Supports contact network - structures for securing supporting and fixing devices contact network , perceiving the load from the wires. Depending on the type of the supporting device, the supports of the contact network are divided into cantilever (with single-track or double-track consoles), racks rigid cross bars (single or paired), supports flexible cross bars and feeder (with brackets only for supply and suction wires). Supports, on which there are no supporting ones, but there are fixing devices, are called fixing devices.
Reinforced concrete integral support of the contact network
Cantilevered supports are divided into intermediate supports - for attaching one contact suspension , transitional, installed on conjugations of anchor sections , - for fastening two contact pendants and anchoring, receiving forces from wire anchoring . As a rule, the contact network supports carry out several functions simultaneously. For example, the support of a flexible cross member can be anchored, consoles can be suspended on racks of a rigid cross member. On the supports of the contact network, brackets for reinforcing and other wires.
Supports of the contact network are made of reinforced concrete, metal (steel) and wooden. On domestic railways, mainly supports are made of prestressed reinforced concrete, conical centrifuged, with a standard length of 10.8; 13.6; 15.6 m. The metal supports of the contact network are usually installed in cases where it is impossible to use reinforced concrete (for example, in flexible cross-bars) according to the bearing capacity or the dimensions. Wooden supports The contact network is used in rare cases only as temporary. For sections of direct current, the reinforced concrete supports of the contact network are manufactured with additional rod reinforcement located in the foundation part of the supports designed to prolong their service life and to reduce damage to the reinforcement of the supports by electrocorrosion caused by stray currents.
Depending on the installation methods, the reinforced concrete supports of the contact network and the rack of rigid crossbars are separate, installed in glass reinforced concrete foundations, and inseparable, installed directly into the ground. The required stability of the undivided supports of the contact network in the ground is ensured by the installation of one upper leg or support plate.
In most cases unseparated supports are used; separate use for insufficient stability of the undivided supports, as well as in the presence of groundwater, which hinders the installation of inseparable supports of the contact network.
In the anchor reinforced concrete polesthe contact network uses pullers that are installed along the path at an angle of 45 ° and fixed to the anchors.
For separate supports of the contact network, reinforced concrete foundations and anchors are used. Foundations in the above-ground part have a glass 1.2 m deep for the installation of a support of the contact network in it, followed by sealing the sinuses of the glass with cement mortar. Foundations and anchors penetrate into the ground mainly by vibration vibration.
Metal supports of the contact network of flexible cross-bars are usually made of a four-sided pyramidal shape with a standard length of 15 and 20 m. The longitudinal vertical struts of the corner rolling are connected by a triangular grid made of a corner.
In areas with increased atmospheric corrosion, metal cantilever supports with a length of 9.6 and 11.6 m are installed. The fastening of metal supports in the ground is carried out on the foundations. Console support of the contact network is installed on prismatic or three-beam foundations, and the supports of flexible crossbars are fixed either on separate reinforced concrete blocks or on pile foundations with grillage. The bases of the metal supports of the contact network are connected to the foundations by anchor bolts.
To fix the supports in rocky soils, in the shallow soils of permafrost areas and deep seasonal freezing, in weak and waterlogged soils, etc., special foundation designs are used.
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Supporting constructions. To maintain the conductors of the contact network at a certain height and in the desired position with respect to the path, consoles are designed, flexible and rigid cross-members. The consoles are installed on the runways or on separate tracks of the stations. They provide mechanical independence of the operation of contact suspensions of different paths and are the most economical design of the listed ones. At stations and multi-track sections, rigid and flexible cross-members are installed, covering up to eight tracks. These designs link mechanically the contact suspension of various paths; if they are damaged, the work of all paths may be disrupted, which is a drawback of such structures.
Consoles are single-track, double-track and multi-track, and in shape - straight and inclined. Inclined consoles (Figure 91, a) can only be single-track. Their advantage is the need for a lower support height than with a straight console (Figure 91, b). Direct consoles are easier to manufacture, so when the height of the supports is sufficient, install them.
The isolated rotary arms are more convenient to use (Fig. 91, c), in which the insulators are embedded in the rod and into the hanger of the console. With such consoles, it is possible to perform work without relieving the voltage in the places where the chain suspension wires are attached to them. The height of the supports with isolated consoles is reduced. When the supports are placed on the inner side of the curve, the brackets with the reverse retaining posts are installed (Fig. 91, d). Consoles with a straight fixation post (dashed lines) are used on supports in recesses and behind cuvettes at a distance from the front edge of the supports to the track axis (dimensions) of 4.9 and 5.7 m. Two-way consoles (Figure 91, d) two rods and a securing pillar for securing the second path lock. Such consoles are installed on supports with a height of 13 m.
The consoles are made from angular or channel steel, and insulated from pipes. From the field side, on the supports, there are consoles on which the amplifying and feeding wires are suspended, 6 (10) kV long-distance power lines, DPR lines.
