After NTSB report, Metro to spend $55 million on wheel repairs

Jul 21, 2023

Metro will reassemble thousands of rail car wheels over three years based on federal data released Tuesday that indicates flaws in how they were pressed onto train axles.

The transit agency said it will spend $55 million to repress all wheels on its 7000-series cars, which were suspended in 2021 when defects came to light during the investigation of a derailment that fall. The findings were part of about 1,400 pages of evidence the National Transportation Safety Board released as part of an ongoing 16-month probe.

The hundreds of pages of technical reports made public Tuesday include test results and analyses meant to help investigators pinpoint the cause of the derailment. The data doesn't include a formal probable cause for the derailment, but a series of specialist reports offers the clearest view yet into findings that will help to shape the safety board's final conclusions.

The timing of Metro's service troubles has coincided with the region's attempts to recover during the pandemic, frustrating elected leaders and commuters while putting Metro's management and safety record under increased scrutiny.

Transit leaders said they will develop a plan for the nearly unprecedented step of refitting 5,984 wheels onto 2,992 axles of all 748 rail cars in the series. Metro Chief Operations Officer Brian Dwyer said Metro aims to reassemble the wheels on about 20 cars each month.

"We appreciate the NTSB making the technical reports available so that we can develop our plan to begin repressing wheels on these trains at a higher standard," Dwyer said in a statement.

Metro is hoping the repairs will be a permanent fix to a time-consuming problem for its staff, which must regularly check wheels on its 7000-series cars under an agreement that allowed for their return to service. Metrorail's safety regulator, an independent agency created by Congress, has agreed with Metro's plan, saying the repressing should improve safety but won't solve all problems tied to the derailment.

The reports raised questions about Metro's tracks, including the positioning of restraining rails that help trains navigate turns and the unusual speed at which rail car wheels are wearing down.

"The investigation has shown there are likely multiple contributing factors to all of this," said Max Smith, spokesman for the regulatory Washington Metrorail Safety Commission. "The design needs for the axle assembly can affect one of the factors, but it doesn't affect all of the factors."

The transit agency has looked to move beyond the pandemic and rail car suspension — dual crises that have cut Metrorail's ridership by half amid a shift to telework while denting the agency's financial stability.

NTSB begins investigation into Metro derailment that prompted evacuations

The agency has embarked on an aggressive plan to bring back frequent rail service by the summer, similar to levels the transit system operated before the pandemic. Metro spokeswoman Kristie Swink Benson said the wheel reassembly project, lengthy as it is, won't slow those plans.

What began as a relatively minor derailment on Oct. 12, 2021, between the Rosslyn and Arlington Cemetery stations on the Blue Line — with no serious injuries — spiraled into one of the longest service problems in the transit agency's history. An NTSB investigation into the incident found that a single car on the eight-car train had slipped off the tracks because its wheels had moved about two inches apart on the car's fixed axles.

The defective car caused the train to derail multiple times on its final journey, re-railing itself at switches before stopping short of the Arlington Cemetery station. It uprooted concrete grout pads while brake discs and other parts were broken along the way, causing damage of $161,750 to the track, signal and train control components, the report said.

Investigators, including those at Metro and the safety commission, have said they suspect the defect causing wheels to move apart from fixed axles is the result of many factors, such as how the cars interact with the track and the force with which wheels were pressed onto axles. They have said they do not blame the manufacturer, Kawasaki Rail, which delivered the cars to Metro between 2014 and 2020.

Emergency inspections and a review of records in the days after the derailment found similar movements in about 50 other cars over a four-year span. Despite the repeated recurrences, neither Metro inspectors nor supervisors notified safety department officials, top transit agency leadership or the safety commission, deeming the defects isolated events that required repairs or replacements under the cars’ warranty.

Shortly after the derailment, NTSB Chair Jennifer Homendy said the wheel movement could have been catastrophic if not caught. The safety commission suspended the 7000-series cars on Oct. 17, 2021.

Metro suspends more than half of its rail cars after investigation uncovers safety problems

The cars had been Metro's most modern and reliable to that point, accounting for nearly 60 percent of the transit agency's fleet. Their suspension created a train shortage, requiring transit officials to pull 40-year-old cars from storage and expedite repairs on older cars to cobble together enough trains for the system to stay open.

The shortage forced Metro to lower frequencies dramatically, with some rail lines initially running trains every 25 minutes.

In May 2022, the discovery of a lapse in recertifications among half of train operators led some officials, including D.C. Mayor Muriel E. Bowser (D), to publicly question Metro's leadership, resulting in the resignations of Metro Chief Executive Officer Paul J. Wiedefeld and Chief Operating Officer Joseph Leader on the same day.

