Grading stations
Docking stations for sections with different current systems
The docking of sections, one of which is with alternating current, and the other with direct current, occurs at precinct stations. At the station, the contact network is sectioned so that one part works on DC, the second - on a variable, and the third - has a double supply. At such stations, it is better to use a longitudinal type circuit, and then the neck on the side of the even direction operates on alternating current, and the neck on the side of the odd direction operates on direct current, and the central neck has a double supply.
Parallel passages between receiving parks make it possible to transfer locomotives between sections of parks with the simultaneous departure of trains. At such stations, it becomes more difficult to work with trains coming into disbandment from an odd direction, because a shunting locomotive must be sent behind them and moved through the entire station to the exhaust track for disbandment.
Grading stations designed for mass processing of wagons, re-formation of through, district, prefabricated and transfer trains.
Classification
1 Depending on the organization of car traffic:
Network - designed to form routes that must follow without processing through several passing SS located at a distance of 1500-2000 km;
Regional - form trains following the station of the section, desalted to the network SS and located at a distance of 300-400 km;
Auxiliary - serve local loading, unloading of manufacturing and mining enterprises.
2 Depending on the type of sorting devices:
SS with a high power slide;
SS with a slide of medium power;
SS with a slide of low power.
3 Depending on the number of sorting kits
(sorting kit is a kit that includes: reception park, slide, sorting park, departure park and transit section):
Unilateral SS;
Bilateral SS.
4 According to the relative position of the parks:
With a consistent arrangement of parks;
Combined location.
5 Depending on the locomotive depot:
With the main;
With turnover.
Figure 14 - Scheme of a marshalling yard with a sequential arrangement of parks
The reception park (Figure 14) is designed to receive trains entering the disbandment. Even-numbered trains are accepted on the path of the park to the lower section P2, following the bypass track. Odd trains to the upper section P1.
Train locomotives from the arrived trains go to the LH through the foothill mouth from odd trains or through the entrance throat from even trains. After appropriate processing in the PP, the hump locomotive drives along the free path to the tail of the train and performs thrust and dissolution.
The upper part of the tracks of the joint venture is specialized for odd car traffic, and the lower part for even.
The purpose of marshalling yards, the operations performed on them and the main devices
Sorting stations are intended mainly for the mass processing of car flows, i.e. disbanding and formation of freight trains in accordance with the current plan for the formation of trains. At sorting stations, transit and local car flows are processed, through, precinct, prefabricated and prefabricated trains are formed for adjacent lines, as well as export and transfer trains to the nearest freight stations of the hub and industrial stations, partial processing of cars is carried out with a change in the mass and length of the trains, selection (grouping) of wagons in the compositions of transfers to freight stations and non-public tracks, as well as in the compositions of prefabricated and other multi-group trains.
The formation of through trains at marshalling yards makes it possible to pass these trains without processing through precinct and some passing marshalling yards, which speeds up the delivery of goods, car turnover and reduces the cost of transportation. Sorting stations are the main strongholds for the organization of car traffic on the network railways. From successful work these stations depends on the rhythm of the work of entire directions and polygons of the network, as well as the fulfillment of the specified traffic sizes and operational indicators.
In addition to the organization of car flows, marshalling yards perform: maintenance and commercial inspection of transit freight trains and trains of their own formation; uncoupling repair of wagons; maintenance, equipment and repair of locomotives; change of locomotives and locomotive crews; maintenance of non-public roads. At a number of marshalling yards, sorting of goods and the formation of combined wagons with containers and small shipments, maintenance of refrigerated rolling stock, supply of trains with livestock with water, etc. are organized.
To perform the above operations at marshalling yards, there are parks for receiving trains entering processing, departure parks for formed trains, as well as separate tracks or parks for receiving, processing and sending transit trains. To perform sorting work, sorting parks, sorting yards and exhaust paths are being built. A complex of devices, including a park of reception, sorting and departure, together with a sorting hump and exhaust ways of forming, forms a sorting system (sorting kit).
The marshalling yards also house locomotive and wagon facilities, maintenance and repair bases for track distances, power supply and water supply, material warehouses, technical and service buildings, and, if necessary, sorting platforms for small shipments and container sorting sites, points for preparing wagons for transportation, points Maintenance and equipment for refrigerated wagons, devices for supplying wagons with livestock with water.
