Background
Thun (pronounced “Tuun”, the English th-sound doesn’t exist in German) is a city of 44271 people (as of 2019) in central Switzerland. Thun is located on the northern and northwest shores of Lake Thun (“Thunersee”), 27km/16.8mi south-southeast of Bern, the Swiss capitol, and 98.5km/61mi southwest of Zürich (both measurements in linear distance).
Coming into Thun Main Station from the south is the Thunerseebahn (“Lake Thun Railway Line”), a partially double-track electrified main line connecting Thun with Spiez and Bönigen at a track length of 27.9km/17.3mi. Opened in its full expansion in 1901 the line is owned today by the BLS AG, a railway company supplementing the SBB’s (Swiss national railway) services owned mainly by the Canton of Bern. While regional traffic was recently reduced there is still a lot of long distance passenger and freight trains using the railway line. This includes German ICE high speed trains travelling to Interlaken, which are controlled by Swiss drivers after crossing into Switzerland.
The trains involved
Approaching Thun from the south was ICE 278, an Intercity Express service from Interlaken to Berlin Ostbahnhof. The train was under the control of a Swiss train driver (who had been certified for the German high speed train) and staffed by a German crew with an unknown number of passengers. It can’t be said for sure, but as the accident happened early in the ICE’s trip the train most likely was far from fully occupied. On the day of the accident the service was provided by train set (Tz) 173, a 14-part first generation Intercity Express train introduced into service in March 1992. The Mk1 ICE is a German high speed train (similar to the TGV in France or the Shinkansen in Japan) that was introduced in 1988. A full train (2 motor cars and 12 center cars)weights 795 metric tons at 358m/1174.5ft in length. With each motor car putting out 4800kw/6437hp the trains can carry 703 passengers in a two-class configuration at up to 280kph/174mph (310kph/193mph have been achieved in testing).
Moving within Thun Main Station was a so-called “Lokzug” (“Locomotive Train”), a train consisting of nothing but two locomotives. Leading the pair was BLS series 465 number 014, towing number 017 of the same series. The Re 465 is a four-axle 18.5m/61ft electric multipurpose locomotive introduced in 1994. The Re 465 has a power output of 6270kw/8408hp, allowing a top speed of 230kph or enough power to pull heavy express- or freight trains. They are also compatible with various other BLS and SBB (Swiss national railway) locomotives for flexible use in multiple-unit configurations.
The accident
On the 28th of April 2006 at approximately 6:25am Re 465 014 and 017 are standing at the southern end of Thun Main Station, awaiting permission to cross the incoming main line to pick up a freight train waiting in a siding on the other side of the station. In Switzerland so-called “Zwergsignale” (“Dwarf Signals” are widely used in stations, rather than mounting the lights high up on a pole or even above the track these signals are not even waist high altogether.
At his position the driver of the BLS locomotive can see the signal in front of his locomotive (ZS 233A), which shows “stop”, as well as another dwarf-signal a few meters away (259A). A third signal(269A) is yet to come into the driver’s field of view. At 6:30am the dispatcher sets the nearest signal (233A) to “proceed”, allowing the locomotives to start moving. At the same time ICE 278 is approaching Thun Main Station from the south, the driver has just started decelerating to 60kph/37mph as he is meant to pass through the station without stopping and proceed to Basel, where the driver will be replaced by a German colleague.
As his train picks up speed the BLS-driver passes signal 259A, which dictates “proceed at caution”. Believing this to be the last signal for him before crossing the main line the driver passes it at 25kph/15.5mph. At this point he is met with the sight of the third signal (269A), which dictates “stop”. His shock and surprise delays the reaction, by the time he initiates an emergency stop he can already see the ICE closing in. The ICE’s driver sees the blue locomotives moving into his path, triggers an emergency stop himself, lowers the pantograph (cutting power to the train) and turns off the main control switch (similar to turning off the engine in a car). Knowing he did all he can to slow his train the driver leaves his seat and heads for the door at the back of the driver’s cab, planning to seek safety in the engine compartment. Moments later, at 6:31am, the ICE hits the near-stationary locomotives head-on at 56kph/34.7mph, throwing them back 63m/207ft on impact. Both trains suffer severe damage to their forward sections, had the BLS-driver not jumped off his train at the last moment he might not have survived. As it happened he remained uninjured, while the driver and 30 passengers of the ICE suffer minor injuries. Three axles of the leading motor car as well as the rear two axles of cars 3–8 of the ICE derail as the cars run into one another, as do the forward two axles of the leading Re 465.
