NTSB -- NTSB IDENTIFIES SIGNAL FAILURE IN FATAL DC METRORAIL COLLISION; ISSUES URGENT SAFETY RECOMMENDATIONS TO TRANSIT AUTHORITY, FEDERAL RAIL AGENCIES, AND CIRCUIT MANUFACTURER

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NTSB PRESS RELEASE

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National Transportation Safety Board

Washington, DC 20594

FOR IMMEDIATE RELEASE: September 22, 2009

SB-09-53

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NTSB IDENTIFIES SIGNAL FAILURE IN FATAL DC METRORAIL

COLLISION; ISSUES URGENT SAFETY RECOMMENDATIONS TO TRANSIT

AUTHORITY, FEDERAL RAIL AGENCIES, AND CIRCUIT MANUFACTURER

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The National Transportation Safety Board (NTSB) today issued

nine safety recommendations, six of which are urgent, to

address concerns about the safety of train control systems

that use audio frequency track circuits. The recommendations

are the result of NTSB's ongoing investigation into the

collision between two Washington Metropolitan Area Transit

Authority (WMATA) trains on the Red Line near the Fort

Totten station in Washington, D.C., on June 22, 2009.

During the investigation, the NTSB has discovered that a

failure occurred in which a spurious signal generated by a

track circuit module transmitter mimicked a valid signal and

bypassed the rails via an unintended signal path. The

spurious signal was sensed by the module receiver which

resulted in the train not being detected when it stopped in

the track circuit where the accident occurred.

The NTSB made specific recommendations to the Washington

Metropolitan Area Transit Authority and to Alstom Signaling,

Inc., the manufacturer of the track circuit modules at the

Fort Totten station, to examine the WMATA track circuits and

work together to eliminate adverse conditions that could

affect the safe performance of these systems. Additionally,

the NTSB called upon WMATA to develop a program to

periodically determine that the electronic components in its

train control systems are performing within design

tolerances.

Although the NTSB's investigation is not yet complete and no

determination of probable cause has been reached, the NTSB

is concerned about the safety of train control system

circuitry used in comparable rail and transit operations in

other parts of the country. Therefore, the NTSB recommended

that the Federal Transit Administration (FTA) and the

Federal Railroad Administration (FRA) advise all rail

transit operators and railroads that use audio frequency

track circuits in their train control systems about these

findings from the Fort Totten accident investigation.

The NTSB also recommended that the FTA and FRA have transit

operators and railroads that use audio frequency track

circuits examine their track circuits and work with their

signal equipment manufacturer(s) to eliminate adverse

conditions that could affect the safe performance of these

systems, and to develop programs to periodically determine

that the electronic components in their train control

systems are performing within design tolerances.

"After only 3 months, this complex investigation is far from

complete, so we are not ready to determine the probable

cause of the accident on WMATA," said Chairman Deborah A.P.

Hersman. "However, our findings so far indicate a pressing

need to issue these recommendations to immediately address

safety glitches we have found that could lead to another

tragic accident on WMATA or another transit or rail system."

In accordance with NTSB protocol, the letters were addressed

to the heads of each organization with a request for a

response from each organization within 30 days on the urgent

recommendations, addressing the actions taken or planned in

response to the Board's recommendations.

The safety recommendation letter to WMATA may be found here:

http://www.ntsb.gov/recs/letters/2009/R09_15_16.pdf

The safety recommendation to Alstom Signaling, Inc., may be

found here: http://www.ntsb.gov/recs/letters/2009/R09_23.pdf

The safety recommendations letter to FTA may be found here:

http://www.ntsb.gov/recs/letters/2009/R09_17_18_19.pdf

The safety recommendation letter to the FRA may be found

here: http://www.ntsb.gov/recs/letters/2009/R09_20_21_22.pdf

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NTSB Media Contact: Bridget Serchak

202-314-6100

Bridget.serchak@xxxxxxxx

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