Skip Ribbon Commands
Skip to main content
Safety Recommendation Details

Safety Recommendation R-10-025
Details
Synopsis: On Monday, June 22, 2009, about 4:58 p.m., eastern daylight time, inbound WMATA Metrorail train 112 struck the rear of stopped inbound Metrorail train 214. The accident occurred on aboveground track on the Metrorail Red Line near the Fort Totten station in Washington, D.C. The lead car of train 112 struck the rear car of train 214, causing the rear car of train 214 to telescope1 into the lead car of train 112, resulting in a loss of occupant survival space in the lead car of about 63 feet (about 84 percent of its total length). Nine people aboard train 112, including the train operator, were killed. Emergency response agencies reported transporting 52 people to local hospitals. Damage to train equipment was estimated to be $12 million.
Recommendation: TO THE MASSACHUSETTS BAY TRANSPORTATION AUTHORITY, THE SOUTHEASTERN PENNSYLVANIA TRANSPORTATION AUTHORITY, THE GREATER CLEVELAND REGIONAL TRANSPORTATION AUTHORITY, THE METROPOLITAN ATLANTA RAPID TRANSPORTATION AUTHORITY, THE LOS ANGELES COUNTY METROPOLITAN TRANSPORTATION AUTHORITY, AND THE CHICAGO TRANSIT AUTHORITY: Work with Alstom Signaling Inc. to establish periodic inspection and maintenance procedures to examine all General Railway Signal Company audio frequency track circuit modules to identify and remove from service any modules that exhibit pulse-type parasitic oscillation.
Original recommendation transmittal letter: PDF
Overall Status: Closed - Acceptable Action
Mode: Railroad
Location: Washington, D.C., DC, United States
Is Reiterated: No
Is Hazmat: No
Is NPRM: No
Accident #: DCA09MR007
Accident Reports: Collision of Two Washington Metropolitan Area Transit Authority Metrorail Trains Near Fort Totten Station
Report #: RAR-10-02
Accident Date: 6/22/2009
Issue Date: 8/10/2010
Date Closed: 9/12/2011
Addressee(s) and Addressee Status: Chicago Transit Authority (Closed - Acceptable Action)
Greater Cleveland Regional Transit Authority (Closed - Acceptable Action)
Massachusetts Bay Transportation Authority (Closed - Acceptable Action)
Metropolitan Atlanta Rapid Transit Authority (Closed - Acceptable Action)
Southeastern Pennsylvania Transportation Authority (Closed - Acceptable Action)
State of California, County of Los Angeles, Metropolitan Transportation Authority (Closed - Acceptable Action)
Keyword(s): Maintenance,

Safety Recommendation History
From: NTSB
To: Chicago Transit Authority
Date: 1/31/2011
Response: The NTSB is pleased that the CTA worked with Alstom in December 2009 to examine GRS AFTC modules on the CTA’s Purple, Yellow, Red, Brown, and Green Lines and changed out power supplies that were significantly out of tolerance. We are aware that Alstom representatives returned to CTA in September 2010 to perform a comprehensive audit of all GRS track circuits on the system. At the time of the audit, no AFTC modules were observed to exhibit pulse-type parasitic oscillation. We also note that CTA performs preventive maintenance quarterly. The actions detailed in your letter fully address this recommendation; accordingly, Safety Recommendation R-10-25 is classified CLOSED -- ACCEPTABLE ACTION.

