The Polish railway signalling system provides a complex outlook of traffic situations, yet is quite easy to understand. Signals can be divided into following categories:near and distant displays — signals (semi-automatic, automatic)
Most signals are colour lights.
On few stations remained mechanical signals, as well as old colour light signals.
Semi-automatic is the most important type of signal on Polish railways. Its name reflects the fact that it switches to a red (stop) aspect automatically after a train has passed it but it must be switched back to clear by an explicit action from a signal box or dispatch centre. It is the typical signal in use at stations.
A semi-automatic signal can be recognized by its post which is painted with red and white strips. Dwarf versions have their boxes painted so.
A red (stop) aspect on a semi-automatic signal must not be passed.
As presented on this compact chart, semi-automatic signals can display both near and distant functions. Near signals either command a stop or impose a certain speed limit beginning at that signal. Distant signals tell the driver what to expect at the next signal, especially when braking is required.
Since 2007 the Ie-1 code which regards signalling allows other speed limits. They are indicated by a number representing the speed in tens of km/h (e.g. 5 means 50 km/h) which is lit only with adequate aspect of the signal. These numbers are incorporated into signalling so, that they always loosen the restriction presented by the aspect of signal.speed 50 km/h is indicated by digit 5 with aspects S10—S13
speeds 70, 80, 90 km/h are indicated by digits 7, 8, 9 with aspects S10a—S13a
speed 130 km/h is indicated by number 13 with aspects S6—S9
On distant signals and repeaters these other speeds are not displayed, therefore more restrictive aspect is effectively announced.
Semi-automatic signals on a station are tagged with consecutive letters of Latin alphabet, or with a letter followed by a number.
The nameplates also contain speed indication which appears as a superscript or a fraction. The numbers have following meaning:1 this signal is followed by a switch with straight direction, Vmax is possible
2 this signal is followed by a switch with diverging direction of 40 km/h
3 this signal is followed by a switch with diverging direction of 100 km/h
4 this signal is followed by a switch with diverging direction of 60 km/h
Therefore, a nameplate H 1/2 means a signal named H that aside S1 will also display S2-S5 aspects for straight direction and S10-S13 for diverging direction. Whereas P3 2 means a signal of name P3 that aside S1 only displays S10-S13 aspects because it is only followed by diverging direction.
There may also be a letter m which specifies that this signal also functions as a shunting signal (see below).
Automatic signals are used on lines equipped with automatic block signaling. Their colour language is the same as aspects S1-S5 of semi-automatic signals. The main difference regards the S1 (red) aspect - After stopping, it can be passed but the subsequent maximum speed is limited to 20 km/h.
Automatic signals have their posts painted white (without red strips) to be easily distinguished from semi-automatic signals.
Distant-only signal (Pol. tarcza ostrzegawcza literally meaning warning shield) is used on lines not equipped with ABS. Placed in the braking distance, allows the driver to stop before the signal ahead. Its colour language is the same as signal aspects S2-S5, making them technically a signal which is just incapable of displaying a S1 (stop) aspect.
Their posts are painted grey and equipped with the distant-only signal sign.
When a signal aspect is not visible from the proper distance (because of track curves for instance), a repeater signal is installed to aid drivers. Up to three repeaters may be installed if needed. A repeater signal is not a substitute for a distant-only signal.
Their posts are painted grey and equipped with plates with Roman numerals: III, II, I where the "I" stands closest to the main signal. Their colour language is identical to warning shields, except the fact they also have a continuously glowing white light, which informs that this is not a main signal but a repeater.
The following table presents as an example, a station-entry signal designated "B" displaying the aspect S13 (speed limit 40 km/h, stop at the next signal) preceded with distant-only signal and three repeaters:
Level crossing warning is placed in a braking distance before an automatic level crossing. The signal tells the driver whether automobile drivers are warned about an approaching train (blinking red lights, barriers). Normally, level crossing warning signals display no aspect (i.e. are unlit). They light up in the front of an approaching train which is the first clue that the system is working correctly.
Level crossing warning signals are unrelated to other signals, therefore in case of Osp1 signal a train must proceed at 20 km/h regardless the higher speed allowed by last signal.
Their posts are painted black and white strips.
Shunting signal (Pol. tarcza manewrowa literally manoeuver shield) is used exclusively at stations. A consist shunting on such signals must not leave the station. Shunting signals are either stand-alone or incorporated into semi-automatic signals, which bear letter "m" on such occasions.
Stand-alone shunting signals have their posts painted gray.
The colour light signals installed between 1959 and 1969 differ from the contemporary system. They are still in use on several stations. As a matter of fact they can also be used with ETCS Level 1, only the LEU unit must be reprogrammed to understand certain combinations of lights differently.