Driveway
In the railway sector , a route is a technically secured route for rail vehicles to travel over the railway tracks of a train station or the free route .
It is implemented through the use of key or interlockings . The signal dependency ensures that the signal belonging to the route at the beginning of the route (start signal) can only be set to travel if all the route elements in the route and in the slip path - z. B. Switches - are in the correct position and the route (including slip path) is free of vehicles. As soon as a track section (also called a train sequence section ) has been claimed by a route, it cannot be claimed by another route until it is canceled. However, this does not apply to slip paths as it is considered very unlikely that two trains will slip through at the same time. While a route is in existence, it is closed , which means that the movable route elements can no longer be repositioned until they are no longer required for the train journey. Only then can the route be resolved . In Central Europe, flank protection is also ensured for train routes . The stop position of the signal and the route resolution are brought about manually or automatically by the action of a train, depending on the interlocking technology. If a part of the route is occupied by another vehicle in the case of a relay or electronic interlocking , or if an edge protection condition is subsequently violated, the main signal at the beginning of the route stops. In the case of mechanical interlockings, this is not possible due to the system.
Route exclusion
Route exclusions are in place to protect enemy train journeys from one another. A hostile train journey is a train journey that can potentially endanger another train journey (the train journey to be protected). Such a hazard can exist in a following, opposite or flank travel.
In Central Europe, there are usually two types of route exclusions:
- Simple route exclusion
- It comes about automatically when two enemy routes have at least one route element - e.g. B. a switch - claim in different positions at the same time. Since in this case only one of the two routes can be created, this case does not have to be explicitly planned, but results from the interlocking logic. However, slip paths of different routes can overlap.
- Special route exclusion
- This exclusion is always configured manually and applies to all cases of route exclusions in which no route elements are required with different assignments. Typical cases are journeys in the opposite direction of the respective route or entries from different directions into the same station track, if it is not divided by train cover signals ( counter-run protection ). Other cases can arise when planning the interlocking and must be planned by hand and implemented in the interlocking logic.
Signal dependence
According to legal provisions such as Section 14 (9) of the German Railway Construction and Operating Regulations (EBO) or Section 11 (11) of the Austrian Railway Construction and Operation Ordinance (EisbBBV) , points that are used by trains towards the tip must be be dependent on the signals valid for the train journey in such a way that the signals can only be brought into the driving position when all switches for the route are correctly positioned and locked. However, this is not required for simpler conditions, in Germany for example not on branch lines if the speed there does not exceed 50 km / h . Remote turnouts, which are used by passenger trains against the tip, must also be secured against moving under the train or individually secured. Usually, the infrastructure operators go far beyond this requirement by including all points in the guideway as well as those that provide flank protection and those that are driven on from the top in slip paths. This task is carried out by the route closure (signal dependency part 1). Closed routes can be withdrawn without any auxiliary action that is required to be counted. An additional requirement for the signal release is the route definition. A defined route can only be resolved by the operator using the auxiliary resolution, which is subject to counting and verification, if the intended journey cannot take place. The route definition also switches on the operational termination criteria. A main signal that is in motion maintains the route closure even if the route is temporarily closed (signal dependency part 2). However, due to the principle involved, this is only important in the case of mechanical interlockings because of the signal lever that has to be moved manually.
In electronic interlocking, a is in the track on the tape start signal retaining monitoring detector (FÜM) furnished. This is square and can have three states: not available, flashing, idle light. As soon as a route has been set and is secured at shunting route level (i.e. still without side protection), the FÜM appears flashing. As soon as all the requirements for the train journey are met, the FÜM switches to idle.
In track diagram interlockings as well as in mechanical and electromechanical interlockings at points that are not visible to the attendant, a track vacancy detection system ensures that occupied points cannot be changed even if the route is not set.
For passenger trains, the EBO requires special edge protection measures , but only on branch lines if they are traveling faster than 50 km / h. In practice, the butt-used points are also included. An exception are points in the slip path, which would be stumped over by a slipping train ("bluntly slipped"). With these so-called control position switches, there is no lock.
On high-speed lines, side protection locks in all side tracks and additional cover signals must be set up for routes in main tracks .
These requirements of the EBO are usually far exceeded by the railway companies. Normally, all turnouts, not just those approaching the tip, and other devices are included in the signal dependency. In track diagram interlockings, safety devices at level crossings such as barriers, flashing lights or traffic lights are usually included in the signal dependency. In this case, the signal that allows travel can only be brought into a travel position when the level crossing is secured.