From: Chicago Transit Authority
To: NTSB
Date: 11/8/2010
Response: CC# 201000413: - From Richard L. Rodriguez, President: The Chicago Transit Authority (CTA) is in receipt of NTSB Recommendation R-10-2S in the wake of the June 22, 2009 collision of two Washington Metropolitan Area Transit Authority (WMATA) Metrorail trains near Fort Totten station. One of the identified causes of the accident was a failure of the track circuit modules, built by GRS/Alstom Signaling Inc., that caused the automatic train control system to lose detection of train 214 (the struck train) and thus transmit speed commands to train 112 (the striking train) up to the point of impact, with GRS/Alstom Signaling Inc.'s failure to provide a maintenance plan to detect spurious signals that could cause its track circuit modules to malfunction a contributory factor. Recommendation R-10-25 directs CTA to "work with Alstom Signaling Inc. to establish periodic inspection and maintenance procedures to examine all General Railway Signal Company audio frequency track circuit modules to identify and remove from service any modules that exhibit pulse-type parasitic oscillation. CTA has GRS2 audio frequency track circuits installed for train detection and speed control on the Evanston, (Purple), Skokie (Yellow), Howard (Red), Ravenswood (Brown) and South/Englewood/Jackson Park (Green) lines. Immediately follOWing the WMATA train collision, the CTA inspected each relay house and observed the operation of the GRS 2 track circuits and verified the status of all track circuit audio maintenance logs. Additionally, CTA began working with Alstom to investigate the functionality of these track circuits on the CTA system. In December 2009, Alstom representatives visited CTA and observed the track circuits in a few relay houses to view the electrical behavior and become more familiar with the track circuitry and installations that were made in the 1970s. During this visit, Alstom noted that the power supplies for these track circuits had to be observed and maintained within a certain tolerance, As a result, CTA signal maintenance engineers performed measurements for all power supplies and identified those that were out of tolerance. Power supplies that were significantly out of tolerance were immediately changed out. Installation of capacitors in the remaining power supplies that are out of tolerance has been scheduled. In September 2010, Alstom representatives returned to CTA to perform a comprehensive audit of all GRS!Alstom track circuits on the system. The audit consisted of technicians taking digital recordings of the receiver voltages for all track circuits while trains were passing through the circuits. Alstom is analyzing the recordings and will be providing a report from the results regarding any track circuits that may require additional investigations into their performance and adjustment. At the time of the audit, no track circuits were observed operating out of sequence or failing to detect trains. The CTA received a preliminary report from Alstom on November 3, 2010, which is being reviewed to determine if any additional interim steps are required prior to the issuance of the final report. Additionally, CTA performs preventive maintenance quarterly, including measuring the voltage levels of the transmit and receive signals for each track circuit and making adjustments as\ needed to allow for proper operation. Results of the measurements are compared to the previously recorded levels in the on-site log book that provides a history of the track circuit maintenance. Significant deviations in the measurements result in the signal maintainers initiating an investigation into the cause of the change. Signal maintainers also observe the operations of the track circuits as trains pass through the area, to see if the relays are operating in the correct sequence, as well as staying de-energized when a train is in the circuit. CTA senior engineers conduct a weekly field audit of select maintenance logs to confirm that the daily wayside logs are up-to-date and scheduled preventive maintenance is on-going. Twice a year, senior signal engineers audit the maintenance logs to ensure that preventive maintenance has been conducted and documented in a timely manner.

From: NTSB
To: Chicago Transit Authority
Date: 8/10/2010
Response: From the safety recommendation letter to Alstom Signaling, Inc. dated August 10, 2010, and written in response to the June 22, 2009 collision of two Washington Metropolitan Transit Authority (WMATA) metrorail trains near the Fort Totten station. Urgent Safety Recommendation R-09-23, previously classified “Open—Acceptable Response,” is reclassified "Closed -- Superseded" by Safety Recommendation R-10-23, issued to Alstom Signaling Inc., and Safety Recommendation R-10-25, issued to the six other transit agencies that use GRS audio frequency track circuit modules. The NTSB also issued safety recommendations to the U.S. Department of Transportation, the Federal Transit Administration, the Tri-State Oversight Committee, the Washington Metropolitan Area Transit Authority Board of Directors, the Washington Metropolitan Area Transit Authority, the Massachusetts Bay Transportation Authority, the Southeastern Pennsylvania Transportation Authority, the Greater Cleveland Regional Transit Authority, the Metropolitan Atlanta Regional Transportation Authority, the Los Angeles County Metropolitan Transportation Authority, and the Chicago Transit Authority.

From: NTSB
To: Southeastern Pennsylvania Transportation Authority
Date: 12/30/2010
Response: The NTSB notes that SEPTA was notified by Alstom on July 29, 2010, that the Generation 2 GRS audio frequency track circuit modules having pulse-type parasitic oscillation were installed by the Washington Metropolitan Area Transit Authority (WMATA) near Fort Totten during the 1970s. Alstom supplied SEPTA with Generation 4 audio frequency track circuit modules developed in the 1990s that reflect design developments, including a completely redesigned module housing that holds the track circuit electrical components, additional filters, and various circuit changes. Alstom's November 2009 testing of Generation 4 audio frequency track circuit modules on SEPTA, which revealed no evidence of pulse-type parasitic oscillation with any Generation 4 modules, satisfies Safety Recommendation R-10-25; accordingly, this recommendation is classified CLOSED – ACCEPTABLE ACTION.

