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Details and dimensions of the contact network. Contact network fittings. Pairing anchor sections

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console pin suspension network

Introduction

1. Theoretical section

1.1 Calculation of loads acting on catenary

1.2 Calculation of maximum permissible span lengths

1.4 Tracing the contact network of the stage

2. Technological section

2.1 Routine repair of consoles

3. Economic section

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

Conclusion

Bibliography

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 - 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 rolling stock through reliable, economical and environmentally friendly current collection in design weather conditions at established speeds, types of pantographs and values of transmitted current.

The main elements of a contact network with a catenary suspension are contact wires (contact wire, supporting 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 electric rolling stock and other current collection conditions; find the span lengths; choose the length of anchor sections, types of supports and supporting devices for hauls; develop contact network designs in artificial structures; place supports and draw up plans for the contact network at stations and stages with coordination of zigzags of wires and taking into account the implementation of overhead switches and sectioning elements of the contact network (insulating mates of anchor sections and neutral inserts, sectional insulators and disconnectors).

In recent years, the movement of heavy and long trains on the country's roads has been expanding, new high-power electric rolling stock has been put into operation, the speed of passenger and freight trains is increasing, and freight traffic is increasing.

This diploma project examines the design of a direct current contact network in order to gain skills in design, equipment selection, construction of installation curves and checking the condition, adjustment and repair of a sectional insulator.

1. Theoretical section

1.1 Calculation of loads acting on the suspension

From the 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 supporting 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 the loads on the supporting cable are determined.

1.1.1 Minimum temperature mode

The supporting 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 dead weight of 1 linear meter of wires in daN/m is determined by the formula:

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

n - number of contact wires;

gс - load from the own weight of strings and clamps uniformly

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

The main routes of the station and stage:

1.1.2 Maximum wind mode

In this mode, the supporting cable is subject to a vertical load from the weight of the catenary wires and a horizontal load from wind pressure on the supporting and contact wires (there is no ice). The wind of maximum intensity is observed at air temperature +. The vertical load from the weight of the catenary wires is determined above using formula (1.1).

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

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

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

Standard wind speed of greatest intensity, m/s; repeatability once every 10 years is determined according to table 18 p.102;

d - diameter of the supporting 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 more than 5 m high:

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 more than 5 m high:

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

1.1.3 Icy conditions with wind

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

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

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

Thickness of the ice wall on the supporting cable, mm.

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

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

where is the standard thickness of the ice wall, mm;

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

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

For the main tracks of the station and the section for the supporting cable M-95 we take =0.98.

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

For a straight stretch 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 assumed to be 50% of the thickness of the ice on the supporting cable;

Average diameter of contact wire, mm

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

Straight section and curves of different radii:

Excavation up to 7m deep:

Embankment more than 5m high:

Straight section and curves of different radii:

Excavation up to 7 m deep:

Embankment more than 5 m high:

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

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

Straight stretch and curves of various radii:

Excavation up to 7m deep:

Embankment more than 5m high:

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

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

Excavation up to 7m deep:

Embankment more than 5m high:

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 more than 5m high:

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

Straight section and curves of various radii:

Excavation up to 7m deep:

Embankment more than 5m high:

1.1.4 Selecting the initial design mode

The results of calculating the loads acting on the catenary wires are summarized in Table 1.1; By comparing the loads of different modes (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 area

Loads acting on catenary

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 and ice mode, based on this, we accept the design mode - wind.

1.2 Determination of span lengths on straight and curved sections of the track

Rules for the design and technical operation of the contact network of electrified railways (TsE-868). It is recommended that the span lengths for current collection be no more than 70 m.

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

On curves:

We finally determine the span length taking into account the specific equivalent load using the formulas:

On curves:

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

Maximum permissible 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 supporting cable from the weight of all wires of the chain suspension;

T 0 - tension of the supporting cable when the contact wire is in a weightless position.

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

where T is the tension of the catenary support cable in the design mode, daN;

Length of the hanging 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 suspended insulators in a garland, 0.73 m with three, 0.90 m with four insulators;

Span length, m.

We finally determine the span length taking into account the specific equivalent load:

Straight section:

Excavation up to 7m deep:

Embankment more than 5m high:

Curve with radius 1300 m:

We take the span length to be 45m.

Curve with radius 2000 m:

We summarize further calculations in Table 1.2.

Table 1.2

Span lengths on straight and curved sections of the track

1.3 Development and justification of the power supply and sectioning circuit for the contact network of the station and adjacent sections

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

To ensure reliable operation and ease of maintenance, the contact network of the electrified area is divided into separate sections, electrically independent of each other. Sectioning is carried out using insulating couplings of anchor sections, sectional insulators, sectional disconnectors, and mortise sectional insulators.

Longitudinal sectioning involves separating the station contact network from the railway contact network along each main track.

Longitudinal sectioning is carried out by four-span and three-span insulating interfaces, which are located between the input signal and the outer switch.

At the insulating junctions, longitudinal sectional disconnectors are installed that shunt them, designated by capital letters of the Russian alphabet: A, B, V, G.

Transverse sectioning between tracks is carried out by sectional insulators, transverse disconnectors and mortise insulators in transverse fixing cables and in non-working branches of contact suspensions. Transverse disconnectors connecting contact pendants 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 carried out using sectional disconnectors with grounding blades; denoted by the letter “Z”.

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

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

On double-track DC sections, the power supply of the lines extending from the traction substation to the overhead contact network of the sections 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 installed at the points of connection to the contact network.

Supply line disconnectors are designated “F” with digital indices.

The station partitioning power supply circuit is shown in Figure 1.1.

Figure 1.1 Power supply and sectioning diagram of the station contact network

1.4 Tracing the contact network of the stage

Tracing contact networks hauling

Plans for the overhead contact network are drawn at a scale of 1:2000 on graph paper. The required length of the sheet is determined based on the specified length of the section, 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 overhead contact network is drawn in the following sequence:

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

Marking the anchor sections of the contact network, the approximate location of their interfaces. In the middle of the anchor sections, places for medium anchors are marked, where it is subsequently necessary to reduce the span lengths.

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

The number of anchor sections on the stretch 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 1600 m;

Next is the placement of supports on the stretch. The placement of supports is carried out in spans, if possible equal to those allowed for the corresponding area of terrain, obtained as a result of calculations of span lengths. Spans with medium anchorages should be reduced when compensated: two spans by 5% of the maximum design length for the corresponding terrain area;

Processing the haul plan. Having arranged the supports and zigzags of the contact wire, the final breakdown of the contact network of the run is made into anchor sections and their connections are drawn.

Figure 1.2 shows the passage of overhead catenaries in artificial structures.

Figure 1.2 Catenary passage in artificial structures

1.5 Selection of support structures

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

Non-insulated channel consoles No. 5 (NR-II-5) were used in the project. Channel consoles are marked NR (non-insulated with tension 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 by Transelectroproject for areas with a standard ice wall thickness of up to 20 mm inclusive and with wind speeds of up to 35 m/s with climatic loads repeating at least once every 10 years.

The selection of standard non-insulated and insulated consoles for direct and alternating current lines is carried out depending on the type of supports and the location of their installation. In addition, for direct current lines on straight sections of the track, it is necessary to take into account the installation dimensions of anchor supports.