Aftermath
When initiating an emergency stop the BLS-train had essentially shut down traffic in the area and started the process of dispatching police and rescue personnel to the site. The driver of the BLS-train had remained uninjured while the passengers, assisted by staff, and driver of the ICE managed to leave the stricken train on their own. 8 people were taken to the hospital for their injuries, 22 were evaluated/treated on site and released. Most of the injuries centered around bruising/concussions and whiplash from the sudden deceleration when the ICE hit the 168 metric ton obstacle. While both train drivers were interviewed and underwent drug testing after the accident it was quickly clear that neither of them were the person to blame. Blame lay firmly with the dispatcher setting paths and controlling the signals who had, according to his statement by accident, failed to follow safety protocols. The SBB’s guidelines said that the last two dwarf signals ahead of a different train’s path have to be set to “stop”. However, as shunting operations aren’t subjected to the usual block system controls built into the signaling system this minimum isn’t automatically maintained. In his statement the dispatcher admitted that he had wanted to let the BLS-train move closer to the main line to shorten the time needed for the shunting operation once two trains passed through, so he set up the signals for “proceed” and “proceed at caution”. This meant there wasn’t enough space left behind the third and last signal for the train to stop before moving into the ICE’s path.
In the end the largest consequence of the accident was the severe damage to the rolling stock and tracks, coming in at 13.83 million Euros/16.45 million USD. Most of the ICE was re-tracked and towed back to Germany, only the leading motor car and leading two first class cars were so severely damaged that they had to be transported on the road. Since the train was still very much needed the DB (German national railway) quickly decided to rebuild the damaged train rather than writing it off. This required reconstruction of the entrance-areas of the two leading first class cars, which had been severely compressed in the collision, as well as extensive repairs to the leading motor car. In 2008 the train was reintroduced into service temporarily with two first class cars from Tz 111 (which had suffered a derailment in the Landrücken Tunnel in April 2008) and an unknown leading motor car. When the motor car returned from Switzerland a few months after the accident (having stayed for the duration of the investigation) it was rebuilt with parts from motor car 401 020 (retired after a fire) and 401 511 (the rear motor car involved in the infamous 1998 Eschede Disaster). By 2010 the train was back in service in its original configuration. The two BLS-locomotives involved in the accident where rebuilt and returned to service as well.
Despite their advanced age the DB is not planning to retire the first generation ICE trains anytime soon, the 58 still existing units (of an original 60) are planned to stay in service until at least 2030, with a second round of modernization having only begun in 2019 (scheduled to go until 2023). The 4th generation ICE, introduced in 2020, does take over some of the more prestigious high capacity connections and the DB has started shortening the trains by 3 cars, but they are definitely still a vital part of the DB’s services. Similarly, despite the BLS having received more modern locomotives in the meantime they are not planning on retiring the Re465 anytime soon and is currently upgrading them to receive newer multi-unit control systems (allowing cooperation with said new locomotives), a new paint job and repairs to the chassis and frames to remove signs of advancing age.
Video
The Swiss national television’s news broadcast (in German) from the day of the accident, showing footage from the site, is available online under this link:
Trivia
ICE 173 holds a special place in German railway- and diplomatic history. When Queen Elisabeth II visited Germany in October 1992 the DB was asked to provide a “royal transport”. The response was to remove the ICE from service and reduce it to just 9 middle cars. Instead of the usual configuration the train held 2 first class cars (smokers/non-smokers), a restaurant, the service-car for the staff, two second class cars for the queen’s staff, a second restaurant car which had received a custom “throne room” interior and lastly two first class cars for guests of the British delegation. This was the first of two times a ICE 1 had been converted for royal use, with a different train undergoing extensive modifications for a visit by the Japanese Emperor and his wife in 1993.
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