Construction, Coverage, Corrosion: The 2024 Pardubice (Czechia) Train Collision
Background
Pardubice is a city of 92149 people (as of 2023) in central Czechia, located in the district of the same name 20.5km/13mi south of Hradec Králové and 95km/59mi east of Prague, the Czech capital (both measurements in linear distance).
Pardubice is located on the Prague-Česká Třebová rail line, a double- to triple-tracked electrified main line which is considered the country’s most important rail corridor. The 164km/102 mile line opened in 1845, was electrified in the 1950s and underwent modernization after the turn of the millennium. Pardubice main station itself, the third-largest train station in Czechia by travelers, had undergone extensive modernization in the 2020s, with the work being officially finished on the 31st of May 2024 (just 5 days before the accident).
The Trains Involved
Nex 41340 was a chartered international freight train from Bratislava (Slovakia) to Bremerhaven (Germany) carrying shipping containers with various cargo. The train, provided by CD Cargo (Czech freight train operator), was pulled by CD 363 529. The Czech Class 363 (referred to as the Class ES499.1 until 1988) is a four-axle multi-purpose dual system electric locomotive introduced in 1984. The Class 363.5, which was the version involved in this accident, is effectively a 363 created by converting a Class 163 (formerly E499.3) to dual-system capability in the 2010s. Each unit of the type measures 16.8m/55ft in length at a weight of 87 metric tons and can reach 120kph/75mph top speed.
RJ 1021 was an international overnight express passenger service from Prague (Czechia) to Kosice (Slovakia), from where part of the train would continue to Cop (Ukraine). The train was operated by the private Czech rail service provider RegioJet, hence the RJ-abbreviation. The train was pulled by RegioJet 388 205, a third generation Bombardier Traxx F160 MS. The four-axle multi-purpose electric locomotive was introduced in 2019, being equipped with multi-system capabilities allowing operation under 4 different electrification-standards. This allows easy operation of international trains, skipping the otherwise necessary locomotive-swap at the border. The capability cleared the way for 388 205 to operate in six different countries, including Czechia, Slovakia and Germany. The type weighs 86 metric tons at a length of 18.9m/62ft and is geared for a 160kph/99mph top speed (versions for up to 200kph/124mph exist). RegioJet is the type’s largest user with 31 units in their fleet. RJ 1021 carried 380 passengers across 15 cars at the time of the accident.
The forward part of the express train consisted of several sleeper cars which RegioJet had acquired used and refurbished for their services. The sleeper car immediately behind the locomotive (numbered car 15) was a type Bcmz 59–70 “Couchette” car which had been delivered new to the ÖBB (Austrian national railway) in 1981 and was among 14 of its type sold to RegioJet. The four-axle express passenger car measured 26.4m/87ft in length at an empty weight of 41 metric tons and offered nine compartments for up to four passengers each.
The Accident
RJ 1021 had it’s first stop after starting in Prague main station at Pardubice’s main station, stopping to load and unload passengers at approximately 10:35pm on the 5th of June 2024. The driver was notified upon arrival that, once he got cleared to depart, he was meant to wait at the exit signal regardless of its indication for an inbound freight train to pass first. The modernization-work at and around Pardubice main station had seen the construction of a new regional train station adjacent to the eastern end of the main station called “Pardubice Central”. The process of integrating the new station into the city’s rail network required the RegioJet to use a different track than usual, putting it on intersecting paths with the freight train.
The conductor cleared RJ 1021 for departure at 22:47pm, right on schedule, with the exit-signal turning green. The driver pulled away from the platform and accelerated to approximately 60kph/37mph, driving past the signal a moment before realizing his mistake and triggering an emergency stop. The train dumped air pressure and applied full brakes, grinding to a halt 160m/525ft past the signal. This, unfortunately, already put it past the set of points splitting track 1 (which the RegioJet had been on) off from track 2 (which the freight train was on). It’s unclear if the freight train’s driver saw the oncoming passenger train before the collision occurred, but either way the freight train failed to stop in time and crashed into the stopped express train head-on at 40kph/25mph. The Traxx’ crash protection worked as intended, minimizing compression as the locomotive was shoved backwards. Fatally, train car 15 did not handle the accident nearly as well. It found itself caught between 14 stopped four-axle passenger cars and its own locomotive, and instead of impact-forces being transferred through its frame, allowing it to move backwards with the locomotive, it experienced a fatal frame-fracture just behind the forward wheelset, causing extensive compression as the body folded out of the way of the encroaching locomotive. This led to a catastrophic loss of survival space, costing the lives of four passengers in one of the forward compartments. Another 27 people aboard the train survived with injuries while the express train’s driver was unharmed.