If marshalling yards are part of railway junctions with separate passenger and freight stations, then at the marshalling yards, passenger and freight operations are carried out in small volumes. For boarding and disembarking passengers, including station workers in commuter and local trains, passenger stopping points are arranged on the main tracks. Local loading and unloading operations are carried out mainly on separate tracks of the locomotive and wagon facilities and material warehouses. However, small marshalling yards may have approximately the same volume of passenger facilities as precinct yards.
Marshalling stations are equipped with devices for electrical interlocking of switches and signals, mechanized cleaning of switches, mechanized devices for automatic or semi-automatic action for securing rolling stock, means for inspecting cars in technical and commercial terms (industrial television installations, electronic clearance gates, electronic scales), devices for testing automatic brakes, transportation of wagon parts, for fencing trains on the tracks of technical inspection and uncoupled repair of wagons, modern means of communication, automated system management technological process station, within which the tasks of planning train formation, processing information about trains, calculating performance indicators, etc. are solved.
The design of the foothill park is determined by: the number of tracks, the scheme of the necks, the longitudinal profile. foothill park is designed on a horizontal platform with a three-element profile. It is allowed to have this park on the slope towards the hill on a slope of 1-1.5 %about. During the reconstruction of the station, the location of the foothill park at an elevation of up to 2% is allowed only in especially difficult local conditions with proper justification.
The longitudinal axes of the foothill and sorting parks are designed on the same straight line. Deviations from this rule are allowed only in difficult local conditions.
On fig. 5.24 shows a diagram of the combined fleet of receiving one-way stations in the presence of two approaches in the preferred direction (from B and G) and one general approach (from BUT and AT) in the non-dominant (even) direction, which may be adjacent to the foothill or to the inlet neck.
Sections of the park are specialized for receiving trains of odd and even directions, for maneuverability, congresses are laid in the necks, allowing you to receive trains from each approach to any section of the park. Entrance mouth of the park fis. 5.24) provides the following parallel operations:
Simultaneous reception of trains from two approaches (B and G);
Check-in of a hump locomotive on the path of the middle sections;
Cleaning the train locomotive from trains that arrived from BUT.
With two or more approaches to the park, the running track for hump locomotives is located in the middle of the park, and the dead end for these locomotives is between the main tracks in the neck.
In case of acceptance of transit corner trains B-G or G-B to the reception park from it it is necessary to arrange an exit to the main departure route.
Weekends(piedmont) reception park neck are among the busiest elements of marshalling yards. Their designs differ: depending on the number of thrust tracks, the location of exits for train locomotives and the presence of an adjoining approach for trains of a non-dominant direction.
In the scheme (see Fig. 5.24) there are two thrust paths and two descend paths. The exit to the track bypassing the hill can be given as a continuation of track 4. Train locomotives from arriving odd trains leave along track II.
In the scheme, the paths in the necks are sectioned and ramps are laid to perform parallel operations. The following parallel operations are performed in the neck:
Acceptance of trains from BUT or AT(on paths 9 and 10);
Thrusting of the train to the hump of the hill (along the paths 5a and 6a);
Dissolution of the composition;
Cleaning the train locomotive from trains that arrived from B and G on the way
4a, and then with the intersection of the overthrust paths cleaning into the locomotive facilities.
Reception Park Diagram two-way station due to the lack of approach of another direction is simplified.
To hump the neck of the marshalling yard is subject to the following requirements:
The neck should be as short as possible. For execution
this condition in the hump necks between the centers of turnouts
dove lay straight inserts of minimum length (with passing laying
4.50 m, with a counter it is allowed to lay without a direct insert), note
draw curves for minimum allowable radii of 200 and 180 m;
The paths should have approximately the same resistance. To complete
to overcome this condition, symmetrical arrows are used in the hump necks.
nye transfers of brand 1/6, the paths are combined into bundles of 4 ^ 8 paths in each;
Straight sections are allocated for laying brake retarders.
From the downhill tracks there should be an exit to all the tracks of the marshalling yard. To exit the foothill park to the sorting park, bypassing the mountains
ku (for wagons with dangerous goods that cannot be lowered from the hill), workarounds are laid connecting the receiving park with the extreme bundles of the marshalling yard. Laying detours makes it possible to remove locomotives from the marshalling yard after debarking (without delaying the dissolution of trains), to transfer individual groups of cars from the receiving yard to the yard bypassing the hill, and, if necessary, to receive trains directly on the tracks of the yard. On fig. 5.25 shows an example of a hump neck.
