When two or more cars (units) are connected via drawbar, they are called "drawbar-connected". Drawbars are rarely seen in North America anymore, as car ID. Any stenciling for former car IDs must be removed (painted over) and AEI tags updated to represent the new configuration.

Unit Designations

Each unit is assigned a letter - unit A is always at one end and unit B at the other. If the car has three or more units, letters for the intermediate units are assigned alphabetically starting at the unit attached to unit B.

For example, a 5-unit drawbar-connected car would have the individual units designated as follows: B-C-D-E-A. A 3-unit drawbar-connected car would have the individual units designated as follows: B-C-A.

Component Position Nomenclature

CAUTION: Position nomenclature is different for Articulated Cars

Side of Car:

When facing the B-end of a car, or in this case the end of Unit B, the left side of the car is to the left and the right side is to the right.

Axle Positions:

Car axles are always numbered sequentially starting with 1 as the first axle from the B end of the car, which in the case of drawbar-connected cars means the end of unit B.

For example, a 3-unit drawbar connected car would have the axles numbered as follows (assuming each unit has two 2-axle trucks): B [1-2-3-4]-[5-6-7-8]-[9-10-11-12] A

For purposes of Car Repair Billing, axle numbers 10 or higher are translated into letters starting with Z and proceeding in reverse alphabetical order (10=Z, 11=Y, 12=X, 13=W, etc.).

Wheelset Positions:

Wheelsets position is equivalent to axle position.

Wheel / Bearing Positions:

Positions for wheels and bearings are denoted as the side of the car the component is on (L or R) combined with the corresponding axle number (1,2,3, etc.)

For example, the bearing on the 3rd axle on the left side of the car is in the L3 position. Likewise, the R1 wheel is the wheel on the 1st axle on the right side of the car.

Truck Positions:

Truck positions are assigned letters such that the A truck is the last truck on the A end of the car and the B truck is the first truck on the B-end of the car. Any intermediate trucks are assigned C, D, E, etc. starting after the B truck.

For example, a 3-unit drawbar connected car would have the trucks denoted as follows (assuming each unit has two 2-axle trucks): [B-C]-[D-E]-[F-A].

Bolster Positions:

Bolster positions are equivalent to the Truck Position.

Sideframe Positions:

Sideframe positions are a combination of the side of the car it is on and the letter for that truck.

For example, the left sideframe on the C truck is the LC sideframe.