Select your localized edition:

Close ×

More Ways to Connect

Discover one of our 28 local entrepreneurial communities »

Be the first to know as we launch in new countries and markets around the globe.

Interested in bringing MIT Technology Review to your local market?

MIT Technology ReviewMIT Technology Review - logo


Unsupported browser: Your browser does not meet modern web standards. See how it scores »

{ action.text }

Model Railroad

Just two decades ago, eastern Wyoming’s Powder River basin was a barren, treeless outback with few people and no industry. But the region had something that as of the early 1990s the United States suddenly needed: lots of low-sulfur, relatively clean-burning coal. In fact, a thick seam of coal stretches under the eastern third of Wyoming. And the only practical way to move so much coal out of the remote Powder River basin is by rail.

The two railroads that serve the area-Union Pacific and Burlington Northern Santa Fe-have spent more than $5 billion to build the biggest, most modern industrial rail system in the country. Driven by tightening air pollution regulations, demand for low-sulfur coal is now booming beyond anyone’s wildest dreams; one section of the line has become the first stretch of rail in history to support more than one billion kilograms a day.

And because the railroad and the mines are new, the Powder River operation provides a clean slate for the creation of the most efficient operation possible-without the burden of older infrastructure and the outdated technology that railroads have often kept running. Nowhere to be seen are the workers who once laboriously copied down all car numbers and faxed them to headquarters. As each empty train enters the mine, and as each loaded train leaves, scanners read automatic-identification tags, recording each car number and reporting the data to Union Pacific’s Harriman Dispatching Center in Omaha, NE.

The Harriman Center is the heart of an ambitious effort to direct an entire railroad system from a central location-to dispatch trains using a computer program that chooses the points at which they meet or pass. The Harriman system controls traffic on more than 27,000 kilometers of Union Pacific track in 23 states-though human dispatchers can intervene at any time if they disagree with the computer’s choices-and it allows for the coordination, days ahead of time, of movements over the entire railroad rather than on a single line or division.

Empty trains enter the Powder River basin’s coal-containing silo under the railroad equivalent of cruise control. Trains creep in at around 1.5 kilometers per hour, speeds that only the most skillful engineer could match by hand. Computerized loading chutes fill each car with the planned weight of coal-100,000 kilograms, accurate to within about .2 percent. A train can be filled with coal in 45 minutes, or about twice as fast as previous automatic loaders could manage.

As coal trains pull out of the Powder River fields, the locomotives constantly “talk” to Union Pacific headquarters in Omaha. The stream of data gives a running narrative of the train’s condition, as reported by an array of sensors that monitor, for instance, the oil pressure, operating temperature, horsepower output and the rate of fuel usage. In the old days (say, the early 1990s), engineers knew that something was amiss with a locomotive only when it was already in serious trouble. That’s when alarm bells would ring, or the engine would suddenly shut down or start smoking. Union Pacific is outfitting its entire fleet with onboard computers that constantly track the locomotives’ location and health, then report this information to a maintenance desk at headquarters.

Once the fleet is equipped, a given locomotive will signal the Omaha center that it has a problem long before it tells the engineer. The sensors should usually catch problems hundreds or thousands of kilometers before they become severe enough for the engineer to care. Information that an engine is using 15 percent more fuel than normal, for instance, is of little concern to the engineer but of great interest to the maintenance technicians monitoring the locomotive.

Installing computers on locomotives is not exactly like putting them in the controlled environment of an office. Dirt, vibration and extremes of hot and cold are part of everyday railroad operation. Union Pacific experimented for months with various types of shock mountings and vibration-controlling material. According to chief technology officer Lyden Tennison, lessons were drawn from another enterprise that knows a thing or two about adapting high-tech equipment for inhospitable conditions. “We learned a lot from the military,” he says. Locomotive technicians were at first amused, for instance, to learn that the military kept processors plugged into their sockets under constant vibration by tying them down with dental floss. Amused, but impressed: Union Pacific adopted this solution.

2 comments. Share your thoughts »

Tagged: Communications

Reprints and Permissions | Send feedback to the editor

From the Archives


Introducing MIT Technology Review Insider.

Already a Magazine subscriber?

You're automatically an Insider. It's easy to activate or upgrade your account.

Activate Your Account

Become an Insider

It's the new way to subscribe. Get even more of the tech news, research, and discoveries you crave.

Sign Up

Learn More

Find out why MIT Technology Review Insider is for you and explore your options.

Show Me