The Hp system

Hp-Hauptsignal  Hp-Vorsignal  The Hp system was tested by the Deutsche Reichsbahn in 1928 and introduced into the Signalbuch (signal code) in 1935, however few colour light signals were erected before the end of Word War II. The main usage was and is in West Germany.

pictures 

The aspects are the same as the night aspects of the semaphore signals.

Its signals consist of main signals which are at least capable of indicating "stop" and "clear". The main signals (Hauptsignal) may show "line clear with medium speed" as well as some other aspects like "stop, shunting permitted" or give an indication of what speed exactly is allowed (by a speed indicator Zs 3). At 400 m - 1000 m before the main signal, a distant signal (Vorsignal) is showing the aspect the driver has to expect at the main signal.
If the visibility is limited, additional distant signal repeaters (Vorsignalwiederholer) may be used.

If the block length is about 1000 m, the position for the distant signal for the main signal in advance comes close to the position of the main signal in rear. In this case, the distant for the main signal in advance is usually mounted at the post of the main signal in rear, you will find this often with entrance signals.

Signal Heads

There are different signal heads in use, depending on the supplier and/or the aspects that are to be displayed. These heads vary slightly in shape (corners may be angled or not) and in the arrangement of lamps. The signal indication does not depend on where in the head the lamp is placed.

Here I show you some examples:

Blocksignal  Einfahrsignal  Ausfahrsignal  Ausfahrsignal  Kompaktsignal 
This one can just say 'clear' or 'stop', usually used with block signals  This one can also display 'clear with 40 km/h', the lower red is an emergency red which lights if the 'main' red fails These two can display the (now obsolete) 'double-red' Hp00 as well as 'shunting permitted', this is most probably an exit signal  This is a compact head equipped with additional lamps 

main signal Aspects

Hp 1 

Hp 2  Hp 0    or Hp 0 (alternativ)  Hp 0 + Sh 1 
Hp 1: line clear (with timetable speed) Hp 2: line clear with slow speed (40 km/h if not indicated otherwise) Hp 0: stop* Hp 0 + Sh 1: stop, shunting permitted**

*) For the double-red aspect, see my peculiarities page. For the rules applying to a signal showing Hp 0-stop or at failed signal see also post plates.
**) If Hp 0 is displayed in conjunction with Sh 1, Hp 0 is displayed with only one red light.

Distant Signal Aspects:

Vr 1  Vr 2  Vr 0  Vr 1, verkürzter Abstand 
Vr 1: expect clear Vr 2: expect clear with medium speed Vr 0: caution, expect stop distant signal repeater or main signal at reduced distance

When a distant signal is in a reduced distance to the corresponding main signal, it carries a white light on the upper left edge.
If visibility is poor, e.g. a curved track around an hill, additional distant signal repeaters may be added between the distant signal and the main signal. These repeaters also carry the additional white light, but unlike the initial distant signal have no post plate and are not preceded by approach markers.

In former DR area, a distant signal that is not mounted in conjunction with a main signal may display only one light. The Vr 2 aspect may have the amber and green lights exchanged to avoid confusion with the Hl 3a aspect. Also, a repeater signal may not have the white light but may be marked with a special post plate.

When a distant signal and a main signal are mounted at one post, the main signal is on the upper position. If that main signal shows "stop", the distant signal is dark:

Hp 2 + Vr 1, verkürzter Abstand  Hp 0, Vorsignal dunkelgesteuert 
Hp 2: medium speed (40 km/h) (above)
Vr 1: expect clear (below)
distance to corresponding main is reduced (white light)
Hp 0: stop (above)
off (below)

Additional Aspects (Subsidiary Signals)

To allow safe operation on a failed main signal, a main signal may be equipped with subsidiary signals. These subsidiary signals may consist of a small device carrying additional lamps, or, as with the Hp compact heads, they may be placed within  the same head.

Please note that a signal may be failed, when either one or more of the lamps are non-functional, or the signal's state cannot be changed from Hp 0 (red) to something else, due to switch box or other technical problems. That is, the aspects below may be displayed with or without the red light.

For the exact meaning of the Zs signals please refer to the Subsidiary Signals page.

Hp 0 + Zs 1  Hp 0 + Zs 7  Hp 0 + Zs 8  Kennlicht 
Zs 1:
May pass this signal.
Zs 7:
May pass this signal, proceed on sight
Zs 8:
May pass this signal, continue on wrong track
This is not a signal, but the Kennlicht (marker light): Ignore this signal, it has been switched off.

Related Boards

With Hp signals (as well as with the other systems' signals) some boards are used. To begin with, there are three (in rare cases up to five) distant signal approach markers (Ne 3: "Vorsignalbaken") that are placed before a distant signal. At the distant and the main signal posts, post plates (Mastschilder) are mounted that indicate the position of the signal. So even in the worst case (all signal lamps failed) the signs indicate that there is a signal. Note that a failed main signal means 'stop' unless a Subsidiary Signal (see previous section) is displayed. For all post plates refer to the Post Plate Page.

Ne 3 bei 250 m  Ne 3 bei 175 m  Ne 3 bei 100 m  Ne 2  Mastschild 
1st approach  marker
250m before distant
2nd approach  marker
175m before distant
3rd approach  marker:
100m before distant
Ne 2: distant signal post plate  main signal post plate 

If a distant signal is mounted on one post with main signal, the approach markers and distant signal sign are not used, only the main signal post plate will be at the signal's post.

Also a signal may be equipped with a speed indicator.