WASHINGTON — The National Transportation Safety Board (NTSB) released a preliminary report on Wednesday that detailed how a Metro train had "increased wear on the wheels" and came off the tracks twice on the day it later derailed along the Blue Line in Arlington last October, stranding nearly 200 passengers on board.
The derailment occurred on October 12 between the Rosslyn and Arlington National Cemetery stops before everyone onboard needed to be evacuated and a passenger was transported to a hospital with injuries.
Following the incident, the NTSB led an investigation and uncovered issues with wheels on the Washington Metro Area Transit Authority's 7000-series train cars.
The investigation led to all of the agency's newest series cars being pulled from the tracks to see how widespread the problems were.
In the report released on Wednesday, the NTSB noted how WMATA found an additional 20 wheel and axle assemblies that were out of design specifications and showed the outward movement of the wheel on the axle.
The agency also released findings from the derailment in October.
According to investigators, the Blue Line train was going around 33 miles per hour when one wheelset on the fourth car of the train came off the tracks.
After the derailment, the train traveled around 1,800 feet before coming to a stop inside a tunnel.
The investigation further reported that the same train car had issues earlier that day.
According to the report, around 90 minutes before the final derailment, one of the train cars wheelsets derailed and rerailed while moving through a pair of switches before traveling on to Largo Town Center station.
About 50 minutes later, the same wheelset came off and on the tracks as it left Largo Town Center and moved through a pair of switches.
Almost 35 minutes later, the final derailment occurred.
In Wednesday's report, investigators reported finding broken sections of brake discs north of the Arlington Cemetery station and at a turnout near Largo Town Center station.
Following the derailment, inspections of the train car that derailed found that both wheels had moved "outboard from their seats" and beyond design specifications.
The NTSB also reported "increased wear of the wheels."
On Wednesday, the findings led to the agency issuing a Safety Alert while calling on rail transit groups and commuter railroads across the country to examine their fleets for wheelsets not meeting design specifications.
The NTSB later implored for immediate action to be taken if problems are found.
“The Safety Alert identifies the issue of wheelset movement on transit railcars and commuter railroads as a serious problem that has the potential to create a catastrophic event,” said Robert Hall, Director of the NTSB’s Office of Railroad, Pipeline and Hazardous Materials Investigations. “As we continue to conduct the investigation of this derailment, it is imperative that the safety issues identified are addressed immediately to protect the American public traveling daily on our transit system.”
The investigation into the derailment and 7000-series cars is ongoing.
On Wednesday, the agency said future work will focus on failure analysis of the wheelsets, evaluations of the response from rail traffic controllers, oversight of the WMATA system, and identifying other possible wheelset issues on rail cars.
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