Friends of the Rail Forum

Six killed as Washington DC metro trains collide

* Ed Pilkington in New York
* The Guardian, Tuesday 23 June 2009


At least six people died and 70 were injured, some seriously, in a train crash in the Washington DC metro last night.

The accident happened when two trains, both moving in the same direction, collided. One of the trains had stopped, waiting for another train ahead to move out of a station when the second train rammed into its rear end.

The second train rose up and over the front train's final carriage. The woman driver of the rear train died, along with three passengers.

"Obviously something went terribly wrong for two trains to be on the same track," a Metro spokeswoman said.

The DC Metro prides itself on its efficiency and relatively good safety record. Last night's crash was between the Takoma and Fort Totten stations in north-east Washington, near the border between the District of Columbia and Maryland.

There has only been one other case of deaths of passengers in the 33 years of the Metro, in January 1982, when three people died in a derailment beneath downtown Washington DC.

Last night's accident occurred at about 5pm local time on the Metro's Red Line, which is its busiest. The fact that it was at rush hour increased the challenge for emergency workers. They brought in heavy equipment to cut open the wrecked carriages.

An eyewitness, D'Ana Williams, who lives next to the Takoma Metro station told the Washington Times she had heard the crash. She said it sounded like "two dump trucks colliding into each other, like they dumped a load."

Jodie Wickett, a nurse travelling on one of the trains, told CNN she was sending text messages on her phone when she felt the impact. "From that point on, it happened so fast, I flew out of the seat and hit my head."

Officials said it was too early to determine what caused the crash.

Human errors compounded? Human and technical errors compounded?

I am in the middle of a book on train accidents that influenced or changed train operations. One area they say was a major improvement, related to carrage design and build - and I guess the above bears this out. If one thinks of the forces and impacts involved it is impressive that the figures were not higher.

Train accidents in the early part of the 20th century reflected horrendous injuries in just "minor" (relatively) accidents - design issues as well as the materials used.

Modern carriage design is already supposed to prevent one train riding up over the other. The technology exists and is in use. That's why Mk I coaches have been banned in UK (except on low speed heritage line).

Indeed so, John. Unfortunately all those couplers only work well internally within a properly coupled train consist, and indeed, probably worked well in this accident too, keeping the cars locked together and in-line. However, when two separate trains collide, they have never been properly coupled and therefore cannot resist any of the vertical forces that may occur at the point of impact. This seesm to have happened in this collision.
See http://www.greatlakesrailcar.com/couple ... chor304320 for sketches of various types of "Janney" couplers used in the USA, including the anti-climb "tightlock" types mandated for passenger train use.
Regrettably, whilst SA uses Janney-type couplers, such anti-climb versions are not used in South Africa, so we still face the risk of coaches uncoupling vertically and climbing over each other in a collision. The only exception that I am aware of is in the Blue Train which, I am told, uses European-style Scharfenburg-type couplers interally within the trainset.

Several killed as two trains collide on Washington DC metro

Nine confirmed dead and 70 injured after one train rams into rear of another in north-east of city

* Ed Pilkington and agencies
* guardian.co.uk, Tuesday 23 June 2009 17.19 BST


At least nine people died and 70 were injured when a Washington DC metro train crashed into the rear of another at the height of the city's evening rush hour yesterday.

One of the trains had stopped and was waiting for another train ahead to move out of a station when the second train crashed into it from behind. The front end of the second train jack-knifed into the air and fell on top of the first.

The woman driver of the rear train was among those killed. Transit officials have now confirmed an earlier report which had put the death toll at nine.

The city's mayor, Adrian Fenty, told a news conference that two people were in a critical but stable condition in local hospitals.

A Washington fire department spokesman, Alan Etter, said crews had to cut some people out of what he described as a "mass casualty event". Rescue workers used steel ladders to reach the upper train carriages and help survivors climb to safety. Seats from the smashed carriages were spilled over the track.

"Obviously something went terribly wrong for two trains to be on the same track," a Metrorail spokeswoman said.

Barack Obama sent his condolences to the victims of the crash. "Michelle and I were saddened by the terrible accident in north-east Washington DC, today," the president said in a statement.

