Coursework: Calculation of the section of the contact network of the station and stage. Contact network In areas equipped with compensated chain suspension, rotary consoles are used, usually tubular, hinged on supports

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Introduction

On electrified lines, the electric rolling stock receives power through the contact network from traction substations located at such a distance between them that a stable nominal voltage is provided on the electric rolling stock and protection against short circuit currents works.

The contact network is the most critical component of electrified railways. The contact network must ensure a reliable and uninterrupted supply of electricity to the rolling stock in any climatic conditions. Contact network devices are designed in such a way that they do not limit the speed set by the train schedule and ensure uninterrupted current collection at extreme air temperatures, during the period of the greatest ice formations on the wires and at maximum wind speed in the area where the road is located. The contact network, unlike all other devices of the traction power supply system, does not have a reserve. Therefore, high demands are placed on the contact network, both in terms of improving designs and in terms of the quality of installation work and careful maintenance under operating conditions.

The contact network is a contact suspension located in the correct position relative to the axis of the track with the help of supporting, fixing devices, which, in turn, are fixed to the supporting structures.

The contact suspension, in turn, consists of a carrier cable and a contact wire (or two contact wires) attached to it by means of strings.

On the main tracks, depending on the category of the line, as well as on station tracks where the speed of trains does not exceed 70 km / h, a semi-compensated chain suspension (KS-70) should be used with vertical strings displaced from the supports by 2-3 m and articulated clamps.

On the main and receiving-departure tracks, which provide for non-stop passage of trains at speeds up to 120 km/h, semi-compensated leaf spring suspension KS-120 or compensated KS-140 is used.

On the main tracks of hauls and stations, at a train speed of more than 120 (up to 160) km / h, as a rule, a compensated spring suspension with one or two contact wires KS-160 is used. On existing electrified lines, it is allowed to operate semi-compensated spring suspensions KS-120 with articulated clamps and compensated spring suspensions KS-140 - 160 km / h until renovation or reconstruction.

On the railways of the Russian Federation, there are several types of main contact suspensions, each suspension is selected for different transport operating conditions (speed, current loads, climatic and other local conditions) based on a technical and economic comparison of options. This takes into account the possible future increase in the speed and size of train traffic and the mass of freight trains.

The supports of the contact network, depending on the purpose and nature of the loads perceived from the wires of the contact suspension, are divided into intermediate, transitional, anchor and fixing.

Intermediate supports perceive loads from the mass of contact suspension wires and additional loads on them (ice, frost) and horizontal loads from wind pressure on the wires and from changing the direction of the wires on curved sections of the track.

Transitional supports are installed in the places of the interface of the anchor sections of contact hangers and air arrows and perceive loads similar to intermediate supports, but from two contact hangers. The transitional supports are also affected by the forces from changing the direction of the wires when they are removed to the anchoring and on the arrow curve.

Anchor supports can only take the tension loads of the wires attached to them or, in addition, carry the same loads as intermediate, transitional or fixing supports.

The fixing supports do not bear loads from the mass of wires and perceive only horizontal loads from changing the direction of the wires on curved sections of the track, on overhead arrows, when leaving for anchoring and from wind pressure on the wires.

According to the type of supporting devices of the contact network fixed on the supports, there are:

Cantilever supports with fastening on the console of the catenary suspension of one, two or several tracks;

Supports with a rigid crossbar, or, as they are called, crossbar or portal, with fastening of contact suspensions of electrified tracks on a rigid crossbar (crossbar);

Supports with a flexible cross-beam with fastening on it of contact suspensions of electrified tracks blocked by this cross-beam.

For tracing the contact network on single-track and double-track sections (runs), string-concrete conical supports with a height of 13.6 m and a concrete wall thickness of 60 mm of type C are used for AC sections and CO for DC sections. Recently, on direct and alternating current, supports СС, ССА (Fig. 1) are being introduced.

The posts of these supports are hollow conical seamless pipes made of prestressed reinforced concrete reinforced with high-strength wire. Transverse reinforcement is taken in the form of a spiral. Mounting rings are provided to prevent contraction of longitudinal reinforcement when winding the spiral along the length of the uprights.

Mixed reinforcement is provided at the bottom of the supports - i.e. with the installation of additional rods of non-stressed reinforcement: for supports with a rack height of 10.8 m, 2 meters from the bottom of the support, for supports with a height of 13.6 m - by 4 meters. Mixed reinforcement increases the crack resistance of supports.

The most important characteristic of the supports is their bearing capacity - the permissible bending moment M0 at the level of the conditional cutoff - UOF, which is 500 mm below the level of the rail head (UGR). According to the bearing capacity, the types of supports are selected for use in specific installation conditions.

Picture 1

Reinforced concrete racks have holes: in the upper part - for embedded parts of supports, in the lower part - for ventilation (to reduce the effect of temperature differences between the outer and inner surfaces).

To install reinforced concrete supports, glass foundations of the DS-6 and DS-10 types are used. The foundations of the DC consist of two main structural parts: the upper one - the glass and the lower one - the foundation part. The upper part is a reinforced concrete glass of rectangular section. The lower part of the DS foundations has an I-section. The conjugation of the top of the foundation with the lower I-beam part is made in the form of a pyramidal cone.

I-beam anchors of the DA-4.5 type were used to fix the guys of the anchor reinforced concrete supports in the ground. The anchors are made in the same dimensions as the DS foundation, but without the glass part. To fix the braces in the upper part of the anchor, lugs made of strip steel are laid.

The grounding of the contact network poles is made by individual grounding conductors connected to the traction rails using spark gaps, as well as by a group grounding cable for the poles behind the platform.

The choice of supports begins, as a rule, with the calculation and selection of supports for curved sections of the track, because these conditions for the installation of supports are the most burdened, especially in curves of small radii.

For the calculation, it is necessary to draw up a calculation scheme, showing on it all the forces acting on the support, and the shoulders of these forces relative to the point of intersection of the support axis with the UOF. The calculation of the total bending moments at the base of the supports is determined for three design modes according to the standard loads: in the modes of ice with wind, maximum wind, minimum temperature. According to the largest of the moments obtained, they choose a support for installation.

To maintain the wires at a given level from the rail head, supporting devices are used - brackets with rods, called consoles, which are classified:

According to the number of blocked tracks - single-track, in accordance with Figure 2 (a, b, c); double-track, in accordance with Figure 2 (d, e); in some cases three-track;

In shape - straight, curved, inclined;

By the presence of insulation - non-insulated and insulated.

Figure 2 - Contact network consoles: a - curved inclined console; b - straight inclined console; c - straight horizontal; g - double-track horizontal with one locking post; d - double-track horizontal with two fixing posts; 1 - bracket; 2 - thrust; 3 - support; 4 - fixing post

The consoles used for fastening the wires of a catenary catenary, as a rule, are single-track - excluding mechanical connection with other suspensions. According to the degree of isolation, they can be non-isolated from the support of the contact network, and isolated. According to the type of bracket location, there are inclined, curved and horizontal consoles. Inclined insulated consoles, regardless of the size of the support, are equipped with struts.

When tracing a contact network, the type of consoles is selected depending on the type of support device (cantilever support, rigid crossbar), size, installation location (straight section, inner or outer side of the curve) and purpose of the support (intermediate, transitional), as well as loads acting on the console . When selecting cantilever devices for a transitional support, it is necessary to take into account the type of interface between the anchor sections of contact suspensions, the location of the working and anchored branches of the suspension relative to the support, and which of the branches is attached to this console.

The console consists of a bracket, rod and strut; it is hinged to the support with the help of a heel and is held on the support with the help of a rod. The heels of the consoles and rods can be swivel and non-swivel; consoles that also have swivel nodes are called swivel. Cantilever rods, depending on the direction of application of loads, can be stretched and compressed.

Single-track consoles can be: uninsulated, when the insulators are located between the carrier cable and the bracket and in the latch; insulated, in accordance with Figure 4, when the insulators are mounted in the bracket, rod and brace at the support; insulated with reinforced (double) insulation, in which insulators are available both in the bracket, rod and brace at the supports, and between the carrying cable and the bracket.

In recent years, insulated (Fig. 3) or non-insulated double straight inclined consoles (Fig. 4) have been installed with normal and enlarged dimensions, the bracket of which has a straight shape and consists of two channels with connecting strips or pipes.

Figure 3 - Insulated inclined single-track console: 1 - bracket; 2 - thrust (stretched); 3 - adjusting plate; 4 - yoke with lamellar earring; 5 - thrust (compressed); 6 - adjusting pipe; 7 - fixing bracket; 8 - brace

Figure 4 - Uninsulated straight inclined consoles: 1 - adjustable insert; 2 - console thrust; 3 - yoke; 4 - straight bracket; 5 - fixing brackets; 6 - clamps

Dynamic resistance to pressure of the pantograph is achieved by a more advanced design of the contact suspension. The verticality of the suspension KS-200 with a fixed position relative to the axis of the carrier cable path provides greater wind and dynamic stability than traditional suspensions for attaching the carrier cable of the main tracks with a zigzag corresponding to the zigzag of the contact wire; insulated horizontal consoles with a brace made of galvanized steel or aluminum pipes were used with the support cable fixed in a rotary support saddle suspended on a horizontal rod of the console. The design of the consoles is designed for dimensions of 3.3--3.5 m; 4.9 m; 5.7 m and provides convenience, speed and accuracy of their assembly. Additional clamps - made of aluminum profile, without wind strings; racks of articulated clamps - steel, galvanized. Single-track insulated consoles of the compensated catenary suspension of the main tracks on hauls and stations are installed on supports or on rigid crossbars on console racks.

Figure 5 - Non-horizontal insulated console

For an AC contact network, as a rule, isolated consoles are used, and for a DC contact network - non-isolated ones.

Straight inclined non-insulated consoles from two channels are designated by the letters HP (H - inclined, P - stretched thrust) or HC (C - compressed thrust), from a pipe - by the letters NTR (T - tubular) and NTS.

Isolated consoles from a pipe are designated ITR (I - isolated) or ITS, and from channels - IS or IR. The Roman numeral indicates the number of the console type along the length of the bracket, the Arabic numerals indicate the number of the channel from which the console bracket is made, the letter p indicates the presence of a strut, the letter y indicates reinforced insulation. Inclined insulated consoles, regardless of the type and size of the support, must be equipped with braces.

On multi-track sections of the railway (stations), as well as in the case of installation of supports with an increased dimension in the recesses behind the ditch, rigid crossbars are used. Rigid crossbars (crossbars) are metal trusses with parallel belts and an oblique triangular lattice with spacers at each node. For reinforcement in the nodes, another strut is installed diagonally. Separate truss blocks are joined together with corner steel plates (welded or bolted). Depending on the number of tracks blocked by rigid crossbars, they can have a length of 16.1 to 44.2 m and be assembled from two, three and four blocks. Rigid crossbars with a design length of more than 29.1 m, on which searchlights are installed to illuminate the station tracks, are equipped with decking and railings. Crossbars of frame-type rigid crossbars are installed on reinforced concrete posts of type C and CA, 13.6 m and 10.8 m long.

Devices by which contact wires are held in a horizontal plane in the required position relative to the axis of the path (axis of the current collector) are called clamps.

On the main tracks of hauls and stations and receiving and departure tracks, where the speed exceeds 50 km / h, articulated clamps are installed, consisting of main and light additional rods connected directly to the contact wire.

Overturning of fasteners of high-speed contact suspension (KS-200) is prevented by an unloaded wind string 600 mm long, connecting the additional rod of the fastener with the main rod (Fig. 7).

Direct clamps are used for negative (toward the support) zigzags of the contact wire or with a horizontal force directed from the support in case of a change in the direction of the contact wire; reverse clamps - with positive (from the support) zigzags of the contact wire or horizontal force to the support (supporting device).

Figure 6 - Types of clamps: a - FP-3; b - UFP; c - FO-25; d - UFO; e - FR; 1, 8, 9 - insulators; 2 - detail of the articulation; 3 - main rod; 4 and 11 - racks of direct and reverse clamps; 5 - additional latch; 6 - fixing clamp; 7 and 10 - oblique and safety strings; 12 - string and contact wire holders; 13 - steel thimble; 14 - UFO retainer stand

Figure 7 - Reverse latch with a wind string: a - installation diagram of the wind string on the reverse latch; b - installation diagram of the wind string on a direct latch; c - general view of the wind string; 1 -- the core of the main reverse latch; 2 - wind string; 3 - fixing clamp; 4 -- additional latch; 5 -- rack; 6 -- the core of the main straight latch

Figure 8 - Direct retainer FP with windstring

With large efforts (more than 200N) from a change in the direction of the contact wire, flexible clamps are mounted on the outer side of the curve. The Rules for the Design and Technical Operation of the Contact Network define the conditions for installing flexible clamps.

In the notation of the clamps, letters and numbers indicate its design, the voltage in the contact network for which it is intended, and the geometric dimensions: flexible, C - air shooters, R - diamond-shaped suspensions, I - isolated consoles, U - reinforced, number 3 - for voltage 3kV (for DC lines), 25 - for voltage 25kV (for AC lines); Roman numerals I, II, III, etc. - characterize the length of the main rod of the latch.

The lengths of the main rods of the clamps are selected depending on the size of the installation of the supports, the direction of the zigzag of the contact wire, the length of the additional rod. The length of the additional rod is 1200mm.

Clips for insulated consoles differ from clips for non-insulated consoles in that at the end of the main rod facing the console, instead of a threaded rod for connecting to the insulator, an eyelet is welded for connecting to the console.

In those places where electrified railway tracks intersect, an intersection of the corresponding contact suspensions is formed in the contact network, which is called an air arrow. Air arrows must ensure a smooth, without shocks and sparks, the transition of the pantograph skid from the contact wires of one path (exit) to the contact wires of the other, free mutual movement of the suspensions forming the air arrow, and the minimum mutual vertical movement of the contact wires in the pickup area of ​​the current collector skid of the adjacent wire way.

Figure 9 - Scheme of the air arrow of the contact network: 1 - the zone of passage of the non-working part of the pantograph skid under the non-working part of the contact wire; 2-- main electrical connector; 3 - non-working branch of the contact wire; 4 -- location of the fixing device; 5-- area of ​​​​pickup by the skid of the current collector of contact wires; 6 - contact wire of the direct path; 7 - contact wire of the deviated path; 8 -- additional electrical connector; 9 - the intersection of the contact wires

Air arrows over ordinary and cross turnouts and over blind intersections of tracks must be fixed with the possibility of mutual longitudinal movements of contact wires. On secondary routes it is allowed to use non-fixed air arrows.

Strings are used to fasten the contact wires to the carrier cable in chain suspensions. The strings must ensure the elasticity of the suspension, and in a semi-compensated chain suspension, also the possibility of free longitudinal movements of the contact wire relative to the carrier cable with temperature changes. The string material must have the necessary mechanical strength, durability and resistance to atmospheric corrosion. The connection between the contact wire and the carrying cable should not be rigid, so the strings are made in separate links.

