Rail Yard

AAR Car Type Codes Explained & Resources

The Association of American Railroads (AAR) developed the car code. The first letter of the code identifies the major category of the railcar. The following three numbers identify more specific characteristics about the railcar such as dimension, roof type, door type, capacity (gallons or cubit feet), load limit, floor type, coupler type, tank type, unloading type, etc. The three number categories are different for each major category of railcar.

An AAR Car Type example:

TILX 3238 has a car type of C112. It is a covered hopper with gravity unloading and a capacity of 3,000 to 4,000 cubic feet. This type of railcar could be used for shipping frac sand or cement.

Here is the breakdown of the code:  C = major category of the railcar. Covered hoppers three numbers are as such: 1st number = type of unloading mechanism; 2nd number = type of roof; 3rd number = capacity in cubit feet.

C = covered hopper; 1 = gravity unloading; 1 = LO covered hopper; 
2 = capacity of 3,000 to 4,000 cubic feet

TILX 261848 has a car type of T106. It is a general service carbon steel tank car with a capacity of 22,000 to 24,000 gallons. It could be used for shipping asphalt.

T = tank car; 10 = general service cars - carbon steel (welded or
riveted) (includes rubber lined); 6 = capacity of 22,000 to 24,000

Below is a table showing the major categories of railcars. But it is not possible to provide a generic table for the numeric part of the car code since the categories vary depending on the major car category. To really know what the numeric part of the code means, you need to refer to some other resources.

The ultimate resource is The Official Railway Register 0r sometimes affectionately called the “big yellow book”. You will need to buy this for $379 per year (digital or print) and can order it online. You’ll want to refer to the Section IX, Exhibit D & M. If you don’t want to pay the $379, there are some rail fan sites (here is one) that are pretty comprehensive in explaining all of the numeric codes for each major car type, but they may be out of date and accuracy can’t be guaranteed.

BNSF Railway has a pretty nice page where you can paste or enter any railcar and see its characteristics along with the AAR Car Type Code.

Code Description
A Equipped box cars
B Unequipped box cars
C Covered hopper cars
D Locomotive
E Equipped gondola
F Flat cars
G Unequipped gondola
H Unequipped hopper
J Gondola car
K Equipped hopper cars
L Special type cars
M M-O-W, Scale, Passenger, Caboose, and End-of-train information systems
P Conventional intermodal cars
Q Lighter weight, low-profile intermodal cars
R Refrigerator cars
S Stack car
T Tank cars
U Containers
V Vehicular flat cars
Z Trailers

I hope that you have found this article a helpful resource. If you have some ideas to share, please comment and start the conversation!

All the best,


Railcar Management System (RMS) can store the characteristics such as the AAR Car Type Code, which then can be included on custom reports that are sent automatically to recipients.

Jim Dalrymple


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  1. Varnit Jain on March 16, 2017 at 11:00 pm

    Thank you very much for valuable information

  2. Joe Bacon on August 16, 2017 at 10:47 am

    Is there a code on tank cars/coal cars that tells the cars destination?

    • Jim Dalrymple on August 22, 2017 at 2:27 pm

      Hi Joe,

      There is not a code that is a permanent attribute of a railcar that specifies its destination. That would be information that comes from the waybill. The waybill includes the origin, destination, route, commodity, shipper, consignee, care of, freight payer, net weight and more. If your company is party to the shipment (i.e. it is either the shipper, consignee, care of, freight payer), you can request a copy of the waybill. See this article on how to do that.

      Hope this helps.


  3. […] and cars would often get lost. There was a code-based system in place for tracking these cars, but it is complex and incomprehensible to the average […]

  4. Michael E. Ure on May 24, 2020 at 9:20 am

    Hello. I’m a member of Burlington Northern & BNSF group on Facebook. Recently a question came up about a stencil on an old B2 boxcar. The car number is BN 951016 with a stencil marking on the side sill of TP 6-81. Do you have any idea what that means?

    • Jim Dalrymple on May 29, 2020 at 12:22 pm

      Hi Michael,

      I looked up the railcar in Umler (the North American rail industry’s equipment database) and that equipment id is no longer valid. Umler is a great resource to get specifics about railcars. It appears that the 6-81 is probably a date (June 1981) and relates to the last time the railcar was shopped. I’m not sure what the “TP” stands for though. Sorry about that. If you find out, please comment!

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