Red Line Collision between Ft Totten and Takoma on (6/22/09)

"NellieBly"
I know Bill Pettit. I worked with him a decade ago on a job for CSX. He knows his stuff. However, I'm sure he doesn't want to get caught in a pissing match between Catoe and the Washington Post.

You didn't happen to read the last 2 paragraph in the wtop.com article I linked to above?


"Also on Wednesday, Bill Petit, an independent consultant quoted in the Washington Post story, wrote an e-mail to transit leaders:.

"I just looked at the article in the Washington Post today and they completely misrepresented anything I said. I used those words somewhere within the conversation but not in the sense they reported them. I don't see any reason for me to continue talking with them based on this.

- Signed William A. Petit"

###

http://ntsb.gov/Pressrel/2009/090723.html

THIRD UPDATE ON NTSB INVESTIGATION INTO COLLISION OF TWO METRORAIL TRAINS IN WASHINGTON, D.C.

The National Transportation Safety Board continues to make progress in its investigation of the June 22, 2009, collision of two Washington Metropolitan Area Transit Authority (WMATA) trains on the Red Line in Washington, D.C. The Board has developed the following factual information:

Two signal companies, Ansaldo STS USA (US&S) and Alstom Signaling Inc. (GRS), that designed and manufactured the automatic train control components for the WMATA system, are providing technical assistance to the NTSB investigation.

As previously reported, an impedance bond (#15) for the track circuit where the accident occurred was replaced on June 17th, 2009, five days before the accident. Continued review of the maintenance logs has identified that the impedance bond (#14), located on the other end of the same circuit, was replaced in December 2007. WMATA records reveal that this track circuit's train occupancy signal has been intermittently fluctuating since the replacement was installed in December 2007.

The NTSB has requested trouble tickets for the last 18 months to see if these problems had been reported, and seeking records to see if any operators reported problems on this circuit.

The investigation is identifying possible sources of interference affecting the automatic train control (ATC) operation. These potential sources include Electromagnetic Interference (EMI), traction power harmonics and signal crosstalk, communication lines, and system upgrades and changes.

Following the accident, WMATA began to review operations data and identified some problems at other circuits. These anomalies are being examined by NTSB and WMATA to determine if they are the same kinds of problems as were found in the location of the accident site.

Testing has identified that the circuit problems are occurring more frequently during the rush hour time period. As a result, the NTSB and WMATA testing at the accident location on the Red Line is continuing. These tests may result in occasional delays on the Red Line in the Fort Totten area. All testing in the Fort Totten area is closely coordinated with WMATA and is scheduled to minimize delays on that area of track during rush hour.

On Saturday, July 18, the NTSB conducted a sight distance test at the accident location. Information collected from the test will be correlated with rail markings documented after the accident, the braking characteristics of the striking train, and the speed information gleaned from the WMATA Operations Control Center records.

farecard wrote:http://ntsb.gov/Pressrel/2009/090723.html

THIRD UPDATE ON NTSB INVESTIGATION INTO COLLISION OF TWO METRORAIL TRAINS IN WASHINGTON, D.C.

The National Transportation Safety Board continues to make progress in its investigation of the June 22, 2009, collision of two Washington Metropolitan Area Transit Authority (WMATA) trains on the Red Line in Washington, D.C. The Board has developed the following factual information:

Two signal companies, Ansaldo STS USA (US&S) and Alstom Signaling Inc. (GRS), that designed and manufactured the automatic train control components for the WMATA system, are providing technical assistance to the NTSB investigation.

As previously reported, an impedance bond (#15) for the track circuit where the accident occurred was replaced on June 17th, 2009, five days before the accident. Continued review of the maintenance logs has identified that the impedance bond (#14), located on the other end of the same circuit, was replaced in December 2007. WMATA records reveal that this track circuit's train occupancy signal has been intermittently fluctuating since the replacement was installed in December 2007.

The NTSB has requested trouble tickets for the last 18 months to see if these problems had been reported, and seeking records to see if any operators reported problems on this circuit.