The safety commission allowed Metro to put cars back into service this past summer under a plan that required Metro to regularly screen the wheels of 7000-series cars.

Friction between Metro and regulator eases as train wait times drop

After contentious public disputes between Metro and the safety commission over the pace of releasing 7000-series cars back into service, the commission in January allowed transit officials to conduct wheel inspections less frequently. That move freed Metro to ramp up train frequencies to a point where agency officials expect to run pre-pandemic levels of service this summer.

Among the reports released Tuesday was an October 2022 test report from Kawasaki, the rail car manufacturer, which cited the results of what it calls the "wheel back to back distance investigation," or "B-t-B."

"Through the test results, it is presumed that a combination of outward lateral forces applied on the wheel and variations of bending stress on the axle which occur during running (both on mainline and in yard) causes a widened wheel B-t-B distance," Kawasaki found.

A separate January 2023 report from rail engineering firm Hatch LTK said its analysis of the troubled wheelsets and review of published papers on unsafe wheel movements led to the conclusion that under higher steering loads, wheels and axles that are pressed together with enormous amounts of pressure lose some of that bond and become vulnerable to bending.

The 2023 report said those findings are also "consistent" with Hatch LTK's prior investigation, which indicated that the wheelset assembly has insufficient contact pressure due to it being assembled without the adequate amount of force "for the 7K vehicle operating in WMATA's environment."

Regulator approves Metro plan for less-frequent rail-car inspections

Metro said in a response to a separate analysis by the firm MxV that all parties to the NTSB investigation agree that "the wheelset incurs a loss of contact pressure during operation and that the mitigation proposed by Metro — to increase interference fit and to also increase the press tonnage — will effectively address all likely mechanisms identified that might cause wheel migration on the 7000-series fleet."

But Metro also said separate probable cause theories raised by MxV involving vibration and temperature "are not conclusive and lack the supporting data to provide the level of certainty that Metro was seeking from MxV's work."

The documents also point to long-running safety management issues facing Metro and underscore concerns raised by the rail system's safety regulator. In responses to questions from the NTSB on Metro oversight, the safety commission said it "has had to address Metrorail's ongoing efforts to massage or ignore relevant safety data and information."

Metro's safety regulator also said it had been left in the dark about key issues in safety meetings.

"Metrorail did not inform the [safety commission] of back-to-back measurement exceedances in any of these rail car meetings, did not provide any information regarding these exceedances as part of documentation for the [safety commission's] Railcar Audit, and did not mention these back-to-back measurement exceedances or the growing number of these detected exceedances in any way when repeatedly asked orally and in writing about any safety concerns that had not been discussed," the safety commission wrote.

The investigatory documents released Tuesday also pointed to many leaders inside Metro being caught off-guard by a wheelset defect that had been surfacing more frequently before the derailment. Investigators pointed to a lack of clear reporting guidelines that allowed recurring wheel inspection failures to slip past Metro's safety department.

Metro Chief Safety Officer Theresa M. Impastato told investigators there were no barriers that would have prevented the Metro department that monitors the reliability of vehicles or any other department from knowing about the recurring wheel problems, according to the federal documents released Tuesday.

She said that when the issue first was identified, the transit agency had no criteria that supervisors could reference to determine whether the wheelset issue should be elevated to other departments. Impastato told investigators that Metro is overhauling its process for reporting safety issues.

Meanwhile, federal investigators conducted walking inspections of Metro's track and spotted issues that have been previously raised more than seven years ago regarding the width of rails, as well as other design issues that could contribute to — but not cause — derailments.

TTCI, a consultant Metro hired after the derailment, also found 27 spots that are more challenging for car wheels to maneuver than elsewhere in the system. The problem areas, the consultant said, were unlikely to cause wheels to move without other contributing factors.

The report underscored what officials have been saying for months: The wheel movement is not being driven by just one factor.

"At this time, TTCI does not believe that any of these locations produced a severe enough impact to move the wheel and be called the sole root cause," an investigatory report concluded.

Sonic boom: NTSB to begin crash investigation after boom heard across D.C.

Railroad crossings: 400 will be upgraded or eliminated under program

Metro discount: Half-price fare program to launch for lower-income riders

DCA flights: Adding flights at Reagan National would increase delays, FAA says

Maryland mishap: 798,000 license plates promote Philippines gambling site

Debt ceiling: Ailing transit agencies to keep pandemic funding in deal