Baldwin Class System
first number = Total no. of wheels (lead, driver, & trailing wheels)
second number = locomotive size, based on diameter of the cyliners
Fraction after the second number = either information on wheel arraingment or indicates a larger cylinder size for an exsisiting class
Letter = wheel arraingment
The class may be followed by a number, indicating the consecutive number of the loco built to this class in order of construction.
The class is sometimes followed by a plan number.
Cylinder size
8 = 7" diamiter
10 1/2 = 8" diamiter
A cylinder size show as a fraction is a compound locomotive, indicating diamiter of the high and low preasure cylinders respectivly
A cylinder size which includes a fraction means
1/4 indicates the truck(s) are placed at both ends of the locomotive
1/3 indicates the truck is placed at the rear of the locomotive
1/2 indicates a larger cylinder size
Letter code
A Special class of high speed locos with one pair of driving wheels and rack locomotives
B one pair of driving wheels
C two pair of driving wheels
D three pair of driving wheels
E four pair of driving wheels
F five pair of driving wheels
4-x-c  0-4-0
6-x-c 2/4/2000