In the next few weeks, Metro says it expects to put up to 64 of the 7000-series rail cars back on the tracks.
The cars were pulled from service in October after a train derailed on the Blue Line between Rosslyn and Arlington Cemetery stations. That derailment was blamed on an issue with the wheels alignment.
Metro said in the released plan that it has not discovered “the root cause” of the phenomenon that is causing wheels to drift apart.
“Metro reiterates its commitment for a safe return to service of the 7000-series railcar fleet,” the report states. “Metro understands the root cause of the wheel migration has not been identified and resolved and is wholly committed to the safe and reliable return to service of the 7000-series through carefully controlled operation of the vehicles within the specified criteria for the wheelsets.”
The detailed plan says there will be daily inspections of the cars in the beginning. It said it will start by easing in the number of cars they bring back, beginning with no more than eight per day.
According to the plan, only cars with 350,000 miles or less of service (as of May 17) will be placed back into service. The report says there are 248 cars that fit that criterion.
Metro will need approval from the Washington Metrorail Safety Commission if it wants to change its rollout plan or increase the number of cars it brings back into service.
There will not be a daily mileage limit for these cars, according to the report. But the proposed plan would limit the mileage in between inspections.