The investigation is identifying possible sources of interference affecting the automatic train control (ATC) operation. These potential sources include Electromagnetic Interference (EMI), traction power harmonics and signal crosstalk, communication lines, and system upgrades and changes.

Following the accident, WMATA began to review operations data and identified some problems at other circuits. These anomalies are being examined by NTSB and WMATA to determine if they are the same kinds of problems as were found in the location of the accident site.

Testing has identified that the circuit problems are occurring more frequently during the rush hour time period. As a result, the NTSB and WMATA testing at the accident location on the Red Line is continuing. These tests may result in occasional delays on the Red Line in the Fort Totten area. All testing in the Fort Totten area is closely coordinated with WMATA and is scheduled to minimize delays on that area of track during rush hour.

On Saturday, July 18, the NTSB conducted a sight distance test at the accident location. Information collected from the test will be correlated with rail markings documented after the accident, the braking characteristics of the striking train, and the speed information gleaned from the WMATA Operations Control Center records.

With more problems ocuring during rush hour imbalance in rail negative returns can be one of the problems. The wee zee bond does provide dc connections to rails for balancing the return however if the conductance on one rail is far better than the other the current flow through the bond bar may be excessive saturating and detuning the bond. Restaining rail on one rail would be one of the major causes and is remedied by adding bare copper clamped to the other rail.[size=150][/size]

Taken from: http://www.wmata.com/business/procureme ... _30_09.pdf

This is the 4k rehab spec. From what it is saying, the 4k crashworthiness will be upgraded to meet the standards of the 7k. This would most likely mean additional reinforcements on the framing itself. This is good news.

I wonder if similar measures were made on the 2/3k rehabs when they were at Alstom.

WMATA has posted photos of the wreck on their web site:

Fort Totten Metrorail Station Accident and Investigation Photos

Be advised the linked thumbnail photos are large files (1.5 to 5.5 MB).

Thanks for the post Sand Box John. I have to say, the CAF car looks like it withstood the impact like a tank. Sure, a few windows shattered but for the most part, the bulkhead looks in decent shape.

Yeah, it seems that for the most part, the cars that get hit do fairly well, while the colliding car crumples. Recall that 4018 sustained very little damage in the Woodley Park-Zoo collision. If not mistaken, the NTSB report stated that there was no cab interior damage on that car.

And that means 4018 ought to be pulling civilian passengers once again unlike 1078/79, which will have to be scrapped, and these will be the second consecutive Rohr pair to be totalled in an accident, since 1076/77 was totaled 5 years ago and now we have a large gap 01074/75 and 01080/81. Yikes!

SchuminWeb wrote:Yeah, it seems that for the most part, the cars that get hit do fairly well, while the colliding car crumples. Recall that 4018 sustained very little damage in the Woodley Park-Zoo collision. If not mistaken, the NTSB report stated that there was no cab interior damage on that car.

Some cab compartment damage, but the operator's compartment was intact ...

The NTSB wrote:The lead car (4018), although the forward carbody was intact and uncompromised, sustained damage to the front-end cab compartment. The left side window was pushed inward about 27 inches, and the forward body-end door was pushed inward about 20 inches at the top and about 6 inches at the bottom. The operator’s compartment, including the ceiling panels, was intact and undamaged.

I wonder what it is about the moving train that makes it crumple? Or have we just seen more moving older stock hit stationary newer stock? (3252 vs 3191 at Shady Grove would break that thought.)

"justalurker66"
I wonder what it is about the moving train that makes it crumple? Or have we just seen more moving older stock hit stationary newer stock? (3252 vs 3191 at Shady Grove would break that thought.)

The Breda cars were structurally similar to the Rohr cars at the time of the Shady Grove wreck.

See Figure 8 page 13 in NTSB Shady Grove report for Breda car under frame. (1.78 MB PDF file)

See Figure 6 Page 17 in NTSB Woodley Park- Zoo report for Rohr car under frame. (2.90 MB PDF file)

"CTC"
With more problems ocuring during rush hour imbalance in rail negative returns can be one of the problems. The wee zee bond does provide dc connections to rails for balancing the return however if the conductance on one rail is far better than the other the current flow through the bond bar may be excessive saturating and detuning the bond. Restaining rail on one rail would be one of the major causes and is remedied by adding bare copper clamped to the other rail.

