AAR Classification, designation and designating lettering of cars
Association of American Railroads
Operations and maintenance department
This page sets out the types of freight car equipment as recorded by the Association of American Railroads (AAR). By clicking on the links below or using the links from header at the top of the page you can see more information about each type of car and the designations given to them.
Freight Equipment Cars
- Class “F” – Flat Car Type
- Class “G” – Gondola Car Type
- Class “H” – Hopper Car Type
- Class “L” – Special Car Type
- Class “N” – Caboose
- Class “S” – Stock Car Type
- Class “T” – Tank Car Type
- Class “X” – Box Car Type
Scale Equipment Cars
- Class “MS”
Maintenance of Way Equipment
- No entry
Passenger Equipment Cars
Adopted 1910; Revised 1936 and periodically to date of last revision; 1979.
A passenger train car is defined as a car of suitable construction, equipped to operate in passenger trains, its characteristics to include:
- All steel, steel underframe or equivalent construction;
- Passenger type air brake equipment, or of type to function with other passenger car brakes;
- Trucks suitable for satisfactory operation in passenger train service;
- Train line connections for signaling, heating, power, or other function s as required for the train assignment;
and be in accordance with definitions and designating letters fir general passenger train service as follows:
- PB – A car constructed for passenger train service and equipped to handle baggage, express, mail merchandise or similar products.
- PD – Car equipped for food or beverage service.
- PA – Car equipped to handle passengers.
- PS – Company service car, including office cars, instruction cars, display cars, etc.
Where car serves two purposes, as coach and baggage, combine symbols as “PAB”.