According to Deutsche Bahn's driving service regulations, the signal dependency is deemed to be canceled if a main signal can be set to travel,
- although the tongue or frog locks of points do not work properly;
- if the tongue monitoring devices such as tongue checkers or bolts do not work properly;
- if a control and safety technology specialist has declared the dependency to be lifted in the work and fault log;
- or if a replacement key is used instead of the original key for a key-dependent device.
The signal dependency is no longer valid if the fire alarm system is in the signaling rooms
- Relay room
- Anteroom to the relay room
- or power supply room
indicates a fire.
Flank protection
The flank protection protects train journeys from flanking and is implemented either directly by lying flank protection elements ( switches , track closures or signals ) in the neighboring tracks, which flow directly or via a switch connection into the route, or indirectly through operational regulations (maneuvering ban, parking ban).
Flank protection only occurs in train stations, as it only protects against parked vehicles and shunting trips. Alternate junctions are an exception, in which vehicles lock themselves in and then release the route again. The protection against hostile train movements is already carried out by route exclusions. This is why the lines at junctions that open into it have no safety switches.
The track sections between the track switches and their side protection elements form the side protection area. This must always remain free. If a track vacancy detection system in the flank protection area reports an occupancy or malfunction, the covering main signal falls into the stop position.
Which side protection measures have to be provided is determined within the framework of a standardized risk analysis. Direct flank protection is to be provided on tracks that are driven on at over 60 km / h. Flank protection is mandatory at speeds over 160 km / h. High-speed routes with overtaking tracks therefore always have safety switches.
Direct flank protection
Mandatory flank protection
Track closures and safety switches offer mandatory flank protection .
Safety points are set points that deflect dangerous journeys. Track barriers are used to protect from confluent tracks. If the track barrier is on the track, it will derail vehicles when driven over. Only sidings can be secured with track blocks. Track blocks may not be used on main tracks.
Side protection is not mandatory
Signals do not offer mandatory flank protection (so-called light protection ), as they require active human action.
Simple light protection is understood to be a single signal indicating a stop. If single light protection is not sufficient, double light protection must be provided. This means that two signals showing stop must follow one another (usually a main signal and a low-level blocking signal immediately in front of the switch) in order to ensure edge protection. The flank protection area to be kept free is limited to the area up to the signal adjacent to the route switch. This is intended to protect against unintentional vehicles driving past a stop signal. However, escaping cars cannot be stopped in this way. Technically, double light protection can be implemented in some relay interlockings and electronic interlockings as a shunting target block . If this is set up, no shunting route can be set for the corresponding signal if it is used as flank protection for a route.
Indirect flank protection
Maneuvering on tracks with a gradient of more than 4 ‰ and side protection that is not mandatory are considered hazardous maneuvering movements and are prohibited during the train journey. The same applies to maneuvering without direct flank protection.
Another possibility is parking bans. However, this means that tracks on which vehicles are scheduled to be parked cannot be recorded. Direct side protection measures are therefore to be provided for these tracks.
Route types
While in interlockings with old technology routes are usually only set up for train journeys, relay interlockings and electronic interlockings also have secured routes for shunting trips ( shunting routes ). In addition, relay interlockings offer a number of different levels for setting and securing routes. A distinction is made here between train and auxiliary routes.
Train routes have to meet higher safety criteria, so in shunting routes there is usually no track vacancy notification of the target track. Shunting must be possible on occupied tracks. Train and shunting routes that lead directly to their destination are referred to as regular train routes or regular shunting routes . If there are several routes between the start and the destination, routes can alternatively be created in modern track diagram interlockings , so-called bypass routes or bypass routes.
A train route for a train entering the station is called an entry route, and for an exiting train an exit route . Such train routes start at main signals . On multi-track railway lines , it is also possible, if necessary, for a train to enter from mainline tracks without an entry signal, i.e. when deviating from right -hand drive operation, an entry auxiliary train route , and an exit auxiliary train route for the exit from the station onto the left-hand track . In mechanical and electromechanical interlockings, the route levers in the opposite direction are used for this purpose, thrown to the auxiliary position and secured with an auxiliary lock. This simple procedure does not work with track diagram interlockings because the route would enter in the wrong direction until it was determined and would not resolve properly when traveling in the opposite direction. Therefore, auxiliary routes must be planned and set up separately in this case, provided routes into and out of the respective opposite track are not planned from the outset. However, if an auxiliary route is set, the main signal at the beginning remains in the stop position. In this case, the dispatcher gives his consent to the train journey with an additional signal or with a written order. On multi-track railway lines with track changing operations, there are full routes with appropriate signaling for entrances and exits to and from the opposite track .
