Train crash near Bad Aibling in Bavaria 9th February 2016

[whole diary]

[chrisr_75]

In a collision like this where the only way that the energy can be lost is through the structure of the train - no braking, little interaction with the track such as after a derailment, just 2 trains impacting at maximum line speed. The welds are always going to be a weak point I the structure, with the energy of a 120mph collision between 2 objects of several hundred tonnes each, they're just going to burst like a tin can.

If you want an idea of the violence of the impact, take a look at this (nuclear flask crash test) https://m.youtube.com/watch?v=ZY446h4pZdc

[ellendune]

In a collision like this where the only way that the energy can be lost is through the structure of the train - no braking, little interaction with the track such as after a derailment, just 2 trains impacting at maximum line speed. The welds are always going to be a weak point I the structure, with the energy of a 120mph collision between 2 objects of several hundred tonnes each, they're just going to burst like a tin can.

If you want an idea of the violence of the impact, take a look at this (nuclear flask crash test) https://m.youtube.com/watch?v=ZY446h4pZdc

I cannot speak for trains, but a weld need not always be the weakest point.  I know a weld training school that shows its students how their piece always breaks somewhere other than the weld!

[stuving]

If you look at the trains, both had their front ends squashed a long way back and then one pushed inside the other. It was fortunate that the side of the 'outer' train burst at the seam, as it allowed the 'inner' train to diverge to the right. Otherwise there would have been even more severe penetration of the interior of the 'outer' train.

In this case the damage, to people as well as vehicles, would have been less if the trains had been able to slip past each other more easily. For example an off-centre distribution of mass and solid structure at the front end would have had that effect. However, if that led to several carriages going into the canal it might have been worse. And there might be other cases where keeping the trains on the track is the least bad outcome overall, though not for those in the first carriage.

On the whole, hindsight from just one accident shouldn't dictate designs.

[Red Squirrel]

In a collision like this where the only way that the energy can be lost is through the structure of the train - no braking, little interaction with the track such as after a derailment, just 2 trains impacting at maximum line speed. The welds are always going to be a weak point I the structure, with the energy of a 120mph collision between 2 objects of several hundred tonnes each, they're just going to burst like a tin can.

If you want an idea of the violence of the impact, take a look at this (nuclear flask crash test) https://m.youtube.com/watch?v=ZY446h4pZdc

To call it a 120mph collision is a bit misleading - the collision energy absorbed by each train will have been more or less the same as if it had hit a solid block of concrete at 60mph. Adding the speeds of the trains together gives us a bigger number for our headlines, but isn't very useful for anything else.

[JayMac]

Human error to blame, says prosecutor. From the BBC^» (British Broadcasting Corporation - home page):

Human error by a train controller was to blame for a crash in Bavaria, Germany, last week that killed 11 people, prosecutors said.

More than 80 people were injured after two commuter trains collided on a single-track stretch of railway.

An area controller opened the track to the two trains and tried to warn the drivers, according to the prosecutors.

The man, a 39-year-old, is likely to be charged with involuntary manslaughter and could face five years in jail.

"If he had complied with the rules... there would have been no collision," said Chief Prosecutor Wolfgang Giese.

The trains crashed head-on while both were travelling at about 100km/h (60mph) east of Bad Aibling, a spa town about 60km south-east of Munich.

Investigations focused on why the trains were on the tracks at the same time despite safety mechanisms. The crash site is on a bend, meaning the drivers no visual contact so collided largely without braking, officials said.

Prosecutors said the controller's actions had catastrophic consequences but they do not believe he acted deliberately.

All those killed in the crash were men aged between 24 and 59.

[stuving]

Not very informative, is it? 

So we don't know if this was the local signaller or a more senior controller, nor whether this was a normal operation of the points and signals or some kind of override. 

There is a little more in the prosecutor's words: the signaller did notice his error immediately and try to make an emergency call (by GSM-R^▸ (Global System for Mobile communications - Railway.) or equivalent) but it didn't get through. Subsequently he didn't admit it at all until Monday. The prosecutors believe his story is now likely to be true, but have yet to cross-check with all the technical records.

[SandTEngineer]

If you are interested you can find more technical information on the Signalbox Forum here: http://forum.signalbox.org/viewtopic.php?f=7&t=7464

[ellendune]

Surely there must be some procedures to go through before a signaller can override.  How easy would it be to do this in the UK^▸ (United Kingdom)?

[Chris from Nailsea]

Hmmmm. 

I'm certainly not an expert on signalling, nor on the safety procedures which should be followed, but I do still have some sympathy with the signaller at Moreton-on-Lugg in January 2010, who was let down by the technology he was using. 

See http://www.firstgreatwestern.info/coffeeshop/index.php?topic=6115.0 for the full story.

[ChrisB]

From the BBC^» (British Broadcasting Corporation - home page)

Germany train crash: Controller 'distracted by computer game'

A German train controller has been arrested over the February rail crash that killed 11 people in Bavaria, as prosecutors suspect he was distracted by a computer game at the time.

According to prosecutors he was playing the computer game on his mobile phone and made a signalling error, then dialled the wrong emergency number.

He has admitted that version of events, German media report.

Two commuter trains collided on a single-track stretch near Bad Aibling.

Eighty-five passengers suffered injuries, some of them life-threatening.

The man could be charged with involuntary manslaughter and could face five years in jail.

The trains crashed head-on while both were travelling at about 100km/h (60mph) east of Bad Aibling, a spa town about 60km (37 miles) south-east of Munich.

Investigators quoted by German media said the timings of the computer game and the crash pointed to "the accused having been distracted from his management of rail traffic at the junction".

