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Spring 2003
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Maintaining More Than 700 Miles of Track

Long Island Rail Road Rolls With GIS

  The TC-82 car
The TC-82, or geometry car, measures all aspects of the track including gauge width, rail profile, cross elevation, and an assortment of other measurements. It also gives a GPS location. Usually three people staff the car as it travels approximately 40 mph down the track.

Barreling down the tracks for 167 years, trains from the Long Island Rail Road (LIRR) carry an average of 290,000 passengers each weekday throughout the Long Island-to-Manhattan corridor. The demands of operating 740 trains daily and maintaining more than 700 miles of track that extend from the eastern tip of the island to the heart of Manhattan might seem daunting to even seasoned managers, but LIRR has it down pat. Last year more than 93 percent of all the trains arrived on time at LIRR's 124 stations.

The Engineering Department where Brian George, assistant manager, Tactical Planning, works at LIRR had been using CAD for several years for system road charts. Road charts are line diagrams of the tracks showing spatial data, but they were in hard copy format and not to scale. As George puts it, "It always was a dream to click on a spot and see what was there. We needed a living road chart."

Approximately four years ago, Christopher Powers, GPS/GIS manager of the Strategic Investments Department, a division at LIRR that tests implementations of long-term procurements, carried out several trials of GIS software and decided that Esri software was the solution. George worked with Powers to learn about GIS and how it could be used in the Engineering Department. He began to use ArcView 3.2 in the Engineering Department and has now migrated to ArcGIS.

click to see enlargement
With data provided with GPS, ArcPad shows track centerlines approximately 13 feet apart. Also shown are areas that are safe for trains but may give commuters a feeling of horizontal movement within the comfort zone.

With an eye toward eventually establishing a corporatewide GIS, LIRR's Strategic Investments Department hired consultant Bowne Management of Mineola, New York, an Esri Business Partner, to develop a basemap that could serve each department's needs. Bowne subcontracted John Chance Inc. to provide accurate aerial surveys of the railroad tracks with a helicopter equipped with a GPS receiver, video imaging, and a reflectorless rangefinder. With an x, y, and z coordinate on every point, George says this produced "an accurate map up to about three and one-half inches--with more than 95 percent accuracy." Bowne digitized the track centerline and all of the other attributes from the flyover including crossings, platforms, and signal bridges and imported them into the GIS for the basemap.

Anxious to put the GIS to use, one of George's first projects while working with Powers in the Strategic Investments Department was to verify the grade at a railroad crossing. This is an important issue because if the grade is too steep for cars and trucks to cross, LIRR could be liable if and when an accident occurs. George input the points from the flyover map into ArcGIS 3D Analyst to determine if the grades at crossings were within tolerances. This process is quicker and cheaper than sending a crew out to survey the crossing.

Sophisticated Cars

As part of LIRR's ongoing maintenance program, a specially equipped car carrying an assortment of sophisticated measuring devices traverses the railroad tracks collecting data and alerting personnel if problems are observed. The car, called the TC-82 or the geometry car, measures all aspects of the track including gauge width, rail profile, cross elevation, and an assortment of other measurements. It also gives a GPS location. Usually three people staff the car as it travels approximately 40 mph down the track, but personnel have been added at appropriate subdivisions along the way.

George says staff members were getting overloaded because the geometry car collects so much information. His supervisor, Steve Daleo, assistant chief engineer, administration, asked if GIS could help with the process. "We took that information, which has all sorts of data--rail defects, points of interest, grade crossings, stations, signals, mileposts-and broke it down into a normal format, which became an Access database. Then we took that table and imported it into the GIS," George says. They were striving for more accurate locations of defects and trend analysis of the tracks and quicker turnaround, and the GPS points and GIS helped achieve that goal.

Sifting Through Stacks of Paper

The GIS is becoming a valuable tool for the Engineering Department as the staff looks at track gauge to determine where a width of track is not within company and federal guidelines. Ideally, tracks should all be the same dimension from each inside rail, but wear and tear can cause them to go out of alignment a few fractions of an inch. For LIRR, the maximum is three-quarters of an inch. Using the GIS and data from the TC-82, which provided points for maximum measurements, George was able to locate areas of track that were outside the normal range of 56 1/2 inches.

  click to see enlargement
Before embracing GPS, the Engineering Department used landmarks to locate defects. Here are shown a platform and a milepost.

"For the first time, we were able to see all of this information on a map. Originally, it was on green bar paper--stacks of it. A supervisor would have to use a ruler and manually locate the gauge discrepancies and other defects. It took a lot of time, but now it's easier." The paper method also limited trend analysis. Now George says he can see wide gauge, tight gauge, cross elevation, and rail twist at a glance. "With the GIS, I can turn around the data from the TC-82 within two weeks from when I receive it, and it's in a format that lets the engineers see and understand where they are; it's a picture."

Being able to place those points on a map and visualize them sold George's bosses on the potential of GIS, and the chief engineer was particularly impressed with its capability to easily sort points that matched a given dimension. "Now we know exactly what we have to fix and where it is. We have the nearest cross street, milepost, or anything on the basemap, and we are within two and one-half feet because of the GPS accuracy on the TC-82."

An ArcPad Application

Striving for maximum efficiency, LIRR is interested in putting handheld computers to use. Currently, the Engineering Department is testing an ArcPad 6 application. "We can locate defects in the tracks picked up by the geometry car," George explains. "I transfer the TC-82 data into a shapefile and then import it into the handheld device. It shows up as a point on the track centerline within the handheld device. We are currently testing GPS units so that we can move to the next step."

The next step to this application is to equip personnel out on the tracks with Trimble GPS units and handheld devices so they can accurately pinpoint the part of track that needs repair. Previously, workers in the field had to find areas of wide gauge or any defect by locating the closest milepost and counting off the number of feet. "This doesn't work well when you get into counting off 2,753 feet," says George. "Now they can go out there with their handhelds and GPS and get their mark."

Sharing Data Corporatewide

Having established GIS applications in the Engineering Department, LIRR has moved to make it available corporatewide. Indeed, the Track Department has now embraced the technology and is using it to locate defects such as twists in the rails. All departments share the basemap data, and George is excited about the capabilities of ArcIMS and being able to bring more of LIRR's employees online as GIS users.

While the railroad would run with or without GIS, George says, "In the future, GIS is going to fill a big spot for us. It will go as far as your imagination will let you. As more of our project managers realize its potential, I get more requests for aerial and property line maps. It is a savings of time and money, and it is definitely showing its usefulness now."

For more information, contact Brian H. George, assistant manager, Long Island Rail Road Tactical Planning (tel.: 718-558-4816, e-mail:

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