to absorb pulling stresses only, whereas coupling shock is absorbed by
buffers set approximately 35 inches to each side of the centerline of the
draft gear. The buffers are labeled in figure 3.5.
Interchanging cars among commercial railroads has brought about the
standardization of rail car components to achieve efficient operation and
With the exception of the superstructure, the design of all
railway cars is generally the same. Some of their components--underframe,
truck assembly, couplers, and draft gear--are common to all rail equipment.
The underframe receives the shock and pulling stresses of the moving car,
supports the car's deck and superstructure, and carries the weight of the
cargo. The truck assembly is the wheeled assembly at each end of the car