Link strings of chain suspensions are made of steel-copper wire with a diameter of 4 mm (Fig. 10), individual links are pivotally connected to each other. Depending on the length, the string can be made of two or more links, while the lower link connected to the contact wire must be no longer than 300 mm in order to avoid breaking. to reduce the wear of the strings, thimbles are installed at the junctions of the links. The link strings are attached to the contact wire and the carrier cable with string clamps, the double contact wires of the semi-compensated suspension are attached to common strings with separate lower links. With temperature changes, the contact wire and the carrier cable move mutually (on both sides of the middle anchorage).

Mutual movement of the wires leads to a distortion of the strings. As a result, both the position of the contact wire in height and the tension of the wires of the chain suspension change. To reduce this influence, the angle of inclination of the string should not exceed 30° to the vertical along the track axis (Fig. 10, c).

Figure 10 - Strings of chain contact suspensions: a - link string; b and c - the location of the string on the compensated and semi-compensated suspension; g - permissible inclination of the string to the vertical; 1 - bearing hummock; 2 - contact wire; 3 - pantograph skid; 4 - string clamp 046

For more uniform elasticity and to reduce the sag of the contact wire with temperature changes at the supporting structures, it is suspended on spring strings (cables) of the BM - 6 brand. The spring strings are made of steel-copper wire with a diameter of 6 mm. The link strings are attached on one side to the spring string (cable) with string clamps or copper brackets, and on the other hand, to the contact wire with the usual fastening of the strings with clamps.

To ensure the current flow through all the wires included in the catenary or through all the wires included in one section, as well as in the case of unanchoring wires on a support or bypassing an artificial structure, electrical connectors are used. Electrical connectors are installed at the junctions of anchor sections and individual sections at railway stations, at the junctions of reinforcing wires with contact suspension and carrying cables with contact wires. They must provide reliable electrical contact, elasticity of the contact suspension and the possibility of longitudinal temperature movements of the wires along the entire length.

Cross connectors (Fig. 11) are installed between all wires of the contact network related to one track or a group of tracks (section) at the station (contact, reinforcing wires and carrying cables). Such a connection ensures the flow of current through all parallel wires.

Longitudinal connectors (Fig. 12) are installed at the junction of the anchor sections, at the points of connection of the reinforcing and supply wires to the catenary. The total cross-sectional area of ​​the longitudinal connectors should be equal to the cross-sectional area of ​​the suspensions connected by them, and for reliable contact, the longitudinal connectors on the main tracks and other critical points of the contact network are made of two or more parallel wires.

Figure 11 - Schemes for installing transverse electrical connectors (a, b) and connecting reinforcing wires (c) and disconnector loops (arrester, surge arrester) to contact suspension (d); 1 and 5 - connecting and supply clamps; 2- carrying cable; 3- electrical connector (MGG wire); 4 and 7-pin and amplifying wires; 6- "C-shaped" electrical connector (wire M, A and AC); 8- loop from the disconnector (arrester, surge arrester); 9-terminal adapter

Figure 12 - Longitudinal electrical connector: 1 - electrical connector (MG wire); 2 - connecting clamp; 3 - carrying cable; 4 - contact wire; 5 - supply clamp

Longitudinal electrical connectors must have a cross-sectional area corresponding to the cross-section of the suspensions connected by them. Longitudinal electrical connectors to the supply and reinforcing wires at the anchorages should be connected to the free ends emerging from the seal, and on non-insulating mates and bypasses - to each carrier cable with two connecting clamps and to the contact wire with one power clamp. With compensated suspension, the length of the electrical connector must be at least 2 m.

All types of electrical connectors and loops are made of copper wires M with a cross section of 70-95 mm2 in sections of alternating current, it is allowed to use copper wires MG of the same cross section.

Transverse electrical connectors between the carrying cables and contact wires on the hauls are installed outside the spring or first vertical strings at a distance of 0.2 - 0.5 m from their attachment points.

To power the contact network from traction substations, there are several traction power supply schemes. The 3.3 kV direct current system and 25 kV and 2x25 kV alternating current systems are most widely used.

With a DC power supply system, electrical energy is supplied to the contact network from positive polarity buses with a voltage of 3.3 kV of traction substations and returns after passing through the traction motors of the electric rolling stock along the rail circuits connected to the negative polarity buses. The distance between DC traction substations, depending on the traffic density, ranges from 7 km to 30 km.

In the AC power supply system, electricity is supplied to the contact network from two phases A and B with a voltage of 27.5 kV (on the buses of traction substations) and returns along the rail circuit to the third phase C. At the same time, power is supplied by one phase opposite to the feeder zone (parallel operation adjacent traction substations) with alternating power for subsequent feeder zones in order to equalize the loads of individual phases of the power supply system. With this power supply system, due to high voltage, traction substations are located after 40-60 km.

In recent years, the Russian railway network, along with the solution of various problems and tasks, has paid special attention to the problem of the throughput of hauls and stations. This problem arises in the face of fierce competition between railways and other sectors of the transport industry of the Russian Federation (marine, automobile, etc.). Success in this largely depends on the fast, high-quality and safe delivery of goods and passengers, which is greatly complicated by the ever-growing freight and passenger traffic. One of the most preferred solutions to this problem is to increase the weight of freight trains.

According to the instructions for organizing the movement of freight trains of increased length and weight, trains with a weight of more than 6000 tons or a length of more than 350 axles are considered heavy trains.

The circulation of trains of increased weight and length is allowed on single-double-track sections at any time of the day at a temperature not lower than -30 C, and for trains from empty cars - not lower than -40 C [L5].

Connected trains are organized at stations or hauls of two, and if necessary, of three trains, each of which must be formed along the length of the receiving and departure tracks, but not more than 0.9 of their length, established by the traffic schedule, as well as taking into account the restrictions on strength traction and power of the locomotive and power supply devices.

Connection and disconnection of trains of increased weight and length is allowed on descents and ascents up to 0.006 in compliance with the traffic safety conditions provided for by the local instruction.

On electrified sections, the procedure for passing connected freight trains is established according to the conditions for heating the wire of the contact network of one track. The total current of all electric locomotives in trains of increased weight and length should not exceed the permissible current for heating the contact network specified in the Rules for the Design and Technical Operation of the Contact Network of Electrified Railways. At sub-zero temperatures, the permissible currents of catenary wires can be increased by 1.25 times.

The number of trains of increased weight and length (for normal power supply) in the area between traction substations should be no more than that included in the traffic schedule. At the same time, to calculate the workload of power supply devices, a train of double unified weight and length is considered to be two trains, a triple train is considered to be three, etc.

Reducing the interval to a predetermined value is possible by alternating the passage of trains of increased weight with lighter trains, the introduction of PS and PPS, or an increase in the allowable current of the contact network.

The introduction of additional substations and substations on double-track sections with significant (at least twice) different loads along the tracks makes it possible to reduce the calculated inter-train interval by about 1.1–1.4 times due to a decrease in currents in the wires of the contact network.

The minimum train interval is checked by the power of the traction power supply devices, the voltage at the current collector of the electric locomotive, the current of the protection settings of the supply lines (feeders) of traction substations, the operation of the elements of the traction rail circuit.

To organize the circulation of trains of increased weight and length on the roads, measures are being developed that provide for an increase in the cross-sectional area of ​​the catenary suspension, improvement of the current distribution in the wires, an increase in the voltage level in the contact network, and other measures.

One of the directions of transport policy is the further development of high-speed train traffic, which poses a number of new technical tasks for electrifiers. In international practice, the following classification has now developed: high-speed lines are considered with a speed of 160–200 km / h, high-speed lines with a speed of over 200 km / h.

It should be noted that changes in design solutions, in the choice of highly electrically conductive materials and corrosion-resistant coatings, in the use of new insulators, improved supporting and supporting structures, in the design of the contact suspension itself, etc., which appeared in connection with the introduction of the KS-200 suspension, show modern trends development of the contact network and are already widely used in the reconstruction carried out on a number of roads to increase speeds up to 160 km/h.

The labor and economic costs required for the operation and overhaul of the contact network on an extended range of electrified railways make it necessary to improve the design of the contact network, the methods of their installation and maintenance.

The KS-200 contact network should provide reliable current collection with the number of pantograph passes up to 1.5 million, high operational reliability, durability of at least 50 years, as well as a significant reduction in operating costs for its maintenance due to improved suspension characteristics: equalization of elasticity in spans; reducing the weight of clamps and clamps, the use of compatible corrosion-resistant materials; anticorrosive coatings; high thermal conductivity and low electrical resistance of the materials used.

There are several options for rebuilding the contact network. Modernization is carried out if on the site the permanent elements of the contact network have worked out more than 75% of the standard service life (resource) and have reduced the bearing capacity or allowable loads by more than 25%. Depending on the volume of replacement of the main permanent elements, a complete or partial modernization of the contact network is carried out.

Complete modernization involves a complete renewal of all permanent elements of the contact network according to standard catenary designs. Contact wires are replaced depending on the degree of their wear. The decision to preserve the supports installed during the previous overhaul and which have not exhausted their service life is made during the design, depending on the possibility of their use in the suspension and the breakdown of the installation sites for the supports.

With partial modernization, a significant update of the permanent elements is carried out and, if necessary, a complete update of individual elements - supporting structures, compensating devices, insulation, load-bearing cables, fittings.

1. Theoretical aspects of the designed site

Technical description of the projected site.

The technical description is a characteristic of the designed site, which should be stated in the following order:

Type of current and power supply system of the projected site;

Length of the station (distance between traffic lights), stationing of the axis of the passenger building;

The number of main and secondary tracks, the distance between the tracks, the presence of dead ends and tracks that are not subject to electrification;

Availability of access roads to cargo yards and warehouses;

The length of the adjacent haul and its characteristics (curves, embankments, excavations, artificial structures)

Development and description of the power supply scheme and sectioning of the contact network of the station and adjacent hauls.

On electrified lines, the ERS receives electricity through a contact network from traction substations located at such a distance between them that a stable nominal voltage is provided for the ERS and protection against short-circuit currents works.

For each section of the electrified line, during its design, a power supply scheme and sectioning of the contact network are developed. When developing power supply and sectioning schemes for the contact network of an electrified line, standard sectioning schemes are used, developed on the basis of operating experience, taking into account the costs of building a contact network.

The role of the "human factor" in ensuring the safety of train traffic.

An analysis of literary sources shows that there is much in common in the activities of the world's railways, including problems. One of them is train traffic safety.

Each human error is always the result of his action or inaction, i.e. manifestations of his psyche, the definition of his aspect. The cause of an error is often not one, but a whole complex of negatively acting factors.

The work of railway transport is inevitably associated with risk, which is defined as a measure of the probability of danger and the severity of damage (consequences) from a safety violation. Transport risk is the result of the manifestation of many factors, both subjective and objective. Therefore, it will always exist. "The battle for security cannot be won once and for all."

The accident cannot be completely eliminated with the help of technical or organizational measures. They only reduce the likelihood of its occurrence. The more effective the counteraction to the risk of emergency situations, the higher the costs of forces and means. Safety costs can sometimes even exceed losses from accidents, crashes and defects in train and shunting operations, which can lead to a temporary deterioration in the economic performance of the industry. Nevertheless, such costs are socially justified and must be taken into account in economic calculations.

The safety of train traffic, the safety of the railway transport system is an integral concept that cannot be directly measured. Usually, safety is understood as the absence (exclusion) of dangers. In this case, danger means any circumstance that can cause harm to human health and the environment, the functioning of the system, or cause material damage.

Train traffic safety is a central system-forming factor that combines various components of railway transport into a single system.

Railway transport is the most important component of the economic activity of the modern state. Security breaches are associated with irretrievable economic, environmental and, above all, human losses.

Considering railway transport as a system "man - equipment - environment", four groups of factors affecting operational safety can be distinguished;

EQUIPMENT (malfunction of the track and rolling stock, failures of signaling and communication means, safety devices, power supply, etc.);

TECHNOLOGY (violation and inconsistency of legislative norms, rules, regulations, orders, instructions, poor working conditions, contradictions between the industry and external infrastructure, ergonomics flaws, errors of developers of technical means, incorrect control algorithms, etc.);

ENVIRONMENT (unfavorable objective conditions - terrain, meteorological conditions, natural disasters, increased radiation, electromagnetic interference, etc.).

A PERSON who directly controls the technical means and performs supporting functions (incorrect performance of his production duties intentionally or due to poor health, insufficient preparedness, inability to perform them at the required level).

Railway transport includes thousands of various technical means, which individually pose a danger to the environment and human life. In the complex, human-machine systems carry a much greater danger, which must be taken into account in their development, implementation and operation. All this points to the need to create a theory of safety - the methodological basis for measures to ensure safety on the railways.

Any violation in engineering and technology is ultimately caused by a person, if not by the one who controls the technical means, then by the commander or maintenance personnel. Therefore, "... any violation of the correct functioning of the first, second and third comes from a person." Over the past five years, about 90% of all accidents and crashes have occurred on the railways of the Russian Federation due to human error.

A person makes mistakes, and this must be reckoned with. A person has the right to make a mistake (of course, we are not talking about intentional violations). And the greater the deviation of a person's condition from his optimal, the greater the likelihood of error. Therefore, it is necessary to build a security system in such a way as to minimize the consequences of these errors.

To effectively solve the problem of monitoring a person's condition and building automatic devices that partially duplicate his actions, a modern approach is needed that considers a person in relationship and interaction with his environment.

At the same time, the "human factor" is understood quite broadly. This:

Actions of managers, railway operators, employees who are not directly related to the movement of trains;

Various kinds of regulation, document flow, development and execution of orders, instructions, orders, rules, laws, etc .;

Selection, selection, placement and training of personnel for both managerial and engineering, operator and working professions (personnel management);

Errors of developers of technical means and algorithms of technological processes;

Research and accounting of the impact of the specifics of the railway environment on the level of human health (working and rest conditions);

Control and assessment of the current state of employees (before the shift, during and after work).

Ensuring traffic safety is the most important task in railway transport and includes three relatively independent functions: design and operational reliability; highly efficient management and reliability of the locomotive crew.

At the same time, if the percentage of occurrence of various technical and technological incidents plays a relatively small role, then the proportion of the causes of marriage of "human" origin, united by the concept of "personal factor", is very high.

A significant reserve here is the study of the causes of human-related incidents and the development of measures to eliminate them on this basis.

Occupational Safety and Health.

The workplace of electricians is an electrified section within the boundaries established for the contact network area.

Performing work on the contact network requires a solid knowledge of safety rules and their strict implementation.