Cross section of subgrade for the sorting park, a sawtooth type is designed with the construction of drainage trays in wide inter-tracks (between bundles).
In the outlet (tail) neck marshalling yard (Fig. 5.26), from 2 to 4 exhaust tracks are laid, on which trains are formed from the accumulated cars. There must be no less than the number of operating locomotives on exhaust tracks. The design of the marshalling yard outlet mouth should provide an exit from any sorting yard track to any exhaust and at the same time allow shunting locomotives to work independently on the exhaust track, in addition, the necks should be compact (short).
To meet these requirements, the paths are combined into bundles that go to the exhaust path, this ensures the independence of work on the hoods. To ensure maneuverability, ramps are laid between the hoods, providing access from any sorting track to any exhaust track. To make the neck compact, between the centers of the switches
water I lay straight inserts of the minimum allowable length. The turnouts stack marks 1/9 in fig. 5.26, a and 1/6 in fig. 5.26, b.
The necks provide for the possibility of supplying train locomotives and departure of formed trains directly from the marshalling yard with minimal interruptions in shunting work.
With a large local car traffic for unloading, which requires grouping into cargo areas, as well as for the formation of a large number of multi-group trains, a low-power hump or an additional sorting and grouping park with a low-power hump can be built on one of the exhaust tracks.
departure park, located in series with the marshalling yard, it is designed from it, at a distance of about 400-500 m. This is necessary to ensure shunting work in the "tail" of the marshalling yard and the possibility of increasing the length and number of tracks in the sorting and dispatch yards. In the profile, the departure park is located on a platform or rise up to 1%o, and in a special difficult conditions when reorganizing the station - up to 2.5% o.
On fig. 5. 27 shows a diagram of the combined departure park of a one-way marshalling yard, in which four parks are combined:
Departure park for odd trains of their Oj formation;
Departure park for even-numbered trains of their formation О 2 ;
Fleet for reception and departure of odd transit trains Ύ χ ;
Park for the reception and departure of even transit trains T 2;
In the departure parks Oj and O 2, trains formed in the marshalling park are put up. Departure operations are performed with them (maintenance, uncoupled repair, commercial inspection). A train locomotive is fed along the running track, and after testing the auto brakes, the train leaves.
In parks transit Tj and T 2 transit trains are accepted, respectively even and odd. The train locomotive is removed, and then the same operations are performed as with the trains of their formation, put up in parks O] and O 2 from the marshalling park. Therefore, the paths of these parks can be interchangeable, i.e. if necessary, trains of their own formation can be rearranged to parks Tj and T 2, and transit trains can be received on the way of parks O ( and O 2 .
The united shipping fleet is divided into sections specialized in areas. External groups of tracks are transit parks of the corresponding directions. The necks of the parks are designed taking into account the interchangeability of the ways of departure of the formed trains and the ways of receiving transit ones. Therefore, it is possible to receive trains from the I main bypass track (from directions B and G) to the section Oj, from BUT and AT to section O 2 , and from the exhaust tracks of the formation, an exit is also arranged on the tracks for receiving transit trains Tj and T 2 . With a small number of transit trains, they are served in the departure park.
In the input the neck of the departure park, the following parallel operations are performed:
Reception of trains from B (G) to the park Tj;
Work on three exhaust ways;
Submission (cleaning) of a train locomotive from trains arriving from B and G
and going to BUT and AT;
Departure of trains B and G from park T 2 .
walking path for train locomotives at a two-way station it is located on the side of the park, and at a one-way station - between the departure parks.
At the outlet neck of the departure park the following operations are performed simultaneously:
Work on the hood 75 with the compositions of transit trains from the park Tj;
Departure of trains A (B) from Oj park;
Submission of a train locomotive from the locomotive economy to a dead end 16;
Reception of trains from BUT(B) to park T 2 .
On fig. 5.28 shows a diagram of a marshalling yard, which corresponds to circuit diagram shown in fig. 5.1.
Marshalling yards are divided into network and regional, serving certain areas. In order to concentrate sorting work at the most technically equipped stations, 10 network and 19 regional marshalling yards have been allocated to Russian Railways. Many marshalling yards in the future will be transferred to the category of district yards.
