Dec 31, 2020
Stopping Between Signals: The 1990 Rüsselsheim S-Bahn Collision
Background
Rüsselsheim is a city of 65881 people (as of December 2019) in the southwest of Germany, 21km/13mi west-southwest of Frankfurt and 12km/7.5mi east of Mainz (both distances measured in linear distance).
The city lies on the “Main Railway” (named after the river Main), a double-track electrified main line connecting Mainz with Frankfurt. Opened in 1863 the railway sees everything from long distance express trains and freight services to regional and suburban commuter trains. Rüsselsheim itself only sees regional train connections as well as the local S-Bahn (rapid transit commuter trains), with freight trains going to the “Opel” car factory just northwest of Rüsselsheim main station. At the time the “Indusi”-signaling system on the affected stretch was the I60-system, which could auto-stop a train if it passed a red signal, but couldn’t monitor or limit a train’s speed. This task was left to the drivers of the trains.
The trains involved
In 1990 S-Bahn service in the area was provided by DB (German national railway) series 420 trains, three car electric multiple units offering space for 192 seated and 266 standing passengers in a two-class configuration. Starting service in the area in 1972 these 67.4m/221ft long trains weighted 129 metric tons empty and put out 2400kw/3200hp. The trains were set up for strong acceleration due to the short distances between most stations, but still managed 120kph/75mph top speed. Involved in the accident were the S-Bahn from Wiesbaden to Mainz main station (S14), the eastbound train, consisting of DB 420 210 (leading car) and the opposite (westbound) 420 205.
The accident
On the 2nd of February 1990 at approximately 4:30pm DB 420 210 is approaching Rüsselsheim station, driven by 24 years old Mr. Hosch (pronounced Hosh). The previous stop at the Opel factory poured a lot of passengers into the train, which is now filled to capacity. Mr. Hosh passes a red pre-signal, telling him the exit-signal of Rüsselsheim station will be red. He acknowledges this information with the push of a button (otherwise the Indusi-system would be set off) as he pulls into the station on track 2, the main eastbound track. An unscheduled train (some sources say a freight train waiting to be allowed into the Opel factory) is parked on track 1 to his left, the usual westbound track. At the same time Mr. Weil (28 years old) is approaching the station from the east with an equally packed train (some sources claim 500 people on board) on his way from Frankfurt to Wiesbaden. Due to the unscheduled train on track 1 this train has to be diverted into the southern track 3, crossing through the eastbound track. At 4:41pm Mr. Horsch observes the closing of his trains doors, it’s unknown if he forgot about the red pre-signal or if he’s misreading the main signal in the distance. Either way he chooses to depart the station, setting off a fatal chain reaction. Despite being fully loaded the series 420 quickly picks up speed, strong acceleration was one of the main objectives of its development. As he passes the end of the platform Mr. Hosch suddenly sees the signal telling him to stop, a moment later he realizes there’s another train right in his path. At 4:42pm his train passes the red signal, causing the Indusi-system to trigger an emergency stop. Too late. The train is going too fast, it won’t stop in time. With full brakes applied the train slides over the set of points keeping it away from the oncoming train, just seconds after Mr. Hosch departs the station his train slams into Mr. Weil’s train head-on with both trains doing approximately 60kph/37mph (estimated). The westbound train drills itself underneath the eastbound one, killing Mr. Weil on impact. The two leading cars get jammed together and stop violently sudden, the momentum of the train causes the eastbound train’s second car to telescope up almost vertically before falling over to the side, crushing several unoccupied cars parked alongside the tracks. In seconds 17 people from 17 to 76 years old are dead, another 145 survive with severe injuries. One of the passengers in the westbound train, Mr. Weidmann, recalls standing at the back of the second car, chatting with a coworker, hearing a bang and being thrown down the length of the car. He’s among the survivors, finding himself pinned in the wreckage with injuries to his lungs as well as a number of broken ribs and vertebrae.
