NTSB Issues Wheelset Safety Alert, Preliminary Report on WMATA Derailment

Written by Marybeth Luczak, Executive Editor
WMATA 7000-Series Rapid Transit Cars: Courtesy Wikipedia

WMATA 7000-Series Rapid Transit Cars: Courtesy Wikipedia

Following the Washington Metropolitan Area Transit Authority’s (WMATA) Oct. 12 derailment, the National Transportation Safety Board (NTSB) has issued a safety alert calling on rail transit agencies and commuter railroads to check their fleets for “wheelsets that do not meet gage specifications”; NTSB also released a preliminary report on the derailment.

NTSB identified a wheelset movement issue during its investigation of the WMATA derailment involving a train traveling southbound on the Blue line between the Rosslyn and Arlington Cemetery stations in Arlington, Va. (See map below.)

Wheels on certain WMATA railcars “moved outward from their mounted position on the axle,” said NTSB.

Safety Alert 083 (Passenger Railcar Wheelset Alert; download below), released Dec. 1, “encourages” rail transit agencies and commuter railroads to assess their fleets for wheelsets not meeting gage specifications and to take immediate action to correct the problem.

NTSB noted that an “out-of-specification wheelset is not easily identifiable with a routine visual inspection.”

The Safety Alert identifies the wheelset movement issue “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.”

In a similar move, one that NTSB said it supports, the Federal Transit Administration (FTA) on Nov. 1 issued a Safety Advisory requiring State Safety Oversight Agencies to report “out-of-tolerance wheel gauges” on all rail transit rolling stock in revenue service, and recommending fleet-wide inspections of wheel gauges at public transportation systems in their jurisdictions.

Map of the WMATA Blue and Silver lines with the locations where car 7200 derailed noted. (Caption and Map Courtesy of NTSB)

According to NTSB’s Dec. 1 preliminary report on the WMATA derailment, one wheelset on car 7200, the fourth of eight on train 407 departing Rosslyn station, derailed. “After it derailed, the train traveled about 1,800 feet before stopping in the tunnel,” the report said. “All railcars remained upright and inline.

“A preliminary review of data from an onboard event recorder revealed the train speed was about 33 mph at the time of the derailment. Based on physical evidence and station video review, between the Arlington Cemetery and Rosslyn stations, one of car 7200’s wheelsets derailed and rerailed while moving through a pair of switches. The train continued traveling toward the Largo Town Center station. NTSB found that when the train departed the Largo Town Center station, the same wheelset on car 7200 derailed and rerailed again while moving through a pair of switches, and the train continued inbound through Washington, D.C., toward Arlington, Virginia, where the accident occurred.”

Additionally, NTSB examined car 7200 and “found that both wheels had moved outboard from their seats, increasing the gage 2 inches, which exceeded the design specifications. The NTSB also observed increased wear of the wheels.”

According to NTSB, the investigation is ongoing and work will “focus on failure analysis of the wheelsets, evaluation of the response from rail traffic controllers, internal and external oversight of the WMATA system, and identification of similar wheelset issues on passenger railcars.”

Categories: Mechanical, News, Passenger, Rapid Transit, Regulatory, Safety Tags: , , , , , ,