Aftermath
The immediate cause of the accident was traced to be the failure of the express train’s driver to remember his instruction regarding departure from the station, which led to his train moving past the exit-signal into the path of the inbound freight train. CCTV-footage of the accident shows the express train coming to a stop right before being struck by the freight train, it’s unclear if he realized his mistake by remembering the instruction or if the realization was triggered when he spotted the headlights of the freight train and realized that they were on a collision course. But, as always with modern rail systems, avoiding a catastrophic event isn’t meant to rely on one “puzzle piece” alone, meaning a mistake by a train driver is intended to be caught by some sort of backup safety system ensuring operational safety. In most cases this added layer is provided by a train control and signaling system which can keep trains from ending up on a collision course by remotely triggering an emergency stop. Likewise, the train driver is the “backup” to a malfunctioning safety-system.
Czechia had been relying on the Liniový Systém (LS) for this purpose on all main lines where speeds above 100kph/62mph were permitted since the 1960s. The modernization of the rail line at/around Pardubice main station had seen the section of the rail line fitted with ETCS, a train control and safety system shared between over a dozen European countries. The acquisition of the new Traxx-locomotives had actually been part of that safety-upgrade, as they were equipped with the train-side components for ETCS. The LS-components at Pardubice main station were removed during the modernization, as those had now been made redundant. However, despite the station being “finished” and reopened with a large celebration on the 31st of May 2024 the ETCS-system was yet to be activated by the time the accident occurred. This means that the rail line was susceptible to human error with no backup safety-system, allowing the RegioJet to enter the path of the freight train.
But a third factor drew the investigators’ attention. Car 15, considered a modern train car despite being several decades old, had suffered a complete structural failure during the collision, fracturing its frame and folding in on itself which led to a total loss of survival space in the forward part of the car. Train cars generally have little crash protection in their body shell, most of their rigidity against lengthwise compression is provided by the steel frame the body is attached to. An identical sleeper car, differing only in interior equipment from the one involved in the accident, had been involved in a minor collision at Salzburg (Austria) in 2018. In that accident (which was covered in this early installment of this blog) the train cars had acted as intended, transferring forces through their frames. At least until they got to car 11 of that group, a Bcmz sleeper car, which buckled in almost exactly the same place where car 15 buckled at Pardubice.
Investigators examined several type Bcmz sleeper cars after the accident at Pardubice and found (in some cases severe) corrosion-damage in structural components. This corrosion was deemed able to significantly weaken the rigidity of the frames, to the point where even fairly low-speed accidents (24kph/15mph for Salzburg, 40kph/25mph for Pardubice) could overwhelm the frames and cause structural failure. It’s not surprising that extensive corrosion was also found on the car destroyed in the accident, presenting the reason why the frame had fractured under the compression forces exerted on it.
RegioJet reacted by pulling all 14 Bcmz sleeper cars that they had from service while the CD (Czech national railway) announced specific testing and examinations of theirs. The CD refused to pull their cars from service, claiming that they were both of different construction and maintained to a higher standard. What they referred to, effectively, was that the CD’s sleeper cars had received additional reinforcements to their frames during repairs and restoration work, while RegioJet ran their cars only with the standard reinforcements. Those, as the investigation found, ended right where the frames had failed during both the accident at Salzburg and the one at Pardubice. The CD reported that they had had their cars of the type undergo compression testing with the results allegedly being up to the required standards. The ÖBB, who still run 28 cars of the type, inspected theirs and found no corrosion damage worth being concerned about.
It’s worth noting that corrosion is very much an expected on train cars, and doesn’t always mean a safety-risk. Some degree of corrosion presents no risk and merely should be documented/”checked in on” regularly, while more extensive corrosion will eventually eat into the metal and reach a degree where it weakens the metal it’s acting on to a significant degree. Since the repairs can get rather costly (and time-consuming) it’s understandable that train operators don’t go after each small rust-spot, instead trying to catch (and fix) corrosion right before it becomes a problem.
The Czech rail traffic ministry decided that, since the corrosion damage had to have grown over quite some time, they were going to conduct in-depth evaluations of RegioJets maintenance operations at an increased frequency after the accident. RegioJet explained in a public statement that they had not been aware of the 2018 accident at Salzburg, since it wasn’t standard to keep track of every operator of such a common train car type. Especially not abroad.
The company’s boss gave a statement about the type’s withdrawal from service with RegioJet, saying that the type “will never see Czech rails again”. How the company plans to move forward remains to be seen. RegioJet’s decision to pull the type from service left a considerable gap in their fleet, which led to a reduction in capacities as the company couldn’t fill them in the short term. Overnight sleeper trains are only recently seeing a resurgence in Europe after almost dying out in the 2010s, now being able to position themselves as a practical and especially eco-friendly alternative to flights and driving. Thus demand for sleeper cars is high, while supply is low for both new and used rolling stock. The ÖBB (Austrian National Railway) reacted by contracting Siemens to construct a whole fleet of new sleeper trains under the “Nightjet”-brand, something not sensible or even possible for a company like RegioJet.
All in all, the accident at Pardubice shouldn’t make one afraid of older rolling stock and it also doesn’t mean that older rolling stock is inherently unsafe. Proper maintenance procedures would have left this accident at material damage and likely minor injuries at the worst, while upholding safety standards on the railway’s side could have avoided it entirely, even with the human error by the train driver. There appears to be no criminal investigation against the train driver at this point (August 2024), or it has not been made public.
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