore they are used for signal halyards and laglines of outboard lags.
The thickness of the plant ropes is measured along the circumference. Depending on it, these cables have special names. So, ropes up to 25 mm thick are called lines, from 100 to 150 mm - beads, from 150 to 350 mm - cable and over 350 mm - ropes (ropes with a circumference of 25-100 mm have no special name).
Rice. 2 Steel cables of different lay: a - single; b - double; c - triple Steel ropes are made of steel, usually galvanized, wire with a diameter of 0.2-5 mm. Depending on the number of strands, cables of single, double and triple strands differ (Fig. 2). The easiest way to make a single lay steel cable. In this case, several wires are twisted directly into the cable.
Such single strand cables are called spiral cables. But more often and in a large assortment, double-lay cables are made: the wire is first twisted into strands, and then several strands are twisted into a cable. If several of these ropes are twisted together, you get a triple lay rope.
Multi-strand cables twist around a central core (Fig. 3), which is used as a steel wire or organic fibers. The core, filling the void inside the cable, prevents the strands from falling to the center, and the organic core containing anti-corrosion grease, in addition, protects the cable wire from rusting, thereby increasing its service life. In addition to the central core, some strands may have an organic core within each strand.
Of great practical importance is the classification of ropes according to their flexibility. The most rigid are single strand spiral cables. Rigid cables are those with a wire core, and cables with a central organic core are semi-rigid. Flexible ropes have multiple organic cores. Triple lay cables are the most flexible.
To designate brands of steel cables, a digital system is adopted, according to which each cable is marked with a product of numbers: the first of them indicates the number of strands in the cable, the second - the number of wires in each strand. When marking a triple strand rope in front, one more factor is added, which indicates the number of strands in the rope. The number of organic cores in the rope is indicated by the last figure.
Rice. 3 Steel cables with a core: a - wire, b - synthetic, c - organic 6 X 24 + 7 means a 6-strand double lay rope, each strand of 24 wires, and 7 organic cores. A six-strand triple-lay cable, each strand of which is twisted from 7 strands of 19 wires and has one organic core, will be designated: 6 X 7 X 19 + 1.
Combined ropes have strands of galvanized steel wires covered with vegetable yarns.
Synthetic ropes are made from artificial fibers, which include nylon, nylon, curalon and the most widespread now polypropylene. In terms of their strength, elasticity, flexibility and durability, these ropes are far superior to the best plant ropes. They are not susceptible to decay and mold, they are almost resistant to the action of oil, oils, alkalis and acids. For ship work, steep three-strand synthetic ropes are most often used, and for mooring ends it is allowed to use eight-strand synthetic braided ropes.
The use of ropes on ships requires knowledge of their main characteristics, of which strength is the most important. The strength of the cable is characterized by its breaking force, which is understood as the minimum load breaking the cable. The breaking strength of the cable depends on its diameter and structure, type of lay and material, wire diameter, steel quality, etc.
The values of the breaking strength of the cables are given in the state standards. For practical purposes, it is often sufficient to know the approximate value of the breaking force, which can be determined by various empirical formulas.
So, for example, breaking force R(in N) and mass G(in kg) 100 normal three-strand Manila tether cable work is determined by:
Where f is an empirical coefficient, the magnitude of which varies within the range of up to 4 when the cable circumference changes from 30 to 350 mm. More precisely, this coefficient can be determined by the formula
f = 650 - 0.75 C 100
WITH- cable circumference, mm.
Table 1
The breaking strength of other types of plant ropes can be determined using the same formulas with the introduction of the correction indicated below (in% of the calculated value R) :
- Manila increased durability + 30;
- Sisal normal - 30;
- The same of increased strength - 0;
- Hemp white, normal - 20;
- Same special + 5;
- The same resinous normal - 25;
- Same special.
Synthetic ropes have a significantly higher strength. The breaking strength of the curalon cable is 1.5 times, and of the nylon and nylon cable - more than 2.5 times higher than that of the Manila cable. At the same time, the weight of synthetic ropes is 10% less than that of plant ropes.
Breaking force and weight of steel ropes can be determined:
Wherek andk 1 — empirical coefficients, the value of which for various types of cables is indicated in table. 1;
d - cable diameter, mm.
In order to choose the right cable for work, it is necessary to know not only the breaking force, but also its working strength (permissible tension). Working strength is the load at which the cable can operate under these conditions for a long time without violating the integrity of individual elements and the entire cable. Working strength R(in newtons) constitutes only a certain part of the breaking force and is determined by:
Where n is the safety factor.
For cables used on ships, n it is usually taken equal to 6. More precisely, it can be selected taking into account the purpose, operating conditions and the type of cable. So, for standing rigging NS decreases to 4, in devices for lifting people it rises to 14.
Example 1. Normal three-strand Manil mooring line, circumference 250 mm. Calculate the breaking force and working strength of 100 m of the rope and the weight of the rope coil at 200 m.
- N a h about d and m co e f and c and e n t f = 650 - 0, 75 × 250 100 = 4, 625;
- DEFINITION R = 4, 625 × 250 2 = 289062, 5 H;
- Then P = 29062.5 6 = 48177.1 H;
- Weight of 100 m of rope G = 0.007-250 2 = 437.5 kg. The mass of a bay of 200 m will be 2 times more, i.e. 875 kg.
Example 2. Steel flexible towing rope with a diameter of 60 mm. Calculate the breaking force and working strength of 100 m. Of the cable and the weight of the bay at 500 m. Of this cable.
- We choose from the table. 1 values & = 350 and k1 =0,3;
- We define R = 350. 60 2 = 1 260 000 N;
- P r and n I in n = 5, about lu h and m P = 1260000 5 = 252000 H;
- Weight of 100 m of rope G= 0.3. 60 2 = 1080 kg, and a bay of 500 m has G — 5-1080 = 5400 kg.
Ships are supplied with ropes in accordance with the Rules for the Classification and Construction of Sea-Going Ships of the USSR Register.
The strength and durability of cables depends not only on their design and quality, but also on correct operation, storage and maintenance procedures. A good cable can quickly become unusable if you do not follow the elementary rules of technical operation and use it in unsuitable conditions.