From: Southeastern Pennsylvania Transportation Authority
To: NTSB
Date: 9/7/2010
Response: CC# 201000361: - From James Fox, Director, System Safety and Risk Management: SEPTA recognizes that the NTSB found that pulse-type parasitic oscillation in the Generation 2 GRS audio frequency track circuit modules at the accident location was one of the contributing factors to the collision. These track circuit modules are an early generation installed during the 1970s. The Alstom supplied audio frequency track circuit modules used at SEPTA are the Generation 4 audio frequency track circuit modules that were developed in the 1990s and reflect significant design developments; including: 1. A complete redesign of the module housing which holds the track circuit electrical components. 2. The addition of certain filters. 3. Various circuit changes. Alstom has performed testing of the Generation 4 audio frequency track circuit modules, and has found no evidence of pulse-type parasitic oscillation with any Generation 4 modules (See enclosed letter Alstom to SEPTA dated July 22, 2010). Alstom has also reminded SEPTA about the dangers and unpredictability of mixing manufacturers' equipment that has not been specifically designed to function together. SEPTA does not replace any component on a system without OEM approval. In November of2009, Alstom visited SEPTA to conduct assessments of our audio frequency track circuits. Based on this site visit, Alstom did not express any concern with SEPTA's system and during testing could not create any pulse-type parasitic oscillation. Unlike WMATA, SEPTA has a commuter rail service as part of our multi-modal operation. Under the commuter rail operation SEPTA is required to conduct testing and inspection activity in accordance with the FRA regulation 49 CFR part 236. SEPTA's Communication and Signals Department adopts the same rigorous inspection and testing requirements promulgated by the FRA for all of our rail transit operations. In addition, SEPTA is in the process of updating the current C & S Inspection and Maintenance protocols. One enhancement being made to these protocols incorporates a test that was conducted by Alstom during their November site visit. SEPTA has forwarded to Alstom the proposed updated audio frequency track circuit testing protocols for review. SEPTA is awaiting a response from Alstom and will incorporate any comments in the final version of the revised Inspection and Maintenance manual. SEPTA's goal is to have the manual updated by fall 2010. In light of the incident at WMATA, SEPTA also implemented a process where all train operators must report any indication of a "no code" at any point during operation. Once this "no code" is reported, the Control Center quickly evaluates the model board status and forwards the "no-code" event to the C & S Department. The C & S Department investigates each event to insure the "no-code" was not associated with a pulse-type parasitic oscillation. SEPTA has not experienced any pulse-type parasitic oscillation on our audio frequency track circuit modules since the installation of the equipment in the late 90s.

From: NTSB
To: Southeastern Pennsylvania Transportation Authority
Date: 8/10/2010
Response: From the safety recommendation letter to Alstom Signaling, Inc. dated August 10, 2010, and written in response to the June 22, 2009 collision of two Washington Metropolitan Transit Authority (WMATA) metrorail trains near the Fort Totten station. Urgent Safety Recommendation R-09-23, previously classified “Open—Acceptable Response,” is reclassified "Closed -- Superseded" by Safety Recommendation R-10-23, issued to Alstom Signaling Inc., and Safety Recommendation R-10-25, issued to the six other transit agencies that use GRS audio frequency track circuit modules. The NTSB also issued safety recommendations to the U.S. Department of Transportation, the Federal Transit Administration, the Tri-State Oversight Committee, the Washington Metropolitan Area Transit Authority Board of Directors, the Washington Metropolitan Area Transit Authority, the Massachusetts Bay Transportation Authority, the Southeastern Pennsylvania Transportation Authority, the Greater Cleveland Regional Transit Authority, the Metropolitan Atlanta Regional Transportation Authority, the Los Angeles County Metropolitan Transportation Authority, and the Chicago Transit Authority.

From: NTSB
To: State of California, County of Los Angeles, Metropolitan Transportation Authority
Date: 8/15/2012
Response:

From: State of California, County of Los Angeles, Metropolitan Transportation Authority
To: NTSB
Date: 6/29/2012
Response: -From Arthur T. Leahy, Chief Executive Officer: The purpose of this letter is to provide you an update on LACMTA's actions regarding the subject NTSB recommendation made in the investigation of the June 22, 2009 Washington Metropolitan Area Transit Authority accident at Fort Totten. As you are aware, a probable cause of this accident was the failure of a Generation 2 track circuit module built by GRS/Alstom Signaling, Inc. Since the date of this tragic accident, LACMTA's signals staff worked diligently with Alstom engineers to verify the status and integrity of our Generation 2 track circuits. In your letter dated December 29, 2010, you classified LACMTA's actions as being acceptable, and referenced a conversation with LACMTA's Senior Signal Engineer, Mr. John McGrevey, who informed you that the Alstom Generation 2 track circuits would be removed from service and replaced with Alstom's Generation 4 track circuits that have been redesigned to prevent pulse-type parasitic oscillations. Under the leadership of Mr. Michael Harris-Gifford, Executive Officer of our Wayside Systems department, his team has been replacing track circuits over the last several months with minimum disruption to revenue service, and I am pleased to inform you that prior to commencing revenue operations this morning, we removed and replaced the last Alstom Generation 2 audio frequency track circuit from our rail system. I wish to take the opportunity of thanking the NTSB and FT A for their cooperation in directing and resolving this issue, as well as congratulating the signals staff for a job well done.

