Research Relating to the Action of 4-Wheel Freight-Car Trucks

This paper includes a study of operating and maintenance problems of car trucks that have resulted from increased weights, greater rigidity, and high speeds. The author discusses the 4-wheel truck as a whole, and includes such features of design as cross-equalization, swiveling resistance, self-squaring, car roll and nosing, guard-rail shocks, lateral motion, and four-point suspension.

Harmonic truck-spring action is discussed at considerable length. It is felt that excessive harmonic spring oscillation at critical train speeds may be caused by eccentricity of wheels. Tests will be made to determine this, and the author outlines various tests for determining unknown factors.