Revealing the good quality of the cable depends on the correct acceptance. Upon receipt of the cable, you should carefully inspect it and check the basic design data and the presence of a certificate with a tag. When inspecting steel ropes, they check the integrity of the galvanized steel, the presence of rust, the safety of the wire and the tightness of the wires in the strands. When accepting plant ropes, it is necessary to pay attention to their smell and color, as a musty smell indicates the presence of rot and mold.
The resin rope should be a uniform light brown color, not stained, stick to your hands and not crackle when unbending. The stickiness of the rope indicates excessive resin, and dry crackling indicates that the rope is stale.
The safety of the cable is to a large extent ensured by the correct methods of opening the coils (Fig. 4), which do not allow the formation of loops and creases (pegs), since the creases cause significant local deformation of the cables and the rupture of individual wires, and also make it difficult to work with ropes.
When unfolding, the bay of the plant cable is placed on the edge, the harness is removed and, after passing the inner end of the cable through the inner cavity of the bay, it is released, holding the outer hose with your hands.
To open the coil of the steel cable, it is necessary, holding the coil by the extreme slugs, roll it along the floor and at the same time pull on the running end. A thick steel cable is usually obtained on a ship wound on a drum. In this case, it is best to unwind the rope from the rotating drum, placing it in a horizontal position on two supports.
Rice. 4 Opening of the rope bay: a - vegetable; b and c - steel The ropes that have been loosened from the bay should be stretched along the deck so that they are straightened, and then cut into pieces of the required length. In order for the cable not to unwind at the place of the cut, on both sides of this place it is pre-tied with soft wire or a cable stamps are applied. The cut cable is wound on the view or stored in small coils. The cable protects from moisture the cover, which is put on the view. In good weather, the cover must be removed to dry the cable.
Vegetable cables are usually stored in small, loosely laid bays. The cables are laid in a coil-that is twisted, i.e. cables for direct run cable work - clockwise, and cables for return run and cable work - counterclockwise. To protect against the action of moisture, the bays of the plant cable are suspended or placed on lattices (benches).
In time of rain or fresh weather, the bays should be covered with tarps or covers. All unused cables should be stored in dry, well-ventilated areas. From time to time, the cables must be thoroughly ventilated by hanging them on handrails, between masts or in other convenient places.
Used ropes dry well before laying in bays. Vegetable ropes soaked in sea water are recommended to be rinsed with fresh water before drying. For washing large ropes, you can use the ship's entrance at river mouths, where the rope can be washed overboard in river water.
Synthetic ropes are not afraid of moisture, and drying them is optional, but you cannot wind a wet rope around the view. The rope should be dried in the shade, as it deteriorates from the action of sunlight. If the rope becomes dirty, rinse it out with seawater. Synthetic ropes are very sensitive to abrasion and melting, so drum surfaces should be smooth.
During operation, static electricity builds up on the surface of synthetic cables, which can cause sparks. Therefore, new synthetic ropes can be used on tankers only after antistatic soaking for 24 hours in seawater with a salinity of at least 20%, or in a specially prepared saline solution (20 kg of sodium chloride per 1 m 3 of water). During operation, the rope is necessary periodically, at least 1 time in 2 months. roll on deck with salty seawater, as recorded in the logbook.
Combined cables with a jacket made of vegetable cables also require careful maintenance. These ropes must not be laid in coils wet or damp, as moisture remaining in the jacket can cause intense corrosion of the wire.
Steel cables should be lubricated (lubricated) systematically. This not only protects the cable from corrosion, but, by reducing friction between the wires, helps to reduce wear. As lubricant usually use rope lubricant NMZ-Z or ZZT. Untreated cables must be lubricated with grease at least once a month. The composition of the shooting gallery: 87% grease, 10% bitumen, 3% graphite.
§ 63. Means of communication and signaling on the water.
On small boats, communication and signaling are necessary for communication with the shore and other vessels, for sending distress signals.
All types of communication or signaling devices on small boats are divided into three main types: visual, sound, radio engineering.
1. Visual alarm.
The means of visual communication include flag and light signaling.
A. Flag signaling.
A flag semaphore (Fig. 148, a) is the most common and accessible form of communication. Its essence is that each letter of the Russian alphabet corresponds to a certain position of the hands. In the semaphore alphabet, there are 29 alphabetic characters, 8 service and 4 change of place characters. In order to use a flag semaphore, an amateur navigator must know it well, and on a ship during navigation have two brightly colored flags nailed to the handles for ease of use. You must also have a spare pair of semaphore flags.
Signal flags (see appendix) are used for communication and signaling with posts, beacons and passing ships. If an amateur seafarer does not remember the meaning of each flag or combination of flags, then the ship must have a table where these values would be written down. The combinations of flags given in the appendix, the navigator in sea navigation must know by heart and have prepared combinations on board in order to quickly report a warning or distress signal at the right time or read a signal raised by another vessel.
Single-flag values
A - "I'm doing speed tests"
B - "I am loading (unloading) an explosive"
V - "I need medical attention"
G - "I need a pilot"
D - “Stay away from me. I AM I can hardly manage "
E - "I am steering my course to the right."
F - "I need help"
Z - Coast station alert
AND - "I'm going to do a semaphore message."
TO - "Stop Your Ship Immediately"
L - Stop. I have an important message "
M - "I have a doctor on board."
Rice. 148 a- flag semaphore alphabet;
N - "No", negative
O - "Man overboard"
NS - At sea: "Your lights are out." In port: "The crew get ready for the ship"
R - "My ship is not moving."
Rice. 148 b- individual signs and techniques
WITH - "My machines are running at full speed backwards."
T - "Don't Cross My Course"
Have - "You are heading for danger."
F - “I am not in control. Keep in touch with me "
X - "I have a pilot on board"
C - "Yes", affirmative
SCH - "My ship is not contaminated"
B - "Stop your actions, watch me"
NS - "I'm taking mail"
B. Light signaling.
Light signaling is used at night, when no message can be transmitted by other means of communication. Each letter of the Russian alphabet is assigned a certain combination, consisting of a set of dots and dashes, transmitted by a searchlight, signal device or clot.