From: NTSB
To: State of California, County of Los Angeles, Metropolitan Transportation Authority
Date: 12/29/2010
Response: The NTSB notes that the Los Angeles County Metropolitan Transportation Authority (LACMTA) has identified 56 Generation 2 General Railway Signal Company (GRS) audio frequency track circuit (AFTC) modules supplied by Alstom in a 3.5 mile segment of its Red Line; however, these track circuits are not identical to those that Alstom provided to WMATA. On April 13-15, 2010, Alstom conducted tests on all LACMTA Generation 2 AFTCs similar to those used on WMATA. The result of the track circuit tests did not indicate any pulse-type parasitic oscillation. On October 13, 2010, NTSB staff contacted Mr. John McGrevey, Senior Engineer (Signal), Transit Systems Engineering, regarding LACMTA’s current AFTC testing procedures. Mr. McGrevey, who provided a copy of Alstom’s Receive Signal Data Collection Procedure for Audio Frequency Track Circuits (AFTC) approved June 14, 2010, informed the NTSB that Alstom had recently completed enhanced testing of all LACMTA’s AFTCs, the same testing currently being conducted on other transit systems using AFTCs similar to the GRS/Alstom Generation 2 type track circuits used on WMATA. The AFTC modules functioned as intended without any pulse-type parasitic oscillation. In addition, Mr. McGrevey indicated that LACMTA’s supervisory control and data acquisition system monitors train movements throughout the system on a real-time basis; no loss of trains has been detected. The system monitors track circuits for possible false unoccupied track circuits and generates a real-time alarm upon detection of such occurrences. Mr. McGrevey said that the Alstom testing procedures will become obsolete within 12 months when the Generation 2 track circuits are removed from service and updated to Alstom Generation 4 type track circuits that have been redesigned to prevent pulse-type parasitic oscillation. The NTSB is satisfied that LACMTA does not have any Generation 2 track circuits that exhibit pulse-type parasitic oscillation identical to those on WMATA; accordingly, Safety Recommendation R-10-25 is classified CLOSED --- ACCEPTABLE ACTION.

From: State of California, County of Los Angeles, Metropolitan Transportation Authority
To: NTSB
Date: 8/17/2010
Response: CC# 201000323: - From Arthur T. Leahy, Chief Executive Officer: We have divided our response into the following categories: • General • Testing of Existing Track Circuits • Periodic Inspection and Maintenance Procedures • Additional Steps General LACMTA is aware of the developments and recommendations from the Washington Metropolitan Area Transit Authority (WMATA) accident, and is constantly seeking information and guidance on the status of "Generation 2" track circuits supplied by Alstom. Although Alstom has supplied these track circuits to LACMTA, they are not identical to those that were provided to WMATA. As you may be aware, LACMTA has some 56 Generation 2track circuits in a 3.5 mile segment of our Red Line. Testing of Existing Track Circuits Alstom has conducted on-site testing at LACMTA on a number of our track circuits. We have received a letter from Alstom dated July 29, 2010 (Attachment 1), confirming that their inspection of LACMTA track circuits revealed no immediate cause for concern. This letter also confirms that Alstom is working on possible modifications to Generation 2 track circuits and will advise LACMTA if and when they are complete. Alstom has also informed us in a follow-up email that they will be conducting enhanced testing of LACMTA's Audio Frequency Track Circuits in the near future. Periodic Inspection and Maintenance Procedures With regard to the specific recommendation made to the LACMTA regarding establishing periodic inspection and maintenance procedures, Alstom has informed us in an e-mail response dated August 13,2010 (Attachment 2), that they plan on providing us two test procedures - one will be an enhanced adjustment and test procedure and another will be a newly developed test procedure to specifically test for the existence of parasitic oscillations in Audio Frequency Track Circuits. Upon receipt of these procedures, LACMTA will incorporate them into our maintenance practices. While we await receipt of the above procedures, LACMTA has contacted Alstom (Attachment 3) asking whether a procedure developed by WMATA (Procedure No. T163) is applicable to LACMTA. Given the fact that LACMTA's Generation 2 track circuits are not identical to WMATA's, LACMTA believes that Alstom should provide confirmation as to whether or not we should adopt this procedure as we do not wish to risk harm to the integrity of our train control system. Additional Steps LACMTA has taken additional steps by contacting our other train control equipment manufacturers for our light rail lines to determine whether the anomalies found in the GRS/Alstom equipment could be exhibited in their equipment. We have received responses from these other vendors that conclude (Attachment 4) based on their analysis of their design and the failure in the WMATA incident, their equipment is not prone to a similar type of failure that was the cause of the WMATA incident. And finally, LACMTA has implemented the recommended track circuit monitoring system on all our rail lines at the rail control center. The system monitors our track circuits for "flickering" and possible false unoccupied track circuits and generates a real-time alarm upon detection of such occurrences. We are currently testing and refining the software algorithms to ensure the system does not generate false failures. LACMTA believes that our efforts described above will mitigate the concerns arising from the WMATA accident and are responsive to NTSB's recommendation R-10-25.

