The number of cracked rails on Metro's rail system has soared in recent years, growing from seven in 2008 to 49 broken rails in 2011, according to the agency's records.
Metro had 11 in the first two months of this year, according to the latest data Metro provided in a public records request, putting it on pace to have even more in 2012.
|Metro's growing cracked rail problem|
|Year||Above-ground cracks||Underground cracks||Total|
|* Jan. 1- through Feb. 27|
|NTSB chairwoman: Small problems are warning signs|
|Cracked and kinked rails are just the latest problem that Metro has had recently with its rail system, even after enacting major reforms.|
|In the past seven months, Metro has had three cases of brake equipment falling off moving trains. It has had two derailments. And an agency mechanic was critically injured when a train hit him in a railyard washing station.|
|The individual issues could be a sign of broader problems, according to National Transportation Safety Board Chairwoman Deborah Hersman.|
|"All of these events are really warning signs for Metro. They have to heed these. They have to pay attention to them. And they have to act on them," she told The Washington Examiner at the third anniversary of the deadly Fort Totten crash. "There really is a taxonomy when you see accident investigations. You see close calls. You see incidents and then you see accidents. And it's important really to intervene early in that process."|
Such cracks in the metal rails are severe hazards that can cause long delays for riders -- or even derailments. In March 2009, one cracked rail caused two trains to derail on the Red Line between Bethesda and Friendship Heights. The issue was highlighted again on Friday when a Green Line train derailed after the rail buckled in a heat kink, an expansion of stressed metal.
Metro has typically blamed weather extremes for such rail problems, as in Friday's derailment. After two cracked rails on the same day in January snarled commutes, Metro's chief spokesman said the breaks were caused by a drop in temperatures, not by the transit system's aging infrastructure.
Extreme shifts in temperature, from mild to freezing or warm to hot, cause the metal rails to shrink and expand. In the winter, that can mean cracked rails, while in the summer the rails can warp or pop out in what is called a heat kink.
But 53 percent of the 119 cracked rails found in the past five years have been underground, not above ground, where temperatures do not fluctuate as widely. And some have been found in every month of the year, when temperatures are steadily hot, steadily cold or just plain pleasant. In fact, one of the two cracks that January day occurred on an underground section of track, according to Metro records.
Two former longtime Metro employees -- one an executive and the other a former track walker -- said they were surprised that so many cracks are being found underground.
"Underground temperatures are typically more stable and it used to be extremely rare that a rail would crack in an underground tunnel," the former executive said.
The retired trackwalker said underground rail problems are likely due to water drainage problems and the age of the tracks.
"A lot of it's poor housekeeping," he said.
The transit agency has acknowledged that weather isn't the sole cause.
"The increase in cracked rails is a result of the age of the system, underinvestment in rail replacement over many years, better and more thorough inspections ... and improved training of track inspectors,"said Metro spokeswoman Caroline Lukas.
Metro track walkers inspect the rails twice a week, but do it more often in areas with the oldest rails. An outside contractor uses ultrasonic equipment to spot the breaks five times a year.
Metro also is putting hope in a piece of brand-new equipment that it has likened to the difference between giving tracks an X-ray versus using three-dimensional magnetic resonance imaging -- and using it monthly. "The new track geometry vehicle does ultrasonic testing of rails and can see internal cracks developing that are not visible to the naked eye," Lukas said. "It will be a useful tool, along with ongoing capital rail replacement, to minimize customer disruption from cracked rails in the future."
The agency still has to test the new equipment, though, and doesn't expect it will start using it until later this year. In the meantime, it will continue to use the X-ray-like equipment, called Sperry cars, for another 24 months, Lukas said.