To perform work on the passage and processing of trains at marshalling yards, there are special track parks: the receiving (foothill) park P - for receiving trains and preparing them for disbandment; sorting (podgorochny) depot C - for the accumulation of wagons for the compositions of the departed trains; dispatch park O - to prepare for the departure of trains of their own formation; transit (acceptance-departure) park Tr - for receiving transit trains without processing and preparing them for departure. The receiving park, sorting hump, sorting park, exhaust ways of forming and sending park make up the sorting system, or sorting set.
With a large amount of local work at the station and adjacent sections, a grouping park with a low-power slide is also provided for the selection of cars into groups in the compositions of multi-group trains, transfers and deliveries to cargo points, or a sorting and grouping park for the accumulation and grouping of cars according to certain characteristics when they are repeated processing.
Marshalling yards are classified:
by departmental affiliation - at stations of the general network of railways of the Russian Federation, industrial, united;
according to the significance of their work for the railway network - into network and regional ones;
by the power of the main devices (productivity): at the station of increased power - more than 5500 cars, large - from 3500 to 5500, medium - from 1500 to 3500, small - up to 1500 cars; by the number of systems - into unilateral and bilateral;
according to the relative position of the main parks - with a sequential, combined and parallel arrangement;
according to the location of the main tracks and station track development - with an all-round, one-way and internal location of the main tracks.
At the marshalling yard, devices are designed that serve: freight traffic and perform sorting and grouping work, equipment, maintenance and repair of locomotives and wagons; passenger traffic (in nodes where it is not placed on parallel moves); special devices.
Requirements for track development and technical equipment
The track development and layout of the marshalling yard layout, its technical equipment are determined by the classification status of the station in conjunction with the selected operating technologies, the structure of car traffic, the features of the adjacent network and hub polygon, the climatic zone of location, the development prospects and other local conditions.
The choice of the type of a new or reconstructed marshalling yard is carried out on the basis of modeling the interrelated technological processes of operation of all its devices and is justified by technical and economic calculations.
When designing and choosing a marshalling yard scheme, the following are taken into account:
Projected size of work;
Conditions of staged development;
Requirements for the concentration of processing of car flows closer to the place of origin and at a smaller number of stations;
Rational distribution of technical equipment and work on the complete (and partial) processing (with the necessary grouping) of transit, local car traffic between the projected and other stations;
Interrelations between the parameters of the track development structure, turnouts and marshalling (sorting-grouping, grouping) parks, inter-park connections and the train formation plan;
Opportunities to achieve minimization of losses from hostile intersections of train and shunting routes and the costs of route interchanges in different levels and for parallel passages, minimization of waste operations with the perspective development of the station;
Economic losses on the alienation of land occupied for construction.
New marshalling yards at the first stage of construction are designed, as a rule, one-sided with a consistent arrangement of the combined main parks.
Track development, power of technical devices and their mutual placement at the station should ensure:
The throughput and processing capacity of the station required for the estimated time;
Compliance with the structure of the processed car flows and cargo flows;
The shortest time spent by wagons and trains under operations and runs of trains, wagons and locomotives with a minimum number of route crossings;
Minimum cost of railcar processing;
Safety of cargo and rolling stock personal safety of service personnel.
The projects of marshalling yards should provide for:
The device of an automated control system for the technological process of the station and centralized control of arrows and signals;
Sorting devices of appropriate capacity (hills, exhaust tracks), the type of which is determined depending on the size and nature of the processed car traffic for the tenth year of operation, with devices for automating and mechanizing the processes of shifting, disbanding and forming trains on the hills, and in the future - automatic disconnection of automatic couplers wagons. With a total load of exhaust paths of more than 0.6, a low-power slide should be provided on the formation exhaust path and specially stacked parks (grouping, sorting and grouping);
Devices for transporting wagon parts, as well as for fencing trains on tracks specialized for technical inspection of trains or uncoupled wagon repairs;
Means for technical and commercial inspection of wagons (industrial television installations, electronic clearance gates, electronic scales).
Sorting yards should be equipped with modern types and means of communication between control centers, individual parks, station workshops and performers.
Placement of the main devices As a rule, marshalling yards should have sequentially located combined, receiving, marshalling and dispatch parks. The design of the combined arrangement of parks is allowed in cramped conditions and with appropriate justification, as well as depending on the volume of sorting of cars, the length and weight of the formed, processed and passed trains.
A sorting system or station operating primarily for a hub, port, industrial area, and also in other cases, with appropriate justification, can be designed without a separate sorting park, providing for the departure of trains directly from the tracks of the sorting and departure park. In other cases, the sorting system must have a separate shipping fleet.
