The Deutsche Reichbahn set into motion a system of unifying the literally hundreds of kinds of locomotives used by the regional railroads on April 1, 1920 and with this the DRG also established several fundamental means of identifying locomotives. In German they are the three Bs. There is the always familiar Baureihe (e.g. - BR 01, etc.) a very basic definition. Next is Bauart (e.g. – 2’C1’ h2) and then there is a locomotive’s Betriebsgattung (e.g. - S 36.20). Each of these provides some important information and when taken together we learn much more about a locomotive without seeing a photograph.

While we’re all quite familiar with this one, an exact translation is difficult to come by. According to Desmond Waterstone, an Irish enthusiast of German railroading, told me that "builder’s number" is a good meaning. Another European enthusiast votes for "class" but I would tend to disagree with that since that word is part of the translation for Betriebsgattung, about which more later. So, an exact translation eludes me but suffice it to say it provides some very fundamental information. Given a Baureihe number, let’s say, BR 01 most interested in German locomotives can visualize this machine.

This term is a combination of axle configuration, the number of cylinders in case of a steam locomotive and the type of steam. Thus a BR 01 Lok would also be 2’C1’ h2. The 2’ refers to a two axle pilot truck, the C means three powered axles and the 1’ is the single axle trailing truck. The h in h2 means Heissdampf or superheated steam and the 2 indicates that it is a two-cylinder engine. The number 3 would tell us that it is a three-cylinder machine and so on. Already we know more about the famous BR 01. If the ‘h’ in h2 is replace by an ‘n’, it would be Nassdampf or saturated steam. Sometimes the h2 or n2 is followed by the letter ‘v’. This refers to Verbundverfahren or duplexing. The letter ‘t’ can also be included and it applies to tank locomotives. While useful, Bauart does not yet provide information about the locomotive’s use or service and for that we have to turn to the third B – Betriebsgattung.

The longest of the three Bs provide yet more information. Our BR 01’s Betriebsgattung or service class is S 36.20. Here goes. The S tells us that the BR 01 is a tender locomotive for fast passenger service but it does not reveal what type of tender the BR 01 uses. The 36 tells us that the machine has 3 powered axles and a total of six axles. Last but not least is the 20 which refers to tons of axle loading. This information was considered sufficiently important to be posted on a bolted on plate on both sides of the locomotive’s cabin. Other Gattungszeichen are:

The article "Von 01 bis 99 – Genormt und doch verschieden" provides a handy table for standard locomotives of the DRG but without the Kriegsloks or war austerity locomotives.

"Das Grosse Typenbuch Deutscher Locomotiven" by Weisbrod, Bäzold and Obermeyer, Berlin, Transpress, 1995, ISBN 3-334-70751-5.

"Von 01 bis 99 – Genormt und doch verschieden", Eisenbahn Magazin, July 2000, p. 39.