German railway signalling

Railway signals in Germany are regulated by the Eisenbahn-Signalordnung (ESO, railway signalling rules). There are several signalling systems in use:

History

Reichsbahn

Originally, the railway company of each German state had its own signalling system. After these companies were merged into the German Imperial Railway (Deutsche Reichsbahn), a common signalling system, the H/V system, was created based on two key types of signal. However, Bavaria was permitted to use its own designs of signal, with slightly different meanings, as part of the national scheme for many years thereafter.

Main signals (German: Hauptsignale) allowed the train to proceed or not. These signals were semaphores, whose arms had a circle on their right-hand end, and were painted white with red edges (occasionally the colours were reversed). There would be at least one arm, which meant "stop" when aligned horizontally and "proceed" when inclined upwards at 45 degrees. Up to two additional arms could be mounted below for different routes. They were inclined at 45 degrees upwards when a diverging route was to be taken, and aligned vertically when the main route was set. At night, a horizontal arm showed a red light, a diagonal arm showed a green and a vertical arm showed none.

Route signalling was changed circa 1930 to speed signalling. On a double armed-signal, one horizontal arm meant "stop" (aspect Hp 0), one inclined arm meant "proceed at line speed" (Hp 1) and two inclined arms meant "proceed at reduced speed" (Hp 2 - usually 40 km/h). Third arms were removed; in 1948, the green light of the lower arm was changed to yellow. This system is still in use today.

There were also distant signals (German: Vorsignale) to advise the driver as to what aspect the next main signal showed, so that he could slow or stop his train in time if necessary. Unlike in British practice, every main signal had its own distant; and each main signal-distant signal pair was worked from a single signal lever. German distant signals took the form of a yellow circular board with a black edge. If the board was visible, it meant that the main signal was at "danger". To indicate that the main signal was showing "clear", the board was flipped horizontally through 90 degrees so as to be practically invisible. If the main signal to which the distant applied was a double-armed one, then a yellow arm, bordered black, was mounted on the post below the disc. If the main signal showed "proceed at reduced speed", then as well as showing the disc, the arm was inclined at 45 degrees. At night, distant signals showed two lights, one diagonally left below the other. Reading downwards, green-green meant "expect clear" (Vr 1), yellow-yellow meant "expect stop" (Vr 0), and green-yellow meant "expect clear at reduced speed" (Vr 2).

The first colour-light signals had come into use, but were not widespread when the country was divided in 1949. These signals simply showed the night aspects of the semaphore signals, and as such are not considered as a separate signalling system. Only the S-Bahn systems in Berlin and Hamburg were equipped with newly designed colour-light signals at that time, of the Sv system.

Post WWII

Two new companies were founded; the Deutsche Bundesbahn in West Germany and the Deutsche Reichsbahn in East Germany. The Reichsbahn kept the name of the old Deutsche Reichsbahn, to keep infrastructure and the right to operate trains in West Berlin. Both companies had their own regulations from then on and they continued separately until 1994 when the rail companies were reunified. Even today, the signalling systems of the two halves of the country differ, and although a new system has been created which will eventually become universal, the vast size of Germany's railway network means that different systems are likely to remain in use for many years to come.

West

Shunting signal merged into main signal
Backup signal merged into main signal; cosmetic change

The Deutsche Bundesbahn mainly kept the H/V signalling, with colour-lights directly replacing sempahore signals; nevertheless, the signals did change their design over the years. One very early change was the inclusion of shunting signals (Sh, Schutzsignale) into the main signal's head. This affected mainly exit signals. These signals show two red lights to disallow any train or shunting movements and a red-white-white combination to allow shunting movements only. Later the backup signal aspects (Zs1, Zs7, Zs8), which had their own head, were also merged into the main head. The new signals also underwent aesthetic change; all the signals, whether distant, main or shunting, were merged into a common rectangular head.

The signalling system didn't change much to allow Gleiswechselbetrieb (regular wrong line working - i.e. running on left-hand track instead of right-hand). Only a new aspect (Zs6) was created to inform the driver if he was to be diverted onto the wrong line.

