The first method is installation using a built-in self-supporting cable.

Here a galvanized steel cable is used, which is stretched on consoles attached to support pillars screws. The cable is attached to it using hangers, which are also made of stainless metal. With this installation method, accurate calculation is important: there are sag standards that affect the maximum installation height of the consoles. So, the lowest point of the cable sag should be no lower than 4.5 meters above the ground. Accordingly, the consoles must be strengthened so as to ensure not only compliance with this parameter, but also taking into account the gap for mounting hangers and the free movement of the cable along the loops of the mounting fittings.

Fig. No. 1. Layout of equipment for suspension optical cable on overhead power lines

Work rules:

1. The line on which the cable is suspended must be de-energized. Carrying out work while maintaining a connection to the public network is prohibited.
2. Installation of fiber-optic couplings of any type is allowed while maintaining the network connection to the power supply.
3. The installer must have a working radio with him when carrying out work.
4. Lay out cable lines prohibited on land.
5. The location of the rolling machines on the site should be no closer than three heights from the zero mark to the current position of the rolling roller.
6. Cable rolling is carried out strictly in the air using a “cable leader”; the ends of the cable and cable are connected with a mounting stocking.
7. To protect the cable leader and the mounted OK line from twisting, a swivel is used. Balancers must be used at intervals of 4 meters from each other.
8. Used for different types of supports different types clamps (supporting on intermediate ones and tensioning on anchor-corner ones).
9. To protect against external damage, installation of a protector is mandatory.

Installation of fiber optic lines between houses and buildings.

For these purposes, certain types of cable are used, the characteristics of which are given below.

Fig. No. 2. Photo of OK fastening when pulling between two houses

Characteristics and features of overhead cable lines

OPC is a high temperature resistant fiber optic cable. Can be used in the range from -60 to +70 degrees. Withstands tension up to 12 kN at a pressure of 0.5 kN/cm. Depending on the requirements of the installed communication line, the cable can include from 2 to 48 optical fibers. The filler of the internal cavity is a hydrophobic gel to protect the core from getting wet. A cable of this type can be installed along overhead networks between buildings and existing power lines and supports, including contact networks of railway transport, funiculars, trams, etc., power lines. You can select a cable of this brand in the catalog.

OKPTS is a cable with a central tube, which can contain up to 24 fibers. The external type power element can be a fiberglass rod or steel rope or wire in plastic insulation. This type The cable can also be used at temperatures from -60 to +70 °C. Allowable tension is 4-9 kN. The scope of application and installation procedure do not differ from OPC.

Methods for suspending cables on overhead communication line supports

There are three methods for hanging cables:

• Installation inside a lightning protection cable.
• Winding onto phase and lightning protection wiring.
• Suspension of self-supporting OK on supports.

When installed on existing communication lines, including high-voltage power transmission towers and contact networks, the type of cable used must be resistant to electromagnetic fields of any origin. This means a lightning strike, power line surges, and natural turbulence. In addition, the conductor must comply with the permissible elongation (sagging) indicators, and installation must be carried out in compliance with the dimensions of the cable fastening intervals. A cable made of polyamide threads copes with this task. The strength of this carbon fiber is very high, which allows cable suspension to be carried out at large distances between supports.

The optical cable can also be mounted on a separate cable or other external element. If a dielectric wire is not used, it can be replaced by an optical cable built into the lightning protection cable.

With this choice, the conductor is a means of lightning protection and an information transmitter.

At installation of fiber-optic communication lines in tunnels, conductors must have a non-flammable sheath.

Scope of work.

• pulling the dielectric leader cable;
• FOC broach;
• securing the FOC to the stands in its original position.

Techniques and equipment used.

Equipment for hanging FOC.

1. Cable conveyor.
2. Winch.
3. Dynamometer.
4. Unrolling rollers.
5. Stocking.
6. Swivel.
7. Rope connectors.
8. Leader cable.

You might be interested in: “How to determine the maximum possible span when hanging a cable”

Equipment for mounting couplings and making measurements.

1. Optical reflectometer.
2. Welding machine.
3. Set of tools for cutting cables and installing couplings.
4. Laptop.

Auxiliary equipment.

