After almost two weeks of disruption, the Maryland Transit Administration will restore service to the northern half of Baltimore's light rail system tomorrow - just in time for the Ravens' 1 p.m. game against the Philadelphia Eagles.
The MTA said it can resume service to stations north of North Avenue because it has devised a way to operate trains on slippery tracks without causing damage to the wheels.
A computer system that forced a hard stop when trains encountered slippery conditions - such as fallen leaves - caused so much damage to the wheels that the MTA was sending cars to its maintenance shop faster than it was able to fix them.
First the agency halted rail service between Timonium and Hunt Valley and replaced it with a bus shuttle. After more cars' wheels were damaged on the heavily wooded stretch between North Avenue and Ruxton, Administrator Paul J. Wiedefeld called a halt to all service above North Avenue.
Service between North Avenue and the two southern ends of the system - Glen Burnie and Baltimore-Washington International Thurgood Marshall Airport - was not affected.
MTA spokeswoman Cheron Wicker said the agency is confident it will have sufficient capacity to serve football fans headed for the Ravens game. However, the MTA warned that some trains will consist of single cars, possibly causing crowding at times of peak demand.
Rail shuttles between Pennsylvania Station and Camden Station will not resume tomorrow. Wicker said she did not know when they will be restored. Until then, a bus shuttle will continue to carry passengers between Mount Royal Station and Penn Station.
The resumption of service on the main line was made possible by a software fix developed by the MTA engineering, operations and safety employees, Wicker said. In effect, the revised program will tell the computerized train protection system to apply the brakes gradually rather than suddenly when it senses slippage on the track.
Wicker said the more gentle braking is expected to greatly reduce the flattening on wheel surfaces - a condition found to have contributed to a potentially dangerous crack found in the wheel of a train in an MTA rail yard in April.
The spokeswoman said the MTA will take other steps to prevent wheel damage, including reducing speeds on the sections of track where damage has been occurring, cleaning the tracks overnight with a truck-mounted power washer and increasing the use of sand on the tracks to create greater friction and reduce slippage.