The point is transmitted by short pressing of the key, which closes the electrical circuit. The dash should be three times as long as the dot.
In the absence of electric lighting, the message can be transmitted with an electric pocket torch or oil lantern, covering the light with the palm of your hand or a cap.
Rice. 149. Using a light-signal mirror. a- alignment of the sunspot; b - signaling
Light signaling also includes a light-signaling mirror (heliograph), which is a device that allows beams reflected by a mirror to be sent in the form of light signals at a distance of up to 20 miles. This device is based on aiming the reflection of the solar disk ("bunny") at the object of interest. The signal mirror consists of two hinged metal plates, one of which is chrome-plated and polished. The plate has a sighting hole. To send signals, the mirror should be held in your hand so that the vessel or plane that sends the signal can be seen through its sighting hole on the upper flap (Fig. 149, a). In order for the "bunny" to fall on the target and on the ship or aircraft to notice your signal, it is necessary to turn the mirror so that the beam passing through the sighting hole and reflected from the lower flap onto the inner surface of the upper flap in the form of a light circle coincides with the sighting aperture (Fig. 149.6).
To prevent the mirror from falling into the water, it must have a cord that is worn around the neck during signaling.
Pyrotechnic alarms or pyrotechnic devices serve to signal the position of the vessel or in the event of a distress to the vessel. Pyrotechnics are classified into daytime (thick orange smoke) and nighttime (bright stars or flames).
The RB-40Sh boat parachute rocket takes off to a height of at least 200 m, burns with bright red light and slowly descends by parachute. Burning duration 35 sec. Signal visibility range 10-15 miles.
The night signal cartridge, commonly referred to as a "flare", is held in the hand while burning and produces a torch of red, blue or white fire.
The cartridges are respectively designated F-2K, F-2G and F-2B.
Flares of red light are designed to give distress signals, white - to attract attention, blue - to call the pilot. The signal duration for cartridges of red and blue fire is at least 60 seconds, for cartridges of white - 30 seconds. Visibility range 5 miles.
Hand flares are safe to handle and will not be blown out by the wind.
The daytime signal cartridge, when triggered, emits orange smoke, which is visible from a distance of 3-4 miles. The burning time of the cartridge is not less than 30 sec.
Floating smoke bombs are effectively used in the daytime. Thick orange smoke is visible for at least 5 miles, even in clear and calm weather. Smoke formation occurs within 5 minutes. and passes without an open flame.
Pyrotechnic cartridges are reliable, and preparation for the action of the above-mentioned pyrotechnic means takes no more than 7-10 seconds.
To give a signal, the cap of the cartridge is unscrewed and the ring with the cord is pulled out with a sharp movement. When giving a signal, all cartridges must be kept away from you in the wind.
Visual signaling also includes dyes of the water surface, which are clearly visible from an aircraft.
Dyes include packages with dyes - fluorescein or uranine grade "A", coloring the water surface on an area of up to 50 m 2 in yellow-green color. The visibility range of such a spot from an aircraft reaches 15-20 km.
It is not necessary to have all of the above-mentioned pyrotechnic signaling devices when sailing in open water, but at least 1-2 devices from each of the above-mentioned pyrotechnic groups must be on board. You can have one tool that reliably replaces the other. This is necessary in the event of a distress call. To avoid a fire, ignite the pyrotechnic signals only overboard on the leeward side of the vessel.
2. Sound alarm.
On small boats, all types of car signals, whistles, signal horns, bells are applicable to signaling, attracting attention, indicating their location in fog (poor visibility), in the absence of visual signaling. The range of audibility of a car signal is 1 mile, a horn - 0.5 miles, a whistle - twice as far as hearing a voice, electric, air sirens and steam horns - 2 km.
The P12 distress signal cartridge emits a signaling sound that is audible in calm weather at a distance of at least 5 miles.
3. Radio signaling.
An emergency portable boat radio station "Shlyup" and an emergency aircraft radio station "Kedr-S", which can operate both from an automatic sensor of alarm and distress signals, and from a manual key, are used as a radio technical signaling device for sending distress signals on small boats. The receiver of the radio station "Shlyup" has two wave ranges: 400-550 kHz and 600-9000 kHz. Signals can be transmitted on waves with frequencies of 500, 6273 and 8364 kHz. The station has the shape of a cylinder with a diameter of 280 mm, height 500 mm, weighs 25 kg and is powered by a hand-held generator.
The radio station "Kedr-S" operates at frequencies of 500, 2232, 4465, 8928 and 13392 kHz. In a set weighing 25 kg two types of antennas are included. Powered by dry batteries.
An emergency portable radio station of the "Plot" type, designed to send and receive telegraph and telephone calls and distress signals, as well as to receive signals in the medium ranges (100-550 kHz), intermediate (1605-2800 kHz) and short (6000-8000 kHz) waves. There is automatic sensor alarm.
The radio station is powered by a hand-held generator. The receiver can also be powered by water-filled batteries of the "Smoke" type, which are included in the supply of life-saving appliances. The radio station consumes no more than 35 tue, and when receiving no more than 6 Tue The amount of electricity consumed from water-filled batteries when receiving does not exceed 1.5 Tue
The raft weighs 23 kg, measures 270X300X415 mm and can operate with a 6m telescopic antenna, a 9m mast and a 100m box-kite antenna.
Passive radar reflectors installed on sailing, rowing, wooden, plastic boats also belong to the signaling means by which navigators of ships, where ship radar stations are installed, detect small boats. The installation of passive radar reflectors is necessary for the timely detection of a small vessel by ships of a large fleet both in open water spaces and on inland waterways. There are many cases when the timely detection of a small vessel in poor visibility and in fog prevented the collision of small vessels with large ones when the latter changed its course.
The presence of passive radar reflectors on small craft is critical in rescue operations to locate ships swept out to sea.
The passive radar reflector consists of three precisely mutually perpendicular metal discs with a diameter of 240 mm and thickness 1 mm. TO a steel tube with a diameter of 50 is attached to one of the disks mm and length 130 mm. It is mounted on a two-meter wooden rod, which, together with the reflector, is installed vertically on the mast.
