Speed indicator
A speed indicator shows the maximum permissible speed as a code number for the next section of the railway . The speed is often represented by a tenth of its value in km / h, e.g. B. 8 for 80 km / h or 3.5 for 35 km / h (the term "code number" is part of the respective railway signaling system in both Austria and Germany and is therefore correct; the correct content would be here instead of " code number " Term " key figure ").
Germany
In Germany the speedometer is an additional signal . According to the Railway Signaling Regulations (ESO), it has the following meaning: “ The speed indicated by the code number must not be exceeded from the signal in the subsequent switch area. "
use
|
|
|
|
Symbols of an additional indicator (left as a form signal, right as a light signal) in safety-related plans
|
||
Speed indicators (Zs 3) are used to signal speeds that only apply in the following switch area , whereby these speed limits are to be seen as independent of the line speed. This means that a signal Lf 7 cannot cancel the speed given by a signal Zs 3 (unless it reduces it) and vice versa.
If there are several possible routes behind a speed indicator that can be traveled at different speeds, this is implemented as a light signal. Otherwise it is used as a much cheaper and less maintenance form signal.
Their purpose includes in particular the following cases:
- Branch tracks in turnouts that can be driven on at a lower speed than the main track (most common application)
- Shortened braking distances (downward signaling over several sections) - possibility of upgrading
- Shortened slip path - possibility of upgrading
- as an exception: infrastructure-related restrictions (deficiencies in the substructure or superstructure, track curves), whereby the signaling with the slow speed signal Lf 7 should always be preferred
- Entrances to partially occupied tracks ( expect train cover signal to show stop ) are signaled at 20 km / h (DS 301) or 40 km / h (DV 301)
- Entrances to butt tracks are limited to 30 km / h in the area of the DS 301, in the area of the DV 301 to a maximum of 40 km / h - according to driving dynamics calculations, downward deviations may be necessary
- Upward signaling of existing speed restrictions in the following switch area after the obstacle has disappeared (by means of a stand-alone speed indicator) - equivalent replacement of the end signal Zs 10 , whereby the applicable maximum speed must be specified
In some early project plans, speed indicators always show a speed, including the maximum speed. A speed indicator “12” is shown in the area of the ESTW Dresden-Klotzsche, although the speed limit of the route is already 120 km / h. The reason for this was that these signals can also indicate lower speeds and the speed indicator should not be dark. However, this principle has not caught on. Instead, the parallel signaling of the maximum route speed, i.e. the maximum possible speed in a route section, with slow-speed signals Lf 6 and Lf 7 was retained and expanded. This means that routes nowadays also signal the beginning of higher speed levels.
Locations
_10_Ausfahrsignal_50N2.JPG)
A speed indicator can occur
- in connection with a main signal
- Since a main signal, depending on the signal system, cannot display all speed levels, and the permitted speed cannot always be noted in the book timetable (for example in the case of unscheduled routes), main signals are supplemented by speed indicators. The speed indicator is usually attached above the main signal. The speed then applies in the subsequent turnout area of the respective signal. Speed indicators can also be used with block signals of the free route if a following signal is in the shortened distance. It then often coincides with the schedule speed. In contrast to a train journey with a special order , a speed specified by Zs 3 applies to a block signal of the free route not only until the head of the train passes, but also beyond.
- as a single signal
- The speed indicator stands alone on the track and indicates the maximum permissible speed for the set route.
While the H / V signal system of the Deutsche Bundesbahn provided for the speed signaling via speed indicators only in certain cases (deviating speed of 40 km / h), it was not used at all with the Hl signal system of the Deutsche Reichsbahn, as there were already several speed levels ( 40 km / h, 60 km / h, 100 km / h). There was no need for the signaling of deviating speeds with speed indicators and there were no circuits provided for this. Shape signals may also not be placed on HI signals, but may be placed individually between two HI signals. In the Ks signaling system, the speed indicators represent the central element of the speed signaling. Any variable speed and fixed speeds away from the continuous main tracks, which may not be signaled with Lf 7, are implemented using speed indicators. These are connected to the Ks signals in such a way that the green signal lamp flashes as a warning when a speed indicator lights up. At the location of the speedometer, however, the green light has an idle light (unless a speed indicator is also lit there). The speed indicator does not light up if the following speed is the same or higher and there is no clear route in between. The reason for this is that the speed limit applies in the subsequent turnout area and thus until the next main signal and the announcement of the same or higher speed thus represents unnecessary information that is no longer displayed for reasons of the light point reduction of the Ks signal system. However, if there is a free path in between, the speed may be increased in between, which in turn requires the warning.
