AAR DESIGNATIONS of ENDS for FREIGHT CARSRule 14. The car end upon which the brake shaft is located shall be known as the "B" end and the opposite end shall be known as the "A" end. If the car has two brake shafts the owner shall have the respective ends, "A" & "B", stenciled on the car on both sides, near each end.
Facing the "B" end of the car, in their order on the right side of car, wheels, journal boxes and contained parts(excluding box lids)shall be known as R1, R2, R3 & R4, and similarly those on the left side of the car shall be known as L1, L2, L3 & L4. The same order of numbers shall be used for designating corresponding location of brake beams. In any case where a right or left side is designated on defect, billing repair or joint evidence cards for other parts of cars, the same uniform order of location shall govern.
© S.A. McCall