"Our thoughts and prayers go out to the families and friends affected by this tragedy." Obama thanked rescue personnel who helped to save lives.

The DC metro prides itself on its efficiency and relatively good safety record. Last night's crash was between the Takoma and Fort Totten stations, near the border between the District of Columbia and Maryland.

The crash at around 5pm (10pm BST) happened on the system's red line, the metro's busiest, which runs below ground for much of its length but is at ground level at the accident site.

The Metrorail chief, John Catoe, said the second train was one of the oldest in the metro fleet.

Officials would not say how fast the train was travelling at the time of the accident. The crash occurred in an area with a considerable distance between rail stations in which trains are allowed to travel at higher speeds, said a Metrorail spokeswoman, Candace Smith.

More than 200 firefighters from Washington, Maryland and Virginia converged on the scene. Sabrina Webber, a 45-year-old real estate agent who lives in the neighbourhood, said the first rescuers to arrive had to use the "jaws of life" to pry open a wire fence along the rail line to reach the train.

Webber raced to the scene after hearing a loud boom like a "thunder crash" and then sirens. She said there was no panic among the survivors.

Jodie Wickett, a nurse, told CNN she was seated on one train, sending text messages on her phone, when she felt the impact. She said she sent a message to someone that it felt like the train had hit a bump.

"From that point on, it happened so fast, I flew out of the seat and hit my head." Wickett said she stayed at the scene and tried to help.

"The people that were hurt, the ones that could speak, were calling back as we called out to them," she said. "Lots of people were upset and crying, but there were no screams."

There has been only one other case of deaths of passengers in the 33 years of the Metro: in January 1982 three people died in a derailment beneath central Washington DC.

Crash subway 'warned over trains'

Page last updated at 00:55 GMT, Wednesday, 24 June 2009 01:55 UK
BBC

The Washington DC subway was urged to replace or upgrade aging trains three years before Monday's crash that killed nine people, investigators have said.

The National Transportation Safety Board (NTSB) said the trains had continued running on the system despite a warning the board had given in 2006.

About 70 people were injured as a train ploughed into the back of a second, stationary one in evening rush hour.

Investigators said the moving train was in automatic mode at the time.

The collision happened above ground between Fort Totten and Takoma at 1700 (2200 BST).

The NTSB called for the replacement or upgrading of some carriages on the Metro system after investigating a 2004 accident which injured 20 passengers.

"We recommended to WMATA [Washington's Metro Area Transit Authority] to either retrofit those cars or phase them out of the fleet," NTSB's Debbie Hersman said.

"They have not been able to do that and our recommendation was not addressed."

Metro general manager John Catoe said the authority expected to receive proposals "over the next month or so" to replace the old carriages, but new trains were still years away from being installed.

He insisted the existing carriages were safe.

Ms Hersman also revealed that an emergency brake button was found pushed down in the train that caused into the stationary one.

However, she stressed it was not clear if the brake was engaged when the crash occurred or in the aftermath.

The fact the train was in automatic and not manual mode is standard procedure.

Investigators will be looking at mobile phone and text-messaging records from the train operator, also standard practice, she added.

The city's mayor Adrian Fenty said the crash was "the deadliest accident in the history of our Metro train transit system".

On Tuesday, Metro spokeswoman Candace Smith said two men and seven women had died, confirming early reports of the number of fatalities.

She said that five bodies had been recovered from the wreckage on Tuesday, in addition to the four removed on Monday.

The death toll had been revised down for several hours on Tuesday after Mr Fenty said just seven people had been killed.

Passenger Maya Maroto, who was on board the moving train, said it had been going at "full speed".

"I didn't hear any braking. Everything was just going normally. Then there was a very loud impact. We all fell out of our seats.

"Then the train filled up with smoke. I was coughing," she told the Associated Press.

Driver killed

Theroza Doshi told Reuters news agency: "There was no slowing down of the train, just a jerk. There was no attempt at braking.

"We just slammed into whatever we slammed into."

