No one had intended to make railroad history on May 5, 1998. It's just that there was a shortage of locomotives in Phippsburg, CO. Instead of the usual five locomotives, only four were available to pull a 108-car coal train up Union Pacific Railroad's steep Toponas grade on the western slope of the Rocky Mountains. What followed is, among locomotive builders, legendary.

The locomotives were brand new General Electric behemoths with a twist: their traction motors operated on alternating current rather than direct current. Climbing the Toponas grade that day, the trains slowed to a barely perceptible six meters per minute. No self-respecting engineer would have tried such a foolhardy trick with conventional direct-current motors: wheels would have slipped, the train would have stalled, and the motors themselves would have been fried like an egg. But none of those things happened. Indeed, later investigation showed that the locomotives had been producing more pulling power than was thought possible at that speed. This feat of strength initiated a radical transformation of railroading-a revolution that stems directly from advances in information technology.

Technologically speaking, it is difficult to find anything in railroading that has not changed in the last decade. Dozens of microprocessors in today's diesel locomotives run almost all of their systems, from fuel feed to cab air conditioning. Pole lines that once flashed past the windows of speeding passenger trains are disappearing in favor of microwave or fiber-optic communications. Experimental new dispatching and control systems may soon tell engineers if they are using the most fuel-efficient throttle settings.