Train crossing
A train crossing (in Switzerland train crossing ) is the safe meeting of two trains traveling in opposite directions at an operating point that have previously or afterwards claim the same train route section .
If two trains pass each other on two-track lines on different tracks without using the same train route section before or afterwards, this is an encounter . This can also be safety-relevant if, for example, excessively wide trains are not allowed to meet or there is a ban on entering tunnels . In addition, there may be restrictions on the encounter of unpressurized trains. It may also be forbidden for fast moving trains to meet freight trains. If such a prohibition exists, the trains must be held back at the train station in front of them.
The abbreviated technical term intersection is used in the entire German-speaking area. The procedures for the safe and smooth execution of train crossings are laid down in the driving regulations.
Timetable
When performing an intersection, one of the two trains usually has to stop and wait until the opposite train has reached the crossing station. When constructing the picture timetable of a route, it is determined at which locations trains cross and which train has to wait for the return train. Where this is relevant for the train crew, the place of the train crossing and the number of the crossing train are noted in the book timetable of each train. On branch lines in Switzerland, it is also common for both trains involved to slowly enter the crossing station at the same time and continue their journey without stopping.
Special forms of train crossing
Air crossing
There is an air crossing when the timetable is designed in such a way that the trains (should) theoretically not meet in a train station, but rather on a free single-track route. In practice, this is impossible, so the dispatchers at the neighboring stations have to coordinate the actual location of the train crossing in each individual case.
In the case of frequently delayed trains, this allows more flexible handling of operations. However, this procedure increases the general risk of accidents, as operational safety depends on the careful performance of the railway workers involved. Since the head-on collision near Warngau in 1975, air crossings are no longer permitted on the railways in the Federal Republic of Germany. In the case of trams, on the other hand, this method is still used today as a delay buffer in the timetable, whereby these are then equipped with a driving signal system that safely excludes oncoming journeys with signals.
Pointed intersection
The departure of a train immediately after the entry of the crossing opposite train is a sharp intersection. In order to accelerate this, there is a regulation in the driving service regulation in the form of the conditional acceptance procedure , which in certain cases allows the offer of a train before the arrival of the opposite train.
Flying crossings
To avoid additional scheduled waiting times, clock crossings should always be combined with a traffic stop . If this is not the case, encounter sections or double lane islands allow so-called flying crossings . Encounter section or double lane islands can be on the open route, adjacent to a train station or between two train stations. In contrast to train crossings, trains do not have to stop as scheduled in meeting sections to pass by. The timetable is designed in such a way that the train encounter ideally takes place in the middle of the double-track island. Flying crossings enable shorter travel times because there is no need for additional time due to stopping and acceleration processes, buffer times and times for triggering and creating routes . In addition, energy is saved.
Encounter sections are often used on single-track S-Bahn lines.
Laying intersections
In today's widespread regular service , train crossings always take place at the same points and on the same line at the symmetry minute, apart from those on the edge of the day .
However, if a train is delayed, it can make sense to move the train crossing to another, usually the neighboring station. The relocation of an intersection is only possible without risk if all those concerned have been informed and this has been arranged by a dispatcher. In order to ensure this, the relocation of intersections is regulated in detail in the driving regulations. The communication between the dispatchers involved must be recorded, the relocation of the intersection must be entered in the train logs, the train staff will be informed of the relocation of the intersection with a written order in train control .
requirements
To handle a classic train crossing (i.e. on a single continuous single-track line), a station is required that has a siding in addition to the continuous main track . In the simplest case, this is a dead end track that is connected to the line with a switch and into which it is maneuvered for avoidance. (As planned, this minimum equipment is used in the Goetheweg train station in the Harz Mountains, for example .) The number, location and equipment of the crossing stations are decisive for the performance of a route. Railway stations where crossings take place regularly therefore usually have an infrastructure that does not cause any delays in the execution of the train crossing. This includes a siding on both sides of sufficient length, remote switches and signals and - if the route is not centrally controlled - local operating personnel. However, train crossings can also take place at junction and transfer points.
A train may enter the opposite train even if it slips through , i.e. H. Do not endanger the exit signal when driving past the stop. Simultaneous entry of both trains is only permitted on railways in Germany if the slip path behind the signal is long enough or is secured with safety switches . In order to accelerate a train crossing, the slip paths can be long enough so that both trains can enter the station at the same time. In this case, if neither of the two trains is late, the train crossing is not associated with additional waiting times.
Individual evidence
- ↑ Steffen Dutsch: Lecture documents operational management in public urban and regional transport, TU Dresden, 2013
- ↑ Pachl, Jörn: System technology of rail traffic: plan, control and secure rail operations . 8., revised. u. exp. Edition 2016. Springer Vieweg, Wiesbaden 2016, ISBN 978-3-658-12986-6 , pp. 216 .