Typical brackets are made of metal and wood. The wires of the DPR lines, amplification, supply, suction and return current wires (in areas with suction transformers) are hung on metal ones. Wires of 6 and 10 kV overhead lines with voltages up to 1000 V and wave conductors are mounted on wooden brackets.

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

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

Rigid standard beam-type cross members are through trusses of rectangular cross-section, consisting of individual blocks. The grid is diagonal: directed in vertical planes and non-directional in horizontal ones. Conventional crossbars, intended for areas with design temperatures down to -40C, are made of VSt3ps6 steel of the 1st and 2nd strength groups. The crossbars are made up of two, three or four blocks depending on the length of the design span. The joints of the crossbar blocks in the usual version are welded, in the northern version they are bolted. Marking of crossbar blocks in the usual version is BK (outermost), BS (middle), in the northern version - BKS, BSS. TO letter designation The serial number of the block is added through a dash, for example BKS-29.

Typical articulated clamps developed at Transelectroproekt are selected depending on the type of consoles and their installation location, and for transition 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 (latch), P (direct), O (reverse) are used. The markings contain Roman numerals I, II, etc., characterizing the lengths of the main clamps. In the project, fasteners of the FO-II brand were used, FP-III - on the straight section of the haul and embankment, FP-IV and FO-V in curved sections of the haul, in the excavation.

Contact network supports can be divided into two main groups: load-bearing, which have any supporting devices (consoles, brackets, rigid or flexible crossbars), and fixing, which have 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 paired) and flexible crossbar supports. Cantilever supports are usually divided into intermediate (one contact pendant is attached to them) and transitional ones, installed at the junction of anchor sections and air switches (two contact pendants are attached to them).

In addition to loads in a plane perpendicular to the track axis, supports can absorb forces from anchoring certain wires that create loads in a plane parallel to the track axis. In this case, the supports are called anchor supports. As a rule, contact line supports perform several functions simultaneously, for example, a transition cantilever support can be an anchor support and, in addition, support supply wires.

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

2 . Technological chapter

2.1 Routine repair of consoles

The catenary support console is a supporting device fixed to the support, consisting of a bracket in the rods. Depending on the number of overlapped paths, the catenary support cantilever can be single-, double-, or multi-track. On domestic railways, single-track catenary support consoles are most often used, since with a larger number of catenary support consoles, the mechanical connection between the catenary suspensions of different tracks reduces the reliability of the contact network. Single-track catenary support consoles are used, non-insulated, or grounded, when the insulators are located between the supporting cable and the bracket, as well as in the clamp rod, and insulated, with the insulators located in the brackets and rods. Non-insulated consoles of the contact network support (Figure 2. 1) can be curved, inclined and horizontal in shape.

Figure.2 1 Non-insulated console: 1 -- support cable; 2 -- console thrust; 3 -- console bracket; 4 -- retaining insulator; 5 -- latch; 6 support cable insulators

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

With insulated catenary support consoles, it is possible to carry out work on the supporting cable near the catenary support consoles without disconnecting the voltage, which is unacceptable with non-insulated catenary support consoles. The absence of a garland of insulators on the console ensures greater stability of the position of the supporting cable, which is especially important at high train speeds. Insulated consoles are made only inclined, with brackets in which rod porcelain (cantilever) insulators are included, and rods with rod insulators or garlands of disc insulators.

Classification of consoles

Consoles are single-track and double-track (multi-track). Single-track consoles come in 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 mounted on a support, approximately at the height of the supporting cable. The advantage of a straight console is that it allows for wider adjustment of the position of the supporting cable in the direction across the track and allows you to conveniently place reinforcing wires on the same console.

The type of console that is most widely used in our country. At the end of the console, behind the place where the rod is attached to it, there is a horizontal overhang, which allows you to adjust the position of the insulator in the direction across the track.

Consoles are usually made from two channels or angles, fastened together at several points by welding or rivets. Channels or angles are located with a small gap between them, sufficient to accommodate the eye of the rod from the yoke for fastening the insulator. Cantilevers of tubular cross-section and I-beams can also be used. The console rod is made of round iron, and the length of the rod is adjusted when installing the console using the thread at the end of the rod.

A stepwise method is also used to regulate the length of the rod by inserting adjusting strips made of strip iron with holes located at equal distances between the rod and the part mounted on the support for fastening it. On metal supports, the console and rod are attached to the corners fixed to the supports. The corner for fastening the console heel has two welded sections of the corner with a hole for a pin with a head, through which the console heel is attached. The angle for fastening the rod has a through hole (in the case of fastening the rod on a thread) or is made in the same way as the corner for attaching the console heel (in the case of using adjustment strips). On wooden supports, the fastening part of the console heel is secured using wood grouse and has several holes to allow the height of the console to be adjusted.

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

When supports are located on the inside of the curve and on transition supports, instead of reverse clamps, reverse consoles are sometimes used, having a vertical post that serves to fasten the clamp on the side opposite to the support. The purpose of the reverse consoles is the same as that of the reverse clamps. The use of reverse consoles has the disadvantage that due to the location of grounded parts close to the path axis, the possibility of carrying out live work near them is limited. On double-track and multi-track sections, if due to terrain conditions 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 post along the axis between the electrified tracks for attaching the second track clamp.

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 the consoles for chain suspension, brackets for reinforcing wires, locking brackets and corners for fastening wires anchored to the support are attached to the contact network supports. All these parts are fastened on wooden supports, usually using wood grouse or through bolts, and on metal supports using hook bolts.

Brackets for reinforcing wires and fixing brackets on newly installed 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 constructing a contact network on the stretch

In the course project, the cost of constructing a contact network at a stretch or station should be assessed. The initial data for drawing up estimates for construction and installation work are the specifications for the contact network plans and the prices for the 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 constructing a contact network on the stretch

Name of work or costs	Units of measurement	Estimated cost c.u.	Total quantity

Construction works
Installation of reinforced concrete double supports in glass-type foundations, installed with a base plate by burying at the station
Waterproofing of reinforced concrete supports
Installation of reinforced concrete anchors with guys using vibration immersion at the station and stage
Cost of reinforced concrete supports:



Cost of three-beam foundations:

Cost of three-beam anchors:

Cost of guy lines:


Cost of tubular insulated galvanized consoles
Cost of embedded parts for attaching consoles	set

Small unaccounted expenses
Overheads
The same for the installation of metal structures and their cost
Planned savings
Total costs:
Installation work
Rolling out “on top” of the contact wire:
Single on main roads
Adjustment of contact suspension with two contact wires: chain elastic (spring)
Installation of one-sided rigid anchoring: supporting cable or single
Installation of one-sided compensated anchoring: contact wire
Installation of combined compensated anchorage of the support cable and a single contact wire
Installation of three-span anchor sections without sectioning
Installation of middle anchorage with compensated suspension
Installation of the first wire (reinforcing) on suspended insulators, taking into account the installation of brackets and garlands of insulators
Cost of brackets type KF-6.5
Installation of group grounding wire
Installation of a diode ground electrode
Installation of arrester and horn arrester

Minor unaccounted for work
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 breaks
Diode grounding switch ZD-1
Porcelain insulator with pestle PF-70V
Charges for equipment
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 contact network area

Works on contact networks under voltage

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

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

After checking the insulation, the shunt rods are hung on the catenary wires 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 wires or structures.

