Background
Niklasdorf is a municipality of 2365 people (as of January 2021) in central Austria, located in the federal state of Styria 41km/25mi north of Graz and 127km/79mi southwest of Vienna (both measurements in linear distance).
The municipality has a station on the Bruck an der Mur–Leoben railway, a 23.4km/14.5mi double-tracked electrified main line opened in 1868. The line is one of Austria’s most important rail routes, being part of the Vienna-Venice long distance route. The line is used for both freight and passenger services of all kinds, on the passenger side the range reaches from Austria’s “Railjet” express trains on national and international connections all the way down to regional services as part of S-Bahn Steiermark (“Steiermark” is German for “Styria”), a local transportation network connecting Graz with surrounding towns. In addition to that the DB (German national railway) also runs express passenger services on the line under the “Eurocity” brand, consisting of connections between Austria (in this case usually Graz) and Germany.
The trains involved
EC 216 “Dachstein” was a Eurocity service provided by the DB from Graz to Saarbrücken in Germany via Salzburg, Munich and Stuttgart. On the day of the accident it consisted of 9 DB Intercity/Eurocity passenger cars, including a control car (numbered 6180 8091 1117–4) manned by an Austrian driver for the first part of the train’s journey. The train consisted of second- and first class cars, with first class cars being located at the back of the train, close to the pushing locomotive. The eighth car on the train was a DB series Avmmz 106.1 first class Intercity/Eurocity car with individual compartments offering a total of 54 seats. The car measures 26.4m/87ft in length at 47 metric tons empty and can travel at up to 200kph/124mph while offering air conditioning and two toilets with an enclosed system (similar to what you might find on airliners). The DB’s Intercity and Eurocity cars wear a bright white livery similar to that of the ICE high speed trains, making them easy to tell apart from most of the DB’s bright red rolling stock. A different set of identical cars running as EC 216 had previously been involved in the 2014 Mannheim Train Collision.
Pushing the train at the time of the accident was DB Series 101 number 011–5, a four-axle multipurpose electric locomotive introduced in 1996. Each series 101 measures 19.1m/63ft in length at 84 metric tons and has a top speed of 220kph/137mph. Engineered for both heavy express- and freight trains the series 101 has a power output of 6400kW/8583hp and, having spent most of its life with the Intercity and Eurocity trains, is one of the DB’s flagships.
Coming the other way (eastbound) was ÖBB S8, a regional S-Bahn service from Friesach to Mürzzuschlag. Providing the service on the day of the accident was ÖBB (Austrian national railway) series 4744 number 054, a Siemens “Desiro ML” electric multiple unit specifically developed for the Austrian S-Bahn systems. The three-part trains weight 145 metric tons at 75.15m/247ft in overall length and seat up to 259 people in a two-class configuration. All four axles on both end cars are powered, a total power output of 2600kW lets the trains reach up to 160kph/99mph and most importantly for a regional service accelerate rather quickly. The series 4744 was delivered in 2015, so it was essentially brand new.
The accident
On the 12th of February 2018 EC216 is approaching Niklasdorf from the east, running on the left hand (“oncoming”) track as it had passed a slower train. It’s running 21 minutes behind schedule as an extended stop was needed at an earlier station when a sensor reported excessive heat at one of the trains’ brakes. At 12:39pm the signal box employee in charge of Niklasdorf sets the path for EC216 to pass through the station without stopping, placing it under a 60kph/37mph speed limit.
At 12:44pm S8 passes the entrance-signal on the western end of Niklasdorf station, being told “attention”, meaning to expect a red signal. The driver acknowledges the alert as the train passes over the 1000Hz magnet-sensor of the signaling system (PZB, an intermittent train control system). At this point the system monitors the train’s speed as the driver pulls into the station and stops at the far end of platform 2. There are three tracks to his right, EC216 is preparing to pass on the nearest one. This is the opposite of the usual right hand traffic Austrian Railways operate by, but the system is set up to handle this sort of arrangement just fine. A minute after S8 passed the magnet EC216 is picked up by the station’s system as well, passing the entrance-signal on its side of the station at 56kph/35mph.
At 12:45:33 S8’s driver pulls away from the platform despite a red departure-signal, after a few meters the train leaves the control of the 1000hz magnet and can accelerate beyond 27kph/17mph. At 12:45:55 S8 runs past the red signal at 76kph/47mph. The system triggers an emergency stop on both trains, in the time between the sensor being tripped and air pressure being dumped from the pneumatic system (approximately 1.5–2 seconds) another 2kph/1.25mph are gained. At 12:46:00 S8‘s leading car runs into the side of EC216 at a combined speed of 128kph/79.5mph as the tracks merge. S8 first strikes the rear third of EC216’s fifth car before grinding along cars six and seven before a piece of the deformed driver’s cab becomes caught on car 8’s forward door. With the train’s momentum still forcing it into the side of the EC216 S8’s leading car proceeds to rip a massive strip out of the side of car 8, removing half the struck side’s wall and all but one of the windows, destroying the toilets and vestibule areas. S8’s first two cars derail in their entirety along with cars six, seven, eight and nine of the EC. The stricken Eurocity comes to a stop 238m/781ft past the point of impact while S8 stops after just 43m/141ft. One passenger aboard the first class car is killed in the collision, 31 passengers are injured (one of which severely). Likely to being relatively early in its journey the train was far from being at capacity, which avoided even more tragedy.