§ 64. Rigging on the ship.
Rice. 150. Ropes: a - three-strand and four-strand ropes of cable work; b- hemp rope of cable work and its parts
Rigging refers to all work with ropes in the manufacture of rigging, tugs, mooring lines, etc. Any rope on a ship is called a rope.
There are vegetable, steel and synthetic ropes. Vegetable cables are hemp, manila, sisal and cotton (Fig. 150). Hemp rope can be whitewashed and tarred. Resin rope is more durable, but slightly weaker than whitewash. Of the vegetable ropes, the best for mooring a vessel are hemp whitewashed or resinous. Vegetable ropes are afraid of soot, high temperatures, oils. If the white cable in the middle is light, then its quality is good, if it is brown, then the cable is rotten.
Rice. 151. Steel cables: a - hard; b - semi-rigid; v- flexible; G- benzel
Steel cables are made of galvanized wires (Fig. 151). Having a greater strength than vegetable cables, these cables are more rigid, and therefore not so convenient to work with. The more wires in the rope, the softer, more elastic it is, the more convenient it is to work with it.
The ropes require care: plant ropes are dried after work, steel ropes are lubricated with grease or used oil once a month. Acids and alkalis spoil any ropes.
Rice. 152. Rigging tool 1
- pile, 2
- muskel, 3
- half-muffle, 4
- fights, 5
- scapula, 6
- knife
The rigging tool is used when working with ropes (Fig. 152). With the help of a pile, strands of rope are pierced when fixing lights, rope connections. Draek is used for tightening gazelles, lashing and hanging around rigging lights and knots. Mushkel - a wooden hammer used to hammer ropes. Gardaman is a leather "thimble" with a steel or copper head on the palm.
In addition, the rigging toolkit includes a knife, chisel, hammer and shovel.
2. Nodes.
The knots are used to tie the cables and fasten them to any objects, equipment, etc. They should quickly knit and untie, but not spontaneously unravel. The main nodes (fig. 153).
The straight knot is used to fasten the two ends of a small diameter cable (with a small tensile force to avoid tightening the knot).
The reef knot is used when a quick return of the tied gear is required, for which you need to pull the free end of the cable.
Rice. 153 Marine nodes: a- straight, b - reef, v- noose, G - bleached; d- a simple bayonet; e- locking knot; f- boat unit; h - slack knot; and -shkotovy (left) and bramskotovy (right); k - flat knot; l - towing, m- riot knot
A choke is used to quickly attach the cable to a log and other round surfaces when towing. For the strength of the knot and to reduce slipping, one or two hoses are additionally made on a smooth round surface.
The seam knot is knitted when there is an assumption that the stranglehold will slip.
A simple bayonet is used when attaching mooring lines to eyebrows and bollards. A variety of a simple bayonet is a bayonet with two hoses - it does not crawl or tighten.
The locking knot is used for fastening the boat halyards, when one tow rope is fed to several boats.
The dinghy assembly is used to attach the dinghy, for example, when towing.
The hook knot is knitted for laying the plant cable on the hook.
The clew knot is used to knit sheets into the clew corners of the sails. A variation of it is the brass knot, which is used at heavier loads.
A flat knot is used to tie ropes of various thicknesses, for example, a conductor with a tug (more often, a knot with a backward loop is used for untiing).
The towing knot is used to lay the towing end on the hook.
The booty knot is used when knitting a bootie for an anchor trend.
3. Splash and ogons.
Splashes are used for splicing two cables. They are short and long or accelerating. A short splash gives a slight thickening at the splice. To splice two cables with a short splash, the strands of both ends are loosened (Fig. 154, a). A mark is applied to the cable to protect the cable from unraveling.
Strands of one cable are inserted crosswise into strands of another. Turning the cable in the sun, they pierce the running strand of one cable under the oncoming strand of the other in such a way that when tightening they press each other. Usually, three piercing of each strand is made, then cut off by half a strand and pierced one more time. To splice two cables with a long (accelerating) splice (Fig. 154, b), the rope is dispersed one to one and a half meters and stamps are applied. Then one strand is twisted, and a strand of another cable is twisted in its place. The remaining two untouched strands are tied together, and the ends of the strands are cut off. For splicing two steel cables with an accelerating splash, they do the same. Only the punching of the running strand is carried out against the descent under the two root strands of the other cable, while clamping one root strand on the left. So they punch through all the strands in order from right to left, clamping one root and passing two others under it.
Ogon is a loop made at the end or in the middle of the cable (Fig. 155). A brand is applied to the cable, and its free end is dissolved. Having arranged the loose strands in order, the punching begins with the middle one, passing it under the nearest root strand against the descent. Then they punch the upper left under the next root, while holding the previous root. Turn the fire 180 ° and pierce the third strand under the remaining root. In the process of further punching, you need to look so that the root strand is between the two running gear. Then one strand is pierced under one root. Three punches are made in total.
Rice. 154. Splice: a- short splash (1- 4
- sequential techniques of splicing two cables); b- long splash
To apply a mark (fig. 156), you need to take a pile or a canvas thread, put it in a loop on the cable and wrap it with its free end 10-20 times. Having passed the end into the loop, the latter is dragged in and cut off.
Rice. 155. Simple fire
Rice. 156. Simple brand: 1 - running end; 2
- root end
4. Manufacturing of fenders and mops.
Fenders are used to protect the ship's hull from impacts and friction during mooring and mooring at the berth. You can use hard (wooden) and soft (wicker) fenders (fig. 157). Soft fenders are made from pieces of old cable, tow and crushed cork. A cork or tow is placed in a canvas bag according to the size of the fender, then the old cable is unrolled and the bag is tied crosswise with it, leaving a loop on top. The bag is suspended at a convenient height and passed through the loop of the bobbin. The latter twine around each other. At the end of the work, the free ends are taped under the braid. The mop is made as follows: a piece of unnecessary plant cable is spread over the bobbins, the handle is cut out, as shown in the figure (Fig. 158), the bobbins are evenly covered over the end of the handle and benzene is applied. After that, the bobbins are turned out, tightened and re-fastened with benzene.
