The Metrorail Safety Commission has approved Metro’s testing plan to gather data and learn more about the wheel issues on the 7000-series trains.

The Commission said Friday that they will closely monitor the testing activities.

Metro will use two 7000-series trains as test trains. They’ll run on the system, without passengers, for 12 days to gather data. Metro will then measure the movement of the wheels. If the wheels move too far apart, that can lead to a derailment, like the mid-October incident on the Blue Line.

Both Safety Commission spokesperson Max Smith and Metro spokesperson Ian Jannetta say it’s too soon to say when the trains would return. They also couldn’t specify on if the trains could come back one by one after inspection, or all at once.

“We need to wait and see what (the test) finds,” Smith said.

In the meantime, Metro has moved 32 older 2000 and 3000-series trains from the Shady Grove yard, which are being prepped for service. Metro service will largely remain the same for now: trains every 15 minutes for the Red Line, every 20 minutes on the Green Line, and every 30 minutes for the Orange, Blue, Yellow, and Silver Lines. Metro says it’s making incremental improvements as more trains become available.

After the two 7000-series trains are tested, Metro will submit another plan to implement inspection and other mitigation measures.

“We look forward to receiving that plan,” the Commission wrote in a statement.

Original: Metro submitted a test plan for the 7000-series trains to the Washington Metrorail Safety Commission (WMSC) on Thursday.

The testing plan aims to catch wheels that move too far apart before the problems get so bad it could cause a derailment like what happened on the Blue Line earlier last month. Metro says it thinks inspecting the wheels every eight days should be more than enough to catch minor movements. Metro previously inspected the trains every 90 days, using equipment to measure the distance between the backs of each wheel.

It’s the first step in the process, but the return of the trains is likely still weeks, if not months, away.

“The test plan will allow us to take the data that we have and verify it with the actual experiences,” Metro General Manager Paul Wiedefeld said. “Our team will begin setting up rail cars and inspection stations at Greenbelt to implement the test.”

It’s unclear how long it will take the WMSC to review the plan, but spokesperson Max Smith says “We will be reviewing [Metro’s plan] expeditiously just as we have been extremely responsive to any Metro request for discussion to this point.”

After Metro gets approval for the test plan, it would take about 12 days to test their hypothesis using two trains simulating real-world service levels.

The transit agency will also need to submit an implementation plan for the inspections and get approval for that. It will include the final proposed interval for inspections, the process for inspections, the process for independent oversight of the inspections, and the process for securing trains that are found to have out-of-compliance wheels.

Wiedefeld emphasized that he doesn’t want to rush the process.

“The philosophy we’ve all been following during this whole process is not to set dates,  but rather, let’s make sure it’s safe,” Wiedefeld said. “And that will determine the date. So I think (the WMSC) has the same philosophy we do.

“As soon as they feel comfortable, I think they will get back to us.”

On October 12th, the WMSC forced the 7000-series trains out of service after it learned of dozens of wheels out of alignment, which was a contributing factor to the Blue Line derailment in October. Before the order, Metro had put trains that it had inspected and found had wheel issues back into service, which could’ve led to another derailment.

Metro service has been drastically reduced, as the newest trains make up 60% of the fleet. Metro is working to get more older cars back into service to reduce waiting time. Right now trains are scheduled to run every 15 minutes on the Red Line, every 20 minutes on the Green Line, and every 30 minutes on the Yellow, Blue, Orange, and Silver lines.

This is a developing story and will be updated.