Elephant in the Back: The 2020 Český Brod (Czechia) Train Collision
Background
Český Brod is a city of 7066 people (as of 2021) in the center of Czechia, located in the Kolín Region 30km/18.5mi east of Prague and 65km/40.5mi west of Pardubice (both measurements in linear distance).
The city lies on the Prague-Česká Třebová rail line, a double- to triple-tracked electrified main line connecting the capital with one of the most important cities in eastern Bohemia. The line opened in August 1845 under the Royal Northern State Railways (NStB), a royal Austrian railway. Today the line measures 164km/102mi in length and is part of the Fourth Pan-European Traffic Corridor, carrying all express passenger services who stop in Prague as they connect the country with Austria, Hungary, Poland, Slovakia and Belarus as well as a number of national express services, along with regional passenger services and freight traffic. Some parts of the line are set up for speeds as high as 160kph/99mph, while other sections are limited to as little as 70kph/43.5mph.
The trains involved
Train number 9359 was a regional passenger service offered by the ČD (Czech national railway) from Prague to Řečany nad Labem, provided by a ČD series 471 “CityElefant” (“City-Elephant”). The series 471 is a three-car bilevel electric multiple unit made by Skoda Transportation as the 1Ev, introduced into service in 2001. They gained the CityElefant-branding in 2006 by a public vote, referring to the large gray area on the front end that came with a redesigned livery (note that, at the time of the accident, the train involved carried a different livery). Each 3-car unit measures 79.2m in length at an empty weight of 158 metric tons and can carry 310 passengers in a two-class configuration at up to 140kph/87mph. While the entire train is listed as the series 471 the cars also carry individual numbers, with 471 referring to motorized end cars, 071 being middle cars and 971 being unpowered end cars. At the time of the accident the unit involved was led by the unpowered end car ČD 971 075.
Parked outside Český Brod station was an express freight train of unknown configuration or routing, with a four-axle ČD type 90 “Post W” mail car at the back of the train. The type 90 mail car is based off old baggage cars and weighs 39 metric tons empty at a length of 24.5m/80ft.
The accident
On the 14th of July 2020 regional train service no. 9359 (referred to as the “CityElefant” from here on) is approaching the city of Český Brod at approximately 9:25pm on its way from Prague to Řečany nad Labem. Up ahead an express freight train has stopped before entering the city’s train station, turning the signal a block-section behind it red. Block-sections are fixed segments of a rail line, and each section must hold at most one train to ensure a safe distance between trains which leaves sufficient stopping-distance. As such the system will, once it detects a train entering a specific block-section, turn the signal at the entrance to the section red. Once the train leaves the section the signal will turn green again.
The CityElefant thus stops at the signal by 9:30pm and the driver radioes the local dispatcher inquiring about the reason for the red signal. It’s not clear from the public information if the dispatcher forgot about the freight train, assumed it was further forward and maybe only barely protruded past Český Brod’s entrance signal, or if he assumed an invalid red signal (the block section falsely reporting as occupied in the system). Either way, the dispatcher decides to override the CityElefant’s red signal by approximately 9:32pm, allowing the driver to set his train in motion again. By the driving guidelines of the ČD he is supposed to drive “on sight”, keeping speed low enough that he could stop in case of an obstacle coming into view. While it was a clear night the darkness still limited visibility, and the rail line was also navigating a series of turns rather than going in a straight line. This translated to a very slow speed being required, with the investigation pointing out that anything beyond 40kph/25mph would have been inappropriate.
Despite knowing about the rule the train driver accelerates well beyond the appropriate speed for driving on sight, eventually clocking 70kph/43.5mph. A police car actually passes the parked freight train at 9:34pm, with the car’s dashcam also capturing the approaching CityElefant as well as one of the officers noting “but there was a train there”. Moments later the dashcam captures a loud crash as the CityElefant strikes the back of the parked train at 67kph/42mph. The driver’s cab caves in on impact as the mail car loses several feet in length before the regional train mounts the frame of the mail car, cutting a deep gash into the car’s body before coming to a rest, having shifted the whole freight train forwards a considerable distance. The driver of the CityElefant is the only fatality, with 35 passengers requiring hospitalization for medium to severe injuries.