1. Auto laboratory based on GAZ 66.
2. Aerial platform (AGP or AP).
3. Set of stairs.
4. Measuring laboratory based on UAZ-469.
5. The radios are portable.
6. Optophones.
7. Sequence diagram of the technological process of hanging a fiber optic fiber optic.

1 Cable suspension steps:

1 Place the bracket at the specified level and insert the ends of the clamps into the holes in the bracket. Place nuts on the threaded part of the clamps.

2 Tighten the nuts securing the bracket.

3 Adjust horizontal mount bracket.

4 Hang the rolling roller leash on it, secure the bottom of the leash on the stand.

5 Go to the next rack and install the next bracket in the same sequence.

6 Pulling the leader cable on the anchor section.

2 Scheme of the sequential technological process of pulling the leader cable.

1 Release the reel and unwind the leader cable to a length sufficient to connect the leader cable to the leash attached to the laying roller of the first post.

2 Connect the leader cable to the leash and pull it through the laying roller.

3 Braking the reel with a slight tension, stretch the leader cable to the next post.

4 Repeat the operations performed when pulling the leader cable of the first post, and pull the leader cable through the unrolling roller of the second post; while pulling the leader cable through the unrolling roller, the leader cable is held in a tense position. When pulling the leader cable, replace the coils as necessary.

5 Repeat the operations for all racks of the anchor section

6 After being pulled along the entire anchor section, the leader cable is secured to the outer posts in a tense state, ensuring its dimensions to the ground.

3 FOC suspension on stands:

1 Using a “stocking” cable clamp, the FOC is connected to the cable leader. During docking, it is necessary to ensure that the leader cable is in a taut state and that the dimensions are not violated; on the other side of the anchor section, the leader cable is connected to the traction machine (winch).

2 The fiber optic cable is pulled along all rollers at a speed of up to 30 m/min. Coordination of actions to release the drum brake and simultaneously turn on the traction machine is carried out via radio communication. At the same time, the passage of the cable along the rollers is monitored.

3 After pulling the FOC, the technological stock is unwound from its end at the drum.

4 At the end of the technological stock, a clamp is installed and the FOC is anchored to the stand. The technological stock, in accordance with the design, is wound into a coil and secured to the rack.

5 After anchoring, the fiber optic is tensioned to a force exceeding the table value by 10%, and is maintained in this state for 5-10 minutes. At the site of intermediate anchoring, a mark is applied, the cable is loosened, a supporting clamp is installed, then the FOC is tightened again, and the supporting clamp is anchored to the drain.

6 Technological process repeated at all anchoring points.

7 After installing the last anchor clamp, the traction machine is disconnected from the fiber optic cable, which is then wound into a coil and secured to the stand.

Moscow State University

Ways of communication (miit)

Department of Automation and Telemechanics

on railway transport."

Course work

By discipline:

"Fiber-optical transmission systems."

"Calculation mechanical strength fully

Dielectric self-supporting

Fiber optic cable."

Completed by: student of group TUS-361 Osipov S.E.

Volkova E.S.

Moscow – 2017

1. Description of the cable design A-D(T)2Y.

2. Description of the work performed when hanging a self-supporting fiber optic cable on overhead contact line supports.

3. Mechanical calculation of a self-supporting fiber optic cable.

3.1.Calculation of specific load from own strength cable gravity.

3.2.Calculation of the specific load from the effects of ice during icy conditions.

3.3.Calculation of the specific load due to the cable’s own gravity and the gravity of the ice.

3.4.Calculation of the specific load from wind pressure on the cable (in the absence of ice).

3.5. Calculation of the specific load from the influence of wind on a cable covered with ice.

3.6. Calculation of the specific load from the gravity of the cable, the ice covering it and the influence of wind.

4. Determination of the critical span length.

5.Calculation of boom sag.

Description of the CORNING ADSS A-D(T)2Y cable design.