From: NTSB
To: State of California, County of Los Angeles, Metropolitan Transportation Authority
Date: 8/10/2010
Response: From the safety recommendation letter to Alstom Signaling, Inc. dated August 10, 2010, and written in response to the June 22, 2009 collision of two Washington Metropolitan Transit Authority (WMATA) metrorail trains near the Fort Totten station. Urgent Safety Recommendation R-09-23, previously classified “Open—Acceptable Response,” is reclassified "Closed -- Superseded" by Safety Recommendation R-10-23, issued to Alstom Signaling Inc., and Safety Recommendation R-10-25, issued to the six other transit agencies that use GRS audio frequency track circuit modules. The NTSB also issued safety recommendations to the U.S. Department of Transportation, the Federal Transit Administration, the Tri-State Oversight Committee, the Washington Metropolitan Area Transit Authority Board of Directors, the Washington Metropolitan Area Transit Authority, the Massachusetts Bay Transportation Authority, the Southeastern Pennsylvania Transportation Authority, the Greater Cleveland Regional Transit Authority, the Metropolitan Atlanta Regional Transportation Authority, the Los Angeles County Metropolitan Transportation Authority, and the Chicago Transit Authority.

From: NTSB
To: Massachusetts Bay Transportation Authority
Date: 1/10/2011
Response: The NTSB notes that between August 23 and September 9, 2010, the Massachusetts Bay Transportation Authority (MBTA) and Alstom tested 413 General Railway Signal Company audio frequency track circuits for parasitic oscillation using two different testing procedures and that, as a result, Alstom found six track circuits that had exhibited this problem. Alstom and the MBTA found that, unlike those in the WMATA accident, these oscillations did not appear to be impacting the proper operation of the track circuits; nevertheless, the MBTA removed these circuits from service until they could be repaired. The NTSB also notes that by September 29, 2010, the MBTA had installed ferrite sleeves on these six track circuits and on all Generation 2, 3, and 4 track circuits to provide further protection against parasitic oscillations. Although these circuits had not demonstrated any evidence of pulse-type parasitic oscillation, the NTSB believes that it was prudent to undertake this precautionary measure. The NTSB is pleased that the MBTA and Alstom worked together as described, fully satisfying Safety Recommendation R-10-25. Accordingly, this recommendation is classified CLOSED – ACCEPTABLE ACTION.

From: Massachusetts Bay Transportation Authority
To: NTSB
Date: 10/15/2010
Response: CC# 201000404 - From Richard A. Davey, General Manager: Pursuant to your correspondence dated August 9, 2010, the Massachusetts Bay Transportation Authority (MBTA) provides this response to National Transportation Safety Board (NTSB) Safety Recommendation R-lO-25, which states, "[w]ork with Alstom Signaling Inc. to establish periodic inspection and maintenance procedures to examine all General Railway Signal Company audio frequency track circuit modules to identify and remove from service any modules that exhibit pulse-type parasitic oscillation." The NTSB generated this recommendation as part of its investigation of the June 22, 2009 accident involving two (2) Washington Metropolitan Area Transit Authority (WMATA) Metrorail trains. The MBTA worked with Alstom Signaling, Inc. (Alstom) to examine track circuits and develop periodic inspection and maintenance procedures. We believe these actions ensure an appropriate level of safety as we operate our heavy rail system that serves the transit needs for a large percentage of Massachusetts residents. Concern with Parasitic Oscillations Parasitic oscillation is defined as "[a]n undesired self-sustaining oscillation or a self generated transient impulse in an oscillator or amplifier circuit, generally at a frequency above or below the correct operating frequency." In the case of Alstom track circuits, we are concerned with finding a Type 4 parasitic oscillation in a transmitter amplifier circuit. This type of oscillation follows a path other than through the rails to the receiver causing a track circuit not to recognize the presence of a train. The NTSB identified this issue as one of the causes of the WMATA accident. Classifying Parasitic Oscillations Three possible types of parasitic oscillations could exist on the Alstom track circuits used in the MBTA heavy rail signal system. Type 2 is defined as a constant oscillation along the entire waveform of the transmitted signal. This type is considered harmless. Type 3 is defined as a pulsed oscillation that is in phase with the transmitted signal. This type does not pose a danger if it remains localized to the generating transmitter. Lastly, Type 4 is defined as an oscillation that is out of phase with the transmitted signal where it is found. This type is dangerous because the signal is being generated from another transmitter and may be traveling through a path other than the rails causing the circuit not to recognize track occupancy. Testing of Alstom Track Circuits Between August 23 and September 9,2010, the MBTA and Alstom tested 413 track circuits for parasitic oscillations using two different test procedures. One test performed used a multi-channel recordable oscilloscope to record the level that the receiver is "recognizing" trains as they travel through the circuit. The only path to the receiver should be the running rails, so looking at the receiver signal while the train is traveling through the circuit tells us if there is a signal getting to the receiver that is not traveling via the correct path. The other test used the oscilloscope to record the output signal from each track transmitter to determine if parasitic oscillations exist and to classify the type of oscillation found (if any). On September 17, while analyzing the test data, Alstom found a Type 4 parasitic oscillation in a track circuit near Harvard Station on the Red Line. The following day (September 18), Alstom further notified the MBTA of five (5) other circuits that had Type 4 oscillations on the Red Line (one (1) more at Harvard and four (4) near Quincy Adams Station). Upon notification of track circuits with Type 4 parasitic oscillations, the MBTA immediately took these circuits out of service and implemented manual blocks until the circuits were repaired. In addition, Alstom and the MBTA analyzed the affected circuits and found that, unlike the WMATA incident, these Type 4 oscillations did not appear to be impacting the proper operation of the track circuits. Alstom recommended that the MBTA install a common mode choke (Ferrite Sleeve) on the B28 and common wires of the track modules in the Circuit Instrument Rooms (CIR) and/or Circuit Instrument Houses (CIH) associated with each circuit identified as having Type 4 parasitic oscillation. Fen'ite sleeves provide high impedance to the oscillations that will stop them from travelling to other track circuit modules. This installation also keeps Type 3 oscillations from turning into Type 4 oscillations, and ultimately eliminates the possibility of Type 4 oscillations from reoccurring. On September 19, less than 36 hours after receiving notification from Alstom, the MBTA completed repairs of the track circuits with Type 4 parasitic oscillations at Harvard and Quincy Adams. The MBTA also implemented a bus diversion on sections of the Red Line while these repairs were being made. After all track circuits exhibiting Type 4 oscillations were repaired, the MBTA lifted the manual blocks. In addition, the MBTA Signal Division completed additional work on September 29 by installing Ferrite Sleeves on all Generation 2, 3, and 4 track circuits to provide further protection against Type 4 oscillations. Even though Alstom test data showed these circuits did not demonstrate any evidence of pulse-type parasitic oscillation, the MBTA believes that it was prudent to undertake this precautionary measure. Additionally, the MBTA will be replacing the power amplifier card with a newer version that will stop the oscillation on the card itself. The new cards are currently in the prototype phase and should be available in early 2011. Periodic Inspection and Maintenance Procedures In concert with the recent testing of the track circuits, the MBTA and Alstom developed periodic inspection and testing procedures for parasitic oscillation. We were using these procedures when we discovered the concerns described above. The MBTA has also obtained all of the equipment to perform the necessary periodic inspections and tests on the Alstom track circuits. Since we identified and eliminated the Type 4 parasitic oscillations, we intend to test the circuits every two (2) years, which aligns with our normal track circuit testing cycle. In the future, we will implement a more vigorous testing cycle should we receive information requiring us to adjust the schedule accordingly. In closing, we are looking forward to working with NTSB and Alstom on this important safety concern. In the meantime, if you have any further questions, please do not hesitate to contact Brian Dwyer, Acting Director of System Safety, at 617-222-5007.