Several minor experiments with new signalling systems were made, but only one survived: the Augsburg - Donauwörth line, equipped with Sk-type signals. The signals still exist, and the new common (West and East) signalling system were developed from these.

East

The Deutsche Reichsbahn adopted a new signalling system from the OSShd, an international organization of railways, mainly "Eastern" ones. H/V colour-light signals as built in the West did exist in some places in the GDR where they were installed before the war, but most colour-light signals in the East were of the OSShd-designed Hl system.

Reunification

Several signalling systems and two sets of regulations exist within reunified Germany. The regulations are being gradually merged to form a single set, a process still in progress. Most of the network will come under the control of centralized signal boxes; during this process complete lines generally change to the new common Ks signalling system. However, old-style signals are still installed on a few new lines for various reasons, usually if no surrounding lines have Ks-type signals. Even new semaphores are still occasionally installed, though now mainly as spares in semaphore-only areas. Currently no new signalling system is being developed; the current systems are perfectly adeqate for today's operations. The next logical step will be a system without fixed signals, as current developments show: LZB, ETCS

Compared to other countries

Systems similar to the H/V system can be found in Austria, Switzerland and Finland. Most of the aspects look identical, though the lamps are sometimes aligned differently. Austrian signals have one more and Swiss signals two more possible aspects. They can show a speed limit/announcement of 60 km/h and 90 km/h (Swiss only).

Systems similar to the Hl system can be found in many former Eastern bloc countries.

The Ks system can be considered similar to signals in many countries, at least in appearance, as the colour codes: red for "stop", yellow for "caution" and green for "proceed" are commonly used in other countries.

Compared to UK Signalling

UK Signalling seems to be similar to the Ks system at first sight. The major difference is that British signals do not work on the principle of speed signalling. To prevent trains running over a switch too fast several workarounds are in use. One of them is the "approach release". With this system the train approaches a junction seeing a "warning" aspect, the signal before the junction stays at "stop". It is released to a "clear" aspect once the train has reduced its speed. Normally, however, only the route a train is to take is indicated; with semaphores, this is done using several arms side-by-side, each applying to a separate route; and with colour-lights, a 'feather' - a row of white lights which 'point' in the direction the train is to take. In both cases, speed adjustment depends solely on the driver's judgement and his route knowledge. In Germany route indicators are used in several cases but do not have an influence on the speed; they are used purely to prove to the driver that the route is correctly set.

Main signal/distant signal (H/V)

The most common system is the H/V (Hauptsignal/Vorsignal) system which consists of main signals and distant signals. Depending on the technology used in the signal box, these signals may be indicated by semaphores or colour-light signals. The colour-lights show the same light patterns the semaphores show at night. The aspects shown here may be accompanied by Zs2, Zs2v, Zs3, Zs3v, Zs6 (see section #Additional signals) or Lf signals (see section #Langsamfahrsignale) in order to show speed limits or the choice of track that follows. A main signal (with lights only) is marked by a Mastschild (board with a colour code) to protect in case of a signal lights failure. The location of a distant signal is marked by an Ne2 (unless it is a repetition or it is at the location of a main signal) also for the case where the signal lights fail or where a semaphore distant signal shows Vr1 (see section #Nebensignale).

Hp 0: Stop

A main signal (Hauptsignal) shows Hp 0 by a horizontal semaphore arm, one red light or two horizontal red lights. The signal requires the driver to stop in front of it. (Originally, the aspect with two red lights was called Sh 0 and had a different meaning than a single red light with regards to shunting, but nowadays, the meaning is the same.[1])

Usually, Hp 0 is protected by a 2000 Hz magnet of the PZB train safety system which triggers the emergency brake if the train pass the signal.

Vr 0: Expect stop

A distant signal (Vorsignal) shows Vr 0 by a yellow disc or two yellow lights (the right light is above the left light). This signal indicates that its respective main signal shows Hp 0. As the signal is placed at braking distance from the main signal, the driver needs to apply the brakes immediately to stop the train before reaching the main signal.