A suspended shunt rod reliably monitors the state of insulation and equalizes the potential of all parts touched by the worker at the same time. On an isolated site, no more than three electricians can be present and work at the same time on an isolated platform for railcars and railcars, and on an insulating removable tower - no more than two electricians. They move to isolated areas one by one with the shunt rods removed. Two electricians can climb onto the insulating removable tower simultaneously from both sides.

Unlike work from the towers of railcars and railcars, work from an insulating removable tower, as a rule, is carried out, 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 signalmen.

In areas with single-strand rail circuits, the tower is installed on the track in such a way that the wheel, not insulated 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.

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 during movement . 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 carried out without an order from the energy dispatcher, but with his permission. The energy dispatcher is informed of the location and nature of the work planned to be performed, as well as the time of its completion.

If work is carried out in places where the contact network is sectioned (at an insulating interface, a sectional insulator or a 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 turned on), and the shunt rods are installed on the wires of both sections of the contact network. To equalize the potentials across sections and prevent the flow of equalizing current through the mounting devices at the work site, install a removable shunt jumper made of flexible copper wire with a cross-section of at least 50 mm 2 between the supports no further than one span.

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 other voltages 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 under these conditions leakage current through the insulating parts becomes dangerous. To avoid accidental entanglement of wires and overturning of a removable tower under voltage, do not operate at wind speeds above 12 m/s.

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

In all cases, the manager and other employees strictly ensure that the possibility of bridging 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 supporting cable or other wires, use a light wooden ladder no more than 3 m long with hooks for hanging onto the cable or wire. When working on a ladder, they are secured to the cable with a safety belt.

Technical measures to ensure safety of work under voltage

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

- issuing warnings for trains and fencing work sites;

- performing work only with the use of protective equipment;

- turning on disconnectors, applying stationary and portable shunt rods and jumpers;

- illumination of the work place in the dark.

When working in areas where the contact network is sectioned under voltage (insulating junctions of anchor sections, sectional insulators and mortise insulators), as well as when disconnecting the loops of disconnectors, arresters, suction transformers from the contact network and installing inserts into the wires of the contact network, shunt rods installed on insulating removable towers, insulating working platforms of railcars and railcars, as well as portable shunting rods and shunting jumpers.

The cross-sectional area of copper flexible wires of the specified 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 flexible copper wire with a cross-sectional area of at least 70% of the cross-sectional area of the connected wires.

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

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

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

Technological process of comprehensive inspection and repair of the console

Repair and inspection work on the console is carried out by removing tension from catenary suspension directly from the support or using a 9 m extension ladder; with rise to height; without interruption in train traffic. According to the order, and the order of the energy dispatcher. According to the technological map.

Comprehensive console inspection and repair

Table 4.1

Cast

Conditionsexecutionworks

The work is being done:

1. With stress relieved catenary suspension directly from the support or using a 9 m extension ladder; with rise to height; without interruption in train traffic.

2. According to the order, and the order of the energy dispatcher.

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

1. Extension ladder 9 m (when working on a conical reinforced concrete support) 1 pc.

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

3. Wrench 2 pcs.

3. Scraper 1 piece

4. Rope “fishing rod” 1 pc.

5. Pliers 1 pc.

6. Bench hammer 1 pc.

7. Indicator bracket or caliper with needle jaws 1 pc.

8. Notepad for writing with writing materials 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

Standard time for one console Per person. h.

Types of jobs	When performing work
	directly	from the ladder
Comprehensive condition check and repair:
Single-track non-insulated console on an intermediate support
The same on the transition support of the anchor sections mates
Insulation units for fastening elements of an insulated console on a support
- double track console
Adjusting the console position along the path with one support cable

Notes:

1. When adjusting the position of the console with more than one hanging cables (wires). Add 0.15 people to the standard time for each suspension point. hours when working from a support and 0.24 people. h. - when working from an extension ladder.

2. When checking the condition and repairing a single-track console with a strut, increase the time standard by 1.1 times accordingly.

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

PreparatoryworkAndadmissionwork

1. On the eve of the work, submit an application to the energy dispatcher to carry out work with stress relief in the work area, directly from the support or using a 9 m extension ladder, with a rise to a height, without interruption in the movement of trains, indicating the time, place and nature of the work.

2. Receive a work order and instructions from the person who issued it.

3. In accordance with the results of walk-throughs and inspection tours, diagnostic tests and measurements, select the necessary materials and parts to replace worn ones. Check by external inspection their condition, completeness, quality of workmanship and protective coating, run the threads on all threaded connections and apply a smear to them.

4. Select installation devices, protective equipment, signal accessories and tools, check their serviceability and test timing. Load them, as well as selected materials and parts onto the vehicle, and 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 for 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 wires and equipment from which voltage has been removed using portable grounding 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 secure a 9 m extension ladder to the support.

9. Grant permission to carry out work.

2.3 Sequential process

1. The performer climbs to the place of work directly using a support or an extension ladder.

2. Check by external inspection the condition of the attachment points of the heel and the console rods 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 junctions of the anchor sections of the compensated suspension, check the position and fastening of the traverses on the support.

Pay attention to ensuring articulated 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 rod clamp. It must be at least 200 mm. On a support with embedded parts, the rod should be attached to the part installed in the second hole.

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

5. On isolated consoles, check the condition and repair the attachment points of the rods, struts and console brackets on the support (including cross-beams on the transition supports of anchor sections and insulators in these units).

Inspection of the remaining components and elements of the insulated console is carried out under voltage in the process of checking the condition and repair of the chain suspension, as well as non-insulating and insulating connections of the anchor sections, respectively, according to Technological maps No. 2.1.1, 2.1.2 and No. 2.2.1.

6. For a two-track console, check the correct assembly of the console heel and the presence of rollers (rivets) at the junction of the adapter part with the console bracket.

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

7. Check that the console is installed correctly in a vertical plane. The trunk of curved consoles and the bracket of horizontal consoles should be located horizontally.

Notes:

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

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

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

Tighten loose fasteners, install missing locknuts, replace worn cotter pins and insulator locks (part K-078), apply anti-corrosion lubricant to threaded connections.

Deformation or displacement of console elements and fastening parts 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 the ground rods.

3. Collect materials, installation 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 diploma project, a mechanical calculation of the overhead contact suspension M-95+2NlFO-100 was carried out. As a result of these calculations, data on the load on the wires from wind, ice and their own weight were obtained. Based on these data, the calculated maximum wind regime was selected.

Based on the design mode, the span lengths on the stretch were calculated: 55 m; 70 m; 56 m; 50 m; 66 m. According to the assignment for the diploma design, a plan of the overhead contact network of the section was constructed, in which equipment for the appropriate type of current was selected and compiled into a specification. A power supply and sectioning diagram for the section was drawn up. Calculations were carried out for the following terrain characteristics:

- An embankment more than 5 meters high

Straight stretch and curves of various radii;

Excavation up to 7 meters deep;

The economic section calculates the cost of structures on the contact network on the stretch.

The technological section discusses the issue of dangerous places on the contact network.

The occupational safety section discusses technical measures to ensure the safety of working under voltage.

Completed: circuit tracing...

List of CS products for electrified railways

Fasteners;
Brackets;
Consoles;
Guys;
Products on rigid crossbars;
Grounding nodes;
Products for installing disconnectors and surge arresters on metal and reinforced concrete supports;
KS units and parts for anchoring, fastening and fixing contact wires, spring and tension cables.

