Historically most ordinary fast long-distance trains in Germany were classed as "Durchgangszüge" or "D-Züge" (D-Zug in the singular form, also often referred to as a "Schnellzug" (fast train)), then over the last few decades these have gradually been superseded by other train categories such as Intercity/EuroCity and the now defunct InterRegio. At least until the early 2000s a small number of long-distance trains didn't get classed as IC/EC or IR and remained D trains, particularly those that were formed of older rolling stock. Some overnight trains that were formed of older stock also remained D trains until around that time.
Do any D trains still exist today? If you look up a journey on the DB website and click on "weitere Optionen" (further options) and scroll down to "Verkehrsmittelauswahl" (select mode of transport) one of the boxes that you can tick or untick says "Interregio- und Schnellzüge" (despite DB having abolished the IR train category back in about 2006!).
Ironically, I believe that the D train category outlasted the IR at least by a few years, even if there was only a small handful of D trains remaining by then, even though when the then Deutsche Bundesbahn first launched its IR network in about 1988 the IR was expected eventually to replace most if not all remaining D trains.
Do any D trains still exist today? If you look up a journey on the DB website and click on "weitere Optionen" (further options) and scroll down to "Verkehrsmittelauswahl" (select mode of transport) one of the boxes that you can tick or untick says "Interregio- und Schnellzüge" (despite DB having abolished the IR train category back in about 2006!).
Ironically, I believe that the D train category outlasted the IR at least by a few years, even if there was only a small handful of D trains remaining by then, even though when the then Deutsche Bundesbahn first launched its IR network in about 1988 the IR was expected eventually to replace most if not all remaining D trains.