The stretch of line had an automatic signalling system designed to halt any train that passed a stop signal.

But reports in German media suggested that the system had been switched off to let the eastbound train, which was running late, go past.

The investigation ruled out technical faults with the trains or signalling system as being behind the crash.

All those killed in the crash were men aged between 24 and 59.

Germany's rail safety mechanism

In case signals fail, German railways are fitted with a final safety guard to prevent crashes.

Cab signalling known as PZB (Punktfoermige Zugbeeinflussung - or "intermittent train control") will set off an alarm in the driver's compartment when the train approaches a red light.

If the driver does not respond by pressing a button, the train will brake automatically.

[stuving]

This version, from Reuters, has some significant differences:

A signal controller at the centre of an investigation into a German train crash that killed 11 people admitted on Tuesday to playing a game on his mobile phone while in charge on the day, the public prosecutor's office said.

The man was detained on Tuesday after developments in the investigation into the head-on train collision in Bavaria in February, which was Germany's biggest train crash since 1998. He faces possible charges of causing death through negligence.

The public prosecutor's office in Traunstein, near the border with Austria, said investigations had found the man "turned on his mobile phone during his shift on the morning of the accident, started an online computer game and played actively ... until just before the collision of the trains."

The man denied being distracted by the computer game. But the prosecutor's office said the time period in which he was found to be playing the game meant it could be expected that he was not paying attention to a critical traffic intersection.

The controller gave the trains an incorrect signal and then hit the wrong buttons when issuing a distress signal, meaning it was not heard by the train conductors, the prosecutor's office said.

The trains, carrying about 150 people in all, crashed at high speed on a 6-km (4-mile) stretch of track between the spa town of Bad Aibling and Kolbermoor, near the Austrian border.

The investigation is continuing. No evidence of technical problems has been found to date.

(Writing by Paul Carrel; Editing by Mark Heinrich)

The BBC^» (British Broadcasting Corporation - home page) do seem to have repeated some of the German press reports from earlier, which may no longer be "true", but they still disagree as to whether the signaller has admitted the essential points. Maybe the German sources disagree on that.

[eightf48544]

There is one major difference with the German Block system on double track compared to the British system in that in Germany the line is open until blocked by the signalman at the departing station pulling his starter signal. Once the train has entered the section and the signal returned to danger it locks the signal at danger until the train clears the section and shows occupied on the block indicator. As opposed to the UK^▸ (United Kingdom) where the line is blocked until the signalman in advance gives line clear to allow the signalman in the rear to pull his starter signal. Hence Absolute Block System on the UK .

I believe it's the same on single lines in Germany where the departing signalman grabs the section by pulling his King Lever which unlocks his starter signal and locks the starter signals at other end of the single track section and shows the section occupied. Whereas in the UK the signalman in advance has to give line clear to allow the issue of a token (if there is one) and unlock the starter.

[stuving]

From AP:

Rail dispatcher charged in deadly German train collision
Jul. 18, 2016 8:52 AM EDT

BERLIN (AP) — German prosecutors have charged a railway dispatcher with negligent homicide in the collision of two commuter trains in Bavaria earlier this year that killed a dozen people.

The dispatcher, whose name has not been released in line with German privacy laws, also faces 89 counts of causing bodily harm in addition to the 12 counts of negligent homicide, the dpa news agency reported Monday.

Traunstein prosecutors say the dispatcher is suspected of playing an online game shortly before the two trains he was in charge of collided on a single-track line on Feb. 9.

The crash was near the Bavarian town of Bad Aibling, about 60 kilometers (40 miles) southeast of Munich.
 
The dispatcher has been in custody since April.

[JayMac]

From the BBC^» (British Broadcasting Corporation - home page):

A German train controller has admitted two errors that prompted two trains to collide head-on in Bavaria with the loss of 12 lives.

Named under privacy laws as Michael P, 40, he admitted making a signalling error and then dialling the wrong emergency number.

His lawyer said he also admitted playing on his mobile at the time.

Michael P told survivors that he was aware he had "burdened himself with huge guilt".

"I would like you to know that my thoughts are with you," he added, in a statement read by lawyers.

Those who died in the crash at Bad Aibling on 9 February were all men aged between 24 and 59. Another 89 passengers were injured.

Game 'distracted' controller in Bavaria crash

Prosecutors said Michael P had been playing the fantasy game "Dungeon Hunter 5" on his phone when he allowed the two trains on to a single-track line.

The court heard from one police official that the controller had regularly played on his smart phone while on shift, even though it was banned. Analysis of his phone records showed that his mobile use often corresponded with his working hours.

"He played almost every time," the official said, according to Germany's DPA news agency.

Although the line has a safety mechanism, prosecutors say the controller mistakenly disabled it, sending two commuter trains towards each other. When he tried to warn the train drivers, he then pressed the wrong alarm button, they say.

Michael P is accused of involuntary manslaughter and faces five years in jail if found guilty.

Some of the injured as well as the relatives of those who died were present when the defendant entered the court, wearing a hood to cover his face.

A lawyer representing some of the families described the confession given to the court as a tactical move, because what he had admitted was already proven.

"The really burning question remains unanswered," said Peter Duerr; how intensively had he been playing with his mobile phone at the time, and to what extent had he been distracted?

Although investigators did look into the role of the controller at the time of the disaster, it was only when they sifted through his phone data that he was fully investigated.

[ChrisB]

[quo

"The really burning question remains unanswered," said Peter Duerr; how intensively had he been playing with his mobile phone at the time, and to what extent had he been distracted?

How on earth does he suggest they measure that?