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

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

A set of devices for transmitting electricity from traction substations to EPS through current collectors. The contact network is part of the traction network and for electrified rail transport usually serves as its phase (for alternating current) or pole (for direct current); the other phase (or pole) is the rail network.
The contact network can be made with a contact rail or a catenary. Running rails were first used to transmit electricity to a moving carriage in 1876 by Russian engineer F.A. Pirotsky. The first catenary appeared in 1881 in Germany.
The main elements of a contact network with a catenary suspension (often called overhead) are contact network wires (contact wire, supporting cable, reinforcing wire, etc.), supports, supporting devices (consoles, flexible crossbars and rigid crossbars) and insulators. Contact networks with contact suspensions are classified: according to the type of electrified transport for which the contact network is intended - mainline, including high-speed, railway, tram and quarry transport, underground mine transport, etc.; by the type of current and rated voltage of the EPS powered from the contact network; on the placement of the contact suspension relative to the axis of the rail track - for the central (mainline railway transport) or lateral (industrial transport) current collection; by type of contact suspension - contact networks with simple, chain or special suspension; according to the features of implementation - contact networks of stages, stations, for arts, structures.
Unlike other power supply devices, the contact network does not have a reserve. Therefore, increased requirements are placed on the reliability of the contact network, taking into account which the design, construction and installation, maintenance of the contact network and repair of the contact network are carried out.
The choice of the total cross-sectional area of the contact network wires is usually carried out when designing a traction power supply system. All other issues are resolved using the contact network theory, an independent scientific discipline, the formation of which was largely facilitated by the work of Sov. scientist I.I. Vlasov. The design issues of the overhead contact network are based on: selection of the number and grades of its wires in accordance with the results of calculations of the traction power supply system, as well as traction calculations, selection of the type of contact suspension in accordance with the maximum speed of movement of the EPS and other current collection conditions; determination of the span length (mainly based on the condition of ensuring its wind resistance); selection of types of supports and supporting devices for hauls and stations; development of contact network designs in arts and structures; placement of supports and drawing up plans for the contact network of stations and stages with coordination of zigzags of wires and taking into account the implementation of air switches and elements of sectioning the contact network (insulating connections of anchor sections, sectional insulators and disconnectors). When choosing methods of construction and installation of the contact network during the electrification of railways, they strive to have the least possible impact on the transportation process while unconditionally ensuring high quality of work.
The main production enterprises for the construction of overhead contact networks are construction and installation trains and electrical installation trains. Organization and methods Maintenance and repair of the contact network are selected from the conditions of ensuring a given high level of reliability of the contact network at the lowest labor and material costs, labor safety of workers in the areas of the contact network, and the least possible impact on the organization of train traffic. Production, acceptance for the operation of the contact network is the distance of power supply.
The main dimensions (see figure) characterizing the placement of the contact network relative to other posts and railway devices. d., - height H of hanging the contact wire above the level of the top of the rail head;

The main elements of the contact network and the dimensions characterizing its placement relative to other permanent devices of the main railways: Pcs - contact network wires; O - contact network support; And - insulators.
distance A from live parts to grounded parts of structures and rolling stock; distance Г from the axis of the extreme track to the inner edge of the contact network supports at the level of the rail heads.
Improving the design of the contact network is aimed at increasing its reliability while reducing the cost of construction and operation. F.-b. Contact network supports and metal support foundations are made taking into account the electrocorrosive effect of stray currents on their fittings. Increasing the service life of the contact wire is achieved, as a rule, by using carbon contact inserts on current collectors.
During maintenance of contact networks on domestic railways. without stress relief, insulating removable towers and assembly railcars are used. The list of work performed under voltage has been expanded thanks to the use of double insulation on flexible crossbars, wire anchors and other elements of the contact network. Many control operations are carried out by means of their diagnostics, which are equipped in laboratory cars. The switching efficiency of sectional contact network disconnectors has increased significantly thanks to the use of telecontrol. The equipment of power supply distances with specialized mechanisms and machines for repairing contact networks (for example, for digging pits and installing supports) is increasing.
Increasing the reliability of contact networks is facilitated by the use of ice melting methods developed in our country, including without interruption of train traffic, electrical repellent protection, wind-resistant diamond-shaped contact suspension, etc. To determine the number of areas of contact networks and the boundaries of service areas, the concepts of operational length and deployed the length of electrified tracks, equal to the sum of the lengths of all anchor sections of contact networks within specified limits. On domestic railways, the developed length of electrified tracks is an accounting indicator for regions of the electrical system, power supply distances, road sections, and is more than 2.5 times greater than the operational length. Determination of the need for materials for the repair and maintenance needs of contact networks is carried out along its expanded length.

A contact network is a special power transmission line that serves to supply electrical energy to electric rolling stock. Its specific feature is that it must provide current collection to moving electric locomotives. The second specific feature of the contact network is that it cannot have a reserve. This places increased demands on the reliability of its operation.
The contact network consists of a catenary track suspension, contact network supports, and devices supporting and fixing the contact network wires in space. In turn, the contact suspension is formed by a system of wires - a support cable and contact wires. For a DC traction system there are usually two contact wires in the hanger and one for an AC traction system. In Fig. Figure 6 shows a general view of the contact network.

The traction substation supplies electric rolling stock with electricity through the contact network. Depending on the connection of the overhead contact network with traction substations and between contact suspensions of other tracks of a multi-track section within the boundaries of a separate inter-substation zone, the following schemes are distinguished: a) separate two-way;

Rice. 1. General view of the contact network

b) nodal; c) parallel.

A)

V)
Rice. 2. Basic power supply circuits for track overhead contacts a) – separate; b) – nodal; c) – parallel. PPS - points for parallel connection of contact suspensions of different tracks; PS – sectioning post; TP – traction substation

Separate two-way circuit - a catenary power supply circuit in which energy is supplied to the contact network from both sides (adjacent traction substations operate in parallel on the traction network), but the contact pendants are not electrically connected to each other within the boundaries of the inter-substation zone. The scope of application of such a scheme is the power supply of sections of an electric railway with short intersubstation zones and relatively uniform power consumption in directions.
Nodal diagram is a diagram that differs from the previous one in the presence of an electrical connection between track suspensions. Such communication is carried out using so-called catenary network sectioning posts. The technical equipment of the contact network sectioning posts allows, if necessary, to eliminate not only the transverse connection between track suspensions, but also the longitudinal one, dividing the contact network within the boundaries of the intersubstation zone into separate electrically unconnected sections. This significantly increases the reliability of the traction power supply system. On the other hand, the presence of a node in normal modes allows for more efficient use of contact networks of tracks for transmitting electrical energy to electric rolling stock, which provides significant energy savings in case of uneven power consumption across directions. Consequently, the scope of application of such a suspension is sections of an electric railway with extended inter-substation zones and significant unevenness of power consumption in directions.
A parallel circuit is a circuit that differs from a nodal circuit in a large number of electrical nodes between the overhead contacts of the tracks. It is used when there is even greater unevenness in electricity consumption along the tracks. This scheme is especially effective when driving heavy trains.

Contact network devices

CS is a complex system consisting of many devices. Each of them performs its own individual function. According to the functionality, the requirements for individual elements of the CS also differ. General requirements refer to mandatory serviceability, compliance with quality and safety standards.

