Background
St. Valentin is a town of 9374 people (as of 2023) in northern Austria, located in the federal state of Lower Austria 20km/12.5mi southeast of Linz and 16km/10mi north-northeast of Steyr (both measurements in linear distance).
The town lies on the convergence of two large railway lines with the Westbahn (Western Rail Line), a double-to quad-tracked electrified main line which runs the width of the country as one of Austria’s main rail corridors. As such St. Valentin possesses unusually extensive rail infrastructure compared to the size of the town.
The Westbahn was opened in 1860, then operating under the Empress Elisabeth Railway in the Austro-Hungarian empire before it and its operator were nationalized in 1884. Nowadays operations are performed by the ÖBB (Austrian National Railway), with the line seeing everything from regional traffic to long distance express train as well as national and international freight services at speeds of up to 250kph/155mph on selected sections.
The Train Involved
Z 91005 was the Austrian designation for an international freight service which had originated in Poland and was headed to Linz, Austria. The train consisted of 32 type “Falns” four-axle ballast cars carrying coke, (not the white party powder but in fact) a coal-based fuel-source used by distilling coal. The material, which looks somewhat like gravel, is mostly used to generate heat in iron ore processing as burning coke produces less smoke and sulfur than burning coal for the same purpose. Smaller-grain coke is also used for stoves in homes. The train cars were owned by PKP Cargo, a Polish freight service provider.
At the time of the accident the train was pulled by ÖBB 1116 174–4, a four-axle multipurpose electric locomotive produced between 1999 and 2006 by Siemens as part of the “Eurosprinter”-family, referred to by the ÖBB (and most enthusiasts) as the “Taurus”. Every series 1116 measures 19.28m/63ft in length at a weight of 88 metric tons and can reach 230kph/143mph. The ÖBB uses the Taurus for just about any type of train imaginable, from regional services to freight trains and their high speed “Railjet”-Services. According to the report the train had a total weight of 2066 metric tons at a length of 453m/1486ft including the locomotive.
The Accident
The freight train received its designation Z 91005 at Hohenau station on the 30th of October 2020, after arriving from Czechia. It departs Hohenau station at 5:49pm, stopping at St. Pölten station at approximately 9:20pm for a handover between train drivers. The new driver then departs for Linz, a trip which would see the train pass through the railway hub that is St. Valentin station. The signal box worker in charge of St. Valentin station set a path that would take the freight train south of the station’s platform tracks, which requires it to navigate several sets of points. However, before it reaches any of them an emergency stop brings the freight train to a forced standstill outside the southern entrance to the station at 10:42:14pm, after the train driver had failed to acknowledge a yellow (“slow/attention”) pre-signal within 4 seconds. On the series 1116 train drivers have to operate a button/lever when passing signals to confirm their awareness of the signal.
The freight train remains stationary for 1 minute and 24 seconds as the driver and local signal box worker try to work out why the train had stopped and how they will proceed, with the signal box worker explaining the upcoming route. At last the driver sets the train in motion under a 45kph/28mph speed limit set by the signal he had passed. They then proceeded to use the “release button” (to the left of the attention-button in the image above) to clear the limiter, causing them to pass the entrance-signal to the station, which displays a 40kph/25mph speed limit, at 10:46:03pm at a speed of 63kph/39mph. Despite having received the information about the upcoming points and the required low speed the driver continues to apply full throttle, reaching the set of points number 26 at 10:46:49pm. The data-logger later showed the locomotive reach the points, which have a 40kph/25mph speed limit when turning, at 78kph/48.5mph. Despite going nearly twice as fast as intended the locomotive manages to navigate the points, but the train cars behind it don’t have any such luck. Cars 1 and 2 remain on track, while the cars behind them derail during the sharp S-turn forced upon them by the points. The lateral forces tear the coupling between cars 6 and 7 apart, severing the pneumatic lines which operate the brakes. The resulting total loss of air pressure causes the entire train’s brakes to fully apply in an instant, followed within seconds by power being cut as the derailing train takes down the overhead wires. The leading part of the train finally comes to a halt at 22:47:23pm, largely intact and mostly on the track. Behind it, all cars down to number 20 have derailed, and cars 7 through 19 have fallen over and/or crashed into each other with such force that they end up piling two layers high, spilling their cargo. 13 of the 32 cars would eventually be deemed beyond saving, with all cars requiring repairs.
Aftermath
The driver had noticed none of the mayhem behind him, contacting the local dispatcher at 10:47:53pm to ask if they had any idea why his train had both “dropped the anchor” (stopped hard) and completely lost power for no (to him) apparent reason. By this point the dispatcher had already been contacted by two other train drivers who had witnessed the derailment. One can imagine the awkward moment when the dispatcher had to tell the driver that he had left most of his train piled up at the entrance to the station. The dispatcher also locked down the entire station, meaning no train would enter, leave or pass through on any track, and notified the ÖBB’s emergency response crew as firefighters or ambulances luckily were not required.
As it had survived the accident just about unscathed investigators could quickly rule out a defect aboard the locomotive, and once workers picked the stacks of train cars apart and recovered the train cars which had dug themselves into the ground between the tracks there was no evidence of any defect on these either. Thus, attention soon focussed on the driver and his behavior ahead of the accident. The driver explained that they had had an uneventful journey between St. Pölten and St. Valentin, right up until the pre-signal to the entrance signal had surprised them with an unexpected “attention”-indication. This indication meant that the entrance-signal would likely be red, so the driver, by their recollection, initiated a “fairly strong” deceleration to slow the 2000 ton train in time for a stop at the entrance signal. Supposedly, initiating the deceleration was the reason they failed to push the awareness-button before the timer expired, triggering an automatic stop.