Vr 0 is usually accompanied by an activated 1000 Hz magnet of the PZB train safety system.[2]:5 Passing it triggers hidden[3]:1 timers in the vehicle's part of the PZB system, which first checks that the driver acknowledges the distant signal, then it supervises the braking. If the acknowledgement does not occur in time or if, at any point, the system detects that the train´s speed exceeds the limits of a certain braking profile, it triggers the emergency brake.[2]:6, 11–13


Hp 1: Proceed

Aspect Hp 1, indicated by one raised semaphore arm or a single green light, allows the driver to proceed at the speed indicated in his schedule.


Vr 1: Expect proceed

Vr 1 indicates that the main signal shows Hp 1. On a semaphore, the yellow disc is flipped horizontally through 90 degrees, while colour-light signals (or the semaphores at night) show two green lights with the right one above the left one.


Hp 2: Proceed at reduced speed

If both arms of the semaphore point up, or a green light is show vertically above a yellow light, the train may proceed but at reduced speed. Unless another speed is indicated by additional signals, the train must obey a speed limit of 40 km/h. Hp 2 usually indicates that the next block is free, but that the points/switches are set so as to make running over them at full speed dangerous.


Vr 2: Expect proceed at reduced speed

Vr 2 orders the driver to slow the train to 40 km/h prior to reaching the main signal showing Hp 2. Other speed limits may be indicated by additional signals.

Hl Signals

Hl-signals are used only in East Germany. The upper part of the signal is a distant signal, the lower part is the main signal. Signals can be found without the main signal section or without the distant signal section.

Hl distant aspects

There is a green and a yellow light, both of which can flash or remain steady. There are four different aspects:

Yellow: Expect Stop

Flashing Yellow: Expect Proceed with 40 km/h or 60 km/h

Flashing Green: Expect Proceed with 100 km/h

Green: Expect Proceed with maximum speed

Hl main aspects

There is a yellow and a red light on the signal, and additionally a bar with four green and four yellow lights below the signal.

No Light: Stop, resolve situation by special procedures (both mandated by signal post's color marking)

Red: Stop

Yellow: Proceed with speed limit

If there is a speed limit (yellow light) it is shown by the green or yellow bar:

No bar: 40 km/h

Yellow bar: 60 km/h

Green bar: 100 km/h

Kombinationsignale

After the reunification 1990, a new signalling system using Kombinationsignale (English: combination signals; abbreviated as Ks) was designed to create a common system for East and West. While West Germany uses signals which simply show the night aspects of the semaphores, East Germany designed new light signals similar to those in other Eastern European countries. Since 2000, new signals have mostly been of the Ks system. There are exceptions; for example, H/V signals were installed on the light rail extension in Kassel post-2000 because it the authorities wanted to avoid the risk of driver confusion on busy lines. The new Ks signals have three lights green, yellow and red, and have only three aspects. Basically, the signal meanings of the Ks signals match the ones of the H/V signals and vice versa, although the aspects may look differently. The PZB and LZB technologies are used the same way as for H/V signals.

Hp 0 Stop

One red light. The Ks system uses the same aspect for "stop" as the H/V system.

Ks 1 Proceed at given speed, expect proceed at given speed

One green light. Additionally a white number above the signal (see Zs3) can reduce the speed. It shows the tenth of the speed limit from this signal. There may also be a yellow number below the signal (see Zs3v) showing the speed limit from the next signal, only shown if the speed limit at the next signal is reduced compared to the limit at the current signal. If such a yellow number is shown, the green light flashes.

Ks 2 Proceed at given speed but expect stop

One yellow light. Speed can be reduced from here as described for Ks 1.

Additional signals

A number of additional signals provide additional information to the driver or modify the meaning of other signals. They are named "Zs" (German Zusatzsignal: Additional signal) plus a number. The aspect names differ in East and West; those shown here are the names used in West Germany.

Zs1 Ersatzsignal

Ersatzsignal = Subsidiary signal

Three white lights aligned as a triangle or one flashing white light.

Meaning: Train may pass this signal with a maximum speed of 40 km/h until the last set of points/switch, after last points/switch regular speed is permitted.