The foothill park, for receiving trains, is located, as a rule, on a horizontal platform with a three-element profile.
At the reconstructed stations, it is allowed to keep this park on the descent towards the hill, with a steepness of up to 1‰. Placing a foothill park on a slope with a slope of 1 to 2.5‰ or on an ascent with a slope of up to 2‰ is possible only at re-arranged marshalling yards, in particularly difficult local conditions, with proper justification. The tracks of the dispatch park are located on a site with a three-element profile or on an incline with a steepness of up to 1‰.
In particularly difficult local conditions, during the reconstruction of existing stations, the despatch fleet can be located on a descent or ascent with a steepness of up to 2.5‰.
Reception and departure parks for transit trains, depending on local conditions, are located: next to the departure park for trains of their own formation or parallel to the foothill parks with the possibility of using the latter to receive trains entering the disbandment and push the trains up the hill.
At one-way marshalling yards with humps of low and medium capacity, it is recommended to provide for the possibility of trains departing from the extreme (or the entire bundle of tracks) of the marshalling yard, bypassing the hump towards the sorting direction; at the same time, sorting tracks specialized for the departure of trains are equipped with appropriate wagon facilities.
At two-way marshalling yards, the transfer of corner flow wagons to the receiving depot of another system is ensured, if possible, directly from the tracks of the opposite marshalling depot.
The longitudinal axes of the foothill and sorting parks, as a rule, are designed on the same straight line.
At the new marshalling yards, the last switch of the marshalling yard and the first switch of the departure yard (if the yards are in series) are located at a distance of at least 400-500m from each other in order to ensure the possibility of increasing the number and length of the yard tracks in the future.
The main tracks within marshalling yards are usually designed to be inclusive. In some cases, depending on local conditions, one-sided location of the main tracks from the outside of the parks is allowed, with the construction (if necessary) of overpasses.
In the areas of the greatest location of station workers (hills, wagon and locomotive facilities), passenger stopping points (platforms near the main tracks) are arranged for their service, for the safe passage of people to whom tunnels or pedestrian bridges are being built through the station tracks.
Depending on the nature and volume of work, the locomotive and carriage facilities are located, as a rule, parallel to the foothill park.
The main outfitting devices are located in one place on the territory of the locomotive facilities.
At marshalling yards, devices and structures of the wagon economy are provided: maintenance points (PTO); mechanized point of current uncoupling repair; maintenance and equipment point for refrigerated trains and sections, as well as a maintenance point for autonomous refrigerated cars; car repair facility with an automatic brake control point (if necessary).
The maintenance point and equipment of refrigerated trains and sections, as well as the maintenance point for autonomous refrigerated cars (PTO ARV) with a one-way flow of perishable goods, is located with outside the corresponding transit fleet.
The tracks of the mechanized point for the current uncoupling repair of wagons are located next to the marshalling yard and are directly connected with the hump and outlet neck of the marshalling yard, and the tracks and devices of the wagon repair enterprise - with the marshalling yard and with mechanized points for the current uncoupling repair.
As a rule, two control posts are constructed to accommodate the duty personnel who carry out operational management of the operation of a one-way marshalling yard: a central one - in the area of the hill - and an output switch mouth of the marshalling yard (shunting area of \u200b\u200bformation).
At bilateral sorting yards, four hundred stations are provided, of which one is central.
The following jobs are located at the posts: at the central station - station and shunting dispatchers, duty officer for the reception and slide park, duty officer for the repair of locomotives in the depot, senior shift car foreman, employees of the station technology center for train information, train and transportation documents (STC), duty officer stations, employees of the signaling and communication service, employees servicing computer equipment; at the post in the outlet neck of the marshalling yard - duty officers for the formation area and for the dispatch yard.
The number of marshalling tracks in marshalling yard parks is set depending on the number of destinations according to the train formation plan, the daily number of cars for each destination, and the features of the station's train formation technology.
For each destination of the formation plan, as a rule, a separate sorting track is allocated, and for destinations with a daily car traffic of more than 200 cars - two tracks.
In addition, it is necessary to provide at least two tracks with a widened track between them, as well as between these and adjacent tracks, for cars arriving for repair (taking into account the transfer of labor-intensive repairs from the dispatch park); tracks for wagons arriving for unloading or loading; for wagons requiring sorting or reloading; for corner flow cars (at two-way stations); wagons with dangerous goods; wagons with valuable and nomenclature goods requiring departmental protection; to rearrange wagons while clearing tracks from snow and other local needs.