CS devices usually include: all supporting and supporting structures that are designed to ensure a reliable and stable position of the leading current elements of the CS, organized by the suspension method; parts for fastening and fixing the CS along the supports of the CS or overhead lines on individual overhead line supports; supporting and auxiliary cables of different designs and different purposes depending on the design requirements of the compressor station; the KS wires themselves, which represent the main wire (it is called the contact wire), as well as wires for other purposes - reinforcing, suction, power supply, auto-blocking power supply. devices, power supply, etc.

In the process of work, almost all elements of the CS are influenced by various factors. The largest share of this influence comes from natural environmental factors. Throughout its entire working life, the CS is in the open air, therefore it is constantly exposed to the influence of precipitation, wind, sudden changes in temperature, ice conditions, etc. All these conditions negatively affect the state of the CS and its operation, causing a change in the lengths of the wires, the occurrence of sparking phenomena, and electric current. arcs, the phenomenon of corrosion for supports and other metal elements. It is not possible to completely get rid of these phenomena, however, it is possible to improve the network’s resistance to the external environment using various technical and technological methods, as well as the use of resistant and reliable materials in construction.

The compressor station must provide maximum resistance to external environmental factors, and, moreover, ensure uninterrupted movement of EPS along a line with established standards for weight, speed, schedule and interval between trains passing one after another.

Particular attention should be paid to the stability and reliability of the CS also because, unlike other power supply lines, it does not provide for a reserve. That is, this means that if any of the elements of the CS fails, this will lead to a complete shutdown of the line. It will be possible to resume the movement of rolling stock only after the necessary repair work has been carried out and supply has been restored.

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

Contact network design

When designing a contact network (CN), 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 movement of the EPS and other current collection conditions; find the span lengths (mainly 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; place supports and draw up plans for the contact network at stations and stages with coordination of zigzags of wires and taking into account the implementation of overhead switches and sectioning elements of the contact network (insulating mates 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 Г from the axis of the outer track 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 protected from the electrocorrosive effects of stray currents on their reinforcement. Increasing the service life of contact wires is achieved, as a rule, by using inserts on pantographs with high antifriction properties (carbon, including metal-containing, metal-ceramic, etc.), choosing a rational design of pantographs, as well as optimizing current collection modes.
To increase the reliability of the contact network, ice is melted, incl. without interruption of train traffic; wind-resistant contact pendants are used, etc. The efficiency of work on the contact network is facilitated by the use of telecontrol for remote switching of sectional disconnectors.

Wire anchoring

Anchoring of wires is the attachment of catenary wires 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 a given tension.

In the middle of the catenary anchor section, a middle anchorage is performed (Fig. 8.17), which prevents unwanted longitudinal movements towards one of the anchors and allows you to limit the area of damage to the catenary when one of its wires breaks. The middle anchorage cable is attached to the contact wire and the supporting cable with appropriate fittings.

Wire Strain Compensation

Compensation of wire tension (automatic regulation) 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-load compensator, consisting of a load and several blocks (pulley hoist), through which the load is connected to the anchored wire. The most widely used is the three-block compensator (Fig. 8.18), in which a fixed block is fixed to a support, and two movable ones are inserted into loops formed by a cable carrying a load and fixed at the other end in the stream of a 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 rated tension (a 1:4 gear ratio is provided), but the movement of the load is twice as large as that of a two-6-lobe compensator (with one moving block).

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

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

Contact wire clamp

Contact wire clamp – a device for fixing the position of the contact wire in a horizontal plane relative to the axis of the pantograph. 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.
A non-articulated clamp has one rod that pulls the contact wire from the axis of the pantograph to the support (extended clamp) or from the support (compressed clamp) by a zigzag size. On electrified railways non-articulated clamps are used very rarely (in anchored branches of a catenary suspension, on some air switches), since the “hard point” formed with these clamps on the contact wire impairs current collection.

The articulated clamp consists of three elements: the main rod, the stand and an additional rod, at the end of which the contact wire fixing clamp is attached (Fig. 8.20). The weight of the main rod is not transferred to the contact wire, and it only takes part of the weight of the additional rod with a fixing clip. The rods are shaped to ensure reliable passage of the pantographs when they press 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 stand. On the outer side of curves of small radii, flexible clamps are mounted in the form of a conventional additional rod, which is attached to a bracket, rack or directly to a support through a cable and an insulator. On flexible and rigid crossbars with fixing cables, strip fasteners are usually used (similar to an additional rod), hingedly secured with clamps with an eye mounted on the fixing cable. On rigid crossbars, you can also attach clamps to special racks.

Anchor section

Anchoring section is a section of a catenary suspension, the boundaries of which are anchor supports. Dividing 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 area in the event of a break in the catenary wires, facilitates installation, technical. contact network maintenance and repair. The length of the anchor section is limited by permissible deviations from the nominal tension value of the catenary wires set by the compensators.
Deviations are caused by changes in the position of strings, clamps and consoles. For example, at speeds up to 160 km/h maximum length the anchor section with bilateral 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 of the curve and the smaller its radius. To transition from one anchor section to the next, non-insulating and insulating connections are made.

Pairing anchor sections

Conjugation of anchor sections is a functional combination of two adjacent anchor sections of a catenary system, ensuring a satisfactory transition of EPS pantographs from one of them to another without disturbing the current collection mode due to the appropriate placement in the same (transition) spans of the contact network of the end of one anchor section and the beginning of the other. A distinction is made between non-insulating (without electrical sectioning of the contact network) and insulating (with sectioning).
Non-insulating connections are made in all cases where it is necessary to include compensators in the catenary wires. In this case, mechanical independence of the anchor sections is achieved. Such connections are installed in three (Fig. 8.21, a) and less often in two spans. On high-speed highways, connections are sometimes carried out in 4-5 spans due to higher requirements for the quality of current collection. Non-insulating interfaces have longitudinal electrical connectors, the cross-sectional area of which must be equivalent to the cross-sectional area of the overhead wires.

Insulating interfaces are used when it is necessary to section the contact network, when, in addition to the mechanical one, it is necessary to ensure the electrical independence of the mating sections. Such connections are arranged with neutral inserts (sections of the catenary where there is normally no voltage) and without them. In the latter case, three or four span connections are usually used, placing the contact wires of the mating sections in the middle span(s) 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 transition 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 coupling. However, when the pantograph is in the middle span, the electrical independence of the anchor sections is compromised. If such a violation is unacceptable, neutral inserts of different lengths are used. It is chosen in such a way that when several pantographs of one train are raised, the simultaneous blocking of both air gaps is excluded, which would lead to the short circuit of wires powered from different phases and under different voltages. To avoid burning out the contact wire of the EPS, coupling with the neutral insert takes place on the run-out, for which purpose a signal sign “Turn off the current” is installed 50 m before the start of the insertion, and after the end of the insertion for electric locomotive traction after 50 m and for 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 to the EPS are required. To make it possible to derail the train when it is forced to stop under the neutral insert, sectional disconnectors are provided to temporarily supply voltage to the neutral insert from the direction of train movement.