The figure shows the design of the Corning ADSS A-D(T)2Y cable (dielectric self-supporting fiber optic cable)

1. Dielectric multi-fiber core tube (D)

2. Concentric element carrying tensile load (aramid) (2Y).

3. Polyethylene sheath (T)

Special characteristics include:

Installation without power outage;

Long span lengths;

Light weight;

Small outside diameter

Working temperature from -40 to +40ºС

Description of the work performed when hanging a self-supporting fiber optic cable on overhead contact line supports.

Work on hanging and installing a fiber optic cable can only begin if there is a customer-approved detailed design for the construction of a fiber optic link, albums of typical components and parts, and permission from the power supply service railway for work in the area of ​​the contact network and high-voltage automatic blocking line.

To develop the project, the customer transfers the initial data to the design organization as part of the task for designing a fiber-optic line.

Before the beginning installation work for suspension FOC must be performed following works:

studied project documentation;

a full-scale examination of the FOC suspension route and support structures was carried out;

the order and timing of replacement of supports, the timing of installation of new and additional supports have been established;

supports with insufficient load-bearing capacity were replaced and new and additional supports were installed in accordance with the design of the lines, as well as the guy wires required by the project on the supports;

the anchor sections were clarified and the most rational sequence and direction of installation of the anchor sections were established;

If necessary, trees and bushes were cut down;

railcars, motor carriages, carriages for workers performing work on the suspension of fiber optic cables, mechanisms for loading and unloading cable products, equipment and places for welding work, installation of couplings;

supplies, materials, equipment, tools, radio stations and power supplies were prepared and checked;

the procedure and time for delivery of workers, equipment and tools to the place of work are determined;

the procedure for providing “windows” has been determined.

When hanging and installing a fiber optic cable, “windows” of at least 3 to 4 hours must be provided in accordance with the procedure approved by the head of the railway.

“Windows” for hanging and mounting the FOC should be provided, as a rule, during daylight hours. In areas where “windows” in the train schedule are provided for at night, the manager is obliged to ensure the place where work is carried out in accordance with established standards.

When pulling a fiber optic cable, the following work is performed:

pulling a dielectric cable leader;

FOC broach.

Work on stretching the fiber optic cable can be carried out “from the track” with the voltage removed and the stage taken, or if there are approaches to the track and electrical safety is ensured, “from the field” without voltage removal.

A leader cable is pulled along rollers pre-hung on the brackets. To do this, after engaging in the hauling complex and relieving tension, one cargo trailer with leader cable reels is installed at the beginning of the anchor section 25 - 30 m from the anchor support, and the second trailer, coupled with the railcar, begins to slowly move towards the first anchor support. Opposite the first anchor support, the railcar stops, the mounting cradle with two assemblers rises to the bracket with the roller. The leader cable is detached from the cradle, passed through the roller and reattached to the cradle. In this position, the railcar slowly moves to the next support. At the next support, the leader cable is again passed through the roller and the movement of the railcar resumes. In this way, the leader cable is stretched throughout the entire section. After passing the leader cable through the roller of the outermost anchor support, the railcar with the trailer with cable drums located in front of it moves a distance of 25 - 30 m beyond the last support and stops. While pulling the leader cable, the fitters operating the traction and braking device with reels slow down the coils, ensuring that the leader cable rolls out under tension.

In the extreme position, the leader cable is connected through a device that prevents the FOC from twisting, using a “stocking” cable clamp, to the FOC located in the drum on the cargo trailer. The railcar is uncoupled from the trailer with the cable drum and returns to the first trailer with the reels free from the cable leader. The motors of the traction module are turned on from the railcar using a hydraulic drive and the slow pulling of the fiber optic cable begins. In this case, the drum from which the fiber optic is rolled out is slowed down so that the required sag of the fiber optic in the spans is ensured.

Power line supports are often used not only for their intended purpose, but also as engineering structures for hanging communication cables. Due to the fact that power lines connect even the most remote corners of our country, they are an almost ideal way to organize communications. To do this, a suspension is made on the supports various types fiber optic cables (FOC).