Passenger Abra Jeffers, 25, told the AFP news agency: "I was on the train that got hit. I thought it was an explosion. I thought it was like the train bombings in London. There was smoke and dust everywhere."

On Tuesday morning, Mr Fenty said two of the patients with critical injuries remained in hospital.

The driver of the moving train was among the dead, and was named as Jeanice McMillan, 42, by the Associated Press (AP) and the Washington Post.

Washington fire chief Dennis Rubin said a large crane had been used to separate mangled pieces of wreckage so that rescuers could search for injured or dead.

He said parts of the lower carriage were 70 to 80% compressed, and that rescuers did not know if there were still more bodies to be found.

A thorough search of the sidings and surrounding woodland had been made, he said.

Survivors of the crash describe the accident

Investigators have been trying to find recorders that would have details of the train's speed at the time of the crash and other information which could explain how the accident happened.

The accident happened at the peak of rush hour, at 1700 local time (2200 BST) on a busy commuter line.

But the trains involved were heading towards the centre of Washington rather than to the city's outlying areas.

This meant they were likely to have had fewer people on them, Ms Hersman as said.

The accident is the 33-year-old Metro network's first crash with any passenger fatalities since 1982 when three people were killed in a derailment.

Red Line Train Operator Used Brakes In Failed Bid to Stop Six-Car Train

Investigators Probe Site for Cause of Crash

Experts suspect failure of signal system or operator error in yesterday's deadly Red Line collision. NTSB investigators are on scene today gathering more evidence.

By Lena H. Sun and Lyndsey Layton
Washington Post Staff Writers
Wednesday, June 24, 2009

The operator of the Metro train that slammed into a stationary train in front of it apparently had activated the emergency brakes in a failed effort to stop before the accident, federal officials said yesterday as they searched for the cause of Monday's Red Line wreck that killed nine and injured 80.

Debbie Hersman of the National Transportation Safety Board said the emergency brake button, known as the "mushroom," was depressed, and the steel rails showed evidence that the brakes were engaged. Investigators also said the striking train was in automatic mode, which means onboard computers should have controlled its speed and stopped it before it got too close to the stationary train.

In addition, Metro sources said, the first two cars of that train were two months overdue for scheduled maintenance of some braking components.

Taken together, experts say these facts point to several possible scenarios: The operator activated the brakes too late; the computers that are supposed to stop a train from getting too close to another train faltered; the train's brakes failed; or some combination of those. Some passengers on the striking train have said that they never felt the train slow down.

A team of NTSB investigators painstakingly searched through the tangled heap of metal on the tracks just north of the Fort Totten Station in Northeast Washington. They were examining everything: the condition of the trains, track and signals; the actions of the operator and her downtown supervisors; and the computers that control train movement and are supposed to automatically prevent crashes. Investigators will also look at maintenance work performed this month on the computerized train control system along the stretch of track where the crash took place.

Officials began to remove the cars from the trains yesterday and plan to try to experiment with similar trains to determine approximate speed and stopping distance, Hersman said. Service on the Red Line will continue to be disrupted while the investigation proceeds.

The crash, the force of which vaulted the striking train atop the one it rammed, occurred on a curve where the speed limit is 59 mph, Hersman said. Today's experiment will also try to determine whether the curve, or anything else, obstructed the train operator's view of the stopped train. The operator, Jeanice McMillan, 42, was among those who died in the accident. Investigators will examine her cellphone and text-messaging records, review her work and rest schedule, and analyze blood samples, all standard NTSB procedures.

Investigators are also delving into the automatic train protection system, which is designed to make collisions impossible. Had the system been working correctly, it would have sensed that Train 112 was getting too close to Train 214 and directed the brakes aboard Train 112 to engage.

"I truly believe Metro is a safe system," Metro General Manager John B. Catoe Jr. said. Catoe said it was too early in the investigation to know what caused the crash, but he said there was "no evidence" that the operator was using a cellphone or texting at the time of the crash. After a special board meeting yesterday, he told reporters, "There's not a letter of evidence" to indicate operator error. And right now, he said, there is also no indication of signal failure.

