How necessary is it (in a modern loco) to change from one country's standard to the other at the border? DB and OBB use the same voltage and frequency, but apparently there are some differences, and different settings on machines like the Taurus and Vectron. Yet on Mittenwaldbahn 111s and 1020s run end to end, despite not being multivolt.
Well, Voltage, Frequency and safety systems are the same, so there's no immediate reason why you couldn't theoretically use the wrong setting. What changes on the modern locos is things like the specific behaviour of that feature where the Vectron turns off some motors at low power. So it's just about compliance with the local rulebook. And if you, like a 111 or 1020, don't actually have any fancy extra features that are only legal in one country, then you don't need to switch over anything.
With the Vectron the DB and OBB settings also change the braking curve profiles to suit each countrie's safely protocol.
As long as we are talking only about power, just a matching voltage type is enough and you don't have to do anything. In some cases, you don't need even that - technically if you put 3 kV DC loco under 1.5 kV wire, it will still run, just with less power - as long as it's "old" and not a modern loco where undervoltage protection would deliberately kick in. But in modern world, voltage is not the only thing to be considered, safety systems and other rules apply differently and affect how the control unit should operate the loco to driver's commands, because modern locos are driven by wire and you do not have direct power over the main controller. Take for example the three-state border of CZ, SK and PL - while in all three countries you have same 3 kV voltage, CZ and SK use track circuit safety system while PL uses trackside magnets, so switching the country profile can reconfigure the safety system without you having to go to machine room and physically isolate them and switch them around. CZ and SK have the same (or mutually compatible) safety system, but in SK brake recuperation is/was forbidden, so selecting that profile will disable that functionality again simply on electronic level without you having to perform any other action.
While both Austria and Germany have the same voltage settings (nominally 15 kV) there are actually differences that requires changes to the locomotive function when transitioning between the two networks. From my understanding (and this is 2nd hand from talking with drivers so I may have gotten the "why" slightly wrong since I'm more interested in the "what" when simulating) Germany has a stricter requirement on interference currents in the OHLE that can affect signal systems. More specifically German locomotives have a 100 Hz filter. From my understanding all locomotives that drive in Germany needs this filter, but Austria doesn't require it. It is actually shown in the Lokschutz diagnostics page on the MTD of the BR101 (which will be simulated in the upcoming patch). Speaking of the Lokschutz page, it is pretty crazy how much diagnostics data is available to the driver (probably more meant for engineers or technicians but it is not locked behind a password like on some locomotives). It measures return current, filter current, 100 hz current, voltage and current in the electric train supply and also earth currents (which you definitely don't want to see lol). If someone has more information regarding the 100 Hz filter I'd be interested to know!
There is one change the 1020 would have to comply with on entering Germany, disabling the Nachbremsventil which is not allowed in Germany, but is used in Austria. Sadly I only found out after release about that one!
To my knowledge the 100hz topic is related to the way how free track reporting and signal monitoring works in Germany. It is explained in a document from the EBA that I came across some time ago. Obviously it is in German, however, it is accessible and can be translated… https://www.eba.bund.de/SharedDocs/...Bekanntgabe_01.pdf?__blob=publicationFile&v=6 There are Ril’s referenced in this document, which would probably explain the operational side of things better but I have not located them anywhere as freely available documents. Hope this helps you in any way…
Thanks I sort of assumed it had to do with track occupancy circuits since Germany doesn't use track pulse codes etc for the signalling system.
A driver I just asked speculated that the difference may be that Austria uses axle counters instead of track circuits so there is no need to prevent return current intereference.