Expert opinion

Chief Editor of LinijaOpory

Our colleagues provide consultations in the field of calculations and design of fiber-optic communication lines on overhead lines. On the website VOLS-psd.ru you can familiarize yourself with the list of calculations and consultations performed, as well as find out the conditions for designing a fiber-optic line according to your technical specifications. No question will be left unanswered.

Several options are possible for the construction of fiber optic lines on overhead lines. Each of them has its own advantages and disadvantages. On our website you can find comprehensive information about communication lines of this type. Every year new methods of hanging and laying FOCs appear, but there are several “classic” options, each of which is used quite often.

Self-supporting fiber optic communication cable

Self-supporting optical cable (SSOC) is most often used in the design and construction of fiber-optic lines, since its suspension can be carried out without removing the voltage in the line, and this greatly reduces construction costs.

This cable is characterized by low weight and good stretching capabilities. Its suspension is carried out directly on the body of the support or its traverse (depending on the type and design of the support).

Currently there are many special devices, intended for suspension of OKSN. All of them will be reviewed on our resource.

Optical cable built into ground wire

The cable built into a lightning protection cable (OPGT) is used on high and ultra-high voltage lines. This type of cable is quite widespread, since it is the most acceptable option for large lengths of power line routes.

OPGW performs both the function of information transmission and the classic function of protecting the line from overvoltage. To build a fiber-optic link on an OPGT, it is necessary to turn off the line voltage. When designing, it is necessary to take into account many factors that affect the wear resistance and durability of the cable. OPGT does not create additional loads on overhead line supports.

Optical cable built into phase wire

Optical cable in phase conductor (OCP) - relatively new technology, which is used extremely rarely in the Russian Federation. This is primarily due to the high cost building materials and the complexity of installing such a wire.

When constructing a fiber-optic line using OKFP, the voltage in the line is turned off and the existing phase wire is replaced with a communication cable with similar characteristics. This makes it possible to achieve both mechanical and electrical symmetry in the line. Currently, power engineers rarely allow such manipulations and only when there are no other options for hanging a fiber optic fiber optic (for example, in conditions of large spans).

Winding optical cable

When using this technology, a special machine is launched along the phase wire of the line, which, moving along the wire, evenly winds the FOC onto it.

As a result of winding, the FOC does not require additional fastening on the supports, and increases the load on them only slightly. IN modern construction this technology is used quite often on lines with voltages up to 35 kV. The use of winding machines requires installers to have sufficient knowledge in some technical issues, but this pays off in the results of the work. It is especially important to use serviceable and efficient mechanisms during the installation process.

Construction of fiber-optic lines on overhead lines is a promising direction of communication

The development of fiber-optic data networks is rapid and widespread. A wide variety of engineering structures and cable designs are used. To ensure long and uninterrupted operation, such lines are designed taking into account maximum loads observed over the past 25 years.

In addition to the fact that there are separate documents for standardizing the suspension of FOCs, the Rules for the Construction of Electrical Installations also have a corresponding section.

One of important characteristics design self-supporting cables are permissible external mechanical loads, such as wind, ice and self-weight load. Therefore, one of the most important decisions when building a fiber-optic line is the choice of a fiber-optic cable of an appropriate design that could withstand the various stresses that arise in the cable during construction and operation. These cable parameters can be determined using the method proposed by Incab CJSC.

The speed of construction is very high. You can hang one or two construction lengths of cable in one shift.

The cost of the cable is also not very high and, on average, for light construction options ranges from $2800 to $3600/km.

Having built a fiber-optic line in this way, you need to think about how long it will last and what needs to be done to make it last longer? FOCL based on a self-supporting cable is exposed to a wide variety of influences, primarily atmospheric factors - wind loads, solar radiation, precipitation, icing, mechanical damage caused repair work on other wires, or cable theft. Moreover, if the cable hangs in electric field(which happens everywhere), then as a result of exposure solar radiation Microcracks begin to appear on the surface of the outer moisture-proof sheath of the cable, in which dirt and moisture accumulate and the tracking process begins to develop - the flow of surface currents - tracks. Over time, the density of these currents increases and the cable gradually begins to burn. This is especially evident in the places where the cable is attached to the supports, since the cable is not grounded in the span and enough high density tracks, and on the support the cable is grounded and surface currents naturally flow down the support. The only recommendation to reduce the influence of this factor is the use of a tracking-erosion-resistant moisture-protective shell based on fluoropolymer materials.