Aftermath
The silence after the crash only lasts a moment before cries and screams from survivors fill the air. Civilians waiting at the station run over to the site of the accident, soon met by US soldiers from the Azbill barracks just south of the site. The fire department only takes a few more minutes to arrive, eventually over 800 people fill the scene. Some passengers can leave the wreckage on their own, but especially in the forward cars most survivors are trapped. Inch by inch responders cut up the wreckage, careful not to injure survivors by cutting too deep or in the wrong spot. Ambulances go back and forth between the site and the surrounding hospitals, taxi cabs help out when their own numbers come up short. The impact reduced most of the trains to rubble and barely recognizable metal shapes. Some responders have to leave or take breaks, unable to handle the gruesome sights. A lot of the victims can’t be recovered in one piece, meaning a few responders have to try and match up limbs to bodies. Late at night responders make their way to the remains of the westbound train, finding half the remains of the driver. It’s nearly midnight by the time the site can be declared clear, with no more victims or survivors expected in the wreckage. Investigators are puzzled how the accident could happen, the Indusi-system, developed to avoid this exact thing, was working perfectly fine and even triggered the emergency stop. The day after the accident employees of the DB cut the wreckage into smaller pieces, a couple of flatbed trucks take them away for further examination. Once the investigation finished both lead cars and one middle car was scrapped, the rest was repaired and returned to service for a few more years.
The driver, who survives with several broken bones, swears that he saw a signal allowing departure. This gives the investigators an idea that will lead to 50% of the cause. Rüsselsheim station is one of the last main line stations in Germany to still employ so called “Wing Signals”, a kind of semaphore signals using a large board’s angle to show stop or go. It has been observed that sometimes train drivers look at the signals passingly and/or at an unfortunate angle, wrongly interpreting the angle set. The theory developed from this is that Mr. Hosch passed and acknowledged the pre-signal telling him that he won’t be allowed to exit the station, but due to the distance between the signals he forgot about that by the time he departed the station. This error was aided by the exit signal at Rüsselsheim station being relatively far from where the S-Bahn trains stopped. The long distance between the stopped train and the signal also meant that the series 420 could build up quite a high speed by the time it reached the signal (the first point where the Indusi can interfere). The position of the signals was decided a long time before, when trains were much slower at that point. Because of this the “glide path” (safety-distance for when a train runs a red signal) was too short to stop the powerful new trains. This had simply been overlooked when the new trains had been introduced.
A year after the accident Mr. Hosch was put on trial, charged with negligent manslaughter, negligently causing bodily harm and dangerous interference with rail traffic. The court concluded that he had looked at the signal too briefly, seeing “what he wanted to see” and departet. The train drivers union had been protesting publicly, saying that the DB was largely to blame as they put too much work on their drivers, creating a high pressure to be on time as well as essentially forcing excessive shifts and hundreds of hours of overtime. In the end, while he played a deciding role in negligently deciding to depart, he was found to technically not be the only one to blame, and was sentenced to 10 months probation and a fine of 2500DM/1300 Euros/1450 USD. The DB actually didn’t fire him, but moved him from driving to the maintenance-department, retraining him as a mechanic. In the mid-90s the DB introduced the new “PZB 90”-version of the Indusi system, which can limit a train’s speed automatically. With this system in place even at full throttle the train couldn’t have gotten fast enough to exceed the “glide path” behind the red signal. This means, if the same chain of events would happen again Mr. Hosch’s train would now stop behind the signal but ahead of the set of points and he’d watch on as the other train safely changes from left to right in front of him. The signals were also replaced with modern light-based signals after the accident, which are much less likely to be misread (as they function similar to traffic lights).
The US Army left the barracks in 1993, most of the buildings were torn down in 2005 and replaced with single family housing. Between 2003 and 2014 the series 420 trains were retired from service in the area, today only a handful of modernized series 420 trains remain with the Munich S-Bahn. Their days are numbered, and they’re largely used to help out for special events or during peak traffic hours.
In an interview in 2010 Mr. Weidmann says he still can’t get the sights of the accident out of his head. 20 years after the accident he still suffers from mental and physical issues, mainly relating to his spine. He’s not the only one, it’s known that several responders sought therapeutic support even years after the accident. At the time such things weren’t offered to responders, so ones in need were left to find help on their own. After the accident the red cross started to do more training related to train accidents, hoping to make future responses more efficient.
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