The six cars that made up Train 112 were put together in an unusual way. Metro trains operate in married pairs of cars, and the lead car is almost always an "A" car, which some operators say run more smoothly and communicate better with the electronic devices buried along the track. But in the case of Train 112, the lead car was a "B" car, Metro officials said. It was unclear last night why the train was configured that way. It was also unclear what effect, if any, the configuration could have had on the crash.

The cars were among the oldest in Metro's fleet, purchased between 1974 and 1978 from Rohr Industries for the opening of the subway system. They have been rehabilitated and retrofitted "to keep them in good condition," said Metro board Chairman Jim Graham of the District.

But federal investigators consider the cars to be unsafe because of a tendency during a crash to collapse into one another like a telescope, reducing the "survivability" space, or the area in a car in which passengers can escape harm.

The force of the impact sheared the lead car of Train 112, pushing part of it onto the roof of the trailing car of Train 214 and slamming the rest into the body of Train 214. Two-thirds of Train 112's lead car was crushed, Hersman said.

After a Rohr train telescoped during a 2004 crash at the Woodley Park-Zoo/Adams Morgan Station, the NTSB recommended that Metro retire the Rohrs or strengthen their frames to prevent collapse. But the transit agency declined, saying that the cars make up one-third of the fleet and that Metro could not afford to mothball them ahead of their planned retirement in 2014, and that retrofitting would be costly and impractical. The NTSB, which makes safety recommendations but has no enforcement authority, disagreed with Metro's stance, calling it "unacceptable" at the time.

Yesterday, Hersman again questioned the safety of the Rohr cars and blamed Metro for failing to act. "We recommended to [Metro] to either retrofit those cars or phase them out of service," she said. "Those concerns were not addressed."

Metro uses 290 1000 series cars, which make up more than 25 percent of its 1,126-car fleet.

Graham said replacing the cars would cost almost $1 billion, money that Metro does not have. Metro is the only major transit system in the country without a source of dedicated funds. The agency appeals every year to the District, Virginia and Maryland for funding, a situation that makes long-term planning difficult.

The NTSB also recommended that Metro install data recorders, similar to the black boxes found in airplanes, in all of its cars after the 2004 crash. Although the agency installed recorders in some of its newest cars, the Rohr cars did not have them -- a condition that Hersman also called unacceptable.

Metro officials also did not install critical software revisions that would have allowed investigators to determine whether the operator had applied the emergency brakes and the train's speed during braking, according to a source knowledgeable about the braking systems. Investigators might be able to determine whether the emergency brakes were deployed based on physical evidence.

Metro's automated system is built around electronic relays on the trains and buried along the track that allow onboard computers to control speeds and stop trains from getting too close to one another. Over the past decade, Metro has struggled with troublesome relays. The agency tore out all 20,000 trackside relays in 1999 after discovering that a small portion designed to last 70 years were failing after 25.

The manufacturer, Alstom Signaling, agreed to replace the relays at a cost to Metro of about $8 million. None of the new relays have failed, one Metro official said.

The NTSB and the Federal Transit Administration have criticized Metro for failing to act aggressively to address safety problems, especially at the time of a 1996 crash at Shady Grove that killed a train operator.


Tuesday Red Line service altered as a result of Monday collision

For immediate release: June 23, 2009
Washington Metropolitan Area Transit Authority

Customers should avoid the Red Line Tuesday

Red Line service continues to be severely impacted today, June 23, as a result of a fatal collision on the Red Line on Monday, June 22, between the Fort Totten and Takoma Metrorail stations, that has resulted in nine deaths.

Red Line trains are operating between the Glenmont and Silver Spring Metrorail stations and between the Shady Grove and the Rhode Island Ave-Brentwood Metrorail stations. All trains are six- and eight-car trains, and they are running about eight to 10 minutes apart. Trains are very crowded. The Brookland-CUA, Fort Totten and Takoma Metrorail stations are closed to Red Line traffic. However, the Green and Yellow lines are operating normal service through Fort Totten Metrorail station.

