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November 2010
by Angela Cotey
Two decades ago, railroads employed manual processes to monitor the location and health of rail cars. Yard clerks would walk up and down tracks and manually inspect trains and record the number of cars in a consist. Clerks at larger classification yards would view slow-motion videos of departing trains and write down which cars had left.
The car-tracking job has gotten easier and quicker during the past 20 years after the introduction of automatic equipment identification (AEI) systems, which trace cars via wayside scanners that read transponders placed on the sides of cars as they pass a scanner site.
"AEI has made us more efficient in terms of being able to record information with fewer costs," says Warren Stubbs, director of information systems development for Norfolk Southern Railway. "It's also given the customers much more timely information."
Although some railroad operating officials believe AEI is dated, it still provides the basic information they need to track cars. And since it would take a lot of time and money to install new tracking devices on all cars, railroads are analyzing different ways to use AEI and other existing onboard and wayside technology to maximize the information-gathering process until other viable options emerge.
"We're using and leveraging a lot of our wayside technologies that we have had for a long time, but are learning new ways of exploiting it to keep track of cars, find out what's going on and be proactive on fixing things before they turn into bigger events," says William Blevins, CN's chief mechanical and electrical engineer.
That could mean coupling AEI with data gathered from other sources to obtain more detailed train consist information. For example, NS recently began installing Global Positioning System (GPS) devices onboard locomotives. During the past couple of months, the Class I has begun reporting train arrivals and departures by combining GPS time stamps with AEI scanner readings from GPS locomotive-hauled cars.
In some locations, NS has set up a "geo-fence," a virtual perimeter around a geographical area that enables operating department workers to use a locomotive's GPS time stamp to propagate all the cars in a particular consist.
"By virtue of the fact that this locomotive has entered this geo-fence, we can use those time stamps to automatically report those rail cars in or out of a location," says Stubbs, adding that the Class I plans to continue employing the practice at more locations.
In some cases, NS can track cars via locomotive GPS in areas where AEI scanners have not been installed. When a locomotive enters a geo-fence and the railroad has accurate consist information for the cars that are being hauled by that particular locomotive, NS can use the GPS time stamp and planned list of cars to automatically report cars that moved off of a customer's siding, says Stubbs.
"We're one of the few railroads that has begun to use the raw GPS reporting on locomotives without AEI to do customer siding car tracking," he says.
CSX Transportation also recently began using GPS devices onboard locomotives and geo-fencing to help track train consists.
"We've used it to identify an arrival point, unloading point and departure point, and use that information to help us report car-trace events based on where a train is within that geo-fenced area," says Al Lancaster, CSXT's general manager of business systems for the Class I's Customer Service Operations.
The railroad has implemented the practice with eight customers, mostly coal utility plants. In 2011, CSXT officials hope to add new onboard, GPS-equipped devices that provide further benefits, Lancaster adds.
Short lines and regionals use AEI readers to track cars, as well. Genesee & Wyoming Inc. (GWI), which owns and operates 62 regionals and short lines in the United States, Canada, Australia and the Netherlands, has installed AEI readers at strategic points, although not at all locations.
"If you're a small, five-mile-long short line, you don't need a lot of AEI readers to figure out where your cars are," jokes Tony Long, GWI's senior vice president of operations support.
But where it can, GWI shares car-tracking information with its Class Is interchange partners.
"Certain Class Is give you an added incentive if you report your data in real time," says Long. "For example, we can add 2 percent to the amount we bill them for the month."
Car-tracking keeps shippers happy, too, since it helps them predict when a shipment will arrive.
"Computerized movement of the cars is there for one purpose: to mirror the physical movement of the car around the country," says Long. "It supports operations, customers who need to know where their shipment is and car owners who need to know where their cars are."
Railroads also use car-tracking technology to support rail-car health. CN is "very committed" to using wayside technology to monitor the health of its rail cars, says Blevins.
For example, the Class I has a network of hot-wheel detectors installed about every 30 miles throughout its system. The detectors monitor wheel temperature and set off an alarm if one gets too hot, at which point a crew member has to attempt to identify the source of the problem, says Blevins.
However, for the past several years, CN has begun monitoring wheels more closely when they pass the detectors.
"We found we could be proactive and monitor the wheel before it got hot enough to set off the alarm," says Blevins. "All the wheels should be cold. If we find a warm one, we can ask the crew to make a brake application [to prevent a stuck brake] and release it. Almost every time, we can get the problem to go away."
CN follows a similar procedure to monitor rail-car bearings. Rather than wait until a bearing gets hot enough to set off an alarm, mechanical department workers watch for warm bearings that show signs of failure so they can be replaced before burning off, says Blevins.
The Class I monitors wheel and bearing activity through a 24/7 rail traffic control center desk.
"All the signals from these wayside detectors had to come into a central location so we could handle the data," says Blevins. "Most railways had placed detectors on the wayside that were just local sites and broadcast an alarm by radio to the crew. We did that, but all the signals come back to a central office so we can see everything."
By proactively addressing mechanical issues using information gathered from wayside detectors, CN can reduce visual inspections and, in many cases, prevent an engineer from having to stop a train, Blevins says.
"We're not only using individual technologies that add value to us, but we collectively want to provide a much more detailed inspection of a car and its health," he says. "I'm never one to say all visual inspections will disappear — there's a value to that — but the frequency can be altered and much more detailed looks can be done on brake systems and wheels and bearings, the performance of track and loads of cars, and a number of other factors."
The need for more information is becoming even more crucial. That's why railroads are re-examining their car-tracking needs to determine how new technology could better meet the demand for relevant, real-time data.
"It's an evolving industry; everyone's looking to find that better mousetrap," says CSXT's Lancaster. "There's a need to have data so much quicker. Customers are loading and unloading cars faster. Sometimes you don't show the car's even been placed and they're already unloading it."
Railroads would prefer to implement systems that provide more information about each car, using GPS or satellite technology, says Lancaster.
"It's like having a smart car," he says.
Some Class Is are beginning to explore motes technology, says NS' Stubbs, who describes a mote as a "low-power computer and sensor platform with radio communications."
"Imagine a three-inch transistor radio. In essence, that's what a mote is, but it's much more powerful," he says. "It has a tiny computer chip inside of it and also has the ability to communicate with other motes that are nearby."
Just as AEI transponders are attached to rail cars, motes could be attached to cars and use wireless communications to interact with other nearby motes.
"The technology is self-realizing," says Stubbs. "It knows which car it is and which car it's connected to, and the other car knows it's connected to."
The system also could feature data sensors to detect various conditions, such as chemical radiation, tampering and brake status, Stubbs adds.
"Today, car-tracking has been relegated to knowing where the car is at any point in time," he says. "The mote technology allows us to do data acquisition on that car so we can make better decisions on the health of that rail car and its surroundings. We can have more accurate consists without the need of the older AEI technology."
But for now, AEI systems and other devices that help railroads monitor car location and health will have to suffice until other technologies advance.
"Everything will have its time," says GWI's Long. "They were talking about PTC 15 years ago and that's just now happening, so a new way of using GPS and some other technologies is probably at least that far into the future."
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