From: NTSB
To: Massachusetts Bay Transportation Authority
Date: 8/10/2010
Response: From the safety recommendation letter to Alstom Signaling, Inc. dated August 10, 2010, and written in response to the June 22, 2009 collision of two Washington Metropolitan Transit Authority (WMATA) metrorail trains near the Fort Totten station. Urgent Safety Recommendation R-09-23, previously classified “Open—Acceptable Response,” is reclassified "Closed -- Superseded" by Safety Recommendation R-10-23, issued to Alstom Signaling Inc., and Safety Recommendation R-10-25, issued to the six other transit agencies that use GRS audio frequency track circuit modules. The NTSB also issued safety recommendations to the U.S. Department of Transportation, the Federal Transit Administration, the Tri-State Oversight Committee, the Washington Metropolitan Area Transit Authority Board of Directors, the Washington Metropolitan Area Transit Authority, the Massachusetts Bay Transportation Authority, the Southeastern Pennsylvania Transportation Authority, the Greater Cleveland Regional Transit Authority, the Metropolitan Atlanta Regional Transportation Authority, the Los Angeles County Metropolitan Transportation Authority, and the Chicago Transit Authority.

From: NTSB
To: Greater Cleveland Regional Transit Authority
Date: 1/31/2011
Response: The NTSB notes that Greater Cleveland Regional Transit Authority (GCRTA) has identified 41 Generation 2 GRS AFTC modules supplied by Alstom in a segment of yard lead track 1 (YLT1) about 1 mile long; however, these track circuits are not identical to those that Alstom provided to WMATA. On December 8, 2009, Alstom conducted tests on all GCRTA Generation 2 AFTC modules. The result of these tests did not indicate any pulse-type parasitic oscillation. The Generation 2 AFTC modules are all installed within yard limits at GCRTA’s central storage yard, not in an automatic train control main line environment, such as those at WMATA. On November 8, 2010, NTSB staff contacted Mr. Shaffer regarding the results of the enhanced test performed by Alstom in August 2010. Mr. Schaffer stated that he had spoken with Alstom and had been assured that all Generation 2 AFTC modules functioned as intended and had failed to produce any parasitic oscillation. The NTSB is satisfied that GCRTA does not have any Generation 2 AFTCs that are identical to WMATA’s; accordingly, Safety Recommendation R-10-25 is classified CLOSED – ACCEPTABLE ACTION.