You might be interested in knowing, the receiver WEE-Z bond on the north end of the track circuit is also a negative return bond. The traction power substation is on the east side of the right of way. Diagram of malfunctioning track circuit at wreck site.

The photos of the train control room hardware racks are in fact 1970s vintage hardware. The photos in the linked PDF file matches the pictures in the signal maintainer manual I have that was produced in the 1970s. The lower photo in the PDF labeled train control module is identified as ATP transmitter/receiver module in my signal maintainers manual.

Related Washington Post story:

Probe Focuses on 2 Circuit Modules
Metro Equipment Is From Mid-1970s

By Lena H. Sun
Washington Post Staff Writer
Thursday, July 30, 2009

Robert Paniagua wrote:And that means 4018 ought to be pulling civilian passengers once again unlike 1078/79, which will have to be scrapped, and these will be the second consecutive Rohr pair to be totalled in an accident, since 1076/77 was totaled 5 years ago and now we have a large gap 01074/75 and 01080/81. Yikes!

Yep! 4018 is definitely pulling civilian passengers again. It was fitted with a 3000-Series front. Note the patch under the intercom covering up the hole for the extra intercom button that the 4000's don't have:

http://transit.schuminweb.com/photo-dis ... age_033519
http://transit.schuminweb.com/photo-dis ... age_033522

Interestingly, when it returned, the maps didn't match across the pair. 4018 had the 2001 map (Branch Ave. complete, NYA/Morgan/Largo coming soon), and 4019 had the 2004 map (NYA/Morgan/Largo opening). This was fixed when the 2007 (current) map was introduced. Since these photos were taken in 2006, these cars, like all the 4000's, now have CAF carpet.

Related Washington Post story:

Probe Focuses on 2 Circuit Modules
Metro Equipment Is From Mid-1970s

By Lena H. Sun
Washington Post Staff Writer
Thursday, July 30, 2009

From the article:

As part of the process for replacing the bonds, adjustments were made to track circuit signal strength, the safety board said.

If a track circuit amplifier is generating intermodulation distortion with components interfering on the receiver frequency and you decrease the amplifier gain to the linear region of the amplifier, the distortion and subsequent interference disappears.

Bogie

Sand Box John wrote:"CTC"
With more problems ocuring during rush hour imbalance in rail negative returns can be one of the problems. The wee zee bond does provide dc connections to rails for balancing the return however if the conductance on one rail is far better than the other the current flow through the bond bar may be excessive saturating and detuning the bond. Restaining rail on one rail would be one of the major causes and is remedied by adding bare copper clamped to the other rail.

You might be interested in knowing, the receiver WEE-Z bond on the north end of the track circuit is also a negative return bond. The traction power substation is on the east side of the right of way. Diagram of malfunctioning track circuit at wreck site.

The photos of the train control room hardware racks are in fact 1970s vintage hardware. The photos in the linked PDF file matches the pictures in the signal maintainer manual I have that was produced in the 1970s. The lower photo in the PDF labeled train control module is identified as ATP transmitter/receiver module in my signal maintainers manual.

Related Washington Post story:

Probe Focuses on 2 Circuit Modules
Metro Equipment Is From Mid-1970s

By Lena H. Sun
Washington Post Staff Writer
Thursday, July 30, 2009

I should have added the problem of imbalance I mentioned above increase as the condition gets closer to a substation.

The photos of the train control room hardware racks are in fact 1970s vintage hardware. The photos in the linked PDF file matches the pictures in the signal maintainer manual I have that was produced in the 1970s. The lower photo in the PDF labeled train control module is identified as ATP transmitter/receiver module in my signal maintainers manual.

That diagram explains why I couldn't locate the lineside relay boxes as that functionality is centralized at the nearest station. I never really liked that setup (which is popular in Europe) as long cable runs between the detection point and the vital hardware increases the chance of interference and miswires. It also leaves you vulnerable to a disaster (fire, flood, crash) taking out a HUGE chunk of signaling in one go. I guess its easier on the maintainers and allows for climate control.