The four-digit class number is decomposed in general as follows:

Class No. A B C D

• A - Engine :
  • 0 (not written): Steam
  • 1: Electro
  • 2: Diesel
  • 3: Steam Motor Units
  • 4: EMUs
  • 5: DMUs
  • 6: Driving trailers
  • 7: Intermediate cars of a MU
  • 8: Not used
  • 9: Tender for coal and water
• B - The specific Car :

  Steam

  0-5: developed in Austria or German generalized loco (i.e. class 42, 44, 50, 52)
  6-8: German classes, specific to location of construction (i.e. Wuerttemberg, Baden-Baden, Bayern ....)
  9: None of the above

  Electric

  0-7: AC
  8: AC/DC
  9: DC

  Diesel

  0-9

  Electric Railcars

  0-7: AC
  8: AC/DC
  9: DC

  Driving trailers

  0-4: for Electric Railcars
  5-9: for Combustion-Engine Railcars

  Intermediate Cars

  0-9

  Tenders

  0-4: Austrian construction before 1938
  5: for War locomotives
  6-8: German construction
  9: other countries

• C D - Field of main usage :

  Steam

  01-19: High-Speed loco, coupled tender
  20-39: Localtrain loco, coupled tender
  40-59: Freighttrain loco, coupled tender
  60-79: Localtrain loco, tender on loco
  80-96: Freighttrain loco, secondary lines, tender on loco
  97: Tooth-wheel loco
  98-99: Narrow-gauge loco

  Electric

  01-19: High-Speed loco
  20-39: Freight loco
  40-59: Universal loco
  60-69: Shunters
  70-89: Austrian construction before 1938
  90-99: narrow-gauge loco
  

  Combustion Engine

  01-19: High-Speed loco, more than 2000 HP
  20-39: Freight loco, more than 2000 HP
  40-59: Universal loco, 1000 to 2000 HP
  60-64: Shunters up to 1000 HP, two axles motorized
  65-69: Shunters up to 1000 HP, three axles motorized
  70-79: Shunters up to 1000 HP, four axles motorized
  80-89: Special purpose construction
  90-99: narrow-gauge loco

  Railcars

  01-19: High-Speed Railcar
  20-59: Local Railcar
  60-79: Freight- and luggage Railcar
  80-89: Lightweight Railcar
  90-99: narrow-gauge Railcar

  Intermediate and driving trailers for Railcars

  follows in general the numbers used for Railcars.

  Tenders

  01-09: two axles
  10-79: three axles
  80-95: four axles
  96-97: not used
  98-99: narrow gauge