Aftermath
The two officers who had passed the trains in their patrol car returned to the scene after hearing the crash, becoming the first outside responders to tend to the survivors. They receive reinforcements a few minutes later, both from their own radio-calls and from phone calls placed by survivors. Two of the passengers are flown to hospital with severe injuries, another 35 are taken away by ambulance while the rest is treated at the site, taken to Český Brod station and then released. Firefighters manage to secure the leading car of the CityElefant to the tracks despite the collision having left it several feet in the air at the leading end, allowing responders to cut a path to the remains of the driver’s cab and recover the body of the driver. A helicopter with heat-sensitive cameras also circles the area surrounding the wreckage to ensure no survivors have wandered off in the dark. By 1am the train is declared empty and the site is handed over to the investigators.
A tank from the Czech army is eventually brought in to help in the separation of the wreckage, which is achieved in the early morning hours after more cutting finally unjammed the two trains from one-another.
This had been the second accident of a near-identical pattern that the ČD suffered in under a week after, just three days prior, a different CityElefant had collided with an express train. Furthermore, a collision between two regional trains on the 7th of July had claimed 2 lives. Both accidents would eventually be traced to human error as the sole cause, making the ČD understandably rather uncomfortable when the investigators reported that ČD 471 075 had been in perfect working order. An autopsy of the driver’s body revealed that he hadn’t been under the influence of anything, but it was a different discovery that pulled the investigation away from a clear-cut cause. Namely, the driver had been dead by the time his train crashed into the mail car.
The doctors performing the autopsy found that the driver had died from a heart attack shortly before the accident, essentially making the CityElefant a runaway train for the last several seconds of its journey. Reconstruction of the train’s final moments revealed that the driver was alive and conscious less than a minute prior to impact, operating the dead man’s switch. The term describes a button or pedal in the cab which has to be pressed and released (or vice-versa depending on the version used) at a specific interval to keep the train operational. If a train driver fails to operate the dead man’s switch as required, be it due to distraction, unconsciousness or, well, death, and also ignores a warning-sound, the system will automatically trigger an emergency stop within 4 seconds of sounding the horn.
According to the investigation the driver died from the heart attack so shortly before the collision that the system either had no time to trigger an emergency stop or the triggered stop didn’t get to have an effect on the train’s speed. Since the train had come to a stop at the previous red signal and then accelerated again it was assumed that the driver consciously picked the speed, placing sole cause of the accident on negligence by him. Had he limited himself to an appropriate speed for the conditions the accident might have been completely avoided (with either the dead man’s switch having more time to act or the driver, had he not suffered the heart-attack, seeing the other train and stopping in time), but even if accident had happened at the lower speed the considerably lower forces could have meant less severe injury to the passengers and (again, speculating with the driver not dying from something else) better survival-chances for the driver.
Different sources also say the freight train was standing still with released brakes or had just started moving, with slightly lessened the consequences of the collision as the train would have presented a much more rigid obstacle had it stood there with brakes fully applied.
In the end nobody was legally charged for their role in the accident, since the one person found to be at fault had not survived the accident. Technically, they hadn’t even lived to suffer it. The mail car was pulled from service and scrapped after the accident, as was the CityElefant’s leading car, while the other two cars from it were pulled from service to serve as parts-donors, suffering an unspecified amount of damage from running into each other.
Czechia is in the process of equipping most of its rail lines with the european ETCS train control system, which, once online, will be able to autonomously ensure trains stay at a safe distance and also keep trains from breaching temporary or permanent speed limits, bringing trains in violation of an imposed speed limit to an automatic stop. ETCS Level 2, the system the Prague-Česká Třebová line is to receive, would even be able to fill the role of trackside signals, reducing the potential risk from erroneously overridden red signals.
Video
A few days after the accident the local government of Český Brod released the dashcam-video from the police car which passed the site moments before the accident. The crash isn’t visible, but both trains can be seen and the impact is heard. The video was released to the City’s facebook-page and can be found under the following link:
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