Inspecting Our Rails
Thursday, February 21, 2008 5:19 PM
Call it the annual rite of spring.
Every year - in either March, April or May - METRO tests our 7.5-mile railroad track with a device called a track geometry vehicle.
This machine glides along the rails and employs ultrasonic testing to discover cracks or other flaws. It will detect warps, gage issues, curves, elevations and speed limitations, says Scott Grogan, senior director of rail operations.
"The most recent testing resulted in a permanent speed restriction of 15 mph, implemented at old Main northbound," said Grogan. Geometry testing revealed that the curve at Fannin and old Main did not meet the federal guidelines for allowable speed at that curve because of the elevation of the outside rail. That curve met the federal criteria for a Class 1 speed of 15 mph.
"It should have been 15 mph from the get-go," said Grogan.
The rail flaw detector car was invented by Dr. Elmer A. Sperry, who started eight manufacturing companies and held more than 400 patents. His rail flaw detector car was first used commercially in 1928 to inspect rail. Today, the Sperry Rail Service Corp. is widely used in the industry to test rail, and it's what METRO uses.
In addition to this annual testing, METRO conducts weekly walking inspections performed by track maintainers. "They're looking for any gouges out of the rail, any broken rail, anyplace where the embedded area around the rail might be defective or broken," said Duane Sayers, director of rail transportation, adding, "We want to make sure the switches are all clean and operate properly."
For example, recently track maintainers found that rails were being gouged at certain downtown intersections. After conducting an investigation, we discovered that the city street sweepers were inadvertently causing that to occur. We brought in a welder who specializes in welding rail to repair the problem spots.
Safety, of course, is foremost - and inspectors are always making sure "the rails are in gage, within specs - not too wide, not too narrow," explained Sayers.
Washington Metropolitan Area Transit Authority is planning to buy its own track geometry vehicle to inspect its 106-mile rail system.