Sectioning of the contact network

Sectioning of a contact network is the division of a contact network into separate sections (sections), electrically separated by insulating connections of anchor sections or sectional insulators. The insulation may be broken during the passage of the EPS pantograph along the section interface; if such a short circuit is unacceptable (when adjacent sections are powered from different phases or 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 reliable operation of power supply devices in general, prompt maintenance and repair of the contact network with voltage cutoff. The sectioning scheme provides for such a mutual arrangement of sections in which the disconnection of one of them has the least impact on the organization of train traffic.
Sectioning of the contact network can be longitudinal or transverse. With longitudinal sectioning, the contact network of each main track is divided along the electrified line at all traction substations and sectioning posts. The contact network of stages, substations, sidings and passing points is divided into separate longitudinal sections. At large stations with several electrified parks or groups of tracks, the contact network of each park or groups of tracks forms independent longitudinal sections. At very large stations, the contact network of one or both necks is sometimes separated into separate sections. The contact network is also sectioned in long tunnels and on some bridges with traffic below. With transverse sectioning, the contact network of each of the main paths is divided 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 EPS, when it is necessary to use the cross-sectional area of the overhead catenaries of adjacent tracks.
Sectioning with mandatory grounding of the disconnected section of the contact network is provided for tracks on which there may be people on the roofs of cars or locomotives, or tracks near which lifting and transport mechanisms operate (loading and unloading, equipment tracks, etc.). To ensure greater safety for those working in these places, the corresponding sections of the contact network are connected to other sections by sectional disconnectors with grounding blades; these knives ground the disconnected sections when the disconnectors are turned off.

In Fig. Figure 8.22 shows an example of a power supply and sectioning circuit for a station located on a double-track section of a line electrified with alternating current. The diagram shows seven sections - four on the hauls and three at the station (one of them with mandatory grounding when it is turned off). The contact network of the tracks of the left section and the station receives power from one phase of the power system, and the tracks of the right section - from the other. Accordingly, sectioning was carried out 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 manually operated sectional disconnector is sufficient.

To section the contact network of the main and lateral networks at 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 not sufficient to accommodate insulating connections.
The connection and disconnection of various sections of the contact network, as well as connection to the supply lines, is carried out using sectional disconnectors. On AC lines, as a rule, horizontal-rotating type disconnectors are used, on DC lines - vertical-cutting type. The disconnector is controlled remotely from consoles installed in the duty station of the contact network area, in the premises of station duty officers 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, V, D; 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 paths for equipping and inspecting the roofing equipment of EPS, on the paths for loading and unloading cars, etc.), disconnectors with one grounding blade are installed.

Frog

Air switch - formed by the intersection of two overhead contacts above the switch; is designed to ensure 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 pantograph approaches the air needle, 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 intersection of contact wires above a single turnout is carried out with each wire shifted to the center from the track axes by 360-400 mm and located where the distance between the inner edges of the heads of the crosspiece connecting rails is 730-800 mm. At cross switches and at the so-called. At blind intersections, the wires cross over the center of the switch or intersection. Air gunners are usually fixed. To do this, clamps are installed on the supports to hold the contact wires in a given position. On station tracks (except for the main ones), switches can be made non-fixed if the wires above the switch are located in the position specified by adjusting the zigzags at the intermediate supports. The catenary strings located near the arrows must be double. Electrical contact between the catenary pendants forming the arrow is provided by an electrical connector installed at a distance of 2-2.5 m from the intersection on the arrow side. To increase reliability, switch designs with additional cross connections between the wires of both catenary pendants and sliding supporting double strings are used.

Catenary supports

Contact network supports are structures for fastening the supporting and fixing devices of the contact network, taking the load from its wires and other elements. Depending on the type of supporting device, supports are divided into cantilever (single-track and double-track); racks of rigid crossbars (single or paired); flexible crossbar supports; feeder (with brackets only for supply and suction wires). Supports that do not have supporting devices, but have fixing devices, are called fixing ones. Cantilever supports are divided into intermediate ones - for attaching one catenary suspension; transitional, installed at the junction of anchor sections, - for fastening two contact wires; anchor, absorbing the force from anchoring the wires. As a rule, supports perform several functions simultaneously. For example, the support of a flexible crossbar can be anchored, and consoles can be suspended from the racks of a rigid crossbar. Brackets for reinforcing and other wires can be attached to the support posts.
The supports are made of reinforced concrete, metal (steel) and wood. On domestic railways. d. they mainly use 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, due to their load-bearing capacity or size, it is impossible to use reinforced concrete ones (for example, in flexible crossbars), as well as on lines with high-speed traffic, where increased requirements are placed on the reliability of supporting structures. Wooden supports are used only as temporary supports.

For direct current sections, reinforced concrete supports are made with additional rod reinforcement located in the foundation part of the supports and designed to reduce damage to the support reinforcement by electrocorrosion caused by stray currents. Depending on the installation method, reinforced concrete supports and racks of rigid crossbars can be separated or non-separated, installed directly into the ground. The required stability of undivided supports in the ground is ensured by the upper beam or base plate. In most cases, undivided supports are used; separate ones are used when the stability of non-separated ones is insufficient, as well as in the presence of groundwater, which makes it difficult to install non-separated supports. In reinforced concrete anchor supports, guys are used, which are installed along the track at an angle of 45° and attached to the reinforced concrete anchors. Reinforced concrete foundations in the above-ground part have a glass 1.2 m deep, into which supports are installed and then the cavity of the glass is sealed with cement mortar. To deepen foundations and supports into the ground, the method of vibration immersion is mainly used.
The metal supports of flexible crossbars are usually made of a tetrahedral pyramidal shape, their standard length is 15 and 20 m. Longitudinal vertical posts made of angle bars are connected by a triangular lattice, also made from angle iron. 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 cross beam 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 secure supports in rocky soils, heaving soils in areas of permafrost and deep seasonal freezing, in weak and swampy soils, etc., foundations of special structures are used.

Console

Console is a supporting device mounted on a support, consisting of a bracket and a rod. Depending on the number of overlapped paths, the console can be single-, double-, or less often multi-path. To eliminate the mechanical connection between catenaries of different tracks and increase reliability, single-track consoles are more often used. Non-insulated or grounded consoles are used, in which the insulators are located between the supporting cable and the bracket, as well as in the clamp rod, and insulated consoles with insulators located in the brackets and rods. Non-insulated consoles (Fig. 8.25) can be curved, inclined or horizontal in shape. For supports installed with increased dimensions, consoles with struts are used. At the junctions of anchor sections when installing 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 insulated consoles (Fig. 8.26), it is possible to carry out work on the supporting cable near them without disconnecting the voltage. The absence of insulators on non-insulated consoles ensures greater stability of the position of the supporting cable under various mechanical influences, which has a beneficial effect on the current collection process. The brackets and rods of the consoles are mounted on supports using heels that allow them to rotate along the track axis by 90° in both directions relative to the normal position.

Flexible crossbar

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

The fixing cables take up horizontal loads (the upper one is from the supporting cables of the chain hangers and other wires, the lower one is from the contact wires). Electrical insulation of cables from supports allows servicing the contact network without disconnecting the voltage. To regulate their length, all cables are secured to supports using threaded steel rods; in some countries, special dampers are used for this purpose, mainly for fastening contact suspension at stations.