Targeted fixed Zs 3 can in some places allow earlier acceleration and thus save driving time.
Where the line speed is increased within the adjoining switch area , speed indicators (Zs 3) and speed signals (Lf 7) can also be set up together on the same mast in individual cases. The speed indicator is used to remove a speed limit for the switch area and the speed signal to increase the line speed.
Stand-alone speed indicators must not be arranged in train routes divided by high-performance blocks. Furthermore, they cannot be switched off. This can reduce capacity.
Signal aspect
The speed indicator consists of a black disc with a white border and a white number. The target of the speed indicator has yellow imprints. The light signals only show a white or yellow (advance indicator) glowing number on a black disk. The permissible speed results from the displayed number multiplied by 10 km / h. If the same speed applies to all routes emanating from the signal, then the speed indicator is designed as a form signal, otherwise as a light signal. In deviation, it is also designed as a light signal in tunnel areas, in the vicinity of tunnels or otherwise in poor visibility conditions, in order to increase visibility when there is only one speed to be displayed. The design as a light signal does not automatically result in the possibility of several different identification numbers to be displayed.
| image | description | example |
|---|---|---|
 |
Form signal: A yellow number on a triangular black board with a yellow border. The board is usually on top. | Expect 60 km / h |
 |
Light signal: A yellow glowing code number. | Expect 30 km / h |
 |
Form signal: A white number on a triangular black board with a white border. The board is usually on the tip, but if space is limited, the tip can point upwards. The shape signal on main light signals usually points with the tip upwards. | 60 km / h |
 |
Light signal: A white luminous code number. | 90 km / h |
history
At the Deutsche Reichsbahn the speed indicator was called Zs 5 and was intended as a form signal for a speed of 60 km / h. It initially had a yellow code number, but according to DV 301 it has been white since 1993, although old speed indicators were only gradually converted. They often had to be dismantled on entry signals as the main form signal, because the original meaning only applied to the concept of slow travel and, following the harmonization of the signal book, for all travel terms, after that the maximum speed could no longer be signaled. Initially it was only intended for use on the main form signal or Sv signal, as the Hl signals could not be equipped with speed indicators due to the integrated speed signaling.
Austria
In Austria a distinction is made between
- Speed board - stand-alone board to indicate the permitted speed
- Speed indicator - additional signal for main and protection signals to display the permissible speed when the main or protection signal shows an aspect of the journey.
Both signals indicate the permissible speed with a tenth of its value in km / h.
The code numbers “3” and “2” can also be used on a speed indicator to notify the train that it is entering a short track. A speed indicator is required for the speed indicator if the speed is to be reduced by more than 10 km / h.
An announcement board is required on the speed board if the speed is to be reduced by more than 20% (unless the reduction is less than 20 km / h).
The signal image of the speed board is a red number on a white square with a red border. The shape of the notice board is an inverted triangle.
The signal image of the speed indicator is a white number on a black square, the number can be white luminous or white reflective. The number of the speed indicator is yellow, the shape signal is designed as a black triangle with a yellow border on its tip.
See also
- Speed announcement signal (Lf 6) and speed signal (Lf 7)
Individual evidence
- ↑ A sign takes two minutes . In: DB World . No. 11 , November 2016, p. 9 .
- ^ Frank Mittag, Christian Wilhelmi: Equipped with signal Lf 7 and Zs 3 at the same location . In: Train B practice . No. 4 , April 2017, p. 6 ( PDF ).
- ↑ 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 .
- ↑ Peter Reinhart: ETCS & Co for "maximum performance". (PDF) A workshop report on the Stuttgart digital node. DB Projekt Stuttgart – Ulm GmbH , November 21, 2019, p. 26 , accessed on November 22, 2019 .
Web links
- Speed indicator on stellwerke.de
Signal systems : H / V signal system (Hp, Vr) Hl signal system (Hl) Ks signal system (Ks) Sv signal system (Sv) Sk signal system (Sk)
Signal types: Level crossing signal (Bü) · Contact line signal (El) · Vehicle signal (Fz) · Main signal (Hp) · Slow speed signal ( Lf) · Secondary signal ( Ne) · Shunting signal (Ra) · Rottenwarnsignal (Ro) · Protection signal (Sh) · Signals for push locomotives and blocking trips (Ts) Advance signal (Vr) Turnout signal (Wn) Train staff signal (Zp) Train signal (Zg) Additional signal (Zs)
Main signals : Einfahrsignal · intermediate signal · Ausfahrsignal · block signal · cover signal