Citation

AREA Bull. 1958; 59: 305-361.

Copyright

(Copyright © 1958, American Railway Engineering Association)

DOI

unavailable

PMID

unavailable

Abstract

Two fully loaded 70 ton cars used to determine the effect of spring travel, the height of the center of gravity, and speed on freight car clearance requirements on curved and tangent track. Car A had 5/8-inch travel springs; Car B, 3 11/16-inch travel springs. Static lean tests and dynamic tests were performed. The longer travel- springs gave a softer ride, and when used in conjunction with a damping device resonant vertical oscillations were greatly reduced. The vertical ride was improved, but lateral stability, especially in roll was much less. The average total lateral displacement on Car B with the long travel-springs was about twice that for Car A with short springs. Therefore, use of cars with long travel-springs requires careful considerations of clearances in locations where they tend to be critical. Car B also required higher vertical clearances. The larger displacements for Car B were mostly due to its larger roll angle. Speed was a factor in the dynamic action of the freight cars. Oscillations at lower speeds were sustained, indicating a resonance of the roll mode with some periodic disturbances. There were some large roll amplitudes for the higher speeds at entrances and exits of curves. Only low speeds, such as 5 mph, were free from these oscillations.