Current collection

Current collection is the process of transferring electrical energy from a contact wire or contact rail to the electrical equipment of a moving or stationary EPS through a pantograph, providing sliding (on highway, industrial and most urban electric transport) or rolling (on some types of EPS of urban electric transport) electrical contact. Violation of contact during current collection leads to the occurrence of non-contact electric arc erosion, which results in intense wear of the contact wire and contact inserts of the current collector. When contact points are overloaded with current during movement, contact electrical explosion erosion (sparking) and increased wear of the contacting elements occur. Long-term overload of the contact with operating current or short-circuit current when the EPS is parked can lead to burnout of the contact wire. In all these cases, it is necessary to limit the lower limit of contact pressure for the given operating conditions. Excessive contact pressure, incl. as a result of the aerodynamic impact on the pantograph, an increase in the dynamic component and the resulting increase in the vertical deflection of the wire, especially at clamps, on air switches, 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 ensured by coordinated requirements for contact network devices and current collectors, which guarantees high reliability of their operation at minimal reduced costs.
The quality of current collection can be determined by various indicators (the number and duration of violations of mechanical contact on the calculated section of the track, the degree of stability of contact pressure close to the optimal value, the rate of wear of 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, research results and operating experience make it possible to identify the fundamental principles for creating current collection systems with the required properties.

Rigid cross member

Rigid crossbar - used for hanging overhead wires located above several (2-8) tracks. The rigid crossbar 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 connected either hingedly or rigidly using struts, allowing it to be unloaded in the middle of the span and reducing steel consumption. When placing lighting fixtures on the crossbar, a flooring with railings is made on it; provide a ladder for climbing to the supports for service personnel. Install rigid crossbars ch. arr. at stations and separate points.

Insulators

Insulators are devices for insulating live contact wires. Insulators are distinguished according to the direction of application of loads and the installation location - suspended, tensioned, retaining and cantilever; by design - disc and rod; by material - glass, porcelain and polymer; insulators also include insulating elements
Suspended insulators - porcelain and glass dish insulators - 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 supporting 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 securing the pipe. On AC lines, rod insulators are usually used, and on DC lines, disc insulators are also used. In the latter case, another disc-shaped insulator with an earring is included in the main rod of the articulated clamp. Cantilever porcelain rod insulators (Fig. 8.31) are installed in the 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 direct current lines, polymer insulating elements are used in the form of rectangular bars made of press material, and on alternating current lines - in the form of cylindrical fiberglass rods, on which electrical protective covers made of fluoroplastic pipes are put on. Polymer rod insulators with fiberglass cores and ribs made of organosilicon elastomer 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.

Catenary

The catenary is one of the main parts of the contact network; it is a system of wires, the relative arrangement of which, the method of mechanical connection, material and cross-section provide the necessary quality of current collection. The design of a catenary (CP) is determined by economic feasibility, operating conditions (maximum speed of movement of the EPS, maximum current drawn by pantographs), and climatic conditions. The need to ensure reliable current collection at increasing speeds and power of the EPS determined the trends in changes in suspension designs: first simple, then single with simple strings and more complex - spring single, double and special, in which, to ensure the required effect, Ch. arr. to level the vertical elasticity (or rigidity) of the suspension in the span, space-stayed systems with an additional cable or others are used.
At speeds of up to 50 km/h, 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. 8.10a) or transverse cables.

The quality of 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 wire’s own weight (in case of icy conditions along with ice) and wind load, as well as on the span length and tension of the wire. The quality of current collection is greatly influenced by angle a (the smaller it is, the worse quality current collection), contact pressure changes significantly, shock loads appear in the support zone, increased wear of the contact wire and current collector inserts occurs. Current collection in the support zone can be somewhat improved by hanging the wire at two points (Fig. 8.10.6), which under certain conditions ensures reliable current collection at speeds of up to 80 km/h. It is possible to significantly improve 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 hangers are used (Fig. 8.11), in which the contact wire is suspended from the supporting cable using strings. A suspension consisting of a support cable and a contact wire is called single; if there is an auxiliary wire between the support cable and the contact wire - double. In a chain suspension, the supporting cable and the auxiliary wire are involved in the transmission of traction current, so they are connected to the contact wire by 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 upward. The quality of current collection depends on the nature of the change in elasticity over the span: the more stable it is, the better the current collection. In simple and conventional chain hangers, the elasticity at mid-span is higher than that of the supports. Equalization of elasticity 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 rational arrangement of ordinary strings in the middle part of the span. Double suspensions have more constant elasticity, but they are more expensive and more complex. To obtain a high level of elasticity distribution uniformity in the span, use various ways its increase in the area of the support unit (installation of spring shock absorbers and elastic rods, torsion effect from twisting the cable, 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 catenary is an oscillating system, therefore, when interacting with pantographs, it can be in a state of resonance caused by the coincidence or multiple frequencies of its own oscillations and forced oscillations, determined by the speed of the pantograph along a span with a given length. If resonance phenomena occur, a noticeable deterioration in current collection is possible. The limit for current collection is the speed of propagation of mechanical waves along the suspension. If this speed is exceeded, the pantograph has to interact as if with a rigid, non-deformable system. Depending on the standardized specific tension of the suspension wires, this speed can be 320-340 km/h.
Simple and chain hangers consist of separate anchor sections. The suspension fastenings at the ends of the anchor sections can be rigid or compensated. On the main railways Mostly compensated and semi-compensated suspensions are used. In semi-compensated suspensions, compensators are present only in the contact wire, in compensated ones - also in the supporting cable. Moreover, 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 supporting cable, and therefore the vertical position of the contact wires, remains 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 supporting 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, insulating distances, especially in the area of artificial structures, etc.; in addition, a minimum inclination of the strings must be ensured at extreme values of ambient temperature, when noticeable longitudinal movements of the contact wire relative to the supporting cable may occur. For compensated suspensions, this is possible if the support cable and contact wire are made of different materials.
To increase the service life of the contact inserts of pantographs, the contact wire is placed in a zigzag plan. Various options for hanging the support cable are possible: in the same vertical planes as the contact wire (vertical suspension), along the axis of the track (semi-oblique suspension), with zigzags opposite to the zigzags of the contact wire (oblique suspension). The vertical suspension has less wind resistance, the oblique suspension has 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 supporting cable, are located at supports with opposite zigzags. In the middle parts of the spans, the wires are pulled together by rigid strips. In some suspensions, lateral stability is ensured by the use of two supporting cables, forming a kind of cable-stayed system in the horizontal plane.
Abroad, single chain suspensions are mainly used, including on high-speed sections - with spring wires, simple spaced support strings, as well as with supporting cables and contact wires with increased tension.

Contact wire

The contact wire is the most critical element of the contact suspension, directly making contact with the EPS pantographs during the current collection process. As a rule, one or two contact wires are used. Two wires are usually used when collecting currents of more than 1000 A. On domestic railways. d. 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 underwent some changes; in the beginning. 20th century the cross-section profile took the form with two longitudinal grooves in the upper part - the head, which serve to secure the contact network fittings to the wire. In domestic practice, the dimensions of the head (Fig. 8.12) are the same for different cross-sectional areas; in other countries, head sizes depend on 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 - shaped copper, 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. Bronze copper-cadmium wires have the best wear resistance (2-2.5 times higher than copper wire), but they are more expensive than copper wires, and their electrical resistance is higher. The feasibility of using a particular 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 highways. Of particular interest is the 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, contact wires wear out when collecting current. There are electrical and mechanical components of wear. To prevent wire breakage due to increased tensile stresses, the maximum wear value is normalized (for example, for a wire with a cross-sectional area of 100 mm, the permissible wear is 35 mm2); As wear on the wire increases, its tension is periodically reduced.
During operation, rupture of the contact wire can occur as a result of the thermal effect of electric current (arc) in the area of interaction with another device, i.e., as a result of burnout of the wire. Most often, contact wire burnouts occur in the following cases: above the current collectors of a stationary 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; when the contact resistance between the wire and the contact inserts of the pantograph increases; presence of ice; the closure of the pantograph skid of the different-nopothecial 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, which prevents the pantograph from rising under load and forcibly turns it off when lowered; equipment for insulating connections of anchor sections protective devices, contributing to extinguishing the arc in the area of its possible occurrence; timely measures to prevent ice deposits on wires, etc.