These requirements are due to increased danger: work on the contact network is carried out in the presence of train traffic, with lifting to a height, in various meteorological conditions, sometimes at night, as well as near wires and structures under high voltage, or directly on them without stress relief, in compliance with organizational and technical measures to ensure the safety of workers.

Terms of work.

When working with voltage relief and grounding, completely relieve voltage and ground the wires and equipment that are working. The work requires increased attention and high qualification of the service personnel, since wires and structures can remain energized in the work area. It is forbidden to approach wires under operating or induced voltage, as well as to neutral elements at a distance of less than 0.8 m.

When working under voltage, the worker is in direct contact with parts of the contact network that are under working or induced voltage. In this case, the safety of the worker is ensured by the use of basic protective equipment: insulating removable towers, insulating work platforms for railcars and railcars, insulating rods that isolate the worker from the ground. In order to increase the safety of performing work under voltage, the performer in all cases hangs shunt rods necessary to equalize the potential between the parts that he simultaneously touches, and in case of breakdown or overlap of insulating elements. When working under voltage, pay special attention to that. so that the person working at the same time does not touch the grounded structures and stays at a distance of no closer than 0.8 m from them.

Works near live parts are carried out on permanently grounded supporting and supporting structures, and between working and live parts there may be a distance of less than 2 m, but in all cases it should not be less than 0.8 m.

If the distance to live parts is more than 2 m, then these works are classified as carried out away from live parts. At the same time, they are divided into work with lifting and without lifting to a height. Work at height is considered to be all work performed with a rise from ground level to the feet of the worker to a height of 1 m or more.

During work with de-energization and earthing and in the vicinity of live parts, it is prohibited:

Work in a bent position if the distance from the worker to dangerous elements when he is straightened is less than 0.8 m:

Work in the presence of electrically hazardous elements on both sides at a distance of less than 2 m from the worker;

Perform work at a distance closer than 20 m along the axis of the path from the place of sectioning (sectional insulators, insulating interfaces, etc.) and disconnector loops that disconnect when preparing the work site;

Use metal ladders.

When working under voltage and near live parts, the team must have a grounding rod in case an urgent removal of voltage is necessary.

At night, the work area must have lighting that ensures the visibility of all insulators and wires at a distance of at least 50 m.

Dangerous places on the contact network include:

mortise and sectional insulators separating loading and unloading ways, ways of inspecting roof equipment, etc.;

rotting contact suspension and passing above it at a distance of less than 0.8 m loops of disconnectors and arresters or surge arresters of another section of the contact network with other potentials;

supports where two or more disconnectors, arresters or anchorings of various sections are located;

places of convergence of consoles or clamps of various sections at a distance of less than 0.8 m;

places for the passage of supply, suction and other wires along the cables of flexible crossbars;

common racks of clamps of various sections of the contact network with a distance between the clamps of less than 0.8 m;

supports with contact suspension anchor waste of various sections and grounded anchor waste, the distance from the place of work on which to current-carrying parts is less than 0.8 m;

location of electrorepellent protection;

supports with a horn arrester or surge arrester, on which the suspension of one track is mounted, and the loop is connected to another track or feeder route.

Dangerous places on the contact network are indicated by special warning signs (red arrow or poster "Attention! Dangerous place"). Work to ensure safety in such places is carried out in accordance with the "Cards for the production of work in a dangerous place of the contact network."

Card for the production of work in a dangerous place on the contact network.

Organizational measures to ensure the safety of workers are:

issuance of a work permit or order to the foreman;

briefing by the issuer of the order of the responsible manager, foreman;

issuance by the energy dispatcher of a permit (order, approval of the dispatcher) for the preparation of the place of work;

instruction by the manufacturer of the work of the brigade and admission to work:

supervision during work;

registration of breaks in work, transitions to another workplace, extension of the order and completion of work.

Technical measures to ensure the safety of workers are:

closure of haul tracks and stations for train traffic, issuance of warnings for trains and fencing of the work site;

removal of working stress and taking measures against its erroneous supply to the place of work;

* Checking the lack of voltage;

*imposition of groundings, shunt rods or jumpers, switching on disconnectors;

* Illumination of the place of work in the dark.

Monitoring compliance with safety rules is carried out primarily in the team directly at the work site. In addition, the organization of work in the contact network area is periodically checked.

The work of the brigade on the line is regularly checked by the leaders of the contact network area - the head or the electrician. Periodic inspections are carried out by managers and engineering and technical personnel of the power supply distance and the electrification and power supply service. At the same time, the discipline of the team in ensuring labor safety and the literacy of the conduct and organization of work are assessed.

The basis of successful work without injuries and disruption of normal operation is the maintenance of a constantly stable production and technological discipline at all levels, the prevention of violations of existing rules and instructions.

2. Settlement and technological part

Determination of the loads acting on the wires of the contact network.

For a contact network, climatic loads are decisive: wind, ice and air temperature, acting in different combinations. These loads are random in nature: their calculated values ​​for any period of time can be determined by statistical processing of observational data in the area of ​​the electrified line.

To establish the calculated climatic conditions, maps of the zoning of the territory of Russia are used; for simplified calculations, data for tasks are issued by the teacher.

The load from the weight of the wires is a uniformly distributed vertical load, which can be determined using the literature.

The ice load is caused by ice, which is a layer of dense glassy ice with a density of 900 kg/m3. For calculations, we assume that ice falls in a cylindrical shape with a uniform thickness of the ice wall, according to the effect, the load is vertical.

The intensity of ice formations is greatly influenced by the height of the wire above the ground. Therefore, when calculating the thickness of the ice wall on wires located on embankments, the value of the ice wall thickness should also be multiplied by the correction factor kb.

Wind loads on the wires of the contact network depend both on the average wind speed and on the nature of the surface of the surrounding area and the height of the wires above the ground. In accordance with building codes and regulations “Loads and impacts. Design standards ”, the calculated wind speed for given conditions (the height of the wires above the surface and the roughness of the surface of the surrounding area) is determined by multiplying the standard wind speed by the coefficient kv, which depends on the height of the wires above the ground and on its roughness, the standard value of wind pressure, Pa, q0 , coefficient of non-uniformity of wind pressure along the span, in mechanical calculation, accepted.

The wind load on the catenary wires is a horizontal load.

From a different combination of meteorological conditions acting on the wires of the contact network, three design modes can be distinguished under which the force (tension) in the carrier cable can be the largest, i.e. dangerous for the strength of the cable:

· the mode of the minimum temperature - compression of a cable;

maximum wind mode - cable stretching;

· ice-ice mode with wind - cable stretching.

For these design modes, the loads acting on the carrier cable are determined. In the minimum temperature mode, the carrier cable experiences only vertical load - from its own weight; wind and ice is absent; in the maximum wind mode, the carrier cable is subjected to a vertical load from the weight of the contact suspension wires and a horizontal load from wind pressure to the carrier cable, there is no ice. In the ice-ice mode with wind, the carrying cable is subject to vertical loads from the dead weight of the contact suspension wires, from the weight of ice on the suspension wires, and the horizontal load from wind pressure on the supporting cable covered with ice at the appropriate wind speed.

So, we will calculate the loads for three design modes, the calculation procedure is given below.

The order of calculations.

In minimum temperature mode.

1. Selection of loads from the own weight of the carrier cable and contact wire.

Linear loads from the weight of the contact wire to (N / m) and the weight of the supporting cable (N / m) are determined depending on the brand of wire according to the tables.

where, k - linear loads from its own weight (1 m) of the carrier cable and contact wire, N / m.

The load from the own weight of the strings and clamps, taken uniformly distributed along the length of the span; the value of this load can be taken equal to 1.0 N/m for each contact wire;

Number of contact wires.

where 0.009 H/mm3 is the density of ice;

d is the diameter of the carrier cable;

Ice wall thickness on the carrier cable, mm

where kb is a correction factor that takes into account the influence of local conditions for the location of the suspension on the deposition of ice (Appendix 5, v. 5.7);

0.8 - correction factor for the weight of ice deposits on the carrier cable.

The normative ice wall thickness bн, mm, at a height of 10 meters with a frequency of 1 time in 10 years, depending on the given icy area, is found according to Appendix 5 (v.5.6)

The calculated thickness of the ice wall, taking into account the correction factors, may be rounded up to the nearest whole figure.

On contact wires, the estimated wall thickness of ice is set equal to 50% of the wall thickness adopted for other wires of the contact network, since this takes into account the reduction in icing due to the movement of electric trains and ice melting (if any).

where is the thickness of the ice wall on the contact wire, mm. On contact wires, the ice wall thickness is assumed to be equal to 50% of the ice wall thickness on the carrier cable.

where is the thickness of the ice wall on the carrier cable, mm.

5. Full vertical load from the weight of ice on the wires of the catenary.

where is the number of contact wires;

Uniformly distributed along the length of the span, the vertical load from the weight of the ice on the strings and clamps with one contact wire (N/m), which, depending on the thickness of the ice wall, can be approximately taken from Appendix 5 (v.5.6).

6. The standard value of the horizontal wind load on the carrier cable in N/m is determined by the formula:

...

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EXPLANATORY NOTE.

The guidelines are intended for full-time and part-time students of the Saratov College of Railway Transport - a branch of SamGUPS, specialty 13.02.07 Power supply (by industry) ( railway transport). The guidelines are drawn up in accordance with the work program of the professional module PM 01. Maintenance of equipment of electrical substations and networks.

As a result of the practical work on the MDK 01.05 "Construction and maintenance of the contact network", the trainee must:

acquire professional competencies:

PC 1.4. Maintenance of switchgear equipment of electrical installations;

PC 1.5. Operation of overhead and cable power lines;

PC 1.6. Application of instructions and regulations in the preparation of reports and the development of technological documents;

have general competencies:

OK 1. Understand the essence and social significance of your future profession, show a steady interest in it;

OK 2. Organize their own activities, choose standard methods and methods for performing professional tasks, evaluate their effectiveness and quality;

OK 4. Search and use the information necessary for the effective implementation of professional tasks, professional and personal development;

OK 5. Use information and communication technologies in professional activities;

OK 9. Navigate in conditions of frequent change of technologies in professional activity;

have practical experience:

Software 1. drawing up electrical diagrams of devices of electrical substations and networks;

Software 4. Maintenance of switchgear equipment of electrical installations;

Software 5. operation of overhead and cable power lines;

be able to:

5 to monitor the condition of overhead and cable lines, organize and carry out work on their maintenance;

9 use normative technical documentation and instructions;

know:

Conditional graphic designations of elements of electrical circuits;

The logic of constructing circuits, typical circuit solutions, schematic diagrams of operated electrical installations.

Types and technologies of work on maintenance of switchgear equipment;

The design of the contact network of the station is a complex process and requires a systematic approach to the implementation of the project using the achievements of modern technology and best practices, as well as using computer technology.

The guidelines deal with the issues of determining the distributed loads on the carrier cable of the contact suspension, determining the length of the equivalent span and the critical one, determining the values ​​of the tension of the carrier cable depending on temperature, and constructing mounting curves.

According to the given scheme of the station, it is required:

1. Calculation of distributed loads on the catenary suspension cable for the main and side tracks.

4. Determination of the size of the sag of the contact wire and the carrier cable for the main track, with the construction of curves. Calculation of the average string length.

5. Organization of safe work.

Individual assignments for the implementation of practical work are issued immediately before execution, in the classroom. The time to complete each practical work is 2 academic hours, the time to defend the work done is 15 minutes included in the total time.

General guidance and control over the progress of practical work is carried out by the teacher of the interdisciplinary course.

PRACTICE #1

SELECTION OF PARTS AND MATERIALS FOR CONTACT NETWORK NODES

Purpose of the lesson: learn how to practically select parts for a given chain suspension.

Initial data: type and node of the catenary contact suspension (set by the teacher)

Table 1.1

Table 1.2

When choosing a support node and determining the method of anchoring the wires of a chain contact suspension, it is necessary to take into account the speed of trains in this section and the fact that the higher the speed of trains, the greater the elasticity of the chain contact suspension.

Contact network fittings are a set of parts designed for fastening structures, fixing wires and cables, assembling various nodes of the contact network. It must have sufficient mechanical strength, good conjugation, high reliability and the same corrosion resistance, and for high-speed current collection, it must also have a minimum mass.

All parts of contact networks can be divided into two groups: mechanical and conductive.

The first group includes parts designed only for mechanical loads: wedge and collet clamps for the carrier cable, saddles, fork thimbles, split and continuous lugs, etc.

The second group includes parts designed for mechanical and electrical loads: collet clamps for joining the carrier cable, oval connectors, butt clamps for contact wire clamps, string, string and adapter clamps. According to the material of manufacture, reinforcement parts are divided into: cast iron, steel, non-ferrous metals and their alloys (copper, bronze, aluminum).

Products made of cast iron have a protective anti-corrosion coating - hot-dip galvanizing, and steel products - electrolytic galvanizing followed by chromium plating.

Fig.1.1 Anchoring of a compensated catenary catenary for AC (a) and DC (b) current.

1- Anchor guy; 2- anchor bracket; 3,4,19 - a compensator cable with a steel diameter of 11 mm, a length of 10.11, and 13 m, respectively; 5- compensator block; 6- rocker; 7- rod "eye-double eye" 150 mm long; 8- adjusting plate; 9- insulator with a pestle; 10- insulator with an earring; 11- electrical connector; 12- rocker with two rods; 13.22 - clamp, respectively, for 25-30 loads; 14- limiter for garlands of goods single (a) and double (b); 15- reinforced concrete cargo; 16- cable limiter loads; 17 cargo limiter bracket; 18- mounting holes; 20 - rod "pestle-eye" 1000 mm long; 21- rocker for attaching two contact wires; 23 - bar for 15 loads; 24 - limiter for a single garland of goods; H0 is the nominal height of the contact wire suspension above the level of the rail head; bM is the distance from the loads to the ground or foundation, m.

Rice. 1.2 Anchoring of a semi-compensated AC chain suspension with a two-block compensator (a) and DC with a three-block compensator (b).

1- guy anchor; 2- anchor bracket; 3- rod "pestle-eye" 1000 mm long; 4- insulator with a pestle; 5- insulator with an earring; 6- compensator cable with a steel diameter of 11 mm; 7- compensator block; rod "pestle-eye" 1000 mm long; 9- bar for cargo; 10- reinforced concrete cargo; 11- limiter for a single garland of goods; 12- cable limiter loads; 13- bracket for load limiter; 14- compensator cable with steel diameter 10 mm, length 10 m; 15- clamp for cargo; 16- limiter for a double garland of goods; 17- rocker for anchoring two wires.

Fig. 1.3 Average anchoring of compensated (a-d) and semi-compensated (e) contact hangers for a single contact wire (b), double contact wire (d), fastening of the supporting cable and the middle anchoring cable on an insulated console (c) and on an uninsulated console (e).

