Tragically Tailgating a Train: The 2007 Szőny Train Collision

Komárom is a city of 18805 people (as of 2017) in the northwest of Hungary, sitting on the southern shore of the River Danube which forms the border with Slovakia. In 1977 the town of Szőny was turned into the eastern-most district of the city, located 72km/44.75mi west-northwest of Budapest (Hungary’s capitol) and 42km/26mi east of Győr.

The location of Szőny in Europe.

Szőny sits on the Budapest-Hegyeshalom railway, a 188km/117mi double-track electrified main line that is one of Hungary’s most important railway lines, helping to connect Budapest with Austria at up to 160kph/99mph. The line sees everything from freight traffic and regional trains up to the ÖBB (Austrian national railway) “Railjet” international express trains who connect Budapest with Munich via Vienna.

The approximate site of the accident, the trains moved westbound (right to left).

Running under train-number 45224 was a mixed freight train travelling westbound to an unknown destination. The train consisted of 36 freight cars, 14 box cars followed by 22 empty flatbed freight cars all owned by the DB (German national railway). Pulling the train was MAV (Hungarian national railway) series V43 1333, a 15.7m/51.5ft long four-axle multipurpose electric locomotive weighting 80 metric tons. The V43 is not set up for multisystem-operation in several countries, but thanks to a shared electrical system they can take trains all the way into Austria before handing them over to other locomotives. The report lists the length of freight train 45224 at 695m/760yd, weighting 789 metric tons.

V43 1333, the locomotive pulling the freight train, photographed a few years before the accident.

Following behind the freight train was ÖBB (Austrian national railway) Euregio 9438, an international low-speed regional train from Tatabanya to Wien Südbahnhof (Vienna Southern Railway Station). Pulling the train was ÖBB series 1116–017, a four-axle dual-system electric locomotive made by Siemens as the ES64U2 (nicknamed “Taurus”). Made between 1999 and 2006 the series 1116 is a modified version of the standard 1016, fitted with equipment to allow it unlimited usage in Austria and Hungary (Hungary uses a 25kv electrical system while most of Austria’s electrified railways use 15kv). The Taurus (referring to series 1116 and 1016) weighs 86 metric tons at 19.28m/63.2ft long and can reach up to 230kph/143mph, enough to let it pull everything from regional trains and freight trains to the prestigious “Railjet” express train (sort of Austria’s counterpart to the ICE, TGV or Acela).

An ÖBB Taurus (1116) identical to the locomotive pulling the Euregio photographed in 2021. Note the distinctive near-centered door on the side.

On the day of the accident the Euregio consisted of 4 Austrian series 50 four-axle passenger cars, nicknamed “Schlierenwagen”. Made between 1965 and 1981 each of these train cars measures 23.4m/77ft in length and weights 32 metric tons empty, meaning the locomotive would’ve had no trouble exhausting the cars’ top speed of 140kph/87mph.

A second class series 50 Schlierenwagen, identical to those making up the Euregio.

On the sixth of February 2007 at approximately 5:45pm the signal box engineer at Komarom station notices the indicators for all block sections between his station and Almásfüzitő (the next station east of Szőny) as well as those for two main signals along the route going dark at once. He warns two trains leaving his station that the signals may not display proper instructions and releases them to move “on sight” at a very slow speed. After that he ceases to dispatch trains. He does, however, not notify his colleague at Almásfüzitő station as he is trained to not see a faulty indicator as a faulty signal. Unbeknownst to him that signal box had experienced an error a few minutes prior to his, with their system displaying all the block sections as occupied (which evidently wasn’t the case). Suspecting a short-circuit (but neglecting to measure voltage to ensure this was the case) the staff tries to reset the inverters by disconnecting the 500V/75Hz output wire which supplies the infrastructure towards Komarom. With that they quite literally pulled the plug on Komarom’s signal box, causing the malfunction there. This doesn’t clear the malfunction, so the signal box staff decides to set a 15kph/9mph speed limit for trains departing for Komarom. Earlier in the day maintenance work had been performed on the signal box’ power supply, during which the system was set to battery power. After finishing up their work the maintenance-crew had forgotten to switch the system back to standard power. Two large red lights warned the staff that the batteries were low, but since they assumed power was coming from the city’s grid they didn’t pay much mind to it. There was a small white lamp notifying the staff that there was no input-voltage (as the system ran on internal batteries at the time), but it was easy to miss and covered up when the maintenance-door was opened.

A photo from the report showing the tiny white light that told the staff what’s wrong.

At 6:34pm Euregio 9438 leaves Almásfüzitő, passing the exit-signal at 12kph/7.5mph as instructed. Driving the train is a 49 years old ÖBB-employee who has been a train driver since 1979 and at the time had all the needed training and certification to drive the Euregio on that connection. Further down the track freight train 45224 is moving in the same direction at a similar slow speed. Soon after the signaling-system displays a yellow signal and a 31kph/19mph speed limit in the driver’s cab of the Euregio, and the driver accelerates to meet this new limit rather than obeying the previously dictated “operation on sight”-limit. It was a clear night with no fog or rain, so it’s possible that he felt confident that he could both operate on sight and meet the higher speed limit. As the yellow signal was erroneously sent to the locomotive the driver soon sees his train go past a red signal, causing an automatic application of the brakes bringing the train to a stop. Records of the Taurus’ data logger later show that after having been stopped for 4 minutes the driver operated a switch on the wall behind him, putting the train into shunting mode and then back into normal operational mode. This reset the train’s speed control system, deleting the 15kph/9mph speed limit. The driver’s motive for this action remains a mystery.

The shunting mode handle in the cab of an identical locomotive. “Verschub” means “Shunting”.
A section of the data-logger’s record, showing the red signal as well as the very brief time in shunting mode.