Fig. 91. Console construction schemes:
1 - support: 2 - console; 3 - retainer; 4 and 5 - console, respectively, with a straight and reverse rack; 6 - double-track console; 7 - fixing post
The consoles are denoted by letters: inclined non-insulated from two channels of HP (inclined, stretched pull rod) or НС (compressed thrust), from НТР pipe and НТС (tubular); isolated ITR or ITS (isolated), and from channels of IR or IS.
Flexible crossbars are a system of cables stretched between supports installed on both sides of the path (Figure 92). The transverse carrier cable 2 senses all vertical loads from the chain suspensions and the weight of the cross member. It is made of two, three or four cables: the breakage of one of them does not lead to the destruction of the crosspiece. The upper fixing cable 1 fixes the position of the supporting cable, and the lower fixing cable 6 - fixes the position of the chain conductor of the chain suspension relative to the axis of the path. 
Fig. 92. Flexible crosspiece (dimensions in parentheses for sections of direct current, without brackets for alternating current)
They perceive the horizontal loads acting on the wires from the wind, the breakage of the wires in the curves and the leads to the anchorage. The fixing of the contact wires is carried out by a lock fixed to the lower fixing cable. Depending on the number of overlapping paths, the height of the supports of the flexible cross-bars is 15 and 20 m. The transverse bearing cables are made of steel-copper wires of 70 and 95 mm2 cross-section, and fixing wires - 50 and 70 mm2.
In all cables at the supports are insulators 4, and in the bottom fixing on each side two insulators with a short inset 5 between them. These inserts, 1 m long, are connected by electrical connectors 3 with upper fixing and transverse supporting cables. As a result, a neutral insert 5 is formed, which, if necessary, can be attached to contact suspensions or grounded supports. This
connection allows you to carry out work without removing the voltage from the contact network on the suspension brackets, a flexible crossmember and wipe the insulators on it. To isolate the contact network in the lower fixing cable, an insulator 7 is cut into the corresponding inter-pathway. This insulated flexible cross member is used on roads where, because of the large traffic, it is not possible to remove the voltage from the contact network for repair work.
In some sections of the road uninsulated flexible cross-members are used, in which only the lower fixing cable is insulated. For the production of repair work on the upper fixing and transverse carrying cables, it is necessary to remove the voltage from the contact network, which is connected with stopping the movement of trains.
Rigid cross-pieces are metal trusses (crossbars) fixed on two racks located on both sides of the tracks (Figure 93). As the racks use the stringed conical supports, which are closed directly into the ground or installed on the foundations. 
Fig. 93. Rigid cross member:
1 - bolt; 2 - string; 3 - retainer
When anchoring wires on the racks of rigid crossbars, pullers are used along the path.
Fixing of the contact wires is carried out by the locks fixed on the fixing cable stretched between the posts, or for this purpose the fixing posts serve. To increase the number of overlapping paths on the racks, install one or two consoles.
The length of the crossbars is from 16.1 to 44.2 m and they are assembled from several blocks.
The crossbars are designated with the letter P with numbers. For example, P13-17.7 - the first figures indicate the bearing capacity of the cross-beam (in tons), the second - the calculated span (in m). Cross-bars with a length of more than 29.1 m, on which spotlights are installed to illuminate the station tracks, are designated OP29-ZOD
Rigid cross-bars are simpler in construction and economical compared to flexible cross-bars. However, with them it is impossible to check the condition of the hanging points of the carrier cable and to clean the insulators without removing the voltage from the contact network.
Supports of the contact network. According to the purpose and nature of the perceived loads, the supports are distinguished:
Intermediate, receiving load from the weight of the wires and horizontal forces from the wind;
Transitional, installed between the anchor supports at the junction points of the anchor sections and the supporting wires of these sections;
Anchoring, perceiving the full tension of the wires attached to them, the contact suspension;
Locking, which only perceive horizontal loads from the change in the direction of the wires and from the effect of the wind on them.
Depending on the type of supporting devices, there are cantilever supports and supports of rigid and flexible cross bars. Supports can be wooden, metal and reinforced concrete. Wooden supports were installed in the early years of the electrification of railways. The most common are reinforced concrete pillars, when using which significantly reduces the consumption of metal for the manufacture of poles. However, due to the large weight (1.5-2 tons) of the supports during their installation, cranes are necessary; During transportation and installation, they are often damaged; In addition, these supports on DC roads are subject to electrical corrosion.
Metal supports are installed in those cases where there are no suitable types of reinforced concrete supports, for example, for flexible crossbars at stations. It is convenient to mount various designs and parts to metal supports, their service life is 50 years, weight is 3-5 times less than that of reinforced concrete. However, the use of metal supports is associated with high costs of metal, and for protection against corrosion, they should be periodically painted. Metal supports are made of angular or channel steel. The most widely used lattice supports are from corners, which are used as cantilever, anchor and supports of flexible cross-bars.
Metal supports of flexible cross-bars have a height of 15-20 m. They are performed for various standard moments from 250 to 1500 kNm. Such supports can be simultaneously anchored. They are installed on reinforced concrete foundations and fixed with anchor bolts. The foundations are monolithic, block and pile.