1- main carrier cable; 2- cable of the middle anchoring of the contact wire; 3- additional cable; 4-pin wire; 5 - connecting clamp; 6- middle anchoring clamp; 7- console isolated; 8 - double saddle; 9- middle anchoring clamp for mounting on a carrier cable; 10- insulator.

Rice. 1.4 Attachment of the carrying cable to the non-insulated console.

Rice. 1.5 Fastening the carrier cable to a rigid cross member: a - general view with a fixing cable; b - with a fixing stand; and - a triangular suspension with brackets.

1-support; 2- crossbar (crossbar); 3- triangular suspension; 4- cable fixing; 5- locking stand; 6- retainer; 7- rod with a diameter of 12 mm; 8- bracket; 9- earring with pestle; 10 - hook bolt.

Execution order.

1. Select a support node for a given contact suspension and sketch it with all geometric parameters (Fig. 1.1, 1.2, 1.3,)

2. Select the material and cross-section of wires for simple and spring strings of the support node.

3. Select using fig. 1.1, 1.2, 1.3, 1.4, 1.5, details for a given node, the name and characteristics of which must be entered in table. 1.3.

Table 1.3

4. Apply a part for joining the contact wire and connecting the carrier cable, which are also entered in the table. 1.3.

5. Describe the purpose and location of the longitudinal and transverse connectors.

6. Describe the purpose of non-isolating mates. Draw a diagram of a non-isolating interface and indicate all the main dimensions.

7. Issue a report. Draw conclusions.

Contact network is a set of devices for transmitting electricity from traction substations to EPS through pantographs. It is part of the traction network and for rail electrified transport it usually serves as its phase (with alternating current) or pole (with direct current); the other phase (or pole) is the rail network. The contact network can be made with a contact rail or with a contact suspension.
In a contact network with a contact suspension, the main elements are the following: wires - a contact wire, a supporting cable, a reinforcing wire, etc .; supports; supporting and fixing devices; flexible and rigid cross members (consoles, clamps); insulators and fittings for various purposes.
A contact network with a contact suspension is classified according to the type of electrified transport for which it is intended - railway. mainline, city (tram, trolley bus), quarry, mine underground rail transport, etc.; by the nature of the current and the rated voltage of the EPS powered by the network; on the placement of the contact suspension relative to the axis of the rail track - for the central current collection (on the main railway transport) or side (on the ways of industrial transport); by type of contact suspension - with a simple, chain or special; according to the features of the anchoring of the contact wire and the carrier cable, the interfaces of the anchor sections, etc.
The contact network is designed to work outdoors and therefore is exposed to climatic factors, which include: ambient temperature, humidity and air pressure, wind, rain, frost and ice, solar radiation, the content of various contaminants in the air. To this it is necessary to add thermal processes that occur when the traction current flows through the elements of the network, the mechanical effect on them from the current collectors, electrocorrosion processes, numerous cyclic mechanical loads, wear, etc. All devices of the contact network must be able to withstand the action of the listed factors and provide high current collection quality in any operating conditions.
Unlike other power supply devices, the contact network does not have a reserve, therefore, increased requirements are imposed on it in terms of reliability, taking into account which its design, construction and installation, maintenance and repair are carried out.

Contact network design

When designing a contact network (CS), the number and brand of wires are selected based on the results of calculations of the traction power supply system, as well as traction calculations; determine the type of contact suspension in accordance with the maximum speeds of the ERS and other current collection conditions; find the span lengths (ch. arr. according to the conditions for ensuring its wind resistance, and at high speeds - and a given level of elasticity unevenness); choose the length of anchor sections, types of supports and supporting devices for hauls and stations; develop CS designs in artificial structures; they place supports and draw up plans for the contact network at stations and spans with the coordination of wire zigzags and taking into account the implementation of air arrows and sectioning elements of the contact network (insulating interfaces of anchor sections and neutral inserts, sectional insulators and disconnectors).
The main dimensions (geometric indicators) characterizing the placement of the contact network relative to other devices are the height H of hanging the contact wire above the level of the top of the rail head; distance A from live parts to grounded parts of structures and rolling stock; the distance G from the axis of the extreme path to the inner edge of the supports, located at the level of the rail heads, are regulated and largely determine the design of the elements of the contact network (Fig. 8.9).

Improving the design of the contact network is aimed at increasing its reliability while reducing the cost of construction and operation. Reinforced concrete supports and foundations of metal supports are made with protection against electrocorrosive effects on their reinforcement of stray currents. An increase in the service life of contact wires is achieved, as a rule, by using inserts with high antifriction properties (carbon, including metal-containing; metal-ceramic, etc.) on current collectors, by choosing a rational design of current collectors, and by optimizing current collection modes.
To improve the reliability of the contact network, ice is melted, incl. without interruption of train traffic; wind-resistant contact suspensions are used, etc. The efficiency of work on the contact network is facilitated by the use of remote control for remote switching of sectional disconnectors.

Wire anchoring

Anchoring wires - attaching the wires of the contact suspension through the insulators and fittings included in them to the anchor support with the transfer of their tension to it. Anchoring of wires can be uncompensated (rigid) or compensated (Fig. 8.16) through a compensator that changes the length of the wire if its temperature changes while maintaining the specified tension.

In the middle of the anchor section of the contact suspension, an average anchoring is performed (Fig. 8.17), which prevents unwanted longitudinal movements towards one of the anchorages and allows you to limit the damage zone of the contact suspension when one of its wires breaks. The cable of the middle anchorage is attached to the contact wire and the carrier cable with appropriate fittings.

Wire strain relief

Wire tension compensation (automatic control) of the contact network when their length changes as a result of temperature effects is carried out by compensators of various designs - block-load, with drums of various diameters, hydraulic, gas-hydraulic, spring, etc.
The simplest is a block-cargo compensator, consisting of a load and several blocks (chain hoist), through which the load is attached to the anchored wire. The most widespread is the three-block compensator (Fig. 8.18), in which the fixed block is fixed on a support, and two movable ones are embedded in loops formed by a cable carrying the load and fixed at the other end in the stream of the fixed block. The anchored wire is attached to the movable block through insulators. In this case, the weight of the load is 1/4 of the nominal tension (a gear ratio of 1:4 is provided), but the movement of the load is twice that of a two-to-6-arm compensator (with one moving block).

compensators with drums of different diameters (Fig. 8.19), cables connected with anchored wires are wound on a drum of small diameter, and a cable connected to a garland of loads is wound on a drum of a larger diameter. The braking device is used to prevent damage to the contact suspension in the event of a wire break.

Under special operating conditions, especially with limited dimensions in artificial structures, minor temperature differences in heating wires, etc., compensators of other types are also used for catenary wires, fixing cables and rigid crossbars.

Contact wire holder

Contact wire clamp - a device for fixing the position of the contact wire in a horizontal plane relative to the axis of current collectors. On curved sections, where the levels of the rail heads are different and the axis of the pantograph does not coincide with the axis of the track, non-articulated and articulated clamps are used.
The non-articulated latch has one rod, pulling the contact wire from the pantograph axis to the support (stretched latch) or from the support (compressed latch) by the size of the zigzag. On electrified railways e. non-articulated clamps are used very rarely (in the anchored branches of the contact suspension, on some air arrows), because the “hard point” formed with these clamps on the contact wire worsens the current collection.

The articulated latch consists of three elements: the main rod, the stand and the additional rod, at the end of which the fixing clip of the contact wire is attached (Fig. 8.20). The weight of the main rod is not transferred to the contact wire, and it takes only part of the weight of the additional rod with a fixing clip. The rods are shaped to ensure reliable passage of the current collectors when they squeeze out the contact wire. For high-speed and high-speed lines, lightweight additional rods are used, for example, made of aluminum alloys. With a double contact wire, two additional rods are installed on the rack. On the outer side of curves of small radii, flexible clamps are mounted in the form of a conventional additional rod, which is attached through a cable and an insulator to a bracket, rack, or directly to a support. On flexible and rigid crossbars with fixing cables, strip retainers are usually used (similar to an additional rod), hinged with clamps with an eye mounted on the fixing cable. On rigid crossbars, it is also possible to mount clamps on special racks.

Anchor section

Anchor section - a contact suspension section, the boundaries of which are anchor supports. The division of the contact network into anchor sections is necessary to include devices in the wires that maintain the tension of the wires when their temperature changes and to carry out longitudinal sectioning of the contact network. This division reduces the damage zone in the event of a break in the wires of the contact suspension, facilitates installation, tech. maintenance and repair of the contact network. The length of the anchor section is limited by permissible deviations from the nominal value of the tension of the catenary wires set by the compensators.
Deviations are caused by changes in the position of the strings, detents and consoles. For example, at speeds up to 160 km/h, the maximum length of the anchor section with two-sided compensation on straight sections does not exceed 1600 m, and at speeds of 200 km/h, no more than 1400 m is allowed. In curves, the length of the anchor sections decreases the more, the greater the length curve and its radius is smaller. To move from one anchor section to the next, non-insulating and insulating mates are performed.

Conjugation of anchor sections

Pairing of anchor sections is a functional combination of two adjacent anchor sections of the contact suspension, which ensures a satisfactory transition of the EPS pantographs from one of them to the other without violating the current collection mode due to the appropriate placement in the same (transitional) spans of the contact network of the end of one anchor section and the beginning of another. There are non-insulating mates (without electrical sectioning of the contact network) and insulating (with sectioning).
Non-insulating mates are performed in all cases when it is required to include compensators in the wires of the catenary. This achieves mechanical independence of the anchor sections. Such mates are mounted in three (Fig. 8.21, a) and less often in two spans. On high-speed lines, interfacing is sometimes performed in 4-5 spans due to higher requirements for the quality of the current collection. On non-insulating mates there are longitudinal electrical connectors, the cross-sectional area of ​​which must be equivalent to the cross-sectional area of ​​the wires of the contact network.

Insulating interfaces are used when it is necessary to section off the contact network, when, in addition to mechanical, it is necessary to ensure the electrical independence of the mating sections. Such pairings are arranged with neutral inserts (sections of the contact suspension, on which there is normally no voltage) and without them. In the latter case, three- or four-span mates are usually used, placing the contact wires of the mating sections in the middle span (spans) at a distance of 550 mm from one another (Fig. 8.21.6). In this case, an air gap is formed, which, together with the insulators included in the raised contact suspensions at the transitional supports, ensures the electrical independence of the anchor sections. The transition of the pantograph skid from the contact wire of one anchor section to another occurs in the same way as with non-insulating pairing. However, when the pantograph is in the middle span, the electrical independence of the anchor sections is violated. If such a violation is unacceptable, neutral inserts of different lengths are used. It is chosen such that, with several pantographs of one train raised, simultaneous overlapping of both air gaps is excluded, which would lead to a short circuit of wires powered by different phases and under different voltages. In order to avoid burnout of the contact wire of the EPS, the interface with the neutral insert takes place on the freewheel, for which, 50 m before the start of the insert, the signal sign “Turn off the current” is installed, and after the end of the insert, with electric locomotive traction after 50 m and with multiple unit traction after 200 m, the sign “ Turn on the current "(Fig. 8.21, c). In areas with high-speed traffic, automatic means of switching off the current on the EPS are necessary. In order to be able to withdraw the train when it is forced to stop under the neutral insert, sectional disconnectors are provided for temporarily supplying voltage to the neutral insert from the direction of train movement.

Sectioning of the contact network

Sectioning of the contact network - division of the contact network into separate sections (sections), electrically disconnected by insulating mates of anchor sections or sectional insulators. Insulation can be broken during the passage of the ERS pantograph along the section boundary; if such a short circuit is unacceptable (when adjacent sections are powered from different phases or they belong to different traction power supply systems), neutral inserts are placed between the sections. Under operating conditions, the electrical connection of individual sections is carried out, including sectional disconnectors installed in appropriate places. Sectioning is also necessary for the reliable operation of power supply devices in general, operational maintenance and repair of the contact network with power outage. The sectioning scheme provides for such a mutual arrangement of sections, in which the disconnection of one of them has the least effect on the organization of train traffic.
Sectioning of the contact network is longitudinal and transverse. With longitudinal sectioning, the contact network of each main path is separated along the electrified line at all traction substations and sectioning posts. In separate longitudinal sections, a contact network of hauls, substations, sidings and passing points is distinguished. At large stations with several electrified parks or track groups, the contact network of each park or track groups forms independent longitudinal sections. At very large stations, sometimes the contact network of one or both necks is separated into separate sections. The contact network is also sectioned in long tunnels and on some bridges with a ride below. With transverse sectioning, the contact network of each of the main tracks is separated along the entire length of the electrified line. At stations with significant track development, additional transverse sectioning is used. The number of transverse sections is determined by the number and purpose of individual tracks, and in some cases by the starting modes of the ERS, when it is necessary to use the cross-sectional area of ​​contact suspensions of adjacent tracks.
Sectioning with mandatory grounding of the disconnected section of the contact network is provided for tracks where people can be on the roofs of wagons or locomotives, or tracks near which lifting and transport mechanisms operate (loading and unloading, outfitting tracks, etc.). To ensure greater safety of those working in these places, the corresponding sections of the contact network are connected to other sections by sectional disconnectors with grounding knives; these blades ground the disconnected sections when the disconnectors are disconnected.

On fig. 8.22 shows an example of a power supply and sectioning scheme for a station located on a double-track section of a line electrified on alternating current. The diagram shows seven sections - four on hauls and three at the station (one of them with mandatory grounding when it is turned off). The contact network of the left haul tracks and the station is powered by one phase of the power system, and the right haul tracks are powered by the other. Accordingly, sectioning was performed using insulating mates and neutral inserts. In areas where ice melting is required, two sectional disconnectors with motor drives are installed on the neutral insert. If ice melting is not provided, one sectional disconnector with a manual drive is sufficient.

For sectioning the contact network of the main and side networks at the stations, sectional insulators are used. In some cases, sectional insulators are used to form neutral inserts on the AC contact network, which the EPS passes without consuming current, as well as on tracks where the length of the ramps is insufficient to accommodate insulating mates.
Connection and disconnection of various sections of the contact network, as well as connection with supply lines, is carried out using sectional disconnectors. On AC lines, as a rule, disconnectors of a horizontal rotary type are used, on DC lines - vertically chopping. The disconnector is controlled remotely from the consoles installed in the duty station of the contact network area, in the premises of those on duty at the stations and in other places. The most critical and frequently switched disconnectors are installed in the dispatch telecontrol network.
There are longitudinal disconnectors (for connecting and disconnecting the longitudinal sections of the contact network), transverse (for connecting and disconnecting its transverse sections), feeder, etc. They are designated by the letters of the Russian alphabet (for example, longitudinal -A, B, C, G; transverse - P ; feeder - F) and numbers corresponding to the numbers of tracks and sections of the contact network (for example, P23).
To ensure the safety of work on the disconnected section of the contact network or near it (in the depot, on the ways of equipping and inspecting the roof equipment of the EPS, on the ways of loading and unloading cars, etc.), disconnectors with one grounding knife are installed.