After releasing the brakes Euregio 9438 starts to move again, just as freight train 45224 passes Szőny station. The freight train’s driver notices that all the signals west of the station are dark/have failed, and radioes the local signal box engineer asking why trains were being dispatched relatively closely rather than dispatching one when the other has safely reached the following station. He’s told that such a mode of operation was not allowed as it would cause excessive backup and delays, with guidelines dictating operation on sight at slow speed instead. The freight train’s driver criticizes that guideline/reasoning, but he’s told that the signal box crew can’t override company policy/guidelines.

Before stopping at Szőny station the Euregio reaches 42kph/26mph, bringing it within 500m/0.3mi of the freight train. Due to the power outage in the signal system and the reset computer aboard the locomotive nothing stops the driver from exceeding the speed limit he was instructed to obey. Passing a red signal would trigger an emergency stop even without driver input, but with the system being completely out it’s as if there was no signaling-system at all. At 6:43pm the Euregio departs Szőny station with what the report calls “intensive acceleration”, the Taurus’ 6400kw/8583hp have no problem pulling the lightweight passenger cars as the train quickly picks up speed. 10 seconds after leaving Szőny station the driver operates the train’s vigilance system (a pedal that the driver has to regularly press/release to prove he’s conscious/in control), proving he is aware of the train’s situation. At 6:43:39pm the data-logger shows the accelerator being released, presumably this was the moment the driver saw the 12kph/7.5mph freight train appear ahead of him. Traction power sinks to 0, but the Euregio is already travelling at 102kph/63mph. Two seconds later the dispatcher hears an earth-shaking crash coming from the darkness just west of Szőny station. The Taurus has struck the rear flatbed car at full speed with an excess speed of 90kph/56kph. The driver is killed on impact as the rear flatbed car cuts through 40% of the locomotive just above the frame, tearing off it’s rear bogie in the process. The front of the rear flatbed car is angled down and forced under the second to last flatbed car, which strikes the locomotive at window-height, completely obliterating the driver’s cabin before being pushed out the side of the locomotive. The locomotive and five freight cars derail, with the torn air-lines between the flatbed cars triggering the freight train’s brakes and finally bringing both trains to a stop a few hundred meter past the point of impact.

With the dispatcher at Szőny station being the first to call the emergency services the first responders reach the site less than five minutes after the collision. The situation is best described as chaotic, there are no lights other than the interior light of the Euregio and the headlights of the responders’ vehicles, pieces of train are strewn all over the place and countless passengers are wandering around the site. By sheer luck none of the passengers touched the torn overhead wires before they could be shut off. The Taurus looks like a bomb went off in it’s forward half, above the frame about 45% of the locomotive are just gone.

A section of the Taurus’ nose, being struck above and below by two flatbed cars more or less cut it out of the locomotive.

Knowing there’s nothing to be done for the driver of the Taurus the responders focus at first on rounding up all the passengers, both those inside the Euregio and those who have wandered off. Two passengers of the Euregio suffer severe injuries, another four passengers, the conductor and the freight train’s driver suffer minor injuries. Wandering around the site looking for further passengers one responder finds the Taurus’ control desk, the forces of the collision threw it from the locomotive along with most of it’s wiring.

The mangled remains of the Taurus’ control desk, found sitting in a ditch by the side of the tracks.

Within hours of the accident investigators recover the data-loggers from both locomotives along with radio-protocols and the nights’ paperwork and schedules. Siemens sends an employee to help with extracting information from the Taurus’ data-logger while the ÖBB hands over maintenance-records showing that 1116–017 was in perfect working order.

Responders standing next to the wreckage, with the destroyed locomotive in the background.

The investigation traces the cause of the accident to the deceased driver’s decision to turn the locomotive’s shunting mode on and off, disabling the programmed speed limit and allowing him to go nearly 7x the speed limit. While the report leaves no doubt in the driver being the sole person to blame, it also lists two contributing factors:

  • The power supply of the signaling-system being insufficiently secured against incorrect operation.
  • The decision to dispatch trains relatively close rather than at station distance (see the freight train driver’s complaint), especially when the exact reason for the malfunction wasn’t clear.

The report further notes that the logbook at Almásfüzitő station had several gaps as well as being written in partially illegible handwriting. When it was announced that the cause of the accident was the driver’s negligent treatment of the speed limit his family voiced doubts, claiming that it’s possible that the malfunctioning signaling system could have briefly displayed a green signal, allowing speeds of 100kph/62mph. However, those claims were quickly disproven by the Taurus’ data-logger.

On the 27th of February the ÖBB had their locomotive towed back to Linz in Austria, where it was stripped for parts and then scrapped. The DB had to write off 4 of their freight cars while the freight train locomotive was unaffected by the collision.

The remains of 1116–017 at the ÖBB’s depot. Note that the damage extends all the way to the door.

The V43 is still in service with the Hungarian national railway after over 55 years. However, more and more of the locomotives are being sent to the scrapyard. By 2022 MAV wants to introduce a set of 115 new locomotives, which will largely be the end of the V43.

After ordering 3 new Taurus-locomotives from Siemens 1116–017 II, allegedly rebuilt with some parts from the destroyed locomotive, started testing in December 2009 and could be spotted in regular service by January 2010. It’s currently in service with RailCargo Hungary, pulling cross-border freight trains. The ÖBB removed the “Euregio”-brand from their program in 2009. While Siemens’ new “Vectron”-locomotive was adopted by the ÖBB in 108 units (with options for 92 more) as the series 1293, mostly for freight services, the Taurus’ days are far from over as they’re still a vital part of the Railway’s rolling stock.

The new 1116–017 photographed in January 2010 under a month after entering service

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