The ends of the cables are trimmed evenly, the mop is washed and dried. At the other end of the handle, a hole is drilled for attaching a cable with a loop (the cable is needed so that the mop does not fall overboard).
Rice. 157. Making a soft fender
Rice. 158. Making a mop (sequential manufacturing techniques)
Vegetable ropes used on sea vessels, by the material from which they are made, as well as by design and classification. approved by the State All-Union Standards (GOST), are indicated on the previous pages of the site.
Recently, the use of nylon and nylon cables, made from synthetic fibers. Nylon cables They are characterized by high tensile strength, low water absorption, high elongation when working in tension, good elasticity and chemical resistance. The nylon rope can withstand temperatures up to + 220 ° C.
Nylon has valuable properties of increased technical strength (for example, the tensile strength of dry nylon reaches 6300 kg / cm2). Nylon is elastic, resistant to moisture and abrasion, and is used for durable fishing tackle.
The disadvantage of nylon cables is the melting of threads (fibers) from friction against the surface of the winch drum, windlass or bollards.
General information
Most often, a three-strand cable is used on ships. A four-strand cable is weaker than a three-strand cable of the same thickness by 20-25%.
Wireline ropes are used as tugs and mooring lines, although their strength is 25% lower than the strength of wireline ropes. Their positive qualities include better drying of a wet rope.
Ropes with a thickness of 100 to 150 mm are called beads, from 150 to 350 mm as cables and ropes over 350 mm.
Hemp rope is manufactured white (unsalted) and resinous.
The resin rope has a weight of about 12% more than the white rope, and its strength is 25% lower than that of the white rope. Resin rope lasts longer than white rope due to better weather protection.
The dark matte color of the rope means that the rope is old and of little use. This rope has an unpleasant odor.
Compared to hemp, the Manila cable is more flexible and lightweight.
The Manila cable gets wet a little, floats on the surface of the water, which is valuable when used as tugs, mooring lines and rescue lines.
Coconut rope is elastic, has a strength of about four times less, and its weight is half that of a hemp resin rope of the same thickness.
The Sisal cable floats on the surface of the water, but is inferior in strength to the Manila cable.
Liktros is a soft, gently sloping cable used to sheathe the edges of the sails.
For towing, they often use combination rope, for example, "Hercules", in which its individual strands consist of galvanized steel wires covered with sisal hemp yarn. The strands are twisted around the soft core. Rope "Hercules" is manufactured in four-strand and six-strand.
All plant ropes should be evenly twisted along the entire length and not have defects in the strands (creases, knots, etc.).
The new cable stretches without losing its strength, up to about 8-9%
its original size.
Splash weakens the rope by about 10-15%. The steeper the rope is lowered, the weaker it is. Wet rope is weaker than dry rope.
Sea hemp lines
A vegetable rope with a circumference of less than 25 mm is called a line. Lin in two strands (white and resinous) is called shkimushgar. Lin in three strands (white and resinous) is called yuzen. Special purpose lines include: l aglin, lothlin, diplotlin, signal halyards etc. Lothlin white in 18 threads, three-strand. The diplotlin runs down cable work and has 27 strands with three strands. All other lines of cable work.
Laglini for mechanical lags and signal halyards are made of braided and made from the best quality hemp.
Measurement of plant ropes
The thickness of the plant ropes is measured around the circumference. Usually 10 measurements are taken at different points of the cable. The arithmetic mean of these measurements will determine the size of the rope's circumference.
Plant cable care
The cables must be stored in dry rooms accessible for ventilation. Vegetable ropes are afraid of fire, heat, smoke, as well as all kinds of oils and acids. A wet rope must be dried, since an insufficiently dried rope laid in a bay will wear out and prematurely lose its strength. Ropes that are soiled with silt during use must be thoroughly washed before drying.
Vegetable ropes wet in salt water are recommended to be rinsed with fresh water before drying; for better drying, they should be stored on wooden banquets.
Calculation of plant ropes
The approximate service life (in operation) of the vegetable rope:
a) cable work - 3 years;
b) perline - 2 years;
c) other cables - 1 year.
The cable necessary for work can be selected by calculating its breaking strength according to the formula
R = P r (π d 2/4) (1)
where
d = Ö (4R / Pr * π) ,
where R - breaking strength, kg;
d - cable diameter, see;
P r is the permissible design tensile strength of the rope (usually P r take no more than 100 kg / sq. cm with diameters of the rope block 10d and not more than 80 kg / sq. cm at smaller diameters). Usually, when calculating the ropes, the load from the own weight of the ropes, the force of acceleration of the masses in the initial period of lifting the load and the additional tension when bending around the pulleys of the drums are neglected.
For lifting weights, the selection of the required cable can be made according to the approximate formula
P = nR, (2)
where P is the working strength of the cable;
n - safety factor (safety margin);
R - breaking strength of the cable.
Example 1. Pick up a hemp rope for lifting a load with a weight equal to 1500 kg. Weight Q is suspended by means of one free block on two ropes.
Solution. The calculation is made according to the formula (2), taking a 6-fold safety factor. The tensile force to which the cable is subjected is
R = Q / 2 = 1500/2 = 750 kg.
Having taken a 6-fold safety factor, we get the working strength of the cable
P = 750 kg * 6 = 4500 kg.
To check this calculation from the table GOST 483-41 we select a hemp white cable, looking for in the column "breaking strength of the cable" a number close to 4500 kg. For a cable of increased strength, such a breaking strength is 4477 kg and corresponds to a cable for which d = 31.8 cm. Then, denoting the permissible calculated tensile strength of the cable in tension in kg / sq. cm, through P r, according to the formula (1)
P r = R / ( π
d 2/4) = 750 / ( π
* 3,18 2 / 4)
we get the calculated tensile strength equal to 93 kg / sq. cm, which is quite acceptable.