Free Metrobus shuttles are available to take customers around the incident between the Silver Spring, Fort Totten, Brookland-CUA and the Rhode Island Ave-Brentwood Metrorail stations. Metro also is providing shuttle buses and its regular Metrobus routes 70/71 and 79 (Georgia Avenue) service from the Georgia Ave-Petworth and Silver Spring Metrorail stations. People can expect long waits for buses as a full Metrorail train often carries 100 people or more per car and a bus can only hold about 50 people at a time.

Metro officials recommend that customers who normally use the Red Line between the Glenmont and Silver Spring Metrorail stations should commute to Metrorail stations between the Shady Grove and Grosvenor-Strathmore Metrorail stations, or to use the following Metrobus lines to avoid the service disruption:

• Metrobus C8 line (Glenmont to White Flint)
• Metrobus Q2 line (Wheaton to Rockville)
• Metrobus C2, C4 line (Wheaton to Twinbrook)
• Metrobus J1 line (Silver Spring to Medical Center)
• Metrobus J2, J3, J4 line (Silver Spring to Bethesda)
• Metrobus L7, L8 line (Friendship Heights)

Metro has doubled its bus service on the limited-stop S9 and 79 (16th Street, NW, and Georgia Avenue) lines.

Metro officials recommend that people use the Green and Yellow lines, which are operating normal service between the Greenbelt and Branch Ave and Fort Totten and Huntington Metrorail stations.

MARC’s Brunswick Line service is suspended today (June 23) due to the proximity of its tracks to the accident scene.

Metro safety and operations officials are working hand-in-hand with the National Transportation Safety Board investigating the cause of the accident.

People who believe their relatives may have been on board the trains involved in the accident can call 311 if they live in the District of Columbia or 202-737-4404 or 202-671-0722. A family reunification center has been established at 501 Riggs Road, NE, in Washington.

“This is an incredible tragedy and our hearts go out to the families of those who suffered fatalities and to those whose loved ones are injured,” said Metro General Manager John Catoe. “We are committed to investigating this accident until we determine why this happened and what must be done to ensure it never happens again.”

Metro officials do not know the cause of the 5 p.m. Monday collision and are not likely to know the cause for several weeks or months as the investigation unfolds. According to preliminary reports, two Red Line trains were on the same track headed toward Shady Grove Metrorail station when train 112 collided with train 214.

Train operator Jeanice McMillan, who was operating train 112, died as result of the collision. Officials have confirmed that at least eight passengers also died in the accident. McMillan, 42, of Springfield, Va., had been a Metro employee since January 2007.

Train 112 was made up of all 1000-series rail cars (rail car numbers 1079, 1078, 1071, 1070, 1130 and 1131). Train 214 was made up of a combination of 3000- and 5000-series rail cars (rail car numbers 3036, 3037, 3257, 3256, 5067 and 5066).

Metro has a total of 1,126 rail cars in its Metrorail fleet. There are 290 1000-series rail cars, 364 2000/3000-series rail cars, 100 4000-series rail cars, 188 5000-series rail cars and 184 6000-series rail cars.

The only other time in Metrorail’s 33-year history that there were customer fatalities was in January 1982, when three people died as a result of a derailment between the Federal Triangle and Smithsonian Metrorail stations. The only other time that Metrorail trains collided was in 2004 when two trains collided at the Woodley Park-Zoo/Adams Morgan Metrorail station, in which there were minor injuries.

Customers who were onboard train 112 or 214 can file an injury claim by calling 202-962-1681.

Metro Failed to Detect Hazard

Device Replaced Just Days Before Crash, but Circuit Malfunctioned

By Lena H. Sun and Lyndsey Layton
Washington Post Staff Writers
Thursday, July 2, 2009

Five days before last week's deadly Red Line accident, a Metro crew replaced a key piece of equipment designed to prevent crashes, but the circuitry malfunctioned and no one at Metro detected the problem, investigators and transit officials said yesterday.

The findings raise new questions about whether Metro officials should have discovered the hazard before one train rammed into another June 22, killing nine and injuring 80. It also puts a spotlight on Metro's maintenance crews and the design of a highly automated subway system that is supposed to be "fail-safe."