This signal may be used when a main signal fails. One possibility is that one or more bulbs don't work, and the necessary aspect cannot be shown. For example, a signal which should show Hp2 (green + yellow, proceed with 40 km/h) could have a broken yellow bulb. It would therefore show Hp1 (green, proceed with maximum speed). This would be dangerous because it implies to the driver that he could run faster than is safe, so it must show something else. Another possibility is that one of the 'proving' devices (devices for proving that a section of line is safe - e.g. that a set of points/switch has moved completely). In this case, the section of track or set of points/switch affected must be manually checked to ensure that all is safe for the passage of trains, and the signal Zs1 would be given.

Zs2 Richtungsanzeiger

Richtungsanzeiger = Direction display

Shows one single white letter indicating direction. The letter is usually the initial letter of the next station or the next major station.

This signal does not give any specific command to the driver, as signalling safety devices mean that being diverted to the wrong route is not necessarily dangerous. It does, however, prove to the driver that the route is correctly set up, and if the route is wrongly set he could ask the signalman to re-set the route before starting the train. Otherwise, if the route was set up wrongly, he would start the train, set off down the wrong route, discover the mistake, need to set back, have the route re-set, etc., all of which would waste a lot of time.

Zs2v Richtungsvoranzeiger

Richtungsvoranzeiger = Distant direction display

Shows one single yellow letter, telling the driver how the route is set after the next signal.

Meaning: Expect Zs2

Zs3 Geschwindigkeitsanzeiger

Geschwindigkeitsanzeiger = Speed display

Shows one white number indicating the tenth of the speed allowed from this point.

Usually used in combination with main signals. Zs3 are used for speed limits when leaving the main line. Permanent speed restrictions are displayed using Lf plates.

Zs3v Geschwindigkeitsvoranzeiger

Geschwindigkeitsvoranzeiger = Distant speed display

Shows one yellow number indicating the tenth of the speed allowed from the point where the following Zs3 signal is found.

Usually used in combination with distant signals.

Zs4/Zs5 Beschleunigungsanzeiger/Verzögerungsanzeiger (obsolete)

Beschleunigungsanzeiger = Acceleration display

Verzögerungsanzeiger = Delaying display

Used to indicate the train driver that he should accelerate or slow down to optimize the occupancy of the line. A train driver could slow down to avoid a signal showing "Stop" for himself, or accelerate to avoid a stop for the following train. They became obsolete when in the 1970s the first phones could be installed on trains.

Zs6 Gegengleisanzeiger

Gegengleisanzeiger = Wrong line display

Indicates that the train will be driving on the wrong line (left-hand) from this signal on.

Used only on lines where wrong line working is frequent.

Zs7 Vorsichtsignal

Vorsichtsignal = Caution signal

Three yellow lights aligned as a triangle pointing down.

Meaning: Train may pass this signal but must be prepared to stop at any obstacle. The speed has to be chosen according to visibility, but must not exceed 40 km/h.

Used only in combination with main signals.

This signal is used for the same cases as Zs1. The difference is that for a Zs1 it is checked for the driver that the line is clear, whereas at a Zs7 the train driver must check for himself that the line is clear.

Zs8 Gegengleisfahrt-Ersatzsignal

Gegengleisfahrt-Ersatzsignal = Against track crossing signal replacementl

Three white flashing lights aligned as a triangle or a flashing diagonal light

Indicates that a signal at danger may be passed when wrong line working is in force. If the signal guards points/switches the speed limit is 40 km/h; otherwise, the limit is 100 km/h to the next station. As with other 'wrong line operation' signals, this is only used where wrong line operation is frequent.

Zs10 Endesignal

Zs10

Endesignal = Ending Signal

This Signal indicates that any speed restricitons given by Hp2 or Zs3 end with the rear of the train passing this signal.


Langsamfahrsignale

Lf Signals

Langsamfahrsignale = Slow travel signal (speed limit)

There are several plates to display speed limits, of two basic types: signs showing the maximum speed and, where the speed limit drops, advance warning signs.

The Lf1, Lf4 and Lf6 plates are advance warning boards, while the Lf2, Lf5 and Lf7 announce the start of speed limits. The Lf3 plate marks the end of temporary speed limits, but the end of a permanent speed limit was not usually shown.