Frog

Air switch - formed by the intersection of two contact suspensions above the turnout; designed to ensure a smooth and reliable passage of the pantograph from the contact wire of one path to the contact wire of another. The crossing of wires is carried out by superimposing one wire (usually an adjacent path) on another (Fig. 8.23). To lift both wires when the current collector approaches the air arrow, a restrictive metal pipe 1-1.5 m long is fixed on the lower wire. The upper wire is placed between the tube and the lower wire. The crossing of the contact wires over a single turnout is carried out with the displacement of each wire to the center from the axes of the tracks by 360-400 mm and is located where the distance between the inner faces of the heads of the connecting rails of the cross is 730-800 mm. At cross turnouts and at the so-called. At blind intersections, the wires cross over the center of the turnout or intersection. Air gunners perform, as a rule, fixed. To do this, clamps are installed on the supports that hold the contact wires in a predetermined position. On station tracks (except for the main ones), the switches can be made non-fixed if the wires above the turnout are located in the position specified by adjusting the zigzags at the intermediate supports. Contact suspension strings located near the arrows must be double. Electrical contact between contact suspensions forming an air arrow is provided by an electrical connector installed at a distance of 2-2.5 m from the point of intersection on the side of the wit. To increase reliability, switch designs are used with additional cross-links between the wires of both contact suspensions and sliding supporting double strings.

Contact network supports

Contact network supports - structures for fixing the supporting and fixing devices of the contact network, perceiving the load from its wires and other elements. Depending on the type of supporting device, the supports are divided into cantilever (single-track and double-track execution); racks of rigid crossbars (single or paired); supports of flexible crossbars; feeder (with brackets only for supply and exhaust wires). Supports on which there are no supporting, but there are fixing devices, are called fixing. Cantilever supports are divided into intermediate ones - for attaching one contact suspension; transitional, installed at the junctions of the anchor sections, - for fastening two contact wires; anchor, perceiving the force from the anchoring of wires. As a rule, supports perform several functions at the same time. For example, the support of the flexible crossbar can be anchored, consoles can be suspended on the uprights of the rigid crossbar. Brackets for reinforcing and other wires can be fixed to the support posts.
Supports are made of reinforced concrete, metal (steel) and wood. On domestic railways d. mainly used supports made of prestressed reinforced concrete (Fig. 8.24), conical centrifuged, standard length 10.8; 13.6; 16.6 m. Metal supports are installed in cases where it is impossible to use reinforced concrete ones due to their bearing capacity or dimensions (for example, in flexible crossbars), as well as on lines with high-speed traffic, where there are increased requirements for the reliability of support structures. Wooden supports are used only as temporary.

For DC sections, reinforced concrete poles are made with additional bar reinforcement located in the foundation part of the poles and designed to reduce damage to the pole reinforcement by electrocorrosion caused by stray currents. Depending on the method of installation, reinforced concrete supports and racks of rigid crossbars are separate and inseparable, installed directly into the ground. The required stability of inseparable supports in the ground is provided by the upper bed or base plate. In most cases, inseparable supports are used; separate ones are used with insufficient stability of inseparable ones, as well as in the presence of groundwater, which makes it difficult to install inseparable supports. In anchor reinforced concrete supports, braces are used, which are installed along the path at an angle of 45 ° and attached to reinforced concrete anchors. Reinforced concrete foundations in the above-ground part have a cup 1.2 m deep, in which supports are installed and then the sinuses of the cup are sealed with cement mortar. To deepen foundations and supports into the ground, the vibration immersion method is mainly used.
Metal supports of flexible crossbars are usually made of a tetrahedral pyramidal shape, their standard length is 15 and 20 m. In areas characterized by increased atmospheric corrosion, metal cantilever supports 9.6 and 11 m long are fixed in the ground on reinforced concrete foundations. Cantilever supports are installed on prismatic three-beam foundations, flexible crossbeam supports are installed either on separate reinforced concrete blocks or on pile foundations with grillages. The base of the metal supports is connected to the foundations with anchor bolts. To fix the supports in rocky soils, heaving soils of areas of permafrost and deep seasonal freezing, in weak and swampy soils, etc., foundations of special structures are used.

Console

The console is a supporting device fixed on a support, consisting of a bracket and a rod. Depending on the number of overlapped paths, the console can be one-, two-, and rarely multi-track. To eliminate the mechanical connection between contact suspensions of different tracks and to increase reliability, single-track consoles are more often used. Uninsulated or grounded consoles are used, in which the insulators are located between the carrier cable and the bracket, as well as in the latch rod, and insulated consoles with insulators placed in the brackets and rods. Uninsulated consoles (Fig. 8.25) can be curved, inclined and horizontal in shape. For supports installed with an increased dimension, consoles with struts are used. At the junctions of the anchor sections, when mounting two consoles on one support, a special traverse is used. Horizontal consoles are used in cases where the height of the supports is sufficient to secure the inclined rod.

With isolated consoles (Fig. 8.26), it is possible to carry out work on the supporting cable near them without turning off the voltage. The absence of insulators on non-insulated consoles ensures greater stability of the position of the carrier cable under various mechanical influences, which favorably affects the current collection process. The brackets and rods of the consoles are fixed on supports with the help of heels, which allow them to be rotated along the axis of the track by 90 ° in both directions relative to the normal position.

Flexible cross member

Flexible crossbar - a supporting device for hanging and fixing the wires of the contact network located above several tracks. A flexible cross member is a system of cables stretched between supports across electrified tracks (Fig. 8.27). The transverse carrying cables take all vertical loads from the wires of the chain hangers, the cross member itself and other wires. The sag of these cables must be at least Vio the span between the supports: this reduces the effect of temperature on the height of the catenary hangers. To increase the reliability of the crossbars, at least two transverse load-bearing cables are used.

The fixing cables perceive horizontal loads (the upper one - from the carrying cables of chain suspensions and other wires, the lower one - from contact wires). The electrical isolation of the cables from the supports makes it possible to maintain the contact network without turning off the voltage. All cables to regulate their length are fixed on supports with threaded steel rods; in some countries, special dampers are used for this purpose, mainly for fixing contact suspension at stations.

current collection

Current collection - the process of transferring electrical energy from a contact wire or contact rail to the electrical equipment of a moving or stationary ERS through a current collector that provides sliding (on the main, industrial and most urban electric transport) or rolling (on some types of ERS of urban electric transport) electrical contact. Breaking the contact during current collection leads to the occurrence of non-contact arc erosion, resulting in intense wear of the contact wire and the contact inserts of the current collector. When the contact points are overloaded with current in the driving mode, contact electroexplosive erosion (sparking) and increased wear of the contacting elements occur. Long-term overload of the contact with the operating current or short-circuit current when the EPS is stopped can lead to burnout of the contact wire. In all these cases, it is necessary to limit the lower limit of contact pressure for given operating conditions. Excessive contact pressure, incl. as a result of aerodynamic impact on the pantograph, an increase in the dynamic component and the resulting increase in the vertical squeezing of the wire, especially at clamps, on overhead arrows, at the junction of anchor sections and in the area of ​​artificial structures, can reduce the reliability of the contact network and pantographs, as well as increase the wear rate wires and contact inserts. Therefore, the upper limit of contact pressure also needs to be normalized. Optimization of current collection modes is provided by coordinated requirements for contact network devices and current collectors, which guarantees high reliability of their operation at minimum reduced costs.
The quality of the current collection can be determined by different indicators (the number and duration of mechanical contact disturbances in the calculated section of the path, the degree of stability of the contact pressure, close to the optimal value, the wear rate of the contact elements, etc.), which largely depend on the design of the interacting systems - the contact network and pantographs, their static, dynamic, aerodynamic, damping and other characteristics. Despite the fact that the current collection process depends on a large number of random factors, the results of research and operating experience allow us to identify the fundamental principles for creating current collection systems with the required properties.

Rigid cross member

Rigid crossbar - serves to suspend the wires of the contact network located above several (2-8) tracks. A rigid cross member is made in the form of a block metal structure (crossbar) mounted on two supports (Fig. 8.28). Such cross members are also used for opening spans. The crossbar with the uprights is hingedly or rigidly connected with the help of struts, which allow unloading it in the middle of the span and reducing steel consumption. When placing lighting fixtures on the crossbar, a flooring with railings is performed on it; provide a ladder for climbing to the supports of service personnel. Install rigid cross bars. arr. at stations and points.

insulators

Insulators - devices for isolating wires of a contact network that are energized. There are insulators according to the direction of application of loads and the place of installation - suspended, tension, fixative and cantilever; by design - dish-shaped and rod; by material - glass, porcelain and polymer; insulators also include insulating elements
Suspension insulators - porcelain and glass dish - are usually connected in garlands of 2 on DC lines and 3-5 (depending on air pollution) on AC lines. Tension insulators are installed in wire anchorages, in load-bearing cables above sectional insulators, in fixing cables of flexible and rigid crossbars. Retaining insulators (fig. 8.29 and 8.30) differ from all others by the presence of an internal thread in the hole of the metal cap for fixing the pipe. On alternating current lines, rod insulators are usually used, and on direct current lines, disc insulators are also used. In the latter case, another disc insulator with an earring is included in the main rod of the articulated retainer. Cantilever porcelain rod insulators (Fig. 8.31) are installed in struts and rods of insulated consoles. These insulators must have increased mechanical strength, since they work in bending. In sectional disconnectors and horn arresters, porcelain rod insulators are usually used, less often disc insulators. In sectional insulators on DC lines, polymer insulating elements are used in the form of rectangular bars made of press material, and on AC lines, in the form of cylindrical fiberglass rods, which are covered with electrical protective covers made of fluoroplastic pipes. Polymeric rod insulators with fiberglass cores and silicone elastomer ribs have been developed. They are used as hanging, sectioning and fixing; they are promising for installation in struts and rods of insulated consoles, in cables of flexible cross members, etc. In areas of industrial air pollution and in some artificial structures, periodic cleaning (washing) of porcelain insulators is carried out using special mobile equipment.

Contact suspension

Contact suspension - one of the main parts of the contact network, is a system of wires, the relative position of which, the method of mechanical connection, material and cross section provide the necessary quality of current collection. The design of the contact suspension (KP) is determined by economic feasibility, operating conditions (the maximum speed of the ERS, the highest current taken by pantographs), and climatic conditions. The need to ensure reliable current collection at increasing speeds and power of the EPS determined the trends in changing the designs of suspensions: first simple, then single with simple strings and more complex - single spring, double and special, in which to ensure the desired effect, ch. arr. alignment of the vertical elasticity (or rigidity) of the suspension in the span, space-cable systems with an additional cable or others are used.
At speeds up to 50 km / h, a satisfactory quality of current collection is ensured by a simple contact suspension, consisting only of a contact wire suspended from supports A and B of the contact network (Fig. 8.10, a) or transverse cables.

The quality of the current collection is largely determined by the sag of the wire, which depends on the resulting load on the wire, which is the sum of the dead weight of the wire (with ice along with ice) and wind load, as well as the length of the span and tension of the wire. The quality of the current collection is greatly influenced by the angle a (the smaller it is, the worse the quality of the current collection), the contact pressure changes significantly, shock loads appear in the support zone, there is increased wear of the contact wire and the current collector inserts of the current collector. It is possible to somewhat improve the current collection in the support zone by applying the suspension of the wire at two points (Fig. 8.10.6), which, under certain conditions, ensures reliable current collection at speeds up to 80 km / h. It is possible to noticeably improve the current collection with a simple suspension only by significantly reducing the length of the spans in order to reduce the sag, which in most cases is uneconomical, or by using special wires with significant tension. In this regard, chain suspensions are used (Fig. 8.11), in which the contact wire is suspended from the carrier cable using strings. A suspension consisting of a carrier cable and a contact wire is called single; in the presence of an auxiliary wire between the carrier cable and the contact wire - double. In a chain suspension, the carrier cable and the auxiliary wire are involved in the transmission of traction current, so they are connected to the contact wire with electrical connectors or conductive strings.

The main mechanical characteristic of a contact suspension is considered to be elasticity - the ratio of the height of the contact wire to the force applied to it and directed vertically upwards. The quality of the current collection depends on the nature of the change in elasticity in the span: the more stable it is, the better the current collection. In simple and conventional chain hangers, the mid-span elasticity is higher than that of supports. Elasticity equalization in the span of a single suspension is achieved by installing spring cables 12-20 m long, on which vertical strings are attached, as well as by the rational arrangement of ordinary strings in the middle part of the span. Double pendants have more permanent elasticity, but they are more expensive and more difficult. To obtain a high rate of uniformity of elasticity distribution in the span, various methods are used to increase it in the zone of the support node (installation of spring shock absorbers and elastic rods, torsion effect from cable twisting, etc.). In any case, when developing suspensions, it is necessary to take into account their dissipative characteristics, i.e., resistance to external mechanical loads.
The contact suspension is an oscillatory system, therefore, when interacting with current collectors, it can be in a state of resonance caused by the coincidence or frequency multiplicity of its natural oscillations and forced oscillations, determined by the speed of the current collector along the span with a given length. In the event of resonance phenomena, a noticeable deterioration in current collection is possible. Limiting for the current collection is the speed of propagation of mechanical waves along the suspension. If this speed is exceeded, the current collector has to interact, as it were, with a rigid, non-deformable system. Depending on the normalized specific tension of the suspension wires, this speed can be 320-340 km/h.
Simple and chain hangers consist of separate anchor sections. Suspension fastenings “at the ends of the anchor sections can be rigid or compensated. On the main etc. mainly compensated and semi-compensated suspensions are used. In semi-compensated suspensions, compensators are available only in the contact wire, in compensated ones - also in the carrier cable. In this case, in the event of a change in the temperature of the wires (due to the passage of currents through them, changes in the ambient temperature), the sag of the carrier cable, and, consequently, the vertical position of the contact wires, remain unchanged. Depending on the nature of the change in the elasticity of the suspensions in the span, the sag of the contact wire is taken in the range from 0 to 70 mm. Vertical adjustment of semi-compensated suspensions is carried out so that the optimal sag of the contact wire corresponds to the average annual (for a given area) ambient temperature.
The structural height of the suspension - the distance between the carrier cable and the contact wire at the suspension points - is chosen based on technical and economic considerations, namely, taking into account the height of the supports, compliance with the current vertical dimensions of the approach of buildings, insulation distances, especially in the area of ​​artificial structures, etc .; in addition, a minimum inclination of the strings must be ensured at extreme ambient temperatures, when noticeable longitudinal movements of the contact wire relative to the carrier cable can occur. For compensated suspensions, this is possible if the carrier cable and the contact wire are made of different materials.
To increase the service life of the contact inserts of current collectors, the contact wire is placed in a zigzag plan. There are various options for suspension of the carrier cable: in the same vertical planes as the contact wire (vertical suspension), along the axis of the track (half-oblique suspension), with zigzags opposite to the zigzags of the contact wire (oblique suspension). Vertical suspension has less wind resistance, oblique - the greatest, but it is the most difficult to install and maintain. On straight sections of the track, semi-oblique suspension is mainly used, on curved sections - vertical. In areas with particularly strong wind loads, a diamond-shaped suspension is widely used, in which two contact wires suspended from a common carrier cable are located at supports with opposite zigzags. In the middle parts of the spans, the wires are drawn to each other by rigid strips. In some suspensions, lateral stability is ensured by the use of two carrying cables, which form a kind of cable-stayed system in the horizontal plane.
Abroad, single chain suspensions are mainly used, including in high-speed sections - with spring wires, simple spaced support strings, as well as with carrier cables and contact wires with increased tension.

contact wire

The contact wire is the most important element of the catenary suspension, directly making contact with the EPS current collectors in the process of current collection. As a rule, one or two contact wires are used. Two wires are usually used when removing currents of more than 1000 A. On domestic railways. e. use contact wires with a cross-sectional area of ​​​​75, 100, 120, less often 150 mm2; abroad - from 65 to 194 mm2. The cross-sectional shape of the wire has undergone some changes; in the beginning. 20th century the section profile acquired a shape with two longitudinal grooves in the upper part - the head, which serve to fix the contact network fittings on the wire. In domestic practice, the dimensions of the head (Fig. 8.12) are the same for different cross-sectional areas; in other countries the dimensions of the head depend on the cross-sectional area. In Russia, the contact wire is marked with letters and numbers indicating the material, profile and cross-sectional area in mm2 (for example, MF-150 - copper shaped, cross-sectional area 150 mm2).

