Meaning of ZS

[MrG]

One thing I do not know, can someone say what ZS means please? It is commonly in the fahrplan.

[Johannes]

ZS stands for "Zugsammelschiene", for which I've found several translations: train line, train bus bar or head-end power.

Here is a discussion (in German) on what the ZS symbols mean in the working timetable (TL;DR: turn the train line off or on, but only if the train is pulled by certain types of diesel locomotives). I think in Zusi you cannot simulate turning the train line off or on anyway, so you may ignore the symbols in the working timetable.

[MrG]

Thankyou, I thought it might have been something to do with what, in the UK we call neutral sections; a short electrically isolated section of the overhead power lines - between feeders, for which the driver coasts through. but was confused when I see it on non-electrified lines - most interesting.

Are overhead power line neutral sections not simulated in Zusi3 btw?

I notice a symbol of amps eg 600A in the fahrplan in some areas. Is this a maximum trains can pull to prevent overload or similar?

[Zimmer]

Hello MrG,

the Ampère-notions in the timetable are indeed indicating the maximum a single train (if more than one engine: the sum of all engines) may take out of the catenary.

I'm not aware of a neutral section in Zusi yet, the German expression would be "Schutzstrecke".

The background of the electrical head-end-power to be switched off on non-electrified lines is simple: If the rails are isolated for signalling reasons, the frequency of the AC from the train's electrical heating might (or has already proven to do so) interfere with the signalling equipment and cause severe confusion in the signal box's circuits.

Hope I've helpe,

J

[KlausMueller]

Hi MrG,

In the biggest part of the German railway network generally feeding sections are not separated by neutral zones, as there is a railway-own single phase (to be exact, earth-symmetric 2-phase) high-voltage network which supplies the substations, so all feeding sections have the same phase-angle. Differing from that 25kV/50Hz railways are fed from the public HV grid using different 2 out of the 3 phases for each feeding section, resulting in 120° phase displacement between the sections and therefore the necessity of neutral zones.

In the northeast region of Germany there is no railway-own HV network and the contact line is fed by rotationg or static frequency converters. There the same phase-angle of feeding sections is not ensured and therefore short neutral zones ("verkürzte Schutzstrecke") exist. In the other network they may occure at some locations also, either when continuous feeding would cause problems with electric protection or temporary during works, when electrically safe separation of feeders is necessary. An example for the second case was during refurbishment of the HV line going from Nuremberg to the north. During this time a temporary neutral zone was established in the contact line of the railway line from Nuremberg to Bamberg to avoid overload of the contact line when the HV line had to be switched off.

The ZS sign is independent from this. As "Zimmer" already explained, it indicates areas where the train busbar has to be switched of, as the return current of the train-internal electric supply flowing through the rails back to the locomotive could disturb signalling equipment like track circuits. Most modern signalling equipment is resistant against this influence, but especially on some non-electrified lines older equipment exists which is very sensible.

Klaus