Changes as of 2007:

Lf4/Lf5 are obsolete and are being replaced by Lf6/Lf7;

An increase in speed limit will now always be shown by a Lf7.

Nebensignale

Ne signals

Nebensignale (possible translations: auxiliary/lateral signals) are signals that do not fit in any other category; some of them give hints rather than requiring action.

Ne1 Trapeztafel

Trapeztafel = Trapezoid board

Meaning: Stop here to await permission to proceed.

Trains must stop here to wait for visual or verbal signal to proceed. Found on lightly-used lines where telephone block operation (without signals) is in force; it effectively replaces a station's entry signal.

Ne2 Vorsignaltafel

Vorsignaltafel = Distant signal board

Used alone or in combination with a distant signal. Meaning: This is a distant signal. (Even if there is none visible)

A main signal, shunting signal or a Ne1 will be found at braking distance. Unless a distant signal, distant signal repeater or main signal is visible, the train driver treats this signal as "Vr0 or Ks2: Expect Stop".

Every distant signal is mounted with a Ne2 plate to mark their position (if this plate was not fitted, the driver would not know if he had passed the distant signal or not when showing aspect Vr1, since in this position it is practically invisible). Distant signal repeaters or distant signals mounted in combination with a main signal do not have a Ne2 plate.

Ne3 Vorsignalbaken

Vorsignalbaken = Distant signal beacon

Used to announce distant signals. Posted 250m, 175m and 100m before distant signal.

Generally 3 plates are used, but up to 5 may be used at hard-to-see locations. Fewer than 3 are used if the distance from the previous main signal is too small to install them all.

Ne4 Schachbretttafel

Schachbretttafel = Checkerboardplate

Used to indicate that a signal is not in its usual position (i.e. if the signal is further to the right than normal or if it is on the wrong side of the track to aid visibility). This plate is posted where the signal would be if conditions were normal.

Ne5 Haltetafel

Haltetafel = Stop board

Used to indicate where a passenger train should stop. It can be combined with additional signs indicating what types of trains should stop here, e.g. "240 m" for trains at most this length.

Ne6 Haltepunkttafel

Haltepunkttafel = Stopping point board

Meaning: Expect a stopping point within braking distance.

This is only used to announce halts that are not stations.

Ne7 Schneepflugsignal

Schneepflugsignal = Snowplough signal

Gives information to snowplough crews. A yellow or white 'V' shape indicates 'lower snowplough', an inverted yellow or white 'V' indicates 'raise snowplough'. These are placed to warn the crew to raise the snowplough so as to avoid hitting any obstructions at rail level, such as level crossings/grade crossings.

Schutzsignale

Schutzsignale = guard signals. These signals guard shunting movements. Shunting movements do not leave a station whereas train movements do. These signals are sometimes combined with main signals, which is the reason why main signals sometimes have one red light and sometimes two. Historically, shunting movements were allowed to ignore main signals. They had to stop only at main signals with two red lights, because a double red light means Hp0 (stop for train movements) and additionally Sh0 (stop for shunting movements). When they were allowed to pass this signal, it showed a red and two white lights, still forbidding train movements (Hp0 + Sh1). After a change, a red always means stop for all movements. Therefore only one red light is needed. A double red has the same meaning and Sh0 is now nearly equal to Hp0 and will be replaced in most cases.

Sh0:

A white circle with a black line horizontally across it, mounted on a black box; or, two horizontally-mounted red lights. It means Fahrverbot (literally "movement forbidden"), and all train and shunting movements must stop short of it. 'Black box' indicators fixed at aspect Sh0 are commonly found mounted on buffer stops.

Sh1:

A white circle with a black diagonal line across it, mounted on a black box; or, two white lights aligned diagonally (sometimes with a red light as well). It means "shunting movements allowed but train movements forbidden".

Sh2:

A rectangular red plate used at the end of the track or where the line is blocked, for example by engineering works. It displays a single red light by night.