From: Greater Cleveland Regional Transit Authority
To: NTSB
Date: 10/20/2010
Response: CC# 201000403: From Joseph L. Shaffer, P.E., Director of Engineering and Project Development, Engineering and Project Management Division: The Greater Cleveland Regional Transportation Authority (GCRTA) has been working with Alstom to review the track circuit hardware on the property, and to review the 'recommended testing practices. The following is a response to your letter dated August 10, 2010. GCRTA has 41 of the "Generation 2" track circuits in service on Yard Lead Track 1 (YLT1) supplied by a predecessor to Alstom, GRS. These are all installed on YLT1 within yard limits at our central storage yard. The llGeneration 2" track circuits are on a less than one-mile segment of the yard lead. The track circuit hardware is not identical to the ones supplied to WMATA. The control application is in an ungrounded control energy application. The track circuit application is used on a yard lead, not an automatic train control main line environment as at WMATA. Existing Track Circuits Testing Alstom conducted on-site testing of GCRTA track circuits at Tower City Center Station (TCCS) and the central storage yard complex, including YLT1 in December of 2009 (see Attachment 1). The inspection turned up no immediate cause for concern. Alstom returned to GCRTA in August 2010 to do more enhanced testing. This testing included all Alstom track circuits on the property. GCRTA is currently awaiting the test results. "Generation 2" track circuits on YLT1 have not shown a recorded false proceed condition or other anomalies in over twenty years of use. The GCRTA application is one of ungrounded control circuit energy, removing a potential path for parasitic oscillation, and the hardware differs from that at WMATA. Absent evidence of false indications or material Alstom recommendations, no change from current testing procedures or implementation of monitoring is planned at this time. GCRTA is still requesting Alstom's testing data and recommendations following the testing of track circuits in August of 2010. Other Follow Up We have contacted Ansaldo regarding their AF-700 and AF-700A track circuits in use on GCRTA and they have "advised us that their hardwire is not subject to parasitic oscillation problems based on their designs. Conclusion GCRTA "Generation 2" track circuits on YLT1 have not demonstrated track circuit failures in over twenty years of service. The track circuits are ungrounded and within Yard Limits on a restricted speed track in a non-vital application. Therefore, the continued use of the "Generation 2" track circuits in their present application with testing and maintenance as per the manufacturer's original instructions is warranted.

From: NTSB
To: Greater Cleveland Regional Transit Authority
Date: 8/10/2010
Response: From the safety recommendation letter to Alstom Signaling, Inc. dated August 10, 2010, and written in response to the June 22, 2009 collision of two Washington Metropolitan Transit Authority (WMATA) metrorail trains near the Fort Totten station. Urgent Safety Recommendation R-09-23, previously classified “Open—Acceptable Response,” is reclassified "Closed -- Superseded" by Safety Recommendation R-10-23, issued to Alstom Signaling Inc., and Safety Recommendation R-10-25, issued to the six other transit agencies that use GRS audio frequency track circuit modules. The NTSB also issued safety recommendations to the U.S. Department of Transportation, the Federal Transit Administration, the Tri-State Oversight Committee, the Washington Metropolitan Area Transit Authority Board of Directors, the Washington Metropolitan Area Transit Authority, the Massachusetts Bay Transportation Authority, the Southeastern Pennsylvania Transportation Authority, the Greater Cleveland Regional Transit Authority, the Metropolitan Atlanta Regional Transportation Authority, the Los Angeles County Metropolitan Transportation Authority, and the Chicago Transit Authority.

From: NTSB
To: Metropolitan Atlanta Rapid Transit Authority
Date: 9/12/2011
Response: The NTSB is pleased that, by September 1, 2009, Metropolitan Atlanta Rapid Transit Authority (MARTA) had changed its shunt testing procedures (PM-3), Standard for Audio Frequency Track Circuit Inspection and Maintenance, from the previous interval of once every 2 years to once every 6 months. The shunt testing also included shunting each AFTC at the transmitter, mid-point, and receiver locations. The NTSB notes that, between November 2009, and March 2010, MARTA and Alstom Signaling engineers tested GRS Type 2 AFTCs system-wide for parasitic oscillation and, as a result, identified four AFTC modules that needed corrective action. Three of these defects were caused by diode pad degradation and were corrected by replacing the defective diode pad. The source of the fourth defect could not be identified, but the installation of ferrite filters recommended by Alstom resolved the problem. None of the four defects was similar to those that caused the WMATA accident. The NTSB also notes that between July 19 and August 2, 2010, MARTA and Alstom began testing all GRS AFTCs, employing an enhanced testing method that utilizes digital recording technology. Alstom confirmed that MARTA has no track circuit anomalies. The NTSB also notes that MARTA’s Board of Directors approved a procurement contract in January 2011for the replacement of 854 GRS Type 2 AFTC modules with GRS Type 4 modules within a 3-year period. This will account for 100-percent removal of the GRS Type 2 AFTCs from MARTA’s Train Control System. The NTSB is pleased that MARTA and Alstom worked together and that MARTA has no GRS Type 2 AFTCs that are configured similar to those that prompted the issuance of this recommendation. Accordingly, Safety Recommendation R-10-25 is classified CLOSED—ACCEPTABLE ACTION.