Aftermath
At 12:52pm the ÖBB locks the entire station down, no train goes in or out. 5 minutes later the first responders approach the train and help EC216’s staff to evacuate passengers off the train and back to the station. Dozens of responders arrive at the site within a few minutes, the fire department alone brings in 42 members with 10 vehicles, mostly for manpower and equipment. None of the passengers aboard S8 are injured, however some are treated for shock. The leading car of S8 takes severe damage in the collision, but remains structurally intact. Had it struck the EC a few moments later, hitting the locomotive, it may not have fared so well.
The examination of both trains shows no defect or damage that stemmed from before the collision, similarly the signaling system and points all worked as intended. Tracing the path of S8 from its data-logger and the train’s interaction with the signaling system investigators discover that S8 quite literally slipped through a gap in the system. The sensor the train tripped when it entered the station only covers a certain distance, due to the layout of the station the speed limit imposed by it ends shortly after the train leaves the platform. Until that point an emergency stop would have been triggered if the train proceeded past 45kph/28mph. A 500Hz “extender” of the speed control zone wasn’t in place at the station, neither was a “repeat signal” which would’ve shown the same order as the previous signal with another 1000Hz-magnet. Due to that gap in the monitoring the train was able to reach a much higher speed before passing the red main signal (which triggered an emergency stop), significantly extending the space required to come to a stop.
The driver of S8 made use of his right to not give a statement to the police after the accident, but he did talk to the investigators from the transportation ministry. He recalled standing at the platform and observing the exchange of passengers before closing the doors as the scheduled departure-time rolled around. He claimed not to remember if he saw the signal in the distance, allegedly he has a gap in his memory until the moment he reaches the red signal at speed. The driver claimed that he triggered an emergency stop, if he did couldn’t be verified as the train triggered one itself as it passed the signal. As the collision and ensuing derailment left the train’s intercom inoperable the driver used a backup megaphone to try and keep his passengers from evacuating the train, seeing the torn overhead wires hanging down outside the train. Once responders started to arrive and the overhead wires were confirmed to be turned off the driver assisted his colleague on EC216 and the responders in evacuating passengers and rendering aid to the injured.
With investigators proving that the Eurocity’s driver couldn’t do anything to avoid the collision but did what he could to lessen its consequences (triggering an emergency stop as he realized what had happened and ordering dispatch to alert emergency services) their blame focused largely on the S8’s driver for running the red signal. However, they also pointed out that a modern railway should be secured against “single point of failure” accidents, meaning a single error or defect shouldn’t lead to severe accidents. Had the station had a 500Hz extender or a repeat signal the whole accident would likely not have happened or at the very least have had far less drastic consequences. Flanking collisions like this one, with a train running into the side of another at a very acute angle are any train manufacturer’s nightmare, as there is little room for crash protection engineering in the side of a train car. Not only are train cars by design large metal rectangles, making the sides a structural weak spot, but width is also highly limited and obviously preferably used for passenger space, not thicker walls. And on modern passenger cars with internal corridors for the passengers you can’t exactly install bracing across the width of the interior space.
In early November 2020 the driver of S8 is put on trial on charges of negligent manslaughter and negligent cause of bodily harm. The driver’s lawyer repeatedly tries to shift the majority of the blame to the ÖBB, saying there was insufficient safety-equipment, the points were too close to the signals and the ÖBB’s decision to do away with conductors places an undue workload on the drivers. The judge shot down all of these attempts, repeatedly pointing out that the trial at hand is about the driver’s fault, not the ÖBB’s role in the whole tragedy. The driver expresses that he has 20 years of experience on the line he drove that day, but that he doesn’t remember what happened after he finished loading and unloading passengers. The judge proceeds to ask why he had two smartphones turned on at the time of the accident, saying they were were online with one streaming a sports broadcast. The driver refuses that he used the phones while driving, saying they were in his pocket after he had watched Biathlon on them during a break earlier in the day. This point remains open, as neither party can prove the other wrong. The lawyer representing the killed German passenger’s family later sums up that the driver “did everything wrong he could’ve done wrong.” In the end the driver is sentenced to 8 months in jail set to probation along with a 4320Euro/5108USD fine. A separate criminal investigation targeting the ÖBB for the gap in the signaling system ended without legal consequences.
4744 054 is repaired soon after the accident, receiving a new leading car, and returns to service, as does the locomotive and the leading cars of the Eurocity. Cars 5–9 are written off and scrapped. Around the time of the accident the DB had started replacing the “IC 1” single level cars with new “IC 2” bilevel trains, gradually retiring the old cars from more and more lines. It’s calculated that the single level cars will all be retired by the early 2030s. Similarly the first series 101 locomotives have seen their retirement from service even without defects, with the delivery of new ICE high speed trains creating an oversupply of the locomotive. Retirement in larger numbers is scheduled to start by 2023, a return to freight service under DB Cargo is possible but currently unlikely due to a lack of demand. Meanwhile the ÖBB is expecting to take delivery of their last (200th) Desiro ML in late 2021, the scheduled lifespan for the trains is unknown. Siemens themselves have already started production on the successor (“Siemens Mireo”), with the first units going into service in June 2020.
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