In recent years, low-alloy copper wires with additives of silver and tin, which increase the wear and heat resistance of the wire, have become widespread. The best indicators in terms of wear resistance (2-2.5 times higher than that of copper wire) are bronze copper-cadmium wires, but they are more expensive than copper wires, and their electrical resistance is higher. The expediency of using one or another wire is determined by a technical and economic calculation, taking into account specific operating conditions, in particular, when solving issues of ensuring current collection on high-speed lines. Of particular interest is a bimetallic wire (Fig. 8.13), suspended mainly on the receiving and departure tracks of stations, as well as a combined steel-aluminum wire (the contact part is steel, Fig. 8.14).

During operation, wear of the contact wires occurs during current collection. There are electrical and mechanical components of wear. To prevent wire breakage due to an increase in tensile stresses, the maximum wear value is normalized (for example, for a wire with a cross-sectional area of ​​​​100 mm, the allowable wear is 35 mm2); as the wear of the wire increases, its tension is periodically reduced.
During operation, a break in the contact wire can occur as a result of the thermal effect of an electric current (arc) in the zone of interaction with another device, i.e., as a result of a wire burnout. Most often, burnouts of the contact wire occur in the following cases: over current collectors of a fixed EPS due to a short circuit in its high-voltage circuits; when raising or lowering the pantograph due to the flow of load current or short circuit through an electric arc; with an increase in contact resistance between the wire and the contact inserts of the current collector; the presence of ice; closing by the skid of the current collector of different potential branches of the insulating interface of the anchor sections, etc.
The main measures to prevent wire burnouts are: increasing the sensitivity and speed of protection against short-circuit currents; the use of a lock on the EPS that prevents the pantograph from lifting under load and forcibly turns it off when lowered; equipment of insulating interfaces of anchor sections with protective devices that contribute to extinguishing the arc in the zone of its possible occurrence; timely measures to prevent ice deposits on wires, etc.

carrier cable

Carrying cable - a wire of a chain suspension attached to the supporting devices of the contact network. A contact wire is suspended from the carrier cable with the help of strings - directly or through an auxiliary cable.
On domestic railways on the main tracks of lines electrified at direct current, copper wire with a cross-sectional area of ​​\u200b\u200b120 mm2 is mainly used as a carrier cable, and steel-copper wire (70 and 95 mm2) is used on the side tracks of stations. Abroad, on AC lines, bronze and steel cables with a cross section of 50 to 210 mm2 are also used. The tension of the cable in a semi-compensated contact suspension varies depending on the ambient temperature in the range from 9 to 20 kN, in a compensated suspension, depending on the brand of wire - in the range of 10-30 kN.

String

A string is an element of a chain contact suspension, with the help of which one of its wires (usually a contact one) is suspended from another - a carrier cable.
By design, they distinguish: link strings, composed of two or more spherically connected links of rigid wire; flexible strings made of flexible wire or nylon rope; rigid - in the form of spacers between the wires, used much less frequently; loop - from a wire or a metal strip freely suspended on the upper wire and rigidly or hingedly fixed in the string clamps of the lower (usually contact); sliding strings attached to one of the wires and sliding along the other.
On domestic railways e. the most widely used link strings made of bimetallic steel-copper wire with a diameter of 4 mm. Their disadvantage is electrical and mechanical wear in the joints of individual links. In the calculations, these strings are not considered as conductive. Flexible strings made of copper or bronze stranded wire, rigidly attached to string clamps and acting as electrical connectors distributed along the contact suspension and not forming significant concentrated masses on the contact wire, which is typical for typical transverse electrical connectors used in link and other non-conductive strings. Sometimes non-conductive contact suspension strings made of nylon rope are used, for fastening of which transverse electrical connectors are required.
Sliding strings capable of moving along one of the wires are used in semi-compensated catenary contact hangers with a low structural height, when installing sectional insulators, at anchoring points of a carrier cable on artificial structures with limited vertical dimensions, and in other special conditions.
Rigid strings are usually installed only on the overhead arrows of the contact network, where they act as a limiter for lifting the contact wire of one suspension relative to the wire of another.

reinforcing wire

Reinforcing wire - a wire electrically connected to the contact suspension, which serves to reduce the overall electrical resistance of the contact network. As a rule, the reinforcing wire is suspended on brackets on the field side of the support, less often - above the supports or on consoles near the carrier cable. The reinforcing wire is used in sections of direct and alternating current. The decrease in the inductive resistance of the AC contact network depends not only on the characteristics of the wire itself, but also on its placement relative to the wires of the contact suspension.
The use of a reinforcing wire is provided at the design stage; as a rule, one or more stranded wires of type A-185 are used.

electrical connector

Electrical connector - a piece of wire with conductive fittings, designed for electrical connection of wires of the contact network. There are transverse, longitudinal and bypass connectors. They are made of uninsulated wires so that they do not interfere with the longitudinal movement of the wires of contact suspensions.
Cross connectors are installed for parallel connection of all wires of the contact network of the same path (including reinforcing ones) and at stations for contact suspensions of several parallel paths included in one section. Cross connectors are mounted along the path at distances depending on the type of current and the share of the cross section of the contact wires in the total cross section of the wires of the contact network, as well as on the operating modes of the EPS on specific traction arms. In addition, at the stations, the connectors are placed in the places of starting and acceleration of the EPS.
Longitudinal connectors are installed on overhead arrows between all wires of contact suspensions that form this arrow, at the junctions of the anchor sections - on both sides with non-insulating mates and on the one hand with insulating mates and in other places.
Bypass connectors are used in cases where it is required to replenish the interrupted or reduced cross-section of the contact suspension due to the presence of intermediate anchorings of reinforcing wires or when insulators are included in the supporting cable for passing through an artificial structure.

Contact network fittings

Contact network fittings - clamps and parts for connecting the wires of the contact suspension to each other, with supporting devices and supports. Armature (Fig. 8.15) is divided into tension (butt, end clamps, etc.), suspension (string clamps, saddles, etc.), fixing (fixing clamps, holders, lugs, etc.), conductive, mechanically lightly loaded (clamps supply, connecting and transitional - from copper to aluminum wires). The products that make up the fittings, in accordance with their purpose and production technology (casting, cold and hot stamping, pressing, etc.), are made of ductile iron, steel, copper and aluminum alloys, and plastics. The technical parameters of the fittings are regulated by regulatory documents.

The Metalloprom company is one of the leaders in Russia in the supply and production of parts for the contact network for the electrification of railways, as well as linear fittings for overhead power lines. One of the main specializations of the company is the overhead contact network of the railway.

Every year we increase production and master the production of a new range. Along with products for electrified railways, our company has launched the manufacture of a number of products for high-voltage power lines.

A guarantee of high quality is the compliance of manufactured units, parts and elements for the contact network of the railway with the requirements of the Department of Electrification and Power Supply of Russian Railways, as well as OST 32.204-2002.

List of CS products for electrified railways

• Fasteners;
• brackets;
• Consoles;
• Guys;
• Products on rigid crossbars;
• Grounding nodes;
• Products for the installation of disconnectors and surge arresters on metal and reinforced concrete supports;
• Units and parts of KS for anchoring, fastening and fixing contact wires, spring and tension cables.

One of the priorities of Metalloprom is to expand the geography of the sales market in the Russian Federation and CIS countries.

From year to year, the professionalism of the company's staff is growing. Thanks to well-coordinated work, experience and the latest equipment, labor productivity increases, which will reduce the time of production and delivery of products, while the quality of the products remains consistently high.

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console pin suspension network

Introduction

1. Theoretical section

1.1 Calculation of loads acting on catenary

1.2 Calculation of the maximum allowable span lengths

1.4 Tracing the contact network of the stage

2. Technology section

2.1 Maintenance of consoles

3. Economic section

4.1 Organizational and technical measures to ensure the safety of workers. Working conditions in the area of ​​the contact network

Conclusion

Bibliographic list

Introduction

The contact network is the most important element of the traction power supply system for electric transport. The successful performance of the main function of railway transport, which is the timely transportation of passengers and goods in accordance with a given traffic schedule, largely depends on the reliable operation of the contact network.

The main task of the contact network is the transmission of electricity to the rolling stock due to reliable, economical and environmentally friendly current collection in design weather conditions at the established speeds, types of pantographs and values ​​of the transmitted current.

The main elements of a contact network with a contact suspension are the wires of the contact network (contact wire, carrying cable, reinforcing wire, etc.), supports, supporting devices (consoles, flexible crossbars and rigid crossbars) and insulators.

When designing a contact network, the number and brand of wires are selected based on the results of calculations of the traction power supply system, as well as traction calculations; determine the type of contact suspension in accordance with the maximum speeds of the electric rolling stock and other current collection conditions; find the span lengths; choose the length of the anchor sections, types of supports and supporting devices for hauls; develop the design of the contact network in artificial structures; they place supports and draw up plans for the contact network at stations and spans with the coordination of wire zigzags and taking into account the implementation of air arrows and sectioning elements of the contact network (insulating interfaces of anchor sections and neutral inserts, sectional insulators and disconnectors).

In recent years, the movement of heavy and long trains has been expanding on the roads of the country, a new high-capacity electric rolling stock has been put into operation, the speeds of passenger and freight trains have increased, and freight traffic is growing.

This thesis project considers the design of a direct current contact network in order to gain skills in designing, choosing equipment, building installation curves and checking the condition, adjusting and repairing a sectional insulator.

1. Theoretical section

1.1 Calculation of loads acting on the suspension

From the whole variety of combinations of meteorological conditions acting on the contact network wires, three design modes can be distinguished in which the forces (tension) in the carrier cable can be the greatest, dangerous for the strength of the cable:

Minimum temperature mode - cable compression;

Maximum wind mode - cable stretching;

Ice mode - cable stretching.

For these design modes and determine the load on the carrier cable.

1.1.1 Minimum temperature mode

The carrying cable experiences only the vertical load of its own weight and from the weight of the contact wire, strings and clamps.

The vertical load from the own weight of the 1st running meter of wires in daN/m is determined by the formula:

where gt, gk - load from the own weight of one meter of the carrier and contact wires, daN / m; should be taken and

n is the number of contact wires;

gc - load from the own weight of the strings and clips evenly

distributed along the length of the span is assumed to be 0.05 daN/m for each wire.

The main ways of the station and the haul:

1.1.2 Maximum wind mode

In this mode, the carrier cable is subjected to a vertical load from the weight of the contact suspension wires and a horizontal load from wind pressure on the carrier and contact wires (there is no ice). The wind of maximum intensity is observed at an air temperature of +. The vertical load from the weight of the catenary wires is defined above by formula (1.1).

The horizontal wind load on the carrier cable is determined by the formula:

where Cx - aerodynamic drag coefficient of the wire to the wind is determined according to the table p.105;

The coefficient taking into account the influence of local conditions, the location of the suspension on the wind speed, is determined according to table 19 p.104;

Normative wind speed of the greatest intensity, m/s; repeatability 1 time in 10 years is determined according to table 18 p.102;

d - diameter of the carrier cable, mm; p.33.

The horizontal wind load on the contact wire is determined by the formula:

where H is the height of the contact wire p.26.

Excavation up to 7 m deep:

Embankment with a height of more than 5 m:

The resulting (total) load on the support cable in daN/m is determined by the formula:

Excavation up to 7 m deep:

Straight section, curves of various radii:

Embankment with a height of more than 5 m:

When determining the resulting load on the contact wire, it will not be taken into account, because. mostly perceived by fixators.

1.1.3 Ice with wind

In this mode, the catenary wires are subjected to a vertical load from their own weight, the weight of ice and the horizontal load from wind pressure on the wires of the catenary, the wind speed in ice minus C, the vertical load from the dead weight of the catenary wires is defined above.

The vertical load from the weight of ice on the carrier cable daN/m is determined by the formula:

where - the overload factor can be taken: = 0.75 - for protected sections of the contact network (recess); 1 - for normal conditions of the contact network (station, curve); = 1.25 - for unprotected sections of the contact network (embankment);

Ice wall thickness on the carrier cable, mm

d - diameter of the carrier cable, mm; - 3.14.

The thickness of the ice wall on the carrier cable, mm, is determined by the formula:

where is the normative ice wall thickness, mm;

Coefficient taking into account the influence of the wire diameter on the deposition of ice p. 100 ;

Coefficient taking into account the influence of the height of the catenary suspension p. 100 .

For the main tracks of the station and the haul for the supporting cable M-95, we accept = 0.98.

For excavation with a depth of more than 5 m = 0.6.

For a straight section of the haul and curves of various radii = 0.8.

For an embankment over 5m = 1.1.

The vertical load from the weight of ice on the contact wire in daN/m is determined by the formula:

where is the thickness of the ice wall on the contact wire, mm; on the contact wire, the thickness of the ice wall is taken equal to 50% of the thickness of the ice on the carrier cable;

Average diameter of contact wire, mm

where H and A are the height and width of the cross section of the contact wire, respectively, mm.

