By J. Parker Lamb

Nearly half a century has passed since the steam locomotive disappeared from the daily operation of American railroads. Such an elapse allows us to analyze the lifespan of these machines objectively and without the emotion, disappointment, and even paranoia that greeted the rapid decline of steam after World War II.

To the student of engineering, the steam era on the railroads provides a clear illustration of a universal characteristic of technical evolution. History shows that the life cycle of any new technology contains at least four major periods: growth and innovation, maturity and monopoly, decline and competition, and economical limit and replacement.

From this vantage point, we are able to identify some fundamental reasons why steam locomotion, which came to the U.S. from England in the form of the Stourbridge Lion in 1829, was destined to be displaced by other forms of propulsion machinery that were more efficient …