From: Metropolitan Atlanta Rapid Transit Authority
To: NTSB
Date: 10/10/2010
Response: CC#201100230: - From Beverly A. Scott, PhD, General Manager/ Chief Executive Officer: MARTA immediately reviewed its current test procedures and implemented new procedures to examine audio frequency track circuit modules to minimize the risk of parasitic oscillation identified as a casual factor in the Washington Metropolitan Area Transit Authority accident on June 22, 2009, at Fort Totten. A number of initiatives were developed and placed into effect by September 1, 2009. Most prominent of these initiatives was an accelerated schedule for shunt testing of track circuits, from the previous interval of once every two (2) years to a more frequent interval of once every six (6) months. This increased shunt testing also included shunt testing each track circuit in three places (transmitter, mid-point, and receiver). In October 2009, MARTA developed a procedure that focused on testing the receiver signal level for unwanted parasitic oscillation and unintended path or cross-talk voltage. MARTA also collaborated with Alstom to develop maintenance procedures to identify and remove from service any modules that exhibit pulse-type parasitic oscillation. MARTA launched a joint investigation with the manufacturers of the track circuit equipment, Alstom Signaling, to develop a procedure to detect and mitigate all potential pulse-type parasitic oscillation. On November 10, 2009, two (2) Alstom engineers and MARTA staff conducted testing using MARTA's in-house testing procedure. In late November 2009, Alstom Signaling assisted in analyzing the test data and collaborated on a revised version of MARTA's test procedure. Alstom Signaling engineers returned to MARTA for another two (2) days on December 1-2, 2009. The MARTA test procedure PM-3C, specifically identifying parasitic type oscillations, was completed and issued on December 15, 2009. System wide testing at MARTA was underway by December 28, 2009 using the revised procedure developed in concert with Alstom Signaling. This testing was completed by March 2010, with three incidents of unwanted receiver signals identified and mitigated all incidents of a very low level. A revised shunting sensitivity test, co-developed by Alstom and MARTA technical staff, was fully distributed and implemented on May 1, 2010. This new test utilized all previous initiatives and included a new method for identifying any type of un-intended path receiver voltage by placing two shunts at the mid-point, and measuring the receiver voltage. MARTA has adopted the new test into all audio frequency track circuit maintenance procedures. Additionally, MARTA will schedule annual testing, as well as conduct testing each time track circuits undergo any adjustments. Alstom Signaling began testing all of MARTA's Alstom Audio Frequency Track Circuits on July 19 2010, using a test method that uses digital recording technology. Alstom technicians and engineer completed the testing on August 2, 2010 and supplied MARTA with the test data. A draft formal report from Alstom to MARTA of the test results, but did confirm verbally that MARTA has no track circuit anomalies. The final draft of the Alstom Signaling report is currently in review by the Alstom Signaling legal department. MARTA is expecting, along with the final test report from Alstom, a specific recommendation on utilizing this digital recording technology test, with a specific recommended test interval. MARTA has purchased the software and hardware necessary to review the test data and continue this testing. MARTA has a capital project initiative to replace all of the Generation two (2) Alstom audio frequency track circuit modules. This project involves a procurement contract for replacement modules that is currently in final submittal and scheduled for board approval in January 2011. MARTA has scheduled replacement of these modules within a three-year period by MARTA Automatic Train Control maintenance personnel. MARTA continues to communicate with Alstom Signaling technical staff, pending the receipt of the final report from Alstom Signaling and the above-mentioned corrective actions.

From: NTSB
To: Metropolitan Atlanta Rapid Transit Authority
Date: 8/10/2010
Response: From the safety recommendation letter to Alstom Signaling, Inc. dated August 10, 2010, and written in response to the June 22, 2009 collision of two Washington Metropolitan Transit Authority (WMATA) metrorail trains near the Fort Totten station. Urgent Safety Recommendation R-09-23, previously classified “Open—Acceptable Response,” is reclassified "Closed -- Superseded" by Safety Recommendation R-10-23, issued to Alstom Signaling Inc., and Safety Recommendation R-10-25, issued to the six other transit agencies that use GRS audio frequency track circuit modules. The NTSB also issued safety recommendations to the U.S. Department of Transportation, the Federal Transit Administration, the Tri-State Oversight Committee, the Washington Metropolitan Area Transit Authority Board of Directors, the Washington Metropolitan Area Transit Authority, the Massachusetts Bay Transportation Authority, the Southeastern Pennsylvania Transportation Authority, the Greater Cleveland Regional Transit Authority, the Metropolitan Atlanta Regional Transportation Authority, the Los Angeles County Metropolitan Transportation Authority, and the Chicago Transit Authority.