The breaking and permissible working strength of plant cables can be roughly calculated by the formula
R = k С 2, (3)
where R is the breaking strength, kg;
k is the strength factor (Table 2);
C - rope circumference, mm.
table 2
Strength factor for vegetable ropes
Table 3
Determination of the weight of the plant rope
| Rope name | Running meter weight | Note |
| Hemp with a circumference of more than 10 cm | Q = C 2/112 | Q - weight of 1 running meter of rope, kg С - rope circumference, cm |
| Hemp with a circumference of less than 10 cm | Q = C 2/106 | |
| Manilsky | Q = C 2/137 | |
| Sisalsky | Q = C 2/145 |
Table 4
Lapel ropes (ropes), cable work
(GOST 483-55)
|
Rope size, mm |
Elevated |
Normal |
|||||
| circumferentially | by diameter | total number of cables in the rope | weight of 1 meter of rope, g | total number of cables in the rope | weight of 1 meter of rope, g | total strength of the cables of the rope, kg | |
| 150 | 47,8 | 201 | 1710 | 11658 | 201 | 1710 | 10653 |
Table 5
Sisal and Manila ropes (ropes), three-strand drive, cable work
|
Rope size, mm |
the total number of turns of all strands of the cable in a running meter | number of cables in the cable | weight of 1 meter of rope with a moisture content of 12%, g | average breaking force of 1 cable cable, kg | total strength of the cable by the cables, kg | breaking strength of the rope as a whole, kg | |
| by diameter | circumferentially | ||||||
| 25 | 78,5 | 42 | 66 | 420 | 73 | 4818 | 3760 |
| 30 | 94,5 | 35 | 96 | 610 | 73 | 7008 | 5250 |
| 35 | 110 | 30 | 132 | 840 | 73 | 9636 | 6830 |
| 40 | 126 | 26 | 174 | 1100 | 73 | 12702 | 8510 |
| 45 | 141 | 24 | 216 | 1370 | 73 | 15768 | 10550 |
| 50 | 157 | 21 | 270 | 1700 | 73 | 19710 | 12800 |
| 55 | 173 | 19 | 327 | 2070 | 73 | 23871 | 15050 |
Table 6
Ropes (ropes) manila ordinary three-strand rope work
(GOST 1088),
|
Size, mm |
Elevated |
Normal |
||||||||||
|
circumferentially |
by diameter |
number of cables in the cable |
number of cables in the cable |
weight of 1 meter of rope with a moisture content of 12%, g |
average breaking force of 1 cable cable, kg |
total strength of the cable by the cables, kg |
breaking strength of the rope as a whole, kg |
|||||
Table 7
Ropes (ropes) sisal ordinary three-strand rope work
|
Size, mm |
the total number of turns of all strands of the cable in a running meter |
Elevated |
Normal |
|||||||||
|
number of cables in the cable |
weight of 1 meter of rope with a moisture content of 12%, g |
average breaking force of 1 cable cable, kg |
total strength of the cable by the cables, kg |
breaking strength of the rope as a whole, kg |
number of cables in the cable |
weight of 1 meter of rope with a moisture content of 12%, g |
average breaking force of 1 cable cable, kg |
total strength of the cable by the cables, kg |
breaking strength of the rope as a whole, kg |
|||
Table 8
| Main characteristics of nylon ropes | |||
| Dimensions of the rope,mm | Weight 10 pog. m cable,kg | Breaking fortress,kg | |
| circumferentially | by diameter | ||
| 12.7 | 4.0 | 0,13 | 294,6 |
| 19,1 | 6.4 | 0,26 | 543,6 |
| 25.4 | 7,9 | 0,45 | 906,8 |
| 31,8 | 10,3 | 0,66 | 1451,4 |
| 33,1 | 11.1 | 1, 0 | 2087,9 |
| 44.5 | 14,3 | 1,34 | 2834.6 |
| 50.8 | 15,9 | 1, 78 | 3657.6 |
| 57,2 | 18.2 | 2,13 | 4572,0 |
| 63,5 | 20,6 | 2,77 | 5588, 0 |
| 69,8 | 22,2 | 3,27 | 6807.2 |
| 76.2 | 23.8 | 3,92 | 8128,0 |
| 82.6 | 27.0 | 4,56 | 9448,8 |
| 88,9 | 28.6 | 5.39 | 10972,8 |
| 95.3 | 30.2 | 6,14 | 12700,0 |
| 101,6 | 31,8 | 7,03 | 14427,2 |
| 114,3 | 36.5 | 8.80 | 18288,0 |
| 127,0 | 39,7 | 10,94 | 22555,2 |
| 139,7 | 44.5 | 13,28 | |
The information on rope classification given below is far from new, and we can hardly add anything new. You can easily find similar materials on other resources, so why are we hosting it? Looking at the classification presented below, you will understand that there are a large number of rope types and sometimes even a specialist can find it quite difficult to figure out what a rope 12-GL-VK-L-O-N-1770 GOST 2688-80 is.
Working with the same ropes, it is quite easy to decipher everything, but what if the client wants to buy a non-standard rope? This is where “Where to look? Where to get? What does this letter mean in the name? " We have previously published material about the ropes, but did not describe the classification in detail, so we hope that this article will be useful to you.
Classification, technical requirements, test methods, rules of acceptance, transportation, and storage steel ropes are set out in GOST 3241-91 “Steel ropes. Technical conditions ".
Classification of steel ropes
1. By the main design feature:
- single lay or spiral consist of wires twisted in a spiral in one or more concentric layers. Single lay ropes twisted only from round wire are called ordinary spiral ropes. Spiral ropes with shaped wires in the outer layer are called closed ropes. Single lay ropes intended for subsequent lay are called strands.
- double lay consist of strands twisted into one or more concentric layers. Double lay ropes can be single-layer or multi-layer. Single-layer six-strand double-lay ropes are widely used. Double lay ropes intended for subsequent lay are called strands.
- triple lay consist of strands twisted in a spiral into one concentric layer.
2. By form cross section strands:
- round
- shaped(triangular-strand, flat-strand), have a much larger surface of contact with the pulley than round-strand.
3. By the type of strands and ropes of single lay:
- TC- with a point contact of the wires between the layers,
- OK- with a linear touch of the wires between the layers,
- LK-O- with a linear touch of the wires between the layers with the same diameter of the wires along the layers of the strand,
- LK-R- with a linear touch of the wires between the layers at different wire diameters in the outer layer of the strand,
- LK-Z- with a linear touch of the wires between the layers of the strand and the filling wires,
- LK-RO- with linear tangency of wires between layers and layers with wires of different diameters in strands and layers with wires of the same diameter,
- TLK- with combined point-linear contact of wires in strands.