As a result, the service life of fiber optic lines based on self-supporting fiber optics does not exceed 18–20 years.

5.4. Features of hanging a self-supporting fiber optic cable on the supports of the electric railway contact network

The suspension of self-supporting fiber-optic communication cables on contact network supports and high-voltage automatic blocking lines is carried out taking into account the requirements of the “Rules for the construction and technical operation of the overhead contact network of electrified railways” approved by the Ministry of Railways of Russia.

The suspension of the fiber optic cable is carried out on the operating metal or reinforced concrete supports of the contact network, provided that load bearing capacity these supports are sufficient to perceive all effective loads from the suspended fiber optic cable, and the location of the fiber optic cable on the supports makes it possible to carry out work on it in the presence of voltage in the contact network.

The suspension of the fiber optic cable on the contact network supports is carried out from the field side. In exceptional cases, in agreement with the railway power supply service, it is allowed to hang a fiber optic cable with inside supports (from the track side). The distances from the lowest point of the fiber optic cable at maximum sag to the ground surface, as well as the distance to other wires and parts of the contact network, must be no less than the established values.

The suspension of the fiber optic cable on the contact network supports is carried out on brackets, the location of which on the supports is determined by the design. Brackets on supports along the route are usually installed at the same height from the rail head. The brackets are fastened to reinforced concrete supports using clamps. When using a FOC with a metal core or with metal armor, all brackets must be connected to a protective ground circuit. When hanging a FOC with a dielectric core, grounding is not performed. Attaching the brackets to metal supports made using hook bolts or special parts.

Work on the suspension and installation of a fiber optic cable can only begin if there is a detailed design approved by the customer for the construction of a fiber optic cable line and permission from the railway power supply service to carry out work in the area of ​​the contact network and the high-voltage automatic blocking line.

Work on pulling the fiber optic cable can be carried out “from the path” with stress relief, or “from the field” without stress relief.

When working “from the path” with stress relief, high-performance specialized complexes of machines are used, which include:

an AGD type motor carriage for towing cargo trailers, powering traction and braking modules and equipped with an AGP type hydraulic lift for working at heights;

two cargo trailers equipped with traction and braking modules with rotating devices, for installing drums with a wok and reels with a cable leader.

Traction and braking modules must have devices for regulating the tension force of the fiber optic cable and automatically turning it off when the tension force exceeds the maximum tension value established for a given brand of fiber optic cable.

When working “from the field,” a set of special mechanisms is used, including:

a winch with adjustable tension force for pulling the leader cable and fiber optic cable under tension;

lifting and braking device for lifting and adjusting the height of the cable drum;

a device for installing and braking reels with a cable leader; When using a specialized set of machines for work

“out of the way”, the suspension of the fiber optic cable is carried out in the following sequence. The rope leader is pulled along the rollers pre-hung on the brackets. To do this, after engaging in the hauling complex and relieving tension, one cargo trailer with leader cable reels is installed at the beginning of the anchor section 25–30 m from the anchor support, and the second trailer is in the coupling

With the railcar begins to slowly move towards the first anchor support. Opposite the first anchor support, the railcar stops, the mounting cradle with two assemblers rises to the bracket with the roller. The leader cable is detached from the cradle, passed through the roller and reattached to the cradle. In this position, the railcar slowly moves to the next support. At the next support, the leader cable is again passed through the roller and the movement of the railcar resumes. In this way, the leader cable is stretched throughout the entire section. After passing the rope leader through the roller of the outer anchor support, the railcar with the trailer with cable drums in front of it moves a distance of 25–30 m beyond the last support and stops. While pulling the leader cable, the fitters operating the traction and braking device

With coils, slow down the coils, ensuring rolling the leader cable is under tension.

