Chinese Release Report On Rail Crash

[guest]

December 28, 2011/The New York Times

Design Flaws Cited in Deadly Train Crash in China

By SHARON LaFRANIERE

BEIJING — Chinese investigators on Wednesday delivered a long-awaited report into the deadly July 23 high-speed train crash in the eastern coastal city of Wenzhou, attributing it to a string of blunders, including serious design flaws in crucial equipment used to signal and control the trains. Two top former officials of the Railway Ministry — who had already been under investigation for corruption — were singled out for blame.

The disaster was a serious setback to China’s hopes to turn high-speed rail into a symbol of the nation’s technological and industrial progress. It also led to an online wave of public outrage that only died down after government authorities muzzled the domestic media. The intense public reaction to the accident and the bungled rescue effort that followed are considered major reasons why the government is now instituting tighter controls of Internet message boards known as microblogs.

The crash investigators found that faulty equipment was purchased in a process tainted with bidding irregularities and was cleared for use after substandard safety inspections. They said lightning strikes caused the signaling and track equipment on the Wenzhou line to malfunction, leading to the rear-end collision on a viaduct that killed 40 people and injured 191.

Here's the link to the full story:

http://www.nytimes.com/2011/12/29/world/asia/design-flaws-cited-in-china-train-crash.html?_r=1&hp

 

[Anderson]

Amazing...their official explanation actually passes the "smell" test! Mind you, that they had bad signaling equipment or some sort of related failure...that's not a surprise. Now, let's see if they actually fix the problem.

 

[DET63]

How many fatal accidents have the Taiwanese, Korean, and Japanese HSR systems had combined? And how many total fatalities in all of those accidents?

(I'll bet the numbers, especially in answer to the second question, are not anything for the mainland Chinese to crow about.)

 

[guest]

How many fatal accidents have the Taiwanese, Korean, and Japanese HSR systems had combined? And how many total fatalities in all of those accidents?

(I'll bet the numbers, especially in answer to the second question, are not anything for the mainland Chinese to crow about.)

Don't know about Taiwan but the Japanese Shinkansen has never had a fatality due to derailments or collisions, and it's been in service since 1964. That's a pretty good record, yes? (the only deaths have come from people committing suicide in front of the train, for which you can hardly hold the Shinkansen responsible)

 

[Shawn Ryu]

There has never been any fatalities on KTX (Korean Train eXpress)

 

[jis]

I read the entire report such as it is. It sounds like it is a design problem wherein they forgot to ensure that the "failsafe principle" was uniformly incorporated in the design. I find it hard to believe that Siemens supplied them a system which would have this mode of failure, so I suspect that it has something to do with Chinese attempts to improve the Siemens system and make it more efficient. Just speculation on my part on that last bit. Unfortunately the report is more into nailing the fault on a bunch of people instead of giving any real details about eh core technical issues AFAICT. Hopefully there is a more detailed report somewhere that goes into the technical aspects. Maybe George can dig it up somewhere.

 

[Anderson]

I read the entire report such as it is. It sounds like it is a design problem wherein they forgot to ensure that the "failsafe principle" was uniformly incorporated in the design. I find it hard to believe that Siemens supplied them a system which would have this mode of failure, so I suspect that it has something to do with Chinese attempts to improve the Siemens system and make it more efficient. Just speculation on my part on that last bit. Unfortunately the report is more into nailing the fault on a bunch of people instead of giving any real details about eh core technical issues AFAICT. Hopefully there is a more detailed report somewhere that goes into the technical aspects. Maybe George can dig it up somewhere.

To take a guess, they took what Siemens delivered and, in making it "more efficient", they either disabled some important failsafes or allowed them to be overridden.

Where can I find the report itself? Does the NYT story link to it?

 

[George]

Taiwan HSR has had zero fatalities, and only one derailment, and that was one wheel set and due to an earthquake. A few minor injuries, for the most part, bumps and bruises.

Not sure whether or when more detailed information wil be available.

Do not for get, this line in China was not a dedicated high speed line, but a new line built to handle mixed traffic.

 

[DET63]

So it's 0 deaths for the Japanese HSR, 0 deaths for the Korean HSR, and 0 deaths for the Taiwanese HSR. Even allowing that the Chinese system is not a "pure" HSR, the problem of a design allowing mixed traffic for otherwise HSR trains seems like a questionable choice.

I know that such designs do exist in Europe, where HSR trains run part of their route on mixed-traffic lines; how do they avoid the problems that the Chinese seem to have encountered?