Straight section and curves of various radii:

Excavation up to 7m deep:

Embankment with a height of more than 5m:

Straight section and curves of various radii:

Excavation up to 7 m deep:

Embankment with a height of more than 5 m:

The total vertical load from the weight of ice on catenary wires in daN/m is determined by the formula:

where is a uniform vertical load distributed along the length of the span from the weight of ice on strings and clamps with one contact wire, daN/m, which, depending on the thickness of the ice wall, is

Straight section of the haul and curves of various radii:

Excavation up to 7m deep:

Embankment with a height of more than 5m:

The horizontal wind load on the supporting cable covered with ice in daN/m is determined by the formula:

where is the standard wind speed with ice, m/s. = 13 m/s.

Excavation up to 7m deep:

Embankment with a height of more than 5m:

The horizontal wind load on a contact wire covered with ice in daN/m is determined by the formula:

Straight section and curves of various radii:

Excavation up to 7m deep:

Embankment with a height of more than 5m:

The resulting (total) load on the support cable in daN/m is determined by the formula:

Straight section and curves of various radii:

Excavation up to 7m deep:

Embankment with a height of more than 5m:

1.1.4 Selecting the initial design mode

The results of calculating the loads acting on the wires of the contact suspension are summarized in Table 1.1; Comparing the loads of different modes (mode of minimum temperatures, maximum wind and wind with ice), we determine the mode for subsequent calculations.

Table 1.1

Loads acting on catenary, in daN

terrain

Loads acting on contact suspension

p.u. (curve)

As a result of the calculations, it was found that the resulting load in the maximum wind mode is greater than the load in the wind with ice, based on this, we accept the design mode - wind.

1.2 Determination of span lengths on straight and curved track sections

Rules for the device and technical operation of the contact network of electrified railways (TsE-868). It is recommended to carry out span lengths according to the condition of current collection no more than 70 m.

The span length for a straight section of the track is determined by the formula:

On curves:

Finally, we determine the span length, taking into account the specific equivalent load according to the formulas:

On curves:

where K is the nominal tension of the contact wires, daN;

Maximum allowable horizontal deviation

contact wires; from the axis of the pantograph in the span; - on straight lines and - on curves;

a - zigzag of the contact wire, - on straight lines and - on curves;

The elastic deflection of the support, m, is taken from the table at the corresponding wind speed;

where h is the design height of the suspension;

g 0 - load on the carrier cable from the weight of all wires of the chain suspension;

T 0 - the tension of the carrier cable with a weightless position of the contact wire.

The specific equivalent load, taking into account the interaction of the carrier cable and the contact wire with their wind deflection, daN / m, is determined by the formula:

where T is the tension of the contact suspension carrier cable in the design mode, daN;

The length of the suspension garland of insulators, m, the length of the garland of insulators can be taken: 0.16 m (length of the earring and saddle) with insulated consoles; 0.56 m with two suspension insulators in a garland, 0.73 m with three, 0.90 m with four insulators;

Span length, m

Finally, we determine the span length, taking into account the specific equivalent load:

Straight stretch:

Excavation up to 7m deep:

Embankment with a height of more than 5m:

Curve with a radius of 1300 m:

We take the span length equal to 45m.

Curve with a radius of 2000 m:

Further calculations will be summarized in Table 1.2.

Table 1.2

Span lengths on straight and curved track sections

1.3 Development and justification of the power supply scheme and sectioning of the contact network of the station and adjacent hauls

1.3.1 Drawing up a power supply and sectioning of the contact network

The contact network of the electrified section is divided into separate sections, electrically independent of each other, to ensure reliable operation and ease of maintenance. Sectioning is carried out by insulating mates of anchor sections, sectional insulators, sectional disconnectors, mortise sectionalizing insulators.

Longitudinal sectioning provides for the separation of the contact network of the station from the contact network of hauls along each main track.

Longitudinal sectioning is carried out by four-span and three-span insulating mates, which are located between the input signal and the extreme turnout.

On the insulating mates, longitudinal sectional disconnectors that shunt them are installed, indicated by the capital letters of the Russian alphabet: A, B, C, D.

Transverse sectioning between the tracks is carried out by sectional insulators, transverse disconnectors and mortise insulators in the fixing cables of the transverse and in the non-working branches of contact suspensions. Transverse disconnectors connecting contact suspensions of different sections of stations are designated by the letter "P".

The connection of contact suspensions of tracks, where work is carried out near the contact network, is performed by sectional disconnectors with grounding knives; denoted by the letter "Z".

Modern requirements provide for the use of remote and remote control of sectional disconnectors, therefore linear, longitudinal and transverse disconnectors should be designed with motor drives.

The power supply of the contact network from the traction substation is carried out by supply lines (feeders), usually overhead. They feed on feeders: even paths F2, F4; odd F1, F3, F5.

On double-track sections of direct current, the power supply of the line extending from the traction substation to the contact network of hauls is designed separately for each track. The feeder line feeding the station tracks is allocated separately. In the supply lines of the DC contact network, linear disconnectors are arranged at the points of their connection to the contact network.

Power line disconnectors are designated "Ф" with digital indices.

The power supply circuit of the station sectioning is shown in Figure 1.1.

Figure 1.1 Scheme of power supply and sectioning of the contact network of the station

1.4 Tracing of the contact network of the haul

tracing contact networks haul

Plans for the contact network of the haul are drawn on a scale of 1: 2000 on graph paper. The required length of the sheet is determined based on the given length of the stage, taking into account the scale and the necessary margin on the right side of the drawing for the placement of general data and the title block.

The plan of the contact network of the stage is drawn in the following sequence:

Preliminary breakdown of the haul into anchor sections. The arrangement of supports on the stage begins with the transfer to the plan of the stage of the supports of the insulating interface. The location of these supports on the haul plan should be linked to their location on the station plan. Linkage is carried out according to the input signal, which is also indicated on the station plan;

Basting of the anchor sections of the contact network, the approximate location of their junctions. In the middle of the anchor sections, the places of medium anchorings are marked, where it is subsequently necessary to reduce the length of the spans.

When planning the anchor sections of the suspension, it is necessary to proceed from the following considerations:

The number of anchor sections on the stage should be minimal;

The maximum length of the anchor section of the contact wire on a straight line is assumed to be no more than 1600m;

Next, the arrangement of supports on the stage. The arrangement of supports is made by spans, if possible, equal to those allowed for the corresponding area of ​​the terrain, obtained as a result of calculating the span lengths. Spans with medium anchorings must be shortened when compensated: two spans by 5% of the maximum design length for the respective terrain;

Processing of the flight plan. Having completed the arrangement of supports and zigzags of the contact wire, the final breakdown of the contact network of the haul into anchor sections is made and their mates are drawn.

Figure 1.2 shows the catenary passage in artificial structures.

Figure 1.2 Catenary passage in artificial structures

1.5 Selection of support structures

The selection of typical supporting and fixing devices is carried out when designing a contact network by linking the developed structures to the specific conditions of their installation.

The project used uninsulated channel brackets No. 5 (NR-II-5). Channel consoles are marked NR (non-insulated with extended rod) and NS (non-insulated with compressed rod).

The selection of consoles in various installation conditions is carried out in accordance with the tables developed in the Transelectroproject for areas with a standard ice wall thickness of up to 20 mm inclusive and with a wind speed of up to 35 m/s with a recurrence of climatic loads at least once every 10 years.

The selection of typical non-insulated and insulated consoles for AC and DC lines is performed depending on the type of supports and their installation location. In addition, for direct current lines on straight sections of the track, it is necessary to take into account the dimension of the installation of anchor supports.

Typical brackets are designed metal and wood. Wires of DPR lines are suspended on metal, reinforcing, supplying, suction and reverse current wires (in areas with suction transformers). Wires of overhead lines 6 and 10 kV with voltage up to 1000 V and wave guides are fixed on wooden brackets.

Attachments and racks are used in cases where the height of the supports is insufficient to install the required bracket, and also if it is required to place wires above a rigid crossbar.

Extensions and racks are selected depending on the purpose, if necessary, they are checked for specific loads.

Rigid typical beam-type crossbeams are through trusses of rectangular section, consisting of separate blocks. Diagonal grating: directed in vertical planes and non-directional in horizontal. Crossbars in the usual design, intended for areas with design temperatures up to -40C, are made of VSt3ps6 steel of the 1st and 2nd strength groups. The crossbars are completed from two, three or four blocks, depending on the length of the calculated span. The joints of the blocks of crossbars in the usual version are welded, in the northern version they are bolted. Marking of blocks of crossbars in the usual version - BK (extreme), BS (middle), in the northern version - BKS, BSS. The serial number of the block is added to the letter designation through the dash, for example, BKS-29.

Typical articulated clamps developed at Transelectroproject are selected depending on the type of consoles and their installation location, and for transitional supports, taking into account the location of the working and anchored branches of the suspension relative to the support. In addition, take into account which of them the latch is intended for.

In the designations of typical clamps, the letters F (retainer), P (direct), O (reverse) are used. The marking contains Roman numerals I, II, etc., characterizing the lengths of the main fixators. In the project, fixators of the FO-II, FP-III brands were used in the straight section of the haul and embankment, FP-IV and FO-V in the curved sections of the haul, in the excavation.

Contact network supports can be divided into two main groups: carriers, on which there are any supporting devices (consoles, brackets, rigid or flexible crossbars), and fixing ones, on which there are only fixing devices (clamps or fixing crossbars). In the first case, the supports perceive both vertical and horizontal loads, in the second - only horizontal ones.

Depending on the type of supporting device, there are cantilever bearing supports (with single-track or double-track consoles), rigid crossbar racks (single and twin) and flexible crossbar supports. Cantilever supports are usually divided into intermediate (one contact suspension is attached to them) and transitional, installed at the mates of the anchor sections and air arrows (two contact suspensions are attached to them).

In addition to loads in a plane perpendicular to the axis of the track, the supports can absorb forces from the anchoring of certain wires that create loads in a plane parallel to the axis of the track. In this case, the supports are called anchor. As a rule, contact network supports perform several functions at the same time, for example, a transitional cantilever support can be an anchor and, in addition, also support power wires.

For installation on newly electrified lines, CO-type supports are designed for DC sections. The supports fixed on the foundation were used - separate, which, when connected to the foundation of the TS type, become one-piece. Reinforced concrete supports - СС108.6-1, anchor - СС108.7-3, transitional - СС108.6-2. Supporting slabs of brand OP-2 were used in the project; Anchors type TA-1 and TA-3.

2 . Technological chapter

2.1 Maintenance of consoles

The console of the contact network support is a supporting device fixed on the support, consisting of a bracket in the rod. Depending on the number of overlapping tracks of the console, the support of the contact network can be one-, two- and multi-track. On domestic railways, single-track contact network support consoles are most often used, because with a larger number of contact network support consoles, the mechanical connection between contact suspensions of different tracks reduces the reliability of the contact network. Single-track consoles of the contact network support are used, uninsulated, or grounded, when the insulators are located between the carrier cable and the bracket, as well as in the latch rod, and insulated, with insulators placed in the brackets and rods. Uninsulated consoles of the contact network support (Figure 2. 1) can be curved, inclined and horizontal in shape.

Fig.2 1 Uninsulated console: 1 - carrying cable; 2 -- console thrust; 3 -- console bracket; 4 -- fixative insulator; 5 - latch; 6 carrier cable insulators

Previously, curved consoles of the contact network support were widely used. Inclined consoles of the contact network support are much lighter than curved ones and are more convenient to manufacture and transport. Brackets of inclined consoles of the contact network support are made from two channels or from pipes. The latches are attached to the console brackets through insulators. For supports installed with an increased dimension (5.7 m from the axis of the track), consoles with a strut are used. At the junctions of the anchor sections, when mounting two consoles on one support, the support of the contact network uses a special traverse. The horizontal consoles of the contact network support are used in cases where the height of the supports is sufficient to secure the traction.

With insulated consoles of the contact network support, it is possible to carry out work on the carrier cable near the consoles of the contact network support without disconnecting the voltage, which is unacceptable with non-isolated consoles of the contact network support. Isolated consoles are only inclined, with brackets, which include rod porcelain (console) insulators, and rods with rod insulators or garlands of disk insulators.

Console classification

Consoles are single-track and double-track (multi-track). Single-track consoles are of two types: inclined and straight - horizontal. The main advantage of an inclined console is that it requires a lower support height compared to a straight console, since with an inclined console, the rod is located horizontally and is attached to the support, approximately at the height of the carrier cable. The advantage of a straight console is that it allows a wider adjustment of the position of the carrier cable in the direction across the track and allows convenient placement of reinforcing wires on the same console.

The type of console that has received the most widespread use in our country. There is a horizontal overhang at the end of the console behind the point where the rod is attached to it, allowing you to adjust the position of the insulator in the direction across the track.

Consoles are usually made of two channels or angles fastened together at several points by welding or rivets. Channels or corners are located with a small gap between them, sufficient to accommodate the lug of thrust from the yoke for attaching the insulator. Consoles of tubular section and from I-beams can also be used. The console rod is made of round iron, and the regulation of the rod length during the installation of the console is carried out by means of the thread at the end of the rod.

A stepwise method of adjusting the length of the rod is also used by including between the rod and the part mounted on the support for its fastening adjusting strips made of flat iron with holes spaced at equal distances. On metal supports, the console and rod are attached to the corners fixed on the supports. The bracket for fastening the heel of the console has two welded segments of the angle with a hole for a stud with a head, through which the heel of the console is attached. The corner for attaching the rod has a through hole (in the case of fastening the rod on the thread) or is made in the same way as the corner for attaching the heel of the console (in the case of using adjusting strips). On wooden supports, the fastening part of the console heel is attached with capercaillie and has several holes for the possibility of adjusting the position of the console in height.

In areas equipped with compensated chain suspension, rotary consoles are used, usually tubular, hinged on supports.

When the supports are located on the inner side of the curve and on the transitional supports, instead of the reverse clamps, sometimes the reverse consoles are used, which have a vertical post that serves to fasten the clamp from the side opposite to the support. The purpose of the reverse consoles is the same as the reverse clamps. The use of reverse consoles has the disadvantage that, due to the location of the grounded parts close to the axis, the possibility of carrying out work under voltage near them is limited. On double-track and multi-track sections, if, due to the conditions of the terrain, it is impossible to place the suspension of each track on separate consoles, double-track consoles are sometimes used. Double-track consoles are usually supported by two rods and have a vertical stand along the axis between the tracks between the electrified tracks for attaching the second track retainer.

When a support with a double-track console is located on the inside of the curve, reverse double-track consoles are used. In addition to consoles for chain suspension, brackets for reinforcing wires, fixing brackets and corners for attaching wires anchored to the support are attached to the contact network supports. All these parts are mounted on wooden supports, usually with capercaillie or through bolts, on metal supports - with hook bolts.