IN emergency situation The leader cable is connected through a swivel using a cable clamp “stocking” to the fiber optic cable located in the drum on the cargo trailer. The railcar is uncoupled from the trailer with the cable drum and returns to the first trailer with the reels free from the cable leader. The motors of the traction module are turned on from the railcar using a hydraulic drive and the slow pulling of the fiber optic cable begins. In this case, the drum from which the fiber optic is rolled out is slowed down so that the required sag of the fiber optic in the spans is ensured.

When working “from the field” using a set of mechanisms on the side of the track behind the clearance of the contact network supports at the beginning and end of the

of the core section, horizontal platforms are selected at a distance of 25–30 m from the outermost anchor supports. One of them houses a device for installing and braking reels with a leader cable. At the opposite end of the anchor section, a traction winch is installed on the selected site for pulling the fiber optic cable and leader cable. After pulling the leader cable along the entire anchor section, its ends are secured to the outer supports.

To pull the fiber optic cable, a lifting and braking device with a cable drum is installed on the site where the device for reels with a cable leader was located, and then in the same way: the winch is turned on and the fiber cable is pulled along the anchor section.

When working with a set of special mechanisms, the FOC pulling speed should be within 1.8 km/h. During broaching of the FOC, when the stocking clamp approaches the roller and passes through the roller, the broaching speed is reduced to a minimum, almost to a complete stop. Pulling the fiber optic fiber over the rollers, regardless of the use of machines and mechanisms, is performed smoothly with minimal traction force.

After pulling the FOC, they begin work on securing it using various clamps. Work begins with anchoring the fiber optic on the support farthest from the drum.

After hanging the fiber optic cable on the contact network supports or high-voltage line supports, automatic blocking is carried out special work, necessary for the operation of fiber-optic lines. Such work includes:

construction of fiber optic cable inputs into the buildings of communication houses and electrical control posts;

installation of connecting and branching couplings, including fiber welding and welding quality control using instruments;

fastening couplings on supports or other devices with laying out and securing the technological stock of the FOC;

control and measurement work on the installed sections of the fiber optic cable between the regenerators.

5.5. Navigable technology for the construction of fiber-optic lines

Winding of relatively light and inexpensive OC without reinforcement power elements on phase wires of power lines is one of the original and cheap ways to build fiber-optic lines.

The naive technology for the construction of fiber-optic lines is alternative way The gaskets are OK in the lightning protection cable. But, unlike laying OK in a lightning protection cable, in this case there is no need to replace the lightning protection cable and remove the power line from the operating condition.

The OC is wound evenly, using special mechanisms, with a certain pitch around the existing lightning protection cable or phase wire using a special winding machine (Fig. 5.11, Fig. 5.15). The winding machine can move along the lightning protection cable either using a radio-controlled self-propelled mechanism or manually using a special winch. To move the winding machine through power line supports, a special lifting device is used.

		The essence of the winding method is
		is as follows. Reel with cable
	Rice. 5.11. Implementation	lem is installed on the winding
		the car, the car is rolling
	winding machines
	power line wire and simultaneously rotates the
	carcass with a cable around the wire, ensuring
	when balancing and tensioning the cable
	minimal impact on the load-bearing structure
	water As a result, the cable (Fig. 5.12) is spiral-		Rice. 5.12. Navive
	but is wound onto the wire with a constant		fiber optic cables –
	naviva step.

Initially, the weight of the machine with cable did not exceed 37 kg, the maximum rotation range of the reel was 0.4 m, the cable reserve on one reel was 1000 m (for a cable d = 6.5 mm), i.e., when using a cassette of two reels, the maximum construction length is 1 km. The machine is driven by a tow rope, manually, from the ground. The speed of movement of the machine along the wire is about 0.5–1 m/s, crossing the support takes no more than 10 minutes. Lifting the machine onto a support, towing, and crossing the support can be done by a team of installers consisting of 3–4 people. Thus, it takes only about 3–5 hours to lay a straight section 1 km long.

The construction lengths of the wound fiber optic are connected to each other using hanging welding couplings. The welded joints are secured in a standard welding cassette, then the cassette, together with a reel with a spare cable, is placed in a sealed coupling, which is suspended on the wire using standard fasteners (Fig. 5.13).

