Tram accident in Basel

An accident on the Basel tram near Aeschenplatz on April 24, 1947 cost the lives of six waiting passengers . This was the worst accident in the history of the railway from its foundation in 1885 to the present day.

Course of the accident

This Thursday a by leaving at 6:29 Centralbahnplatz coming forth tram line 4, motor car (Ce 2/2 198) with two trailers (C 2 333 + C 2 285), which Basler transporting enterprises (BVB) unrestrained in the after Turnout turning left in the bus stop area on Aeschenplatz. The tram passed through the stop, possibly due to a failure of the braking system. The motor car Ce 2/2 198 collided with a trailer (C 2 433) of an oncoming tram (Ce 2/2 209) of line 12 and levered it into a threatening incline. The wheels on the left side of the car were still in the rails . The second trailer of the train involved in the accident, a light center-entry car (C 2 285), derailed . The clutch loosened due to the forces involved. The trailer turned on its own axis, slid across the stop ("whip effect") and pushed the trailer (C 2 383) of a tram (Ce 2/2 103) waiting at the stop on line 5 off the rails. The first car (C 2 333) of the train involved in the accident also derailed, first the end of the car hit the stop and then hit a catenary mast. This clutch did not separate.

Because of the crowd at the bus stop and in the vehicles, the accident claimed many victims. 6 people died on the tram island, 47 others were injured, some seriously.

The criminal trial uncovered several causes which, individually or in combination, could have led to this serious accident. It was found that the motor vehicle that had caused the accident did not have a speedometer . A temporary failure of the electrical braking system (magnetic rail brake) could not be ruled out. The trailers had incompatible braking systems. The light center entry car had poor running characteristics. The rolling stock was out of date.

Due to the technical defects in the vehicles that could not be ruled out, the 26-year-old driver was acquitted at the request of the public prosecutor .

The accident train

The motor car Ce 2/2 198 was put into service on February 18, 1930. A magnetic rail brake and a handbrake were installed ex works. The motor vehicle had a length over the buffers of 9,420 mm and a center distance of 3,000 mm. Tare weight approx. 14,200 kg. 59 standing / sitting places were offered. After the accident on April 24, 1947, the vehicle was fitted with an air brake between October 31, 1955 and March 24, 1956 . On April 23, 1976, the motor vehicle was taken out of service and broken off.

The first car, the C 2 333, was put into operation on November 21, 1913 as the C 2 233. Between 1916 and 1918 the name was changed to C 2 333. Between 1921 and 1923 a compressed air brake was installed. The car had a length over the buffers of 9,380 mm and a center distance of 2,800 mm. Tare weight 6'800 kg. There were 70 standing / sitting places. The car was involved in an accident on October 15, 1933, at Heiligholz , and on April 24, 1947, at Aeschenplatz , each of which was badly damaged. On June 12, 1948, the name was changed again to C 2 1133, on July 27, 1972 it was withdrawn from service and then demolished.

The second car, the C 2 285, was put into operation on June 23, 1907 as a summer car . In 1922 it was converted into a closed trailer with a center entry and was in service as the C 2 285 all-weather car from October 31, 1922 . With a box length of 7,400 mm, length over the buffers of 8,080 mm, and a short center distance of only 1,800 mm, its running properties could be described as poor. The car tended to roll. Tare weight 5'500 kg. 45 standing / sitting places were offered. After the accident on April 24, 1947, it was converted into advertising vehicle No. 2250 in 1948 . Throughout his entire service he only had a handbrake with a lever and chain hoists. The demolition took place on August 30, 1966.

Actions after the accident

The accident resulted in a number of technical and operational improvements.

In the motor vehicle series Ce 2/2 173–216, the air brakes that were still missing in 13 vehicles were retrofitted. This lasted until 1956.
In 1950 all center entry cars C 2 282–293 were scrapped.
Starting in 1947, 27 of the trailer series C 2 1185–1234 were retrofitted with the missing compressed air brakes.

Trivia

Various points seem strange:

If the braking systems of the three vehicles are compared, it is noticeable that nothing fits.

The driver could only operate the braking system of the motor vehicle. Two unbraked cars were attached .

If the total train weight is calculated, including passengers, this easily adds up to 37 t or more.

The motor vehicle accounts for around 17.2 t. Its braking system is designed for a maximum weight of approx. 22 t (calculated value).

The train involved in the accident drove from Centralbahnplatz to Aeschenplatz. This route runs in a straight line of approx. 400 m along the Aeschengraben and has a slight gradient of 1.85%.

The possible v max. of the motor vehicle was specified with 30 km / h (factory specification).

A well-manned, heavy train can definitely have its v max. reach, or even exceed. Since there was no speedometer, this could easily be overlooked by the driver. Every faster kilometer per hour increases the stopping distance.

The driver assumes that his train's brakes are working. He starts braking at the normal stopping distance in front of the stop. Was his train too fast now? Did the magnetic rail brake drop out? Was the excess weight of the trailer, which the motor vehicle had to brake alone, too great? Had the driver initiated the braking process too late? Or did several points even come together?

The route of line 4 at that time was: Binningen - Centralbahnplatz - Aeschenplatz - Bankverein - Barfüsserplatz - Claraplatz - Kleinhüningen. The slope in front of Aeschenplatz is harmless compared to that of Steinenberg. This lies between the Bankverein and Barfüsserplatz stops and has a gradient of up to 5.2% (!). At the bottom of Steinenberg, line 4 branches off to the right onto Barfüsserplatz.

Due to the technical differences between the three vehicles involved in the accident and the defects described, it is understandable why the public prosecutor pleaded for the driver to be acquitted.

literature

Guido Studer: Events up to 1949. Aeschenplatz: Severe tram collision with six dead. In: www.tram-basel.ch. The independent Basel tram portal. Retrieved October 30, 2013 .
Results of the accident statistics for the sixth five-year observation period 1943–1947. (PDF, 2.3 MB) Swiss Accident Insurance Fund, accessed on October 30, 2013 .