Transit officials would not say yesterday whether they believe the malfunction was a result of faulty equipment or poor installation, citing the investigation by the National Transportation Safety Board.

In the aftermath of the crash on the Red Line between the Takoma and Fort Totten stations, Metro officials analyzed track circuit data and found that one circuit in the crash area intermittently lost its ability to detect a train. The circuit would report the presence of a train one moment, then a few seconds later the train would "disappear," only to return again.

The problem started shortly after June 17, when a Metro crew replaced a device known as a Wee-Z bond, a crucial part of the system that maintains a safe distance between trains, said Dave Kubicek, Metro's rail chief.

Instead of completely failing, the track circuit "fluttered" on and off so quickly that, Kubicek said, the failure would not have been obvious in Metro's downtown operations center, where controllers monitor real-time movement of trains by watching an illuminated graphic depiction of the 106-mile railroad.

"It was happening so fast, you would just blink and miss it," he said. "Realistically, you had to be looking at the exact area at the exact place" at the exact time.

A controller would have to be staring at something the size of "a button on a BlackBerry" to detect the malfunction, he said, adding that Metro did not realize that there was problem until officials began examining data after the accident.

Under normal conditions, if a track circuit goes "dark" or stops working, downtown controllers will see an indicator change colors on the illuminated screen before them. In addition, if the circuit stops working, the adjacent track circuits will automatically force approaching trains to stop before they reach the "dark" stretch. As a backup, train controllers can also intervene to redirect train movement.

But the "fluttering" was so fast and subtle that none of those auxiliary safety measures were activated, Kubicek said. He stressed that the malfunction was an "anomaly" and that the rail system is safe. He said Metro is testing daily to determine whether this "fluttering" is occurring elsewhere. Metro workers have been inspecting all of the transit system's nearly 3,000 track circuits. They have checked more than 65 percent of them and found no problems, Kubicek said.

"From what we have discovered so far, it appears to be a freak occurrence," said John B. Catoe Jr., Metro's general manager.

The Frederick News Post first reported on the Wee-Z bond issue Friday.

Metro officials would not say whether in the days before the crash, other trains experienced trouble along the stretch affected by the malfunctioning circuitry.

NTSB officials said they are reviewing the performance of the track circuit before and after the equipment was replaced June 17.

Metro's rail system is divided into blocks and is designed to keep at least two blocks of distance between trains to prevent a crash. Each block contains at least one track circuit that detects the presence of a train using audio frequencies transmitted between the train and the steel rails.

Within each track circuit are two devices, the Wee-Z bonds, which are about 18 inches square and six inches high and are often mounted on the wooden cross ties that secure the rails. The Wee-Z bonds note the presence of a train and automatically transmit signals to the next train down the line. If the following train gets too close, the Wee-Z bond sends a "zero" speed signal that forces that train to stop.

After the installation, Metro crews tested the equipment. "Everything tested okay upon installation," Kubicek said.

Metro is replacing Wee-Z bonds across the railroad because many are approaching the end of their usefulness, said David Couch, who is in charge of Metro's infrastructure projects.

In last week's crash, the train heading toward Fort Totten slammed into the train in front of it, which had been idling on the Red Line outside the station, waiting for a third train to depart. NTSB investigators said the track circuitry did not detect the presence of the idling train. That would mean the striking train received a "clear" signal and its onboard computers would have been automatically set to travel at 59 mph, the speed limit along that stretch.

Federal investigators say the emergency brakes on the striking train were engaged, but it is unclear at what point the novice operator, Jeanice McMillan, saw the idled train before she deployed them. She was among the nine who died in the crash, which was the deadliest in Metro's 33-year history. NTSB investigators intend to perform tests over the July 18 weekend to establish when McMillan would have been able to see the train ahead of her and measure that against the point where the brakes were deployed, about 425 feet before impact.

Many portions of Metro's automated train control system rely on original equipment based on 100-year-old relay technology that transit officials would like to replace. As part of the agency's major capital improvement starting in 2011, officials want to upgrade track circuits.

