By Ann Scott Tyson
Washington Post Staff Writer
Sunday, November 14, 2010; 7:47 PM
Metro may be the world's largest owner of an outmoded and problematic type of escalator, one that has suffered brake failure accidents in other transit systems and is notorious among experts for requiring a high level of maintenance.
A recent independent audit uncovered widespread deficiencies in Metro's escalator brakes as well as a lack of adherence to escalator maintenance standards. The report suggests that the failure of the moving staircase at L'Enfant Plaza that injured six people last month was not an isolated problem but an accident waiting to happen, according to escalator experts.
The escalator involved is a Westinghouse Modular 100, one of 489 spread throughout the rail system, making up 83 percent of Metro's 588 escalators.
"There is a ton of them out there, and no one is really happy with them," said Ken Smith, an escalator consultant and a member of the escalator code committee of the American Society of Mechanical Engineers. In fact, the model was discontinued 30 years ago.
Metro's escalator problems are amplified simply because it has so many, the experts said. The transit system was designed with escalators as an integral part of moving people in and out of the stations, and Metro has more escalators than any other transit system in North America.
But it's not the only one with problems with the Westinghouse Modular 100.
In Atlanta on New Year's Eve in 2007, braking systems on three of the same type of escalators failed at two different stations that were packed with sports fans headed for the Chick-fil-A Bowl. The escalators accelerated downward, dumping passengers on a pile on the platform and injuring 11 in one incident alone, according to reports.
Earlier this year, the Metropolitan Atlanta Rapid Transit Authority shut down the majority of its 149 escalators - 117 of which are Westinghouse Modular 100s - for a comprehensive review after concerns arose about the thoroughness of a mechanic's maintenance. The agency discovered that 84 escalators needed repair work.
Uncertainty also exists about what work was performed on the L'Enfant Plaza escalator.
A quarterly inspection performed by Metro one month before the accident should have included an inspection of the brakes, said Lisa Farbstein, a Metro spokeswoman. That could have identified that there was a potential problem with the brakes and led to a repair that might have prevented the accident.
A hard copy of the inspection report shows a completed checklist, but an electronic maintenance tracking system indicated the work was not finished, Farbstein said. Metro officials are unsure why the discrepancy exists but are reviewing the incident.
"The investigation continues and needs to run its full course," Farbstein said.
Metro's chronic escalator outages prompted interim General Manager Richard Sarles to initiate in June an independent audit of the moving staircases and of elevators. The assessment by the firm Vertical Transportation Excellence (VTX) covered 30 escalators and nine elevators at the Bethesda, Dupont Circle, Woodley Park and Foggy Bottom stations. The company found a pattern of brake problems.
"All escalator brakes have questionable stopping performance" warned the VTX audit. It also found "brake pads worn beyond usable life expectancy and out of adjustment which could result in a unit freewheeling to stop," it said.
Most of the escalators inspected were Westinghouse Modular 100s. The audit recommended that Metro improve its brake testing and maintenance.
That audit, as well as the discovery of faulty brakes after the L'Enfant Plaza accident and also at the Gallery Place-Chinatown station, led Metro to launch an inspection of all its escalator brakes on Nov. 4 that uncovered scores of other brakes in need of replacement or repair.
A preliminary investigation of the L'Enfant Plaza incident, which occurred as the transit agency experienced record ridership on Oct. 30 for the Jon Stewart-Stephen Colbert rally, found that the brakes failed to hold the escalator in place after the crowd of passengers on it increased the escalator's speed and caused its motors to shut down.
The increase in speed, known as an "overspeed fault," happens when the escalator starts moving at a rate 10 percent higher than its normal speed. That triggers a shutdown in power to the motors and the brakes, which are applied when the power goes off.
But two of the escalator's three brakes were compromised. One had worn pads and the other had oil on the brake shoe, according to Metro. The result: The escalator slid downward for 18 seconds, as passengers ran off or spilled into a pile at the bottom.
Experts said that worn brakes can occur in all escalators, but the design of the Westinghouse escalator could exacerbate them because it is more difficult to maintain.
Unlike most escalators, which have the motors and brakes at the top, the Westinghouse is built in segments with brakes and motors located in each segment at different points along the incline.
The design requires more maintenance, which also takes more time, said one expert on escalator drive systems who spoke on the condition of anonymity because he was not authorized to speak on the record.
"They are just notorious for being noisy and [having] poor ride quality. Particularly as you pass over each of these drives, it's a bump in the road," he said.
Mechanics must constantly adjust the load between the different drive systems, and an imbalance can cause extra wear on one brake, he added.
Metro Assistant General Manager David Kubicek acknowledged during a presentation to Metro's board of directors last month that Metro has suffered from a fluctuating escalator maintenance plan, a shortage of supervisors and a failure to adhere to its own standards.
"The escalator and elevator equipment has been heavily contracted out, brought in, heavily contracted out - its kind of been almost . . . an orphan type of approach on where you really find a home for it so you can start addressing these issues," he said.
Metro lacks "follow-through" on maintenance standards, he said, in part because retirements have cut into the ranks of supervisors, and those on the job tend to work in offices rather than in the field.
"The biggest thing is to get very aggressive about getting supervisors in here," Kubicek said. "We have to have more of a hands-on approach . . . instead of just going through a checklist."
Another problem, experts said, is that unlike buses or rail cars, escalators are constantly in use and cannot be removed to a yard for regular maintenance.
"There is pressure in all transit agencies to provide the amount of time to do effective preventive maintenance," said Patrick J. Welch, chair of the Elevator Escalator Technical Forum at the American Public Transportation Association, which has formed a working group to address maintenance standards for escalators and elevators across the country.
"It's a battle between accessibility to the public and performing effective preventive maintenance," said Welch, who is president of VTX but declined to comment specifically on the company's work with Metro.
"The pressure to get these things back in service so quickly can sometimes turn into 'just get the thing turned back on again,' " he added.