Stopped short

Leaves trigger braking glitch, halting half of light rail indefinitely

November 18, 2008|By Michael Dresser and Brent Jones | Michael Dresser and Brent Jones and,michael.dresser@baltsun.com and brent.jones@baltsun.com

Thousands of Baltimore-area commuters were forced to abandon trains and board buses yesterday, the first workday disrupted by a light rail shutdown that closed the northern half of the system. State officials were unable to say how long service would be curtailed by a problem caused in part by the fall of autumn leaves.

Commuters attempting to take light rail between North Avenue and Hunt Valley were diverted to shuttle buses, which passengers said added as much as 90 minutes to the trip.

Light rail typically serves 30,000 riders a day - about half of whom use the northern stations.

MTA officials were scrambling to find a way to fix a computerized safety system that regularly over-reacts to slippery conditions and brings trains to a hard stop, frequently damaging their wheels and making them vulnerable to catastrophic cracking.

"I understand there has to be train maintenance, but there seems to be lots of train maintenance recently," said Lori Biddle, 30, who was among several dozen commuters waiting for a shuttle to arrive at the North Avenue station about 4:45 p.m. yesterday.

Biddle said it took her an extra half-hour yesterday morning to go from Lutherville to Camden Yards, where she works: "It is a bit frustrating."

Maryland Transportation Secretary John D. Porcari defended the MTA's decision over the weekend to suspend service on the northern section. "They take customer service interruptions very, very personally, as do I," Porcari said. But, he said, "if we ignored it, it could be a safety issue, and safety trumps everything."

Problems with light rail go back to the original design and route of the system, which opened in 1992 under pressure from then-Gov. William Donald Schaefer to get it running in time for the debut of Oriole Park at Camden Yards. The northern section of the line follows a narrow, old railroad right of way along the Jones Falls Expressway through forested parkland before emerging from the woods north of Ruxton.

The problem, Porcari said yesterday, is that trains run over fallen leaves and can grind the wet plant matter into what he described as a "gelatinous substance."

When another train comes along, the wheels of its cars can slip and slide on that substance, triggering an emergency response from a computerized "train protection" system installed after two light rail crashes at Baltimore-Washington International Thurgood Marshall Airport, in which 35 people were injured.

The computerized system, in use since 2004, has succeeded in preventing trains from crashing into each other or into barriers at the end of the line. But according to MTA administrator Paul J. Wiedefeld, its hair-trigger response to slippage on the tracks has resulted in hard, sudden stops that can flatten the metal surface of the wheels - putting them in added danger of cracking.

Wiedefeld said the MTA has paid more attention to the issue of wheel damage since the discovery last spring of a crack in one of the wheels of a car in a rail yard.

That discovery prompted the agency to inspect wheels much more frequently than the 45-day schedule recommended by the manufacturer. That led to service disruptions, including severe crowding and long waits at platforms.

Last week, as train slippage caused by leaves sent a growing number of cars to the shop, the MTA announced that it would terminate its northern service at Timonium, using buses to serve stations between there and Hunt Valley. But by the weekend, the MTA had so many cars out of service that it decided to call an emergency halt to service north of North Avenue - the most leafy section.

Wiedefeld said the agency is attempting to find an interim solution to the problems by recalibrating the train protection system so that it acts more like the anti-lock brake systems found on cars. The "ultimate fix," he said, will not come until the MTA completes its planned midlife overhaul of its train cars - a project expected to be finished about 2011-2012.

Until then, Wiedefeld said, the MTA has its maintenance shop working around the clock to repair or replace wheels. He said the flattened wheels can be fixed three times before they require replacement - a procedure that can put an entire car out of commission for 15 days.

Wiedefeld said he does not have an estimate now of how long it will take to fix the computer problem. He said any proposed solution would have to be tested on the main line and then verified by an independent contractor before it can be implemented. He added, however, that he doesn't think the disruptions will persist for months.

Porcari echoed Wiedefeld's reluctance to be pinned down to a target date for the return of full service, noting that the weather could be a factor in how long the disruptions continue.

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