Once their train was at a standstill the dispatcher instructed the driver to “stay on it” once they get moving, as they were meant to overtake a passenger train. During this conversation the driver supposedly saw their entrance-signal switch to green, with a pre-signal between them and the entrance-signal indicating a 100kph/62mph speed limit, well beyond the 80kph/50mph maximum speed limit the freight train had in general. Believing to have seen a green signal in the distance and seeing the 100kph/62mph-restriction the driver, obeying the instruction to “stay on it”, applied full throttle as they started moving again, bringing the train past 70kph/43mph within a short distance. The acceleration ended when the driver felt a violent jolt as they passed over the set of points number 26, at which point the instruments showed power input dropping to zero, plunging the cab into darkness as the train triggered yet another emergency stop.
The dispatcher gave largely the same story, with one important difference. In their version of the events they told the driver that he would be directed into the oncoming (left hand) track at points #26. The driver didn’t recall receiving this information, explaining that, obviously, he wouldn’t have sped up as much if he had known that he was about to navigate a set of points that had a 40kph/25mph speed limit if set to “turning” rather than “straight”. Informing a driver about entering a station in the oncoming tracks isn’t mandatory, but in this case it played an important role.
Investigators turned to the recordings of the radio transmissions, which allowed them to find out that, in a way, both the dispatcher and driver were telling the truth. The dispatcher hadn’t told the driver explicitly that they would be directed into the oncoming track, but their instruction that they should “stay on it” (meaning: keep the throttle as wide open as they can) to overtake another train ahead of Asten station (13km/8mi down the line) didn’t make sense without a switch of tracks, since overtaking would imply that the regular track is occupied. As far as the investigation could tell the “loose” choice of words by the dispatcher led to the train driver assuming they were overtaking a train stopped at St. Valentin station, which didn’t necessarily involve switching tracks, while the dispatcher meant they would do it out on the rail line beyond the station, which did require that.
Investigators noticed another mistake by the driver as they went through the recordings. After his train was brought to a halt he did contact the dispatcher to discuss the further proceedings, but, against guidelines, never told them that he had stopped because of an automatic brake application. It is a basic rule of operations to inform the dispatcher if one’s train has been brought to a stop by the automatic train control system, as the freight train was upon passing the pre-signal.
With the recordings and statements on record investigators looked into the signaling system, as the driver insisted on the signals he had seen which, frankly, didn’t make sense for him to see when he supposedly did. But the didn’t have to do a lot of searching. There was a pre-signal in front of the driver indicating a 100kph/62mph speed limit, and in the distance the freight train did have a green signal, but only one of these was for the freight train. The pre-signal, as it turned out, was standing 1m/3ft beyond the freight train’s actual pre-signal, and was meant for the parallel track used by the S-Bahn commuter trains. With his focus likely being on the conversation with the dispatcher the driver looked up, saw the pre-signal indicating 100kph/62mph, and took it as referring to him, as the dispatcher was just telling him at that moment to, essentially, hurry up.
Lastly, the driver removed the imposed 45kph/28mph speed limit right after resuming motion, as part of his effort to obey the dispatcher’s instruction to hurry up. This was another breach of the guidelines, which didn’t allow this until the end of the train passes the exit signal.
The report traces the cause of the accident to miscommunication between the driver and dispatcher, along with failure to follow established rules of operation by the driver. As usual for Austrian investigation reports, it expressively doesn’t place blame or criminal fault, and in this case it appears like the public prosecutor’s office either never investigated or at least never charged the driver in connection to the accident. There are also no safety recommendations in the report to this accident, with the investigation explaining that those can be foregone if they would be summarized as “don’t break existing rules”. Total damage is listed at 4.4 Million Euros/4.8 Million USD, with the report also noting “substantial” interference with operations as it took several days to recover the train, clean up the spilled cargo and rebuild several hundred meters of destroyed tracks and infrastructure. Just 660 thousand Euros/715 thousand USD of that total amount was down to the damaged and destroyed rolling stock, the rest was the price of infrastructure (signalling, overhead wires, etc) requiring replacement. On the bright side, nobody was injured in this accident, despite the degree of destruction on display, at a station no less.
As the report already put it, there was no real “fix” that could avoid a repetition of the accident, nothing that could be pointed out as what to do to avoid an accident like this. All safety-systems were in place, such as an automatic speed limiter set by the locomotive passing the pre-signal. This limiter could have ensured safe passage through the station, had the driver not consciously turned it off. The one lesson one might take away, apart from obviously recommending adherence to the guidelines, is that train drivers and signal box staff should carefully pick their words when communicating, since a large part of what motivated the driver’s negligent behavior was the dispatcher’s statement that the driver could “stay on it” for the next several kilometers, rather than precisely instructing him about what to do at which location.
Historic Precedent
The derailment of the freight train in 2020 wasn’t the first time a train had derailed at the station due to excessive speed on a set of points set to “turn”. It was, luckily, the one with the far less catastrophic result.
On the 25th of October 1939 the express train D54 entered the station at full speed, disregarding the entrance signal’s low speed indication. The locomotive started swinging after passing over the first set of points, with the motion worsening for a few seconds before the train completely derailed on the next set of points. On that day, 17 people died.
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