Catenary Signals/Fahrleitungssignale

All these signals consist of a blue diamond-shaped board with various patterns of white markings. As such, only the white markings are described in this section. As catenary signals, they apply only to electric trains.

El1v

Two horizontally-aligned square white dots, on centreline of board. This warns the driver to switch off the locomotive's main switch.

El1

Similar to El1v but with a horizontal line under the square dots (dots do not join the line). Locomotive's main switch must be off when this board is passed.

El2

A square U-shape. Main switch can be turned on after this board.

El3

Two horizontal lines across the board, about one quarter and three-quarters of the way down it. Warns driver to lower the locomotive's pantograph.

El4

One horizontal line across the centre of the board. Pantograph must be down when this board is passed.

El5

Vertical line through the centre of the board. Pantograph may be raised after passing this board.

El6

Concentric squares of blue and white. Indicates 'stop for vehicles with raised pantographs'. This sign is most commonly seen at the end of the catenary.

Miscellaneous

One white light on Hp signal: This signal has failed or is otherwise out of use. Ignore it.

A white light on a H/V distant signal: The distance to main signal is shorter than usual (when signal has a Ne2-plate) or this is a repeater (without Ne2-plate).

A white light in the top left corner of a Ks-Signal: The distance to main signal is shorter than usual.

A white light in the bottom left corner of a Ks-Signal: This is a repeater.

A flashing white light: Not a Kennlicht (marker light), see Zs1

Two white lights: Not a Kennlicht, see Sh1

Examples

Example 1

Example 1

Entering a station (see image)

Left: Secondary line with minimum signalling

Right: Main Line with standard signalling

Example 2

Example 2

The lower track is blocked. A train going from left to right cannot use the regular track. It must use the wrong track. The exit-signal of the left station shows Hp0 (one or two red lights: "Stop"), because there is no regular route to the wrong track. The signal shows also Zs8 (three white flashing lights: "Proceed on wrong track"). The signal cannot show Sh1 ("Shunting allowed") in this case, because the ride would end at the Ra10-plate ("Stop for shunting movements"). When approaching the next station, the train will find an Ne2-plate, which substitiutes a distant signal and in this case means "Expect Stop". At the position of the entry-signal of the right station, a Ne4 plate shows that a signal is not where it is expected. Instead, the signal is mounted right of the track. This signal shows Sh1 (two white lights: "Shunting allowed"), the train may enter the station. The signal could also stand on the left side of the track, the Ne4 plate is not used then.

Example 3

How Kennlichts are used. On the first signal you see Hp1/Vr1 as described in the H/V section of this article. On the next one you see Hp1/Vr0, which means "proceed, expect stop at braking distance". On the third one, you see a Kennlicht, which means that the main signal is switched off (=there is none). The distant signal shows Vr0 + Kennlicht, which means "expect stop before braking distance". The last one shows the expected "stop". These combinations are used, if the signals are mounted at the half braking distance.


Gallery

Footnotes

1: A white cross (with a black border) on a signal informs the driver to disregard the signal.<ref name"=ESO11>Zusammenstellung der Bestimmungen der Eisenbahn-Signalordnung 1959 (ESO 1959), einschließlich der gemäß ESO (4) genehmigten Signale mit vorübergehender Gültigkeit und der gemäß ESO (5) erlassenen Anweisungen zur Durchführung der ESO, gültig für das Netz der Eisenbahnen des Bundes (EdB). (12 December 2012)</ref> In all the cases shown, this is due to the newly installed signals not being operative yet.

References

  1. ↑ "www.sh1.org oddity page". Retrieved 8 October 2013.
  2. ↑ 2.0 2.1 "Bahnbetrieb - Zugbeeinflussungsanlagen bedienen - PZB-Streckeneinrichtungen 483.0101A01" (PDF). 10 June 2012. Retrieved 10 October 2013.
  3. ↑ "Richtlinie Bahnbetrieb - Zugbeeinflussungsanlagen bedienen - Punktförmige Zugbeeinflussungsanlagen bedienen - Allgemeiner Teil 483.0101" (PDF). 10 June 2012. Retrieved 10 October 2013.

External links

Wikimedia Commons has media related to Railway signs in Germany.