A route normally begins at the signal that allows travel (start signal) and ends when entering a train station at the end of the slip path of the destination signal. This is an exit or intermediate signal when entering a through track, a blocking signal when entering a group of tracks, and at the buffer stop when entering a stub track . The target signal in this case is the signal Sh 2 (protective stop) or Sh 0. These signals are fixedly mounted on the respective buffer stop. The last variant was mainly used in terminal stations in the area of the former DR.
The slip path is part of the entrance road . It is included in the signaling security of the route and serves as a reserve in the event that a train does not come to a stop before the destination signal showing the stop. The length of the slip path is calculated according to the permissible entry speed and the incline of the track. In Germany, unlike in some other countries, the slip paths of routes set at the same time are allowed to overlap, as the system seldom causes stopping signals to pass and the simultaneous slip of two trains is considered unlikely and negligible. In countries with a different safety philosophy, overlapping slip paths can be strictly excluded.
The route for a train leaving the station begins at the exit signal (or, at stations without an exit signal, on the station track) and ends at the level of the entry signal for the opposite direction (or, on branch lines with a simplified branch line service, at the level of the trapezoidal board ) at the transition to the free Route.
An exception are middle turnouts within train station tracks. They must be closed when the route is created for journeys into and out of the affected track.
Entry signals are always at a defined distance from the first danger point . As a rule, this is the switchboard , otherwise the first switch if there are no regular shunting trips on the track in question and therefore no switchboard is set up. As with the slip path, the size of the distance depends on the line speed and the incline of the track. However, this area does not belong to any route - it is generally kept free.
As a short driveway routes are designated, starting at an entry signal and end at a stop facing intermediate signal. In contrast, long entrances denote routes that also begin at an entry signal but end at an exit signal indicating a stop. Short exits begin at an exit signal and have the main track to their destination, long exits start at an intermediate signal and lead to the main track:
A partial route is a real subset of a route:
- Partial route formation
- To shorten headways some use interlocking the so-called partial driveway resolution in the station area to at train already completely cleared and freely reported to set the course for other trips available. The individual parts of the entire route are set at the same time, they then run in automatically until they are determined. Only when all the partial routes have been defined and monitored does the start signal come into the drive position. Each partial route that has been driven on and cleared dissolves and the area concerned is available for another trip. Partial routes are possible with route signal boxes, have to be specially planned there and, with clever subdivision, the device effort in the relay room can also be reduced compared to total routes. In lane plan signal boxes, each track vacancy detection section represents its own partial route. Shunting trips are to be considered separately depending on the philosophy of rail operations and the signal box technology.
- An additional partial route formation to minimize train head times is sometimes referred to as a partial route or partial block (cf. station block , route block ); With the help of special signaling, the driving license for a suitably equipped train is only extended for part of the actual route. Typical areas of application of the partial routes in the sense of a partial block are the dense advancement of a following train in the station area of high-speed railways by means of advancement signals and the increase of the performance on high-performance routes, for example by control of line trains ( CIR-ELKE ) or ETCS Level 2 . Such a high-performance block may not be placed between the start and finish of shunting roads in Germany.
Route check
Immediately before a main signal for a train can be set to run, the signal box staff must perform a route check. To do this, it must determine whether the entire route and the slip path are free of vehicles. In the case of mechanical or electromechanical interlockings, this is done by looking (earlier formulation: visual inspection ). In the case of relay and electronic interlockings, this task is usually carried out by a track vacancy detection system that works either with axle counters or track circuits and works automatically with a pulling effect. In the event of malfunctions, however, the operator must check that it is free. If he can, he can do this himself by looking or instruct a member of the company (train driver, local supervisor, other railway staff). If he cannot determine that he is free, he has to let the train ride run on sight. To this end, he can issue a corresponding command or operate a caution signal, if this is available.
literature
- Ulrich Maschek : Securing rail traffic . 2nd Edition. Springer Vieweg. Wiesbaden, 2013. ISBN 978-3-8348-2653-4
- Jörn Pachl : System technology for rail transport . 7th edition. Springer Vieweg, Wiesbaden 2011. ISBN 978-3-8348-2586-5
- Driving regulations of the Deutsche Bahn AG
- Driving regulations FV-NE (driving regulations for non-federal railways)
Individual evidence
- ^ DB Netz AG: Planning LST systems , RiL 819.0202, Frankfurt / Main 2008
- ^ Jörn Pachl: System technology of rail traffic (6th edition). Vieweg + Teubner Verlag, Wiesbaden 2011
- ↑ Study on the introduction of ETCS in the core network of the Stuttgart S-Bahn. (PDF) Final report. WSP Infrastructure Engineering, NEXTRAIL, quattron management consulting, VIA Consulting & Development GmbH, Railistics, January 30, 2019, p. 244 , accessed on April 28, 2019 .