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Germany train crash—ways in which rail safety systems can fail
Germany train crash—ways in which rail safety systems can fail
February 11, 2016 by Sarah Sharples, University Of Nottingham, The Conversation
Whenever we hear of an accident such as the head on train collision that occurred in Bavaria on Tuesday our first thoughts must be with the victims who were killed or injured, and their friends and families. But as with all accidents an investigation is now underway, which should bring answers to how such a tragedy can happen.
In recent decades, there has been significant investment in safety systems to prevent incidents occurring, or to mitigate their impact. These include: developing new materials and structures to strengthen rail carriages to make sure that in the case of a crash, the damage is limited; Automatic Train Protection (ATP), which asks drivers to acknowledge that they have seen an oncoming red signal, and automatically applies brakes if a signal has been passed at danger; and physical interlocking which prevents signals allowing two trains to occupy the same section of track, and which maintains distance between them.
The basic principle of signalling which is used in most parts of Europe at present is the "fixed block" system, where trains are kept a number of blocks apart. A signaller will set a route, and the engineering within the rail system will ensure that the signals display the correct instructions to the train driver. So if a route is set for a train, a signal will display as green; once the train has passed that signal, it will revert to red, the next signal behind will be amber, and the one behind that, double amber.
....
Reports suggest that the trains in the Bavaria crash not only had ATP technology, but also had technologies which help drivers to manage the speed of the train. It is these systems that some have jumped on in the search for a cause – but which we will have to wait for the investigation to reveal. ... However, an "irony of automation", as noted by Lisanne Bainbridge in 1983, is that if we introduce a large amount of technology into a previously manual system, the nature of the work task changes, and there is a danger that drivers can becomes less able to intervene and to problem solve quickly when incidents occur.
February 11, 2016 by Sarah Sharples, University Of Nottingham, The Conversation
Whenever we hear of an accident such as the head on train collision that occurred in Bavaria on Tuesday our first thoughts must be with the victims who were killed or injured, and their friends and families. But as with all accidents an investigation is now underway, which should bring answers to how such a tragedy can happen.
In recent decades, there has been significant investment in safety systems to prevent incidents occurring, or to mitigate their impact. These include: developing new materials and structures to strengthen rail carriages to make sure that in the case of a crash, the damage is limited; Automatic Train Protection (ATP), which asks drivers to acknowledge that they have seen an oncoming red signal, and automatically applies brakes if a signal has been passed at danger; and physical interlocking which prevents signals allowing two trains to occupy the same section of track, and which maintains distance between them.
The basic principle of signalling which is used in most parts of Europe at present is the "fixed block" system, where trains are kept a number of blocks apart. A signaller will set a route, and the engineering within the rail system will ensure that the signals display the correct instructions to the train driver. So if a route is set for a train, a signal will display as green; once the train has passed that signal, it will revert to red, the next signal behind will be amber, and the one behind that, double amber.
....
Reports suggest that the trains in the Bavaria crash not only had ATP technology, but also had technologies which help drivers to manage the speed of the train. It is these systems that some have jumped on in the search for a cause – but which we will have to wait for the investigation to reveal. ... However, an "irony of automation", as noted by Lisanne Bainbridge in 1983, is that if we introduce a large amount of technology into a previously manual system, the nature of the work task changes, and there is a danger that drivers can becomes less able to intervene and to problem solve quickly when incidents occur.
Transportation
After Bad Aibling: railway safety in Europe
After the crash in Bavaria, train travel safety is a hot topic. The EU doesn't have common standards yet, but a system called ETCS is being developed. DW explains it and looks back at recent train disasters in Europe.
Date 10.02.2016
Author Carla Bleiker
The train crash that killed 10 people near the Bavarian town of Bad Aibling has shaken people's trust in train travel and prompted many politicians to voice their shock and sadness. Condolences have come from France's Prime Minister Manuel Valls and Russia's president Vladimir Putin.
....
Of course there's room for improvement. There is currently no unified system in place that has trains respond to the same signals. How exactly trains stop when a break signal doesn't work, a question that might have played a role in the Bad Aibling disaster, varies from country to country, because rail transport systems have historically developed on a national, not an EU-wide basis. ... The goal is to get all railway route networks under one umbrella, so that train travel is equally safe in all EU member states - and that's what the European Train Control System (ETCS) was developed for.
Open-source software makes ETCS more affordable
The ETCS is supposed to replace the many incompatible safety systems operated in the EU, especially on high-speed lines. It deals with signaling and train protection, among other issues.
The basic idea of one common train and railway system has been around for decades. The specifications put forth by the ETCS are accepted Europe-wide, but there are several national exceptions to individual guidelines. Integrating all this into one standard that all trains from Rome to Stockholm and from Lisbon to Bucharest run on is a - rather difficult - work in progress. ... One of the players tackling this challenge is the German Fraunhofer Institute for Open Communication Systems (FOKUS). Researchers at the institute are working to certify an open-source software for ETCS that is developed by Deutsche Bahn.