The weight of the coupling with cable reserve and organizing plate does not exceed 5 kg. Coupling has a streamlined shape, similar to a disk suspended on a wire parallel to the surface of the earth, in order not to provide much resistance to the wind and not to increase the wind load on the supports. And, in addition, during the operation of the line, all couplings are under high voltage, which excludes unauthorized access to them or vandalism. All metal parts couplings in contact with the atmosphere are reliably protected by a weather-resistant coating in accordance with the requirements of the standards. To protect the coupling body from shot penetration, the bottom cover is made of thickened steel.

Despite the fact that only dielectric materials are used in the cable design, current flow is possible short circuit along the surface of the cable sheath. To transfer a fiber-optic cable from a high-voltage wire to grounded support structures, a composite insulator is used at the beginning and end of the winding section, appearance which is shown in Fig. 5.14. Along the longitudinal axis, the composite insulator has a channel for passing a fiber-optic winding cable. At the ends of the insulator there are sealed connectors, with the help of which the cable input and output are reliably protected from atmospheric precipitation entering the insulator channel. The composite insulator is attached to the overhead line wire from above, and from below, using a bracket, to the power line support.

OK winded onto a lightning protection cable is able to withstand any impact environment: ice, wind load, changes

temperatures, as well as short-circuit currents on the line, lightning strikes, vibration, etc. This construction method is used on overhead lines from 35 kV and above (Fig. 5.15).

Rice. 5.15. Rewinding the fiber optic cable to the lightning protection cable

For this type of installation we have developed specialized devices- winding machines. Their principle of operation is as follows: one mechanism (traction) allows the device to move evenly along the cable, the second mechanism (winding) rotates the drum attached to the machine with the construction length of the cable around the cable. The fiber optic cable is simultaneously unwound from the drum and wound onto the cable. Before passing the next span, special “working ladders” are strengthened on the supports, necessary to prepare the mechanisms for work. The winding machine is lifted onto a support and hung onto the cable by a traction device in the direction of movement. A drum with a cable is installed on the machine. Where it approaches the support, the cable is secured with a special clamp that prevents it from unwinding from the cable. After this, the traction and winding devices are started. Winding in progress construction length cable on the span between two supports. When the winding machine approaches the next support (beyond 5–7 m), the cable is again fixed with a clamp that prevents it from unwinding, after which the machine is dismantled and can be used on the next span. On the support itself, the cable is fixed in both directions with anchor clamps. In this way, a tension pass-through unit is formed - the so-called “jumper”.

Improvements in the design of machines for winding fiber optic cables have made it possible to create a device whose operating principle is similar to a spindle. The weight of such a device is no more than 15 kg, and the payload is up to 180 kg, which makes it possible to wind the OC over spans up to 6 km long (Fig. 5.16).

Rice. 5.16. Winding machine:

a) with a base drum; b) with cable length, equal to length span; c) cable carrier - the main element

This device was used for the construction of wound fiber optic lines in the territory Russian Federation. To increase the reliability of fiber-optic lines during operation, the following solution was proposed: until the middle of the span, the cable is wound in one direction, and then in the opposite direction. In the middle of the span, the fiber-optic cable is secured with a special clamp, which, in the event of a break in the supporting wire or cable, releases the cable and thereby avoids its breakage.

The advantages of winding technology are undeniable. First of all, this is the ability to build fiber-optic lines in almost any conditions, both rough terrain (mountains, tundra, taiga where power lines are built) and various industrial barriers (iron and car roads, feeder lines for various purposes, houses, gardens, ravines, etc.) without additional accessories and platforms.

Winding an optical cable onto a phase wire virtually eliminates its icing, which, like vibrations on the spans between supports due to wind loads, is the main cause of breakage of overhead wires. This is achieved by heating the moisture-proof polyethylene sheath of the optical cable wrapped around the wire under the influence of the electromagnetic field of the power line. In addition, increased turbulence air flow, flowing around the “Optical cable – power line wire” system reduces the vibration level by 40–60%.

The technology under consideration provides average speed winding OK up to 5–6 km per shift, allows you to pass difficult and inaccessible sections of the route.