Strands with point contact of wires are made in several technological steps, depending on the number of layers of wires. In this case, it is necessary to apply different wire lay steps for each layer of the strand and wind the next layer in the opposite direction to the previous one. As a result, the wires between the layers intersect. Such an arrangement of the wires increases their wear during shears during operation, creates significant contact stresses, which contribute to the development of fatigue cracks in the wires, and reduces the coefficient of filling the section of the rope with metal.
Strands with a linear touch of the wires are made in one technological step; at the same time, the constancy of the lay step is maintained, and the same direction of the lay of the wires for all layers of the strand, which, with the correct selection of the diameters of the wire in the layers, gives a linear tangency of the wires between the layers. As a result, the wear of the wires is significantly reduced and the performance of ropes with a linear touch of the wires in the strands increases dramatically in comparison with the performance of TK-type ropes.
Strands of point-linear tangency are used when it is necessary to replace the linear tangency of the central wire in the strands with a seven-wire strand, when a layer of wires of the same diameter with a point-contact is laid on a single-layer seven-wire strand of the LK type. Strands may have enhanced anti-spin properties.
4. By core material:
- OS- with an organic core - as a core in the center of the rope, and sometimes in the center of the strands, cores made of natural, synthetic and artificial materials are used - from hemp, manila, sisal, cotton yarn, polyethylene, polypropylene, nylon, lavsan, viscose, asbestos ...
- MC- with a metal core - as a core, in most designs, a double lay rope of six seven wire strands is used, located around the central seven wire strand, in ropes according to GOST 3066-80, 3067-88,3068-88 a strand is used as MC the same design as in the braid. It is advisable to use them when it is necessary to increase the structural strength of the rope, to reduce the structural elongation of the rope during tension, as well as at a high temperature of the medium in which the rope operates.
5. By lay method:
- Non-spinning ropes - H- strands and wires retain their predetermined position after removing the ties from the end of the rope or are easily stacked by hand with slight unwinding, which is achieved by preliminary deformation of the wires and strands when stranding wires into a strand and strands into a rope.
- Untwisted ropes- wires and strands are not pre-deformed or insufficiently deformed before they are twisted into strands and into a rope. Therefore, the strands in the rope and the wires in the strands do not retain their position after the tying is removed from the end of the rope.
6. By the degree of balance:
- Straightened rope - R- does not lose its straightness (within the permissible deviation) in a free suspended state or on a horizontal plane, because after stranding the strands and spar, respectively, the stresses from the deformation of the wires and strands were removed by straightening.
- Unlined rope- does not have such a property, the free end of an unaligned rope tends to form a ring, due to the deformation stresses of the wires and strands obtained in the process of manufacturing the rope.
7. In the direction of the rope lay:
- Right lay- not indicated
- Left lay- L
The direction of the rope lay is determined by: the direction of the lay of the wires of the outer layer - for single lay ropes; the direction of stranding of the strands of the outer layer - for double lay ropes; direction of stranding into a rope - for triple lay ropes
8. According to the combination of directions of the rope and its elements:
- Cross lay- the direction of strands and strands lay opposite to the direction of the rope lay.
- One-sided lay - O- the direction of stranding in the rope and wire in the strands are the same.
- Combined lay- K with the simultaneous use of strands of the right and left directions of the lay in the rope.
9.According to the degree of coolness
- Spinning- with the same direction of twisting of all strands along the rope layers (six- and eight-strand ropes with an organic and metal core)
- Low-spinning- (MK) with the opposite direction of stranding rope elements in layers (multilayer, multi-strand ropes and single lay ropes). In non-rotating ropes, due to the selection of the directions of the lay of individual layers of wires (in spiral ropes) or strands (in multilayer double lay ropes), rotation of the rope around its axis is eliminated when the load is freely suspended.
10. By mechanical properties wire
- VK brand- High Quality
- Grade B- high quality
- Grade 1- normal quality
11. By the type of coating of the surface of the wires in the rope:
- Uncoated wires
- Galvanized wire depending on the surface density of zinc:
- group C- for medium aggressive working conditions
- group F- for harsh aggressive working conditions
- coolant group- especially harsh aggressive working conditions
- NS- the rope or strands are covered with polymer materials
12. According to the purpose of the rope
- Gruzoludskie - GL- for lifting and transporting people and goods
- Freight - G- for lifting and transporting and loads
13. By manufacturing accuracy
- Normal Accuracy- not indicated
- Increased accuracy - T- toughened maximum deviations in the diameter of the rope
14. By strength characteristics
Marking groups of ultimate tensile strength N / mm2 (kgf / mm2) - 1370 (140), 1470 (150), 1570 (160), 1670 (170), 1770 (180), 1860 (190), 1960 (200), 2060 (210), 2160 (220)
Examples of conventional designation of steel ropes
- Rope 16.5 - G - I - N - R - T - 1960 GOST 2688 - 80 Rope with a diameter of 16.5 mm, for cargo use, first grade, made of uncoated wire, right cross lay, non-unrolling, straightened, increased accuracy, marking group 1960 N / mm2 (200 kgf / mm2), according to GOST 2688 - 80
- Rope 12 - GL - VK - L - O - N - 1770 GOST 2688 - 80 Rope with a diameter of 12.0 mm, for gross purposes, grade VK, made of uncoated wire, left one-sided lay, non-twisting, non-aligned, normal accuracy, marking group 1770 N / mm2 (180 kgf / mm2), according to GOST 2688-80
- Rope 25.5 - G - VK - S - N - R - T - 1670 GOST 7668 - 80 Rope with a diameter of 25.5 mm, for cargo use, grade VK, galvanized according to group C, right cross lay, non-twisting, straightened, increased accuracy , marking group 1670 N / mm2 (170 kgf / mm2), according to GOST 7668 - 80
- Rope 5,6 - G - V - ZH - N - MK - R - 1670 GOST 3063 - 80 Rope with a diameter of 5.6 mm, cargo purpose, grade B, galvanized according to group G, right lay, non-twisting, low-rotating, straightened, marking group 1670 N / mm2 (170 kgf / mm2), according to GOST 3063 - 80
Each rope design has advantages and disadvantages that must be properly considered when choosing ropes for specific operating conditions. When choosing, the necessary ratios between the diameters of the winding elements and the diameters of the ropes and their outer wires, as well as the necessary safety margin, ensuring trouble-free operation, should be maintained.
