Sk signal system
The signal combination ( Sk ) is a test system developed by the Deutsche Bundesbahn from the 1970s, which combines the signal screens of the main and distant signals that are separate in the H / V system (main signal / distant signal) .
Introduction and dissemination
After the Second World War , the Deutsche Bundesbahn decided in favor of the H / V system as the signal system , in which the night signals of the form signals were adopted as the light signal system. With the H / V system, the signal screens for the main and distant signals are usually attached to the same mast, which leads to an accumulation of light points. So z. B. for the display of the combination of slow travel (Hp 2) and any distant signal aspect, four signal lights are required. The multi-section-based Sk system simplifies these signal terms and combines several meanings in a signal screen on which only a single light point is shown for all positions (except for the term Hp 00).
In 1977 the Sk signal system was introduced on a trial basis on the Augsburg – Donauwörth line . To do this, the functions of the relay interlockings did not have to be changed on a large scale. Components of the standard light signals of the 1969 design and the 1960 light signals were also used for the route signals. Only the round distant signal screens were newly developed, whereby the existing double lanterns of the standard design were used for lighting. The Sk signal system is still in operation on this route. Other routes were not converted. Shape signals continued to be replaced by light signals in the H / V system until the introduction of the Ks system.
In the second half of the 1970s, it was planned to use the SK signaling system on the first new German high-speed lines that were under construction, after the scheduled train control system had not yet reached operational readiness by the mid-1970s. With the Sk system, it should be possible to drive 200 km / h at block distances of 1500 m. The signal aspect "flashing green" should serve as a stop announcement from 200 km / h, while the signal aspect "green" should stand for at least two free block sections. Instead of the two light points for slow travel (green over yellow) provided in the H / V signal system, a separate speed indicator with the number “4” was provided in the Sk system in addition to the single green light . However, it was not used, instead H / V signals were set up on both new lines.
After the commissioning of a digital interlocking on the Augsburg – Donauwörth line, which is planned for 2021 , the SK signals will be reduced.
Instead of using separate signal screens on a mast for the main and distant signal aspect, as is the case with the H / V system, only one signal screen is required for the Sk signals. The previous signal screens were retained for the main signals; Pure Sk pre-signals are equipped with rectangular signal screens in the direction of Donauwörth; Round signal screens are used in the opposite direction.
Normally each signal - regardless of whether it is a main signal without distant signal function, main signal with distant signal function or pure distant signal - shows only one light point. Only exit signals show two red light points when stopping (previously referred to as Hp 00). For this reason, the signals are called multi-section signals, because a point of light can indicate the passability of two sections (while this was split in the H / V system).
- Hp 0 - one red light or two red lights next to each other: stop.
- Sk 1 - a green light: free travel over two sections (with yellow mast sign) or free travel in this section; the next section is pre-signaled separately (no yellow mast sign)
- Sk 2 - a yellow light: travel free in this section (only with red mast sign); expect train stop at the next signal
The speed limit is uniformly displayed with the signals Zs 3, Zs 3v, Lf 6 and Lf 7. Both upward and downward signals are displayed, whereby the point range rule does not apply in the Sk signal system (i.e. a speed limit applies until a new one is displayed). So stands z. B. at the exit signal Lf 7 with code number 4 (exit at 40 km / h); Behind the last switch is Lf 7 with code number 16 (travel at a maximum line speed of 160 km / h, speed limit for the exit lifted). The code number 20 for a maximum line speed of 200 km / h was also shown on some sections of the route (today a maximum of 160 km / h is permitted in signal-controlled operation in Germany).
The mast label shows the function of the signal:
- red mast sign - main signal
- red-yellow mast sign - combined signal / multi-section signal
- yellow mast sign - distant signal
- ^ Ludwig Wehner: Control of the express rail traffic . In: DB Report 79 . Hestra-Verlag, Darmstadt 1979, pp. 87-92, ISSN 0072-1549 .
- ↑ Bavaria gets the first digital interlocking on a main line in Germany. In: deutschebahn.com. Deutsche Bahn, June 10, 2019, accessed on June 10, 2019 .