Tracks for wagons with dangerous goods must have through exits to the main tracks.
The useful length of the sorting track is determined equal to the length of the formed train, increased by at least 10‰ (not less than the length of the receiving and departing tracks), or the length of the group of cars, also increased by 10‰.
The marshalling yard is designed from several bundles, if necessary, with tracks of different lengths, depending on the type and length of trains for each destination being formed: single-group, multi-group, prefabricated, as well as deliveries to the local work points of the station.
The number of tracks in the receiving, departure and transit parks is determined for the estimated size of the movement of freight trains.
The required number of running tracks in the parks is determined depending on the layout of the station, the adopted technology and the given volume of train and shunting work.
The stations are provided with special ways for parking of snowplows, as well as dead ends for unloading snowplows and snow trains without leaving the haul.
In the switch mouths of the station parks, special rooms are being built for short-term rest and heating of the station workers (inspectors, locksmiths - car repairmen, electricians, switch cleaners).
Marshalling yards are designed for mass disbanding and formation of freight trains, i.e. for the processing of car traffic in significant volumes. Such stations are located in large points of origin and repayment of car traffic, which are divided into three categories: transit without processing, transit with processing, local.
Transit wagons without processing arrive at the station transit trains that are not subject to disbandment. Such trains are accepted on separate tracks of the departure park, where they undergo technical and commercial maintenance. At the same time, wagons are inspected, locomotive crews or locomotives are changed. With transit trains, if necessary, shunting work is carried out to uncouple faulty cars, change the weight and length of the train. The technology for handling transit trains at a sorting station does not differ from the procedure for servicing such trains at a section station (see clause 5.3.).
Transit with processing and local wagons arrive at the marshalling yard as part of dismantling (processing) trains, i.e. to be disbanded. Transit cars with processing are accumulated and formed into new trains according to the formation plan and sent to their destination. Local wagons, in addition, go through cargo operations, after which they are also sent to the appropriate destinations in the trains of their formation.
For the processing of these car flows marshalling stations have the appropriate track development, which is a sorting system (marshalling kit): arrival park; sorting hill; sorting (podgorochny) park, where the accumulation of cars and the formation of trains; departure park.
Depending on the volume of processing of car flows and local conditions, according to the design of the track development scheme, stations can be one-way and two-way with a serial, parallel arrangement of parks.
On fig. 6.1 shows a schematic diagram of the track development of a one-way marshalling yard. As follows from the scheme, transit trains of both directions are taken to the extreme tracks (T) of the departure park (O), where technical and commercial maintenance of the trains is carried out. Trains to be disbanded arrive from all directions to the arrival park (P), where train locomotives are uncoupled and cleaned, train preparation operations are performed for disbandment, and they are pushed onto the marshalling yard.
In the process of disbanding the trains from the hill in the marshalling yard (C), the accumulation of cars occurs according to the destinations of the formation plan. After the completion of the accumulation of wagons by the amount of the composition, the latter is formed and rearranged to the departure park (O), where the train is being prepared for departure.
The processing capacity of one-way marshalling yards reaches 6,000 wagons per day. For greater processing capacity, two-sided sorting stations are being built (Fig. 6.2). The advantage of such stations is the flow of operations with processed cars of both even and odd directions, high processing capacity, and a reduction in the mileage of cars in direct directions.
Marshalling yards are usually adjacent to three or more approaches, which causes the appearance corner wagon flows following on the lines adjacent to the station on the same side as the lines from which the wagons arrived. At one-way stations, such cars, when the train is disbanded, are immediately sent to the tracks of the piedmont park according to their specialization. At two-way stations, corner flow cars are first directed to a separate track in the marshalling yard of this system, then transferred to the arrivals yard of another system, where they are re-sorted according to their destinations. Therefore, the disadvantages of two-way marshalling yards include the appearance of a corner flow, due to which there is additional downtime, mileage and recycling.
Depending on the construction site and local conditions, other marshalling yard schemes may apply. If the construction site is not long enough, the departure park may be located parallel to the marshalling one. In this case, the flow in the processing of car flows is disrupted. In case of insufficient length and width of the construction site, the departure park may not be available. At the same time, the piedmont park is sorting and dispatching.