Single lay round wire ropes - ordinary spiral (GOST 3062-80; 3063-80; 3064-80) have increased rigidity, therefore, they are recommended to be used where tensile loads on the rope prevail (lightning protection cables of high-voltage power lines, fences, stretch marks, etc.)
Double lay ropes with linear tangency of wires in strands with ease of manufacture, they have a relatively high efficiency and have a sufficient number of various designs.
LK-R type ropes (GOST 2688-80, 14954-80) should be used when, during operation, the ropes are exposed to aggressive media, intense alternating bending and work in the open air. The high structural strength of these ropes allows them to be used in many highly stressful crane operating conditions.
LK-O type ropes (GOST 3077-80, 3081-80; 3066-80; 3069-80; 3083-80) work stably in conditions of strong abrasion due to the presence of wires in the upper layer of increased diameter. These ropes are widespread, but their normal operation requires a slightly increased diameter of blocks and drums.
Ropes of the LK-Z type (GOST 7665-80, 7667-80) used when flexibility is required, provided that the rope is not exposed to an aggressive environment. It is not recommended to use these ropes in an aggressive environment because of the thin filler wires in the strands that are easily corroded.
Ropes of the LK-RO type (GOST 7668-80, 7669-80, 16853-80) are characterized by a relatively large number of wires in the strands and therefore have increased flexibility. The presence of relatively thick wires in the outer layer of these ropes allows them to be successfully used in conditions of abrasive wear and aggressive media. Due to this combination of properties, the rope of the LK-RO type construction is universal.
Double lay ropes with point-linear contact of wires in strands of TLK-O type (GOST 3079-80) should be used when the use of ropes by linear contact of the wires in the strands is impossible due to violation of the setting minimum permissible ratios between the diameters of the winding elements and the diameters of the rope wires or when it is impossible to ensure the recommended safety margin.
Double lay ropes with point contact of wires in strands of TK type (GOST 3067-88; 3068-88; 3070-88; 3071-88) not recommended for demanding and intensive installations. These ropes can be used only for non-stressed operating conditions, where alternating bends and pulsating loads are insignificant or absent (slings, bracing ropes, temporary timber-alloy fasteners, supporting and brake ropes, etc.)
Multi-strand double lay ropes (GOST 3088-80; 7681-80) depending on the accepted directions of stranding strands in separate layers are made ordinary and non-rotating. The latter provide reliable and stable operation on mechanisms with free suspension of the load, and a large supporting surface and lower specific pressures on the outer wires allow to achieve a relatively high operability of the rope. The disadvantages of multi-strand ropes are the complexity of manufacturing (especially preliminary deformation), the tendency to delamination, the difficulty of monitoring the state of the inner layers of the strands.
Triple lay ropes (GOST 3089-80) used when the main operational requirements are maximum flexibility and elasticity of the rope, and its strength and supporting surface do not have crucial... Organic cores in strands are useful when the rope is intended for towing and mooring, where increased elastic properties of the rope are required. Due to the use of wires of small diameters in comparison with wires of double-lay ropes, triple-lay ropes for normal operation require pulleys of significantly smaller diameters.
Three-sided strand ropes (GOST 3085-80) They are characterized by increased structural stability, a very high fill factor and a large bearing surface. The use of these ropes is especially advisable for high end loads and high abrasive wear. It is recommended to use these ropes both in installations with friction pulleys and in multilayer winding on drums.The disadvantages of three-sided strand ropes are sharp bends of the wires on the edges of the strands, the increased rigidity of the rope, and the laboriousness of making strands.
Flat ropes (GOST 3091-80; 3092-80) find application as balancing in mine hoisting installations. The advantages of these ropes include their non-twist. However, the manual operations involved in sewing the ropes and the relatively rapid destruction of the thong during operation limit the scope of use of these ropes in industry.
Classification of ropes according to domestic and foreign standards
| GOST | DIN | RU | BS | ISO |
| GOST 2688-80 | DIN 3059-72 | EN 12385 | BS 302 6x19 (12/6/1) FC | |
| GOST 3062-80 | DIN 3052-71 | |||
| GOST 3063-80 | DIN 3053-72 | |||
| GOST 3064-80 | DIN 3054-72 | |||
| GOST 3066-80 | DIN 3055-72 | EN 12385 | BS 302 6x7 (6/1) WSC | |
| GOST 3067-88 | DIN 3060-72 | EN 12385 | BS 302 6x19 (12/6/1) WSK | |
| GOST 3068-88 | DIN 3066-72 | |||
| GOST 3069-80 | DIN 3055-72 | EN 12385 | BS 302 6x7 (6/1) FC | |
| GOST 3070-88 | DIN 3060-72 | BS 302 6x19 (12/6/1) WSC | ||
| GOST 3071-88 | DIN 3066-72 | BS 302 6x37 (18/12/6/1) FC | ||
| GOST 3077-80 | DIN 3058-72 | EN 12385 | BS 302 6x19 (9/9/1) FC | ISO 2408 |
| GOST 3079-80 | ||||
| GOST 3081-80 | DIN 3058-72 | EN 12385 | BS 302 6x19 (9/9/1) WRC | ISO 2408 |
| GOST 7668-80 | DIN 3064-72 | EN 12385 | BS 302 6х36 (14/7 & 7/7/1) FC | ISO 2408 |
| GOST 7669-80 | DIN 3064-72 | EN 12385 | BS 302 6x36 (14/7 & 7/7/1) IWRC | ISO 2408 |
| GOST 14954-80 | DIN 3059-72 | EN 12385 | BS 302 6x19 (12/6 + 6F / 1) IWRC |
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