Support cable

Support cable - a chain suspension wire attached to the supporting devices of the contact network. A contact wire is suspended from the supporting cable using strings - directly or through an auxiliary cable.
On domestic railways. On the main tracks of lines electrified with direct current, copper wire with a cross-sectional area of 120 mm2 is mainly used as a supporting cable, and on the side tracks of stations, steel-copper wire (70 and 95 mm2) is used. Abroad, bronze and steel cables with a cross-section from 50 to 210 mm2 are also used on AC lines. The cable tension in a semi-compensated catenary varies depending on the ambient temperature in the range from 9 to 20 kN, in a compensated suspension depending on the type of wire - in the range of 10-30 kN.

String

A string is an element of a catenary chain, with the help of which one of its wires (usually a contact wire) is suspended from another - the supporting cable.
By design, they are distinguished: link strings, composed of two or more hingedly connected links of rigid wire; flexible strings made of flexible wire or nylon rope; hard - in the form of spacers between the wires, used much less frequently; loop - made of wire or 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. The most widely used are 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 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 for link and other connections, do not have this drawback. non-conducting strings. Sometimes non-conductive catenary strings made of nylon rope are used, the fastening of which requires transverse electrical connectors.
Sliding strings, capable of moving along one of the wires, are used in semi-compensated catenary pendants with a low structural height, when installing sectional insulators, in places where the supporting cable is anchored on artificial structures with limited vertical dimensions and in other special conditions.
Rigid strings are usually installed only on the overhead switches of the contact network, where they act as a limiter for the rise of the contact wire of one suspension relative to the wire of the other.

Reinforcing wire

Reinforcing wire - a wire electrically connected to the catenary, serving to reduce the overall electrical resistance 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 supporting cable. The reinforcing wire is used in areas of direct and alternating current. Reducing the inductive reactance of an AC contact network depends not only on the characteristics of the wire itself, but also on its placement relative to the overhead wires.
The use of reinforcing wire is provided for at the design stage; Typically, one or more A-185 type stranded wires are used.

Electrical connector

Electrical connector - a piece of wire with conductive fittings intended for electrical connection contact wires. There are transverse, longitudinal and bypass connectors. They are made from bare wires so that they do not interfere with the longitudinal movements of the catenary wires.
Transverse connectors are installed for parallel connection of all overhead wires of the same track (including reinforcing ones) and at catenary stations for several parallel tracks included in one section. Transverse connectors are mounted along the path at distances depending on the type of current and the proportion of the cross-section of the contact wires in the general 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 stations, connectors are placed in the places where the EPS starts and accelerates.
Longitudinal connectors are installed on the air switches between all the wires of the catenary pendants forming this switch, in the places where the anchor sections are coupled - on both sides for non-insulating joints and on one side for insulating joints and in other places.
Bypass connectors are used in cases where it is necessary to make up for the interrupted or reduced cross-section of the catenary suspension due to the presence of intermediate anchoring of reinforcing wires or when insulators are included in the supporting cable for passage through an artificial structure.

Catenary fittings

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

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Details and dimensions of the contact network. Contact network fittings. Pairing anchor sections

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2 . Technological chapter

2.1 Routine repair of consoles

Figure.2 1 Non-insulated console: 1 -- support cable; 2 -- console thrust; 3 -- console bracket; 4 -- retaining insulator; 5 -- latch; 6 support cable insulators

Classification of consoles

The type of console that is most widely used in our country. At the end of the console, behind the place where the rod is attached to it, there is a horizontal overhang, which allows you to adjust the position of the insulator in the direction across the track.

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

Brackets for reinforcing wires and fixing brackets on newly installed 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 constructing a contact network on the stretch

In the course project, the cost of constructing a contact network at a stretch or station should be assessed. The initial data for drawing up estimates for construction and installation work are the specifications for the contact network plans and the prices for the 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 constructing a contact network on the stretch

Disconnector

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 contact network area

Works on contact networks under voltage

After checking the insulation, the shunt rods are hung on the catenary wires 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 wires or structures.

Work under voltage is carried out without an order from the energy dispatcher, but with his permission. The energy dispatcher is informed of the location and nature of the work planned to be performed, as well as the time of its completion.

In all cases, the manager and other employees strictly ensure that the possibility of bridging 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 supporting cable or other wires, use a light wooden ladder no more than 3 m long with hooks for hanging onto the cable or wire. When working on a ladder, they are secured to the cable with a safety belt.

Technical measures to ensure safety of work under voltage

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

- issuing warnings for trains and fencing work sites;

- performing work only with the use of protective equipment;

- turning on disconnectors, applying stationary and portable shunt rods and jumpers;

- illumination of the work place in the dark.

The cross-sectional area of ​​copper flexible wires of the specified 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 flexible copper wire with a cross-sectional area of ​​at least 70% of the cross-sectional area of ​​the connected wires.

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

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

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

Technological process of comprehensive inspection and repair of the console

Comprehensive console inspection and repair

Table 4.1

Cast

Conditionsexecutionworks

The work is being done:

1. With stress relieved catenary suspension directly from the support or using a 9 m extension ladder; with rise to height; without interruption in train traffic.

2. According to the order, and the order of the energy dispatcher.

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

1. Extension ladder 9 m (when working on a conical reinforced concrete support) 1 pc.

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

3. Wrench 2 pcs.

3. Scraper 1 piece

4. Rope “fishing rod” 1 pc.

5. Pliers 1 pc.

6. Bench hammer 1 pc.

7. Indicator bracket or caliper with needle jaws 1 pc.

8. Notepad for writing with writing materials 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

Standard time for one console Per person. h.

directly

Notes:

1. When adjusting the position of the console with more than one hanging cables (wires). Add 0.15 people to the standard time for each suspension point. hours when working from a support and 0.24 people. h. - when working from an extension ladder.

2. When checking the condition and repairing a single-track console with a strut, increase the time standard by 1.1 times accordingly.

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

PreparatoryworkAndadmissionwork

2. Receive a work order and instructions from the person who issued it.

4. Select installation devices, protective equipment, signal accessories and tools, check their serviceability and test timing. Load them, as well as selected materials and parts onto the vehicle, and 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 for 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 wires and equipment from which voltage has been removed using portable grounding 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 secure a 9 m extension ladder to the support.

9. Grant permission to carry out work.

2.3 Sequential process

1. The performer climbs to the place of work directly using a support or an extension ladder.

2. Check by external inspection the condition of the attachment points of the heel and the console rods 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 junctions of the anchor sections of the compensated suspension, check the position and fastening of the traverses on the support.

Pay attention to ensuring articulated mobility in the horizontal and vertical planes when moving the consoles.

The cross-sectional area of copper flexible wires of the specified 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 flexible copper wire with a cross-sectional area of at least 70% of the cross-sectional area of the connected wires.

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