To increase the safety and reliability of its trains and railways, railroads have integrated computer controlled information management systems. Some have even moved to satellite tracking. With each upgrade, however, the railroads struggle with the inherent difficulties of automating an old infrastructure .
The need for automation is significant. To run an efficient railroad, the company must monitor each locomotive, car, maintenance crew member, train crew member, passenger, railway switch, crossroad signal, and piece of cargo. It even needs to monitor bad weather.
From Telegraphs to Satellites
In 1851 the railroads discovered that the newly invented telegraph gave engineers and train station operators a new ability to communicate among themselves. For the first time, the arrival and departure of trains could be coordinated safely, which was especially important when multiple trains shared a single track. Later, when the telephone was invented, train management improved even more.
The first computers bought by the railroads, in the 1970s, were minicomputers that recorded and stored critical information in databases. Although the databases represented a significant improvement over paper records, they worked independently of each other: one was for scheduling crews, one for planning cargo shipments, one for moving locomotives, and so on. The databases could not communicate with each other, and most were updated only on a nightly or sometimes weekly basis.
In the 1980s companies adopted a new train-tracking system using bar codes painted on the sides of rail cars. As the trains passed by, the bar codes were scanned and the data was sent to the local computer. In actual operations, however, the bar codes got dirty or the paint wore off so scanners could not read them at high speeds.
Credit-card-sized electronic tags, called transponders, replaced the bar codes. Each one sent out a radio signal that could be read as the train passed by a reader placed along the railway. The technology worked successfully at speeds exceeding 130 kilometers (80 miles) per hour, but the data were collected in local databases, which were not networked together.
In the mid-1990s, railroad companies began linking their databases. The trackside readers became part of an electronic data interchange network that collected data in a worldwide database for the entire rail industry. With these new tools, analysts could spot trends and plan solutions for improved service.
Some railroads consolidated their trackers and analysts in a central operations room, from which they could quickly control almost every aspect of the entire railway. With the aid of these computerized systems, the operators controlled every locomotive, train, signal, and switch on the system.
Satellite tracking was adopted by some railroads in 2000. For example, the CXS Railroad equipped 3,000 locomotives with global positioning system (GPS) technology so the company could track the fuel data and location of each car to within 100 meters (110 yards). Although GPS technology works successfully, its use was still controversial as of 2001. Critics say that the system's high cost rules out widespread application throughout the industry.
Operating a railroad is so complex that when something goes wrong, the effects ripple throughout the company and the communities it serves. For example, in June of 1999, Norfolk Southern Railroad attempted to create a single combined computer system to replace its primary train control system and that of the newly acquired part of Conrail, the Consolidated Rail Corporation. The switch from the old systems to new ones—called a conversion —took place on a single day, but the difficulties lasted for many months.
The first problem became evident immediately when, on conversion day, the wrong magnetic storage tape was loaded onto the new system. The tape held old data ("test data") instead of real information, which tracked real-life trains, crews, and shipments.
The system began creating incorrect waybills, or instructions, which sent trains and cars to the wrong destinations. In some cases, trains filled with cargo sat idle in train yards waiting for crews that never arrived. Several cars held loads that were never emptied as the cars moved undetected back and forth between terminals. Other trains traveled successfully to their intended destination but were empty of cargo. Crews worked overtime and certain crew members, who by law cannot work overtime, had to wait for fresh replacements.
Average train speed dropped from 32 kilometers (20 miles) per hour to 26.9 kilometers (16.7 miles) per hour causing widespread congestion and even slower shipments. Extra trains were added for extraordinarily important shipments, which added to the delays. In Ohio, rail cars blocked a traffic intersection causing emergency vehicles to take a 34-kilometer (21-mile) detour around them.
As the delays increased, shippers pulled their cargo from the railroad, choosing instead to send shipments by truck. Even the Norfolk Southern Railroad was forced to spend millions of dollars ($29 million in June of 1999 alone) to ship cargo for its best customers by alternative means.
In time, the problems receded. Six months after the conversion, the new computer system was operational and experiencing only a few glitches. Although the company was still losing millions of dollars' worth of business, it said the integrated system was facilitating its rail operations.
Positive Train Control
The Positive Train Control (PTC) project, run by the U.S. Department of Transportation's Federal Railroad Administration (FRA), promotes the use of computerized technology to manage and control railroad operations in the United States and Canada.
The project's primary goal is to reduce the probability of collisions. In addition, project planners hope to reduce train delays, increase running-time reliability, increase track capacity, and improve the use of crews and equipment. The project consists of a series of program tests conducted in cooperation with railroad companies.
For example, the Michigan PTC project began in 1995 on Amtrak's 114-kilometer (71-mile) corridor linking Chicago and Detroit. Its centralized computer system monitors operations throughout the railroad. As a train moves down the track, the wayside signal system radios the status information to the locomotive's onboard computer. The onboard system keeps the engineer informed of permitted speeds and limits of operation, and it stops the train if unsafe operation is attempted.
The PTC project in Alaska, launched in 1998, uses computer-aided dispatching to help the Alaska Railroad manage a vast network of track that stretches for many miles without signals through rugged wilderness territory. The centrally controlled computer system enforces critical factors, such as mandatory stops and speed changes, but it has no provisions for detecting broken rails or the position of rail switches.
Not everyone applauds the PTC projects. In December of 1999, the Brotherhood of Locomotive Engineers warned that with too much reliance on technology, engineers could lose their situation awareness and their finely tuned operational skills. The union made several recommendations, including simulator training, to help locomotive engineers keep their skills sharp.
see also Aircraft Flight Control; Astronomy; Display Devices; Navigation.
Ann McIver McHoes
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"Railroads Hot for Satellite Monitoring." Computerworld. April 3, 2000.
Wormser, Richard. The Iron Horse: How the Railroads Changed America. New York: Walker and Company, 1993.
"Federal Railroad Administration Announces Positive Train Control Project." U.S. Department of Transportation web site. <http://www.dot.gov/affairs/1998/fra0298.htm>