After Bad Aibling: railway safety in Europe
After the crash in Bavaria, train travel safety is a hot topic. The EU doesn't have common standards yet, but a system called ETCS is being developed. DW explains it and looks back at recent train disasters in Europe.
Date 10.02.2016
Author Carla Bleiker
The train crash that killed 10 people near the Bavarian town of Bad Aibling has shaken people's trust in train travel and prompted many politicians to voice their shock and sadness. Condolences have come from France's Prime Minister Manuel Valls and Russia's president Vladimir Putin.
....
Of course there's room for improvement. There is currently no unified system in place that has trains respond to the same signals. How exactly trains stop when a break signal doesn't work, a question that might have played a role in the Bad Aibling disaster, varies from country to country, because rail transport systems have historically developed on a national, not an EU-wide basis. ... The goal is to get all railway route networks under one umbrella, so that train travel is equally safe in all EU member states - and that's what the European Train Control System (ETCS) was developed for.
Open-source software makes ETCS more affordable
The ETCS is supposed to replace the many incompatible safety systems operated in the EU, especially on high-speed lines. It deals with signaling and train protection, among other issues.
The basic idea of one common train and railway system has been around for decades. The specifications put forth by the ETCS are accepted Europe-wide, but there are several national exceptions to individual guidelines. Integrating all this into one standard that all trains from Rome to Stockholm and from Lisbon to Bucharest run on is a - rather difficult - work in progress. ... One of the players tackling this challenge is the German Fraunhofer Institute for Open Communication Systems (FOKUS). Researchers at the institute are working to certify an open-source software for ETCS that is developed by Deutsche Bahn.
1 replies
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= new reply since forum marked as read
Last edited Tue Feb 16, 2016, 02:25 PM - Edit history (7)
Dispatcher in Deadly German Train Crash Faces Investigation
By MELISSA EDDY FEB. 16, 2016
BERLIN — A dispatcher is under investigation for involuntary manslaughter following the deaths of 11 people after the German authorities concluded human error led two trains to collide in Bavaria last week, prosecutors said on Tuesday.
The dispatcher, identified only as a 39-year-old man with a family, was overseeing a single-track stretch in southeastern Germany on Feb. 9 at the time of the accident near Bad Aibling, said Wolfgang Giese, the chief prosecutor from Traunstein who is responsible for the investigation..
“Had he behaved according to the rules, according to his duties, the trains would not have collided,” Mr. Giese told reporters at a news conference in Bad Aibling, which is about 35 miles southeast of Munich. The man was questioned on Monday, he said.
The trains and the track were fitted with an automatic brake system that was introduced in Germany after 10 people died in a similar accident in 2011, but the German news media have reported that the system had been turned off at the time of the crash. Prosecutors have declined to comment on the reports, citing the continuing investigation.
By MELISSA EDDY FEB. 16, 2016
BERLIN — A dispatcher is under investigation for involuntary manslaughter following the deaths of 11 people after the German authorities concluded human error led two trains to collide in Bavaria last week, prosecutors said on Tuesday.
The dispatcher, identified only as a 39-year-old man with a family, was overseeing a single-track stretch in southeastern Germany on Feb. 9 at the time of the accident near Bad Aibling, said Wolfgang Giese, the chief prosecutor from Traunstein who is responsible for the investigation..
“Had he behaved according to the rules, according to his duties, the trains would not have collided,” Mr. Giese told reporters at a news conference in Bad Aibling, which is about 35 miles southeast of Munich. The man was questioned on Monday, he said.
The trains and the track were fitted with an automatic brake system that was introduced in Germany after 10 people died in a similar accident in 2011, but the German news media have reported that the system had been turned off at the time of the crash. Prosecutors have declined to comment on the reports, citing the continuing investigation.
Human error caused Bavaria train crash: prosecutors
Published: 16 Feb 2016 15:03 GMT+01:00
A train crash which killed eleven people in southern Germany last week was the result of human error, said Bavarian state prosecutors on Tuesday.
• Controller 'twice tried to warn trains before Bavaria collision' (12 Feb 16)
• Eleventh victim claimed by Bavaria train crash (11 Feb 16)
• All missing accounted for in Bavaria crash (10 Feb 16)
An investigation has now been opened into the actions of the controller who was in charge of the stretch of track in Bad Aibling south-east of Munich on the day of the fatal crash.
If the controller “had acted according to the rules and according to his duty, the collision would not have happened,” lead prosecutor Wolfgang Giese said in press conference held on Tuesday afternoon.
"There is no evidence of technical problems... Our investigation shows that this was human error with catastrophic consequences," he added.
....
Unconfirmed media reports suggest that the controller mistakenly allowed both of the trains onto the track at the same time and tried without success to alert the drivers once he had realized his mistake.
Published: 16 Feb 2016 15:03 GMT+01:00
A train crash which killed eleven people in southern Germany last week was the result of human error, said Bavarian state prosecutors on Tuesday.
