UMLER Codes
I'm probably throwing a kink in the works here, but having worked in the industry quite a few years before retiring, I use the prototype UMLER Car Codes for my equipment. These codes can be found in the back of any Official Railway Equipment Register and though somewhat complicated to set up, these codes give you a very good description of each type of car and replaced the use of the old AAR car type coding years ago. Unless you have a huge fleet of cars, you'd probably find that most of your cars will use more or less the same basic codes.
UMLER (Universial Machine Language Equipment Register) Codes (based on a 1987 OER):
Format: ANNN (ALPHA Car Type followed by 3 digit NUMERIC code)
A - Equipped Box Cars
B - Unequipped Box Cars
C - Covered Hopper Cars
D - Locomotive
E - Equipped Gondola Cars
F - Flat Cars
G - Unequipped Gondola Cars
H - Unequipped Hopper Cars
J - Gondola Car - GT
K - Equipped Hopper Cars
L - Special Type Cars
M - Maintenance of Way Cars
N - Cabooses
P - Conventional Intermodal Flat Cars
Q - Light Weight, Low Profile, Single Platform (FC) And/Or Articulated Intermodal (FCA) Cars
R - Refrigerator Cars
S - Stock Cars
T - Tank Cars
U - Containers/Chassis
V - Vehicular Flat Cars (FA Only)
As Chris correctly pointed out, just saying all your covered hoppers are AAR type "LO", tells you nothing about what type of covered hopper it is and using that code on some computer switch list generating programs could result in covered hoppers intended only for cement loading, winding up at your grain elevator and the other way around!
Of course the same goes for other type cars, such as box cars. Not all box cars are "XM" and the AAR "X?" Code tells you nothing about the car. Is it a 40ft, 50ft, 60ft, sliding doors, plug doors, combination doors, etc.?
Would take me a very long time to type up all the numeric codes that go with the various car types, but here are some examples to give you an idea of how these codes work (based on the 1987 OER):
I have several covered hoppers that would be used for grain/feed/fertilizer and similar bulk commodities and as it happens they are all UMLER code C113 which breaks down as:
C - Covered Hopper
1 - Gravity Unloading - non-pressurized gravity unloading
1 - LO (Covered Hopper)
3 - 4,000 but less than 5,000 cubic foot capacity
Like wise, I have some Airslide Hoppers which are all code C412
C - Covered Hopper
4 - Fluidized Gravity Unloading with gravity discharge outlets
1 - LO (Covered Hopper)
2 - 3,000 but less than 4,000 cubic foot capacity
A typical modern 50ft XM box car might be: B314
B - Unequipped Box Car
3 - 49ft and less than 59ft inside length
1 - XM - Sliding Door inside width 9ft 6in and over
4 - Doors 10ft less than 11ft
A typical modern 50ft XL box car might be: A432
A - Equipped Box Car
4 - 49ft and less than 59ft inside length, cushion draft gear/underframe
3 - XL
2 - Sliding Door - opening 9ft less than 11ft
The only cars that are difficult to get accurate UMLER codes for are T - Tank Cars which require knowing what the Major Class Description of the tank would be, which is shown in Exhibit M of the OER. Since I only have 2 tank car types on my own layout, they use just two of the same code and just a general code type would suffice for our purposes.
I did find a pretty good PDF file on the Internet which could be saved and used for reference here:
http://eaneubauer.ipower.com/type.pdf
Note: That the some of the car type codes and numeric values changed from the 70s to the 80s so use the appropriate era for your layout. My era is the late 70s to early 80s, but I use the codes from the 70s.
If you can't get your hands on an OER or don't want to spend the time to try and get the correct code for each car, then use the basic car type code and make up a simple to understand number code for various car types. Say we have some 50ft "XM" type box cars, some with single sliding doors, some with plug doors, and some with double sliding or double plug doors, and some with combination sliding/plug doors.
B501 - 50ft single sliding door
B502 - 50ft double sliding door
B503 - 50ft single plug door
B504 - 50ft double plug door
B505 - 50ft combination sliding/plug door
Use similar codes for your equipped box "XL" type box cars, by substituting the "B" with "A". Something similar can be used for your covered hoppers to denote the type of covered hopper. You might come up with a numeric code where the first digit denotes the number of compartments, the second digit the type discharge gates/roof hatches, and the third the type of commodity the car is intended to handle. You get the idea.
Just some food for thought and something that might resolve your coding issues for your equipment.
Ed