 

[Bob Dylan]

So it's 0 deaths for the Japanese HSR, 0 deaths for the Korean HSR, and 0 deaths for the Taiwanese HSR. Even allowing that the Chinese system is not a "pure" HSR, the problem of a design allowing mixed traffic for otherwise HSR trains seems like a questionable choice.

I know that such designs do exist in Europe, where HSR trains run part of their route on mixed-traffic lines; how do they avoid the problems that the Chinese seem to have encountered?

They follow the Safety procedures, and their staffers aren't "on the take" like so many are in China during these "Boom Times" in the Peoples Republic!!

 

[George]

So it's 0 deaths for the Japanese HSR, 0 deaths for the Korean HSR, and 0 deaths for the Taiwanese HSR. Even allowing that the Chinese system is not a "pure" HSR, the problem of a design allowing mixed traffic for otherwise HSR trains seems like a questionable choice.

I know that such designs do exist in Europe, where HSR trains run part of their route on mixed-traffic lines; how do they avoid the problems that the Chinese seem to have encountered?

The European mixed high speed with normal traffic lines have had their own sets of problems. There have been several collisions at grade crossings, some with fatalities on the HS train set.

There is the well known Eschede derailment which would take paragraphs to describe.

There have even been a couple of cases of pieces of sheet metal coming off European high speed trainsets.

 

[DET63]

There is the well known Eschede derailment which would take paragraphs to describe.

Here is the Wikipedia article detailing the Eschede disaster.

The Eschede train disaster was the world's deadliest high-speed train accident. It occurred on 3 June 1998, near the village of Eschede in the Celle district of Lower Saxony, Germany. The toll of 101 people dead and 88 (estimated) injured surpassed the 1971 Dahlerau train disaster as the deadliest accident in the history of the Federal Republic of Germany. It was caused by a single fatigue crack in one wheel which, when it finally failed, caused the train to derail at a switch.

Click on the link above if you want more paragraphs (or at least more information).

 

[jis]

I know that such designs do exist in Europe, where HSR trains run part of their route on mixed-traffic lines; how do they avoid the problems that the Chinese seem to have encountered?

The problem that the Chinese encountered has little to do with whether it was HSR or not. It, in some ways, is similar to the problem that Washington WMATA had, causing their last collision. It was a failure in the signaling and train control system to detect a train that was occupying a block thus leading to false clear signal. In case of WMATA it happened because the train detection system failed to latch onto the right frequency detection loop current when present. It is not clear exactly what failed as a result of a severe thunderstorm in the Chinese case. However, the system design really should be failsafe even in face of such failures, and apparently it was not.

In the Chinese case the result would most likely have been similar if the second train (or even both trains) was a run of the mill loco hauled train running at 160kph.

 

[Trogdor]

I don't have specific knowledge of the Chinese design, but I was listening to a few railroad professionals speculate on the cause. They suggested it had to do with a design philosophy that was based more on the aviation philosophy of redundancy rather than the railroad philosophy of being fail-safe.

The difference being that if the primary and backup systems fail, you're in a dangerous situation if you rely on redundancy, but everything defaults to a stop/restrictive aspect in a fail-safe system.

 

[jis]

I don't have specific knowledge of the Chinese design, but I was listening to a few railroad professionals speculate on the cause. They suggested it had to do with a design philosophy that was based more on the aviation philosophy of redundancy rather than the railroad philosophy of being fail-safe.

The difference being that if the primary and backup systems fail, you're in a dangerous situation if you rely on redundancy, but everything defaults to a stop/restrictive aspect in a fail-safe system.

I don't know of any airliner reliability software that fails catastrophically to a random state by design after it runs through its redundant systems, leading to loss of the aircraft. They are designed to degrade progressively and hand over control to a human, the moral equivalent of a railroad control system degrading permission to "Restricted Speed". Afterall airplanes cannot stop dead in their tracks without falling out of the sky, since usually that is a bad thing. At certain points of degradation procedures call for a divert to the closest airport etc.

So frankly, it appears to me that the speculators have a strange notion of what the design philosophy is for aircraft systems. Aviation philosophy is exactly as much "fail-safe" - which means fail to a safe, predictable, well known and survivable state - as any other. The only difference is that the fail safe state is not a dead stop in case of aviation, since that in itself constitutes a serious failure.

Now that is not to say that serious design mistakes are not made in airline designs like the famous one on the DC 10 of routing all three redundant control circuits through the same conduit.