According to an internal Metro report assessing the reliability of various track systems, problematic track circuitry stood out in the fiscal year ending in June 2008. Of 668 incidents that caused delays last year, track circuits accounted for 337, or more than half. The station with the highest number of track circuit delay incidents was the Takoma station.

Kubicek declined to comment, saying he had not seen the report. "We have lots of circuitry, lots of equipment," he said.

The problem circuit in the crash area has been disabled but not replaced because officials are trying to pinpoint what caused the malfunction. As investigators continue to examine the signal system at the scene of the crash, Metro officials have ordered an "absolute block" through the area, which means that Red Line trains must proceed one at a time through the affected stretch. That has considerably slowed speeds. All trains have been operating manually on all lines since the crash, and Red Line's top speed limit is set at 35 mph, which has also created significant delays.

In a statement yesterday, Catoe apologized to riders for the inconvenience but said, "This is critical to gaining a full understanding of why this happened."

Meanwhile, Carolyn B. Jenkins, mother of crash victim Veronica DuBose, filed a wrongful death lawsuit in D.C. Superior Court against Metro and Alstom Signaling, her attorney, Stephen D. Annand, said yesterday. The complaint alleges negligence on the part of both parties. It is at least the third claim filed.

Staff writer Jonathan Mummolo contributed to this report. See recent stories by Lena H. Sun or Lyndsey Layton.

Metro crash probe prompts NTSB 'urgent' recommendation

July 14, 2009 -- Updated 0031 GMT (0831 HKT)

WASHINGTON (CNN) -- In the wake of a deadly June accident, the National Transportation Safety Board on Monday put out a rare recommendation for the Washington Metro to install a system that would automatically warn operators if train sensors behave erratically.
Investigators are shown at the crash scene in Washington. Nine people were killed in the June 22 accident.

Investigators are shown at the crash scene in Washington. Nine people were killed in the June 22 accident.

Washington's Metro reacted almost immediately, saying it would follow the recommendation as soon as possible but that no current warning system fits the bill.

"It is important to know that there are currently no systems available commercially that could provide the Metro system with the kind of alerts that the NTSB has recommended, and that such a system must be invented," Metro said.

In the meantime, Metro is continuing to operate trains on a manual mode to reduce the chance of another accident, Metro said.

The NTSB still has not determined the cause of the crash that killed nine near the Fort Totten station June 22. But Metro has acknowledged a review of computer data revealed a "track circuit" in the area of the crash had behaved erratically in the days before the accident.

The system fluctuated, intermittently indicating the track was occupied and unoccupied. No other circuit in the system shared the same problem, Metro said.

Since the accident, Metro has assigned someone to review the recorded data once a day to identify track circuit anomalies, but daily reviews are "not sufficient to address this safety issue," the NTSB said Monday.

"The NTSB believes that (computer software or hardware) could be developed to continuously evaluate" track data and alert operators when problems are detected, the NTSB wrote in a letter to Metro. Those alerts should immediately slow or stop trains, the NTSB said.

Metro said it is working on developing a system "specifically tailored to Metro," but said systems being used by others, such as San Francisco's Bay Area Rapid Transit (BART), "would not meet our unique needs."

"Metro is in the process of contacting vendors who have the expertise needed to help us develop this service, and we are preparing cost estimates on this application," the transit system said.

The NTSB and Metro said the Washington accident has implications that reach far beyond Metro.

Accordingly, the NTSB also sent a letter to the Federal Transit Administration asking it to notify other transit systems "of the problems identified thus far" in the Washington investigation.

Meanwhile, an industry group, the American Public Transportation Association, is convening an independent panel of experts in signal systems to study the issue even before the NTSB has finished its investigation. And a House of Representatives subcommittee will hold a hearing Tuesday on the Metro accident.

Metro General Manager John Catoe, NTSB member Deborah Hersman and a witness to the crash are among those scheduled to testify.

By chance today I found myself on the Washington metro Red Line, at a station about half a mile from the crash site. A US colleague who was with me told me how he had been commuting home from work that evening and got to the station and found all the trains cancelled because of the accident, and had to face a long commute home by other means. It's still fresh in his memory, and probably many other Washingtonians.