Brackets for reinforcing wires and fixing brackets on newly mounted lines must be of such length that a distance of at least 0.8 m is maintained from the nearest edge of the support to live parts of the suspension

3. Economic section

3.1 Calculation of the cost of building a contact network on the stage

In the course project, it is necessary to estimate the cost of building a contact network on a stage or station. The initial data for the preparation of estimates for construction and installation work are specifications for contact network plans and prices for work.

We accept the exchange rate as of June 1, 2013 equal to 31.75.

The entire economic calculation is summarized in Table 3.1.

Table 3.1

Estimation of the cost of construction of a contact network on the stage

Name of work or costs	Units of measurement	Estimated cost c.u.	total amount
Construction works
Installation of reinforced concrete double supports in cup-type foundations, installed with a base plate by digging in at the station
Waterproofing of reinforced concrete supports
Installation of reinforced concrete anchors with braces by vibration immersion at the station and the stage
The cost of reinforced concrete supports type:
The cost of three-beam foundations of the type:
The cost of three-beam anchors type:
The cost of braces type:
The cost of tubular insulated galvanized consoles
The cost of embedded parts for mounting consoles	set
Minor unrecorded expenses
Overheads
The same for the installation of metal structures and their cost
Planned savings
Total costs:
Installation work
Rolling "on top" of the contact wire:
Solitary on the main roads
Contact suspension adjustment with two contact wires: elastic chain (spring)
Installation of one-sided rigid anchoring: carrying cable or single
Installation of one-sided compensated anchoring: contact wire
Installation of a combined compensated anchoring of a carrier cable and a single contact wire
Installation of a three-span interface of anchor sections without sectioning
Installation of the middle anchorage with compensated suspension
Installation of the first wire (reinforcing) on ​​suspension insulators, taking into account the installation of brackets and garlands of insulators
The cost of brackets type KF-6.5
Installation of the group ground wire
Installation of diode grounding
Installation of surge arrester and horn arrester
Small unaccounted works
Overheads
Planned savings
Total costs:
materials
Bimetallic wire BSM-1 with a diameter of 4 mm (strings)
Other materials not included in the price tag
Planned savings
Total costs:
Equipment
Disconnector RS3000/3.3-1U1/RSU-3000/3.3
Horn arresters with two gaps
Diode grounding ZD-1
Porcelain insulator with pestle PF-70V
Equipment charges
Total costs:
Cost cost:

4. Labor protection and traffic safety

4.1 Organizational and technical measures to ensure the safety of work on the contact network. Working conditions in the area of ​​the contact network

Works on the contact networks under tension

Work under voltage is carried out from isolated platforms for railcars and railcars, from removable insulating ladders. The peculiarity of these works is that the performer of the work is in direct contact with high voltage, so he must be reliably isolated from the ground and the possibility of touching grounded structures must be excluded.

Before work, they inspect the insulating parts of the towers, make sure that all parts are in good condition, wipe the stairs and insulators. Test the insulation with operating voltage directly from the contact network. To do this, after climbing to an isolated platform or ladder, without touching the contact network and being as far away from it as possible, touch one of the elements of the contact network under voltage (string, electrical connector or latch) with the hook of the shunt rod. It is not allowed for the shunt rod to approach the insulator at a distance of less than 1 m and touch the wire under significant mechanical load, since if the insulation of the tower or ladder fails, an arc occurs that can damage the insulator or cause the wire to burn.

After checking the insulation, the shunt rods are hung on the wires of the contact suspension and left in this position for the entire duration of the work. If movement occurs and it is necessary to temporarily remove the shunt rods, the worker, while on the site, should not touch the wires and structures.

A suspended shunt rod reliably controls the state of the insulation and equalizes the potential of all parts that are simultaneously touched by the worker. No more than three electricians can be and work at the same time on an isolated platform, and no more than two electricians can work on an insulating removable tower. They pass to the isolated sites one by one with the shunt rods removed. The insulating removable tower can be climbed by two electricians at the same time from both sides.

In contrast to work from towers, railcars and railcars, work from an insulating removable tower, as a rule, is performed, as a rule, without stopping the movement of trains. Therefore, in order to be able to remove it from the path in a timely manner, the team consists (depending on the weight of the tower) of at least four to five people, not counting the signalmen.

In sections with single-strand track chains, the tower is installed on the track in such a way that the wheel that is not isolated from its lower part is on the traction rail. When installing a removable tower on the ground, its lower part is connected to the traction rail with a grounding copper wire of the same cross section as the wire used for shunting.

They move an insulating tower, railcar or railcar when workers are on the work site only at the command of the work performer located there, who warns all his assistants working on the site to stop work and, making sure that they do not touch the wires, removes the shunt rods for the duration of the movement . The movement must be smooth at a speed of no more than 5 km / h for a removable tower and no more than 10 km / h for a railcar and a railcar.

Work under voltage is performed without the order of the energy manager, but with his permission. The energy dispatcher is informed of the place and nature of the work planned for execution, as well as the time of their completion.

If work is carried out in places of sectioning of the contact network (on an insulating junction, sectional insulator or mortise insulator separating two sections of the contact network), an order from the energy dispatcher is required. In this case, the sections must be shunted (the sectional disconnector is on), and the shunt rods are installed on the wires of both sections of the contact network. To equalize the potentials in sections and prevent the flow of equalizing current through the mounting devices at the work site, no more than one span between the supports, a removable shunt jumper made of copper flexible wire with a cross section of at least 50 mm 2 is installed.

Work under voltage is not allowed under pedestrian bridges, rigid crossbars and in other places where the distance to grounded structures or structures and wires under a different voltage is less than 0.8 m for direct current and 1 m for alternating current. Work under voltage during rain, fog and wet snow is not allowed, since in these conditions the leakage current through the insulating parts becomes dangerous. In order to avoid accidental overwhelm of wires and overturning of the detachable tower under voltage, they do not work at wind speeds above 12 m/s.

When working from insulating towers, it is prohibited to: leave tools and other objects on the working platform that may fall during the installation and removal of the tower; those working below to touch directly or through any objects to the removable tower above the grounded belt; carry out work in which forces are transmitted to the top of the tower, causing the danger of its overturning; move a removable tower on the ground while workers are on it.

In all cases, the manager and other employees strictly ensure that the possibility of shunting the insulating part of the tower or insulators of the isolated site with any objects (rods, wire, clamp, ladder, etc.) is excluded.

If it is necessary to climb onto a carrier cable and other wires, a light wooden ladder no more than 3 m long with hooks for hanging on a cable or wire is used. When working on a ladder, they are fixed to the cable with a safety belt sling.

Technical measures to ensure the safety of work under voltage

Technical measures to ensure the safety of work under voltage are:

- issuance of warnings for trains and fencing of the work site;

- performance of work only with the use of protective equipment;

- inclusion of disconnectors, imposition of stationary and portable shunt rods and jumpers;

- Illumination of the place of work in the dark.

When working in places of sectioning of the contact network under voltage (insulating interfaces of anchor sections, sectional insulators and mortise insulators), as well as when disconnecting loops of disconnectors, arresters, suction transformers from the contact network and installing inserts in the wires of the contact network, shunt rods installed on detachable insulating towers, insulating working platforms for railcars and railcars, as well as portable shunt rods and shunt jumpers.

The cross-sectional area of ​​copper flexible wires of these rods and jumpers must be at least 50 mm 2.

To connect the wires of different sections that ensure the transmission of traction current, it is necessary to use jumpers made of copper flexible wire with a cross-sectional area of ​​at least 70% of the cross-sectional area of ​​the connected wires.

When working on an insulating interface of anchor sections, on a sectional insulator separating two sections of the contact network, mortise insulators, sectional disconnectors shunting them should be switched on.

In all cases, a shunt jumper connecting the contact suspensions of adjacent sections must be installed at the place of work. The distance from the worker to this jumper should be no more than 1 mast span.

If the distance to the bypass sectional disconnector is more than 600 m, the cross-sectional area of ​​the bypass jumper at the work site must be at least 95 mm 2 for copper.

The technological process of a comprehensive inspection and repair of the console

Work on repair and inspection of the console is carried out with the removal of voltage from contact suspension directly from the support or using a 9 m ladder; with a rise to a height; without interruption in the movement of trains. According to the order, and the order of the energy manager. According to the technological map.

Comprehensive inspection and repair of the console

Table 4.1

Cast

Conditionsfulfillmentworks

The work is being done:

1. With stress relief contact suspension directly from the support or using a 9 m ladder; with a rise to a height; without interruption in the movement of trains.

2. According to the outfit, and the order of the energy manager.

3. Mechanisms, mounting devices, tools, protective equipment and signal accessories:

1. Ladder attached 9 m (when working on a conical reinforced concrete support) 1 pc.

2. Grounding rod according to the number specified in the order

3. Wrench 2 pcs.

3. Scraper 1 piece

4. "Fishing rod" rope 1 pc.

5. Pliers 1 pc.

6. Bench hammer 1 pc.

7. Indicator bracket or caliper with needle "sponges" 1 pc.

8. Writing pad with writing utensils 1 set

9. Dielectric gloves 1 pair.

10. Measuring ruler 1 pc.

11. Safety belt 2 pcs.

12. Protective helmet according to the number of performers.

13. Signal vest according to the number of performers.

14. Signal accessories 1 set

15. First aid kit 1 set

Table 4.2

Norm of time for one console In pers. h.

Types of jobs	When performing work
	directly	from a ladder
Comprehensive condition check and repair:
Single-track non-insulated console on an intermediate support
The same on the transitional support of the mates of the anchor sections
Knots of insulation of fasteners of elements of an insulated console on a support
- double-track console
Adjustment of the position of the console along the track with one support cable

Notes:

1. When adjusting the position of the console with hanging cables (wires) more than one. To the norm of time, add 0.15 people to each suspension point. hours when working from a support and 0.24 people. h - when working with a ladder.

2. When checking the condition and repairing a single-track cantilever with a strut, increase the time norm by 1.1 times, respectively.

3. When checking the condition and repairing a single-track non-insulated console with a reverse locking post, increase the time rate by 1.25 times, respectively.

preparatoryworkandadmissionwork

1. On the eve of work, submit to the energy dispatcher an application for work with stress relief in the work area, directly from a support or using a 9 m ladder, climbing to a height, without interrupting train traffic, indicating the time, place and nature of work.

2. Get a work order and briefing from the person who issued it.

3. In accordance with the results of detours and detours with inspection, diagnostic tests and measurements, select the necessary materials and parts to replace worn ones. Check by external inspection their condition, completeness, workmanship and protective coating, drive the threads on all threaded connections and apply a smear on it.

4. Select mounting devices, protective equipment, signal accessories and tools, check their serviceability and test dates. Load them, as well as selected materials and parts onto the vehicle, organize delivery together with the team to the place of work.

5. Upon arrival at the place of work, conduct a current safety briefing with a signature of everyone in the outfit.

6. Receive an order from the energy dispatcher indicating the removal of voltage in the work area, the start and end time of work.

7. Ground the de-energized wires and equipment with portable ground rods on both sides of the work site in accordance with the work order.

8. When working on a reinforced concrete conical support, install and fix a 9 m ladder on the support.

9. To carry out the admission to the production of works.

2.3 Sequential workflow

1. The performer should climb to the place of work directly on the support or on the ladder.

2. Visually check the condition of the attachment points of the heel and the drawbars of the console on the support, as well as the connections of the grounding descent to them. If there are embedded parts on a reinforced concrete support, check the condition of the insulating bushings.

At the interfaces of the anchor sections of the compensated suspension, check the position and fastening of the traverses on the support.

Pay attention to the provision of hinged mobility in the horizontal and vertical planes when moving the consoles.

3. Check the distance from the top of the reinforced concrete support to the cantilever tie rod clamp. It must be at least 200 mm. On a support with embedded parts, the rod must be attached to the part installed in the second hole.

4. Check, if present, the condition and attachment of the strut to the console bracket and support. The strut should be in a taut (compressed) state, slightly loaded. The point of attachment of the strut to the console bracket must be no more than 300 mm from the part for attaching the latch.

5. On insulated consoles, check the condition and repair the attachment points of the rods, struts and brackets of the console on the support (including traverses on the transitional supports of the anchor sections and insulators in these nodes).

Checking the remaining units and elements of the insulated console is carried out under voltage in the process of checking the condition and repairing the chain suspension, as well as non-insulating and insulating mates of the anchor sections, respectively, according to Technological maps No. 2.1.1, 2.1.2 and No. 2,2.1.

6. For a double-track console, check the correct assembly of the heel of the console, the presence of rollers (rivets) at the junction of the transition piece with the console bracket.

Check tension adjustment. Both rods must be loaded evenly, the tension is checked by vibration when hitting the guys with a metal object.

7. Check the correct installation of the console in a vertical plane. The trunk of the curved consoles and the bracket of the horizontal consoles must be horizontal.

Notes:

1. Check the condition, determine the extent of damage and the degree of their danger in accordance with the Guidelines for the maintenance and repair of the supporting structures of the contact set (K-146-96).

2. When checking the condition of all elements and their attachment points, identify the presence of damage: deformations, delaminations, cracks and corrosion of the metal.

Pay special attention to the condition of the welds, the presence of lock nuts and cotter pins, as well as the wear of the elements in the joints; will evaluate the condition of the protective anti-corrosion coating and determine the need for repainting.

Tighten loose fasteners, install the missing lock nuts, replace worn cotter pins and insulator locks (detail K-078), apply anti-corrosion grease to threaded connections.

Deformation or displacement of console elements and fasteners is not allowed

3. When checking the condition of the insulators, clean them from contamination. Insulators with persistent contamination of more than yj of the insulating surface or defects.

Endingworks

1. Disconnect the ladder from the support and lower it to the ground.

2. Remove ground rods.

3. Collect materials, mounting devices, tools, protective equipment and load them onto the vehicle.

4. Notify the energy dispatcher about the completion of work.

5. Return to the EChK production base.

Conclusion

In this graduation project, a mechanical calculation of the contact suspension M-95 + 2NlFO-100 was made. As a result of these calculations, data on the load on the wires from wind, ice and dead weight were obtained. Based on these data, the design mode of maximum wind was selected.

Based on the design mode, the span lengths on the stage were calculated: 55 m; 70 m; 56 m; 50 m; 66 m. According to the task for the diploma design, a plan of the contact network of the stage was built, in which equipment for the corresponding type of current was selected and summarized in the specification.

- An embankment with a height of more than 5 meters

Straight section of the haul and curves of various radii;

Excavation up to 7 meters deep;

In the economic section, the cost of structures on the contact network on the stage is calculated.

In the technological section, the issue is considered - dangerous places on the contact network.

In the labor protection section, technical measures are considered that ensure the safety of work under voltage

Completed: tracing co...

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