Developed in cooperation with the Dutch Railways (NS), these 98 m long four-part trains are built in 1957. Being configured as first class only, they were composed of:
- a power car with compartments for luggage, customs and the train conductor;
- a nine-compartment trailer car with 54 seats in total;
- a kitchen-restaurant trailer car with a 32-seat dining section, and an 18-seat open saloon;
- a driving trailer car with 42-seat open saloon as well as a small sleeping compartment for the on-board mechanic.
The power cars hold a pair of RUHB 1,000 metric horsepower (740 kW / 990 hp each) diesel engines as generators for the electric propulsion-engines in the motor car's bogies (maximum speed: 140 km/h) and a third 300 metric horsepower (220 kW / 300 hp) diesel engine to provide electricity for the onboard systems (like train heating, lighting, air-conditioning and for the kitchen in the dining car). These units are built by Werkspoor (Netherlands), with electrics by Brown, Boveri & Cie (BBC) (Switzerland).
The trailer cars are designed based on SBB's Einheitswagen I (EW I) standard carriage design. Only one entrance vestibule was provided at the front end of the cars, doors were of the folding aluminum type, and windows were double-glazed with a passenger-operated venetian blinds between the panes. These units are built by Schweizerische Industrie Gesellschaft (SIG) (Switzerland).
A total of 5x units of this type are built:
- 2x units for the Swiss Federal Railways (SBB CFF FFS) registered RAm TEEI 501 - 502;
- 3x units for the Dutch Railways (NS) registered DE4 1001 - 1003.
On the evening of February 9th 1971, at approximately 6:30 PM, TEE 56 "Bavaria" was approaching Aitrang, headed for Zürich. It had left Munich at 5:46 PM and was scheduled to reach Kempten, the first stop along the route, at 7:01 PM. That evening the route was served by RAm TEEI 501, running with the motor car pushing and the control car leading. It carried just 53 passengers along with the driver, a mechanic, an attendant and the restaurant staff.
Entering a large S-turn, the 229 metric ton train derailed at 124 km/h, with the control car's forward wheel set climbing the rails and exiting the track at kilometre 34.344, pulling the following restaurant car along into the bed of a small adjacent creek where both cars fell over. The following passenger car derailed and turned sideways, blocking both tracks, while the motor car, due to his lower centre of gravity, did not fall over immediately after derailing but instead dug itself into the gravel on the opposite track.
The dispatcher in Aitrang, less than 500m from the accident site, apparently did not notice what had happened, but the controls in his relay signal box showed him that both tracks were suddenly occupied. Knowing that something was very wrong, the dispatcher immediately revoked the approach-permission for a VT 98 railbus coming from Kempten and headed for Aitrang. Unfortunately it was too late and, despite the rail bus driver attempting to stop, his vehicle struck the wreckage at around 40 km/h.
28 people died in the accident and 42 were injured (19 severely):
- 26 of the victims and 36 of the injured were in the TEE train (most during the initial derailment, as passengers are thrown from their cars);
- 2 of the victims and 6 of the injured were in the rail bus.
Rescue operations were also hampered by the fact the rolling stock was Swiss and the Deutsche Bahn employees supposed to supervise rescue operations were not familiar with it.
Since both drivers died in the accident, the best witness was the dispatcher in Aitrang station, whose statement drew the attention to the braking-system as he claimed he watched the train go by with sparks flying off the motor car's brakes. The trains had a history of issues with its Oerlikon type braking-system, mostly with the brake valve in the control car malfunctioning, which caused a series of unscheduled stops when input from the control car would fail to apply or release the brakes.
Other causes were also brought into question:
- the cold weather might have led to condensation in the pneumatic system causing the pneumatic brakes to fail (this theory was called into question by the SBB, pointing to the train decelerating to 80 km/h without issues when passing Kaufbeuren station just a few kilometres away from Aitrang);
- the driver was confused about his exact location and applied brakes too late (this theory was heavily protested by his coworkers as the train driver was very experienced at his job and knew the area very well, while an autopsy found no trace of a medical emergency or alcohol/drugs in his system).
In the end, no theory could be proven right: the train derailed due to excessive speed, with the cause presumably being a faulty brake system leading to drastically reduced deceleration.
Investigators also pointed out the following aspects:
- none of the glass on the train was safety glass (be it the windows, mirrors or separations between compartments and isle), meaning windows shattered easily allowing people to be thrown from the train and causing shards of glass to fill the interior;
- outside the kitchen, nothing in the restaurant car was bolted down, people and furniture beeing thrown all over the place during the derailment;
- the train had no dead man switch/vigilance control, which had been mandatory for a month (however, while this meant the train technically shouldn't have been in service, it contributed in no way to the accident).
In the following days, once the investigation ended, the control car, passenger car and restaurant car were disassembled for scrap on site, while the almost undamaged motor car was lifted back onto the tracks and towed to Kempten. From there it went to Zürich, before going to the Netherlands were it was finally scrapped two years later. In the end the material damage was claimed to be approximately 2.6 Million Deutsche Mark, which equals approximately 4.77 Million Euros.
The TEE Bavaria was restarted after a week, with conventional trains pulled by a Series 210 replacing the RAm TEE.
In 1976 the remaining unit (unit 502) is sold to Canada, being repainted and fitted with a conventional interior, along with modifications to be allowed on Canadian rail lines. They were in service as the "Northlander" until 1979 (motor cars) and 1992 (remaining cars) before being retired.
Latest update on the 23rd of June 2020 at 23:00
Contributor(s): Tudor C.