Reinforced concrete poles are made of concrete 400 and 500, reinforced with prestressed reinforcement of steel wires (04-5 mm), types SKZ and SKTSo (stringed conical centrifuged). Supports with the index "o" - special, are designed for installation on roads of direct current with increased electrical corrosion. Supports SKZ and SKKo of the ring section (Fig. 94, a) are calculated for the standard bending moments of 45, 60, 80 and 100 kN-m. They are manufactured in length of 10.8 m and installed on foundations (detachable supports) and 13.6 m are installed directly into the ground (all-in-one). 
Fig. 94. Console reinforced concrete supports
In accordance with GOST 19330-73, the supports are designated SKZ-6,0-10,8 or SKTSo-8, 0-13,6 (8 tons, 13.6 meters long).
Supports have embedded parts for securing consoles and brackets. The type of supports is chosen based on the required strength, geometric dimensions, taking into account the economy.
On previously electrified roads, I-beam cross-sections of the SD type (string-concrete, I-beam) are installed (Fig. 94, b).
Stability of supports is provided by their fastening in the ground. The choice of the method of fixing depends on many conditions (such as the support, its load, the characteristics of the ground, the presence of space for the device of braces, struts, etc.). The fixing of supports according to the schemes (Fig. 95, a and c) is carried out with the installation of intermediate metal and reinforced concrete supports on the foundations. Powerful metal supports in weak soils are fixed as shown in Fig. 95, b, and heavy supports with a large external bending moment - according to the schemes in Fig. 95, d, d, e. In the schemes of Fig. 95, a, b, in the foundations work on the eversion, and in the schemes of Fig. 95, d, d, e 
Fig. 95. Supporting structures in the ground
there is an immersion in the ground of one and the eversion of another foundation when the external bending moment acts on the support. Ground reaction forces, shown by arrows, counteract external forces and hold the support in an upright position.
If the tipping moment is applied to the support and its limiting value, supported by the support, is equal to Mp, then the safety factor of resistance is k = Mp / M.
The value of Mp is determined by the moment of the reaction forces of the ground of the underground part of the support, and when the foundation is installed, the moment of the frictional forces of the soil about the foundation wall and the reaction forces of the ground on the basement base. For the supports of the contact network and foundations, the safety factor is assumed to be 2.5-3.
Contact network - a rather complicated design, electrified railways.
Supports of the contact network of railways, load the wires and installed auxiliary equipment. Designs that serve as fixers for fixing and supporting devices are part of the support. The network transmits electricity from the traction substations through current collectors. The current is fed through electrotechnical equipment , which for example is represented by the company "Electric supplies". The main components of the contact network are wires, reinforcing wire, carrying cable, brackets and latches, support devices, fittings, insulators.
The system, power supply of railways, is:
The external part (power plants, transformers, lifts, power lines), it raises and lowers the voltage;
Traction part (traction substations).
Stations, the contact network are divided into groups, isolated sections - this is a constant and alternating current, switchable sections.
Contact networks, depending on the purpose, are: anchor, console and fixing, intermediate.
By type of construction, the supports are classified into: one-piece (without foundation), separate and removable.
There are three types of railroad contact points:
Reinforced concrete;
Metal;
Wooden.
1. Reinforced concrete racks have found application in the design of the carrier carrying the main contact network on electrified railway sections. Used for: brackets, consoles and beams of rigid crossbars. Features of these structures is that these racks are made with the accuracy of the lateral surface, in the form of an annular section. With the use of longitudinal tension and transversely unstressed reinforcement, the frame is made. Racks are made with parallel holes, which are located at a distance and are determined by GOST, they also serve for mounting, bracket, console and ventilation. Racks with a foundation, in which there is a special steel shoe with appropriate mounting holes, are designed for anchoring. The support, which does not have additional fastening elements to the foundation, it can be installed in a drilled cylindrical pit. The underground surface of the product is protected by a special bituminous primer. On the side surface, a marking is applied, always indelible with a special paint. Materials and conditions of use, stands, are denoted by letters and numbers.
2. Metal supports are used as transitional, intermediate, anchor, cantilever elements and serve to distribute the load of the contact network in areas with alternating current. Such supports are used in the construction of lines of the contact network along the railways. Due to the hot galvanizing, the design carries a very significant power load and can last more than five years. GOST defines a marking, which consists of four symbols. These metal racks are used more often than ferro-concrete ones. This is explained by the fact that the installation speed is higher, because of the considerably lower weight, it is not necessary to use expensive cranes for installation, there are no problems of recycling, which also differs from reinforced concrete supports.
3. Wooden supports, they are designed as temporary.
Improvements in the poles, the contact network, is aimed at increasing its reliability, then the cost of operation and construction is reduced.
Reinforced concrete supports and foundations of metal supports are manufactured with protection from the electrocorrosive effect on their reinforcement, as there passes a stray current.