• Controller 'twice tried to warn trains before Bavaria collision' (12 Feb 16)
• Eleventh victim claimed by Bavaria train crash (11 Feb 16)
• All missing accounted for in Bavaria crash (10 Feb 16)
An investigation has now been opened into the actions of the controller who was in charge of the stretch of track in Bad Aibling south-east of Munich on the day of the fatal crash.
If the controller “had acted according to the rules and according to his duty, the collision would not have happened,” lead prosecutor Wolfgang Giese said in press conference held on Tuesday afternoon.
"There is no evidence of technical problems... Our investigation shows that this was human error with catastrophic consequences," he added.
....
Unconfirmed media reports suggest that the controller mistakenly allowed both of the trains onto the track at the same time and tried without success to alert the drivers once he had realized his mistake.
This was a bad time for the automatic train stop system (if that's what they had) to be turned off.
Wikipedia: Bad Aibling rail accident
I am not familiar with that territory. If the line were signaled - that is, if there were railroad signals along the line - the circuitry controlling those signals should have automatically recognized the presence of the trains and have gone to the least permissive position - stop. That's a red signal.
Wikipedia: German railway signaling
Main signal/distant signal (H/V)
The most common system is the H/V (Hauptsignal/Vorsignal) system which consists of main signals and distant signals. Depending on the technology used in the signal box, these signals may be indicated by semaphores or colour-light signals. The colour-lights show the same light patterns the semaphores show at night. The aspects shown here may be accompanied by Zs2, Zs2v, Zs3, Zs3v, Zs6 (see section #Additional signals) or Lf signals (see section #Langsamfahrsignale) in order to show speed limits or the choice of track that follows. A main signal (with lights only) is marked by a Mastschild (board with a colour code) to protect in case of a signal lights failure. The location of a distant signal is marked by an Ne2 (unless it is a repetition or it is at the location of a main signal) also for the case where the signal lights fail or where a semaphore distant signal shows Vr1 (see section #Nebensignale).
https://upload.wikimedia.org/wikipedia/commons/1/11/Hp0_Form.svg
Hp 0 (Semaphore)
https://upload.wikimedia.org/wikipedia/commons/4/47/Hp0_Nacht.svg
Hp 0 (Semaphore at night)
https://upload.wikimedia.org/wikipedia/commons/6/63/Hp0_Licht.svg
Hp 0 (Light)
Hp 0: Stop
A main signal (Hauptsignal) shows Hp 0 by a horizontal semaphore arm, one red light or two horizontal red lights. The signal requires the driver to stop in front of it. (Originally, the aspect with two red lights was called Hp 00 and had a different meaning than a single red light with regards to shunting, but nowadays, the meaning is the same.)
Usually, Hp 0 is protected by a 2000 Hz magnet of the PZB train safety system which triggers the emergency brake if the train {passes} the signal.
Main signal/distant signal (H/V)
The most common system is the H/V (Hauptsignal/Vorsignal) system which consists of main signals and distant signals. Depending on the technology used in the signal box, these signals may be indicated by semaphores or colour-light signals. The colour-lights show the same light patterns the semaphores show at night. The aspects shown here may be accompanied by Zs2, Zs2v, Zs3, Zs3v, Zs6 (see section #Additional signals) or Lf signals (see section #Langsamfahrsignale) in order to show speed limits or the choice of track that follows. A main signal (with lights only) is marked by a Mastschild (board with a colour code) to protect in case of a signal lights failure. The location of a distant signal is marked by an Ne2 (unless it is a repetition or it is at the location of a main signal) also for the case where the signal lights fail or where a semaphore distant signal shows Vr1 (see section #Nebensignale).
https://upload.wikimedia.org/wikipedia/commons/1/11/Hp0_Form.svg
Hp 0 (Semaphore)
https://upload.wikimedia.org/wikipedia/commons/4/47/Hp0_Nacht.svg
Hp 0 (Semaphore at night)
https://upload.wikimedia.org/wikipedia/commons/6/63/Hp0_Licht.svg
Hp 0 (Light)
Hp 0: Stop
A main signal (Hauptsignal) shows Hp 0 by a horizontal semaphore arm, one red light or two horizontal red lights. The signal requires the driver to stop in front of it. (Originally, the aspect with two red lights was called Hp 00 and had a different meaning than a single red light with regards to shunting, but nowadays, the meaning is the same.)
Usually, Hp 0 is protected by a 2000 Hz magnet of the PZB train safety system which triggers the emergency brake if the train {passes} the signal.
(The same information is also available at Wikiwand: German railway signalling)
German railway signals showing aspect Hp 0 (Stop)
(From Wikipedia: Railway signal)
The engineer encountering such a signal would have applied the brakes and brought his train to a stop. Sometimes, when a red signal is not expected, the train overruns the signal, but at least it would have done so at a lower speed.
In North America, all the railroads operating intercity passenger service are equipped with two-way train-to-dispatcher radios. Germany, I don't know. If he had a radio, the engineer would have got on it to notify the dispatcher that he was encountering a red signal. He would want to know why.
In dark territory - that without signaling - things get dicey. I'll relate a story about that in a post later today. It is grisly.
