Bonn The recent ghost ride of the 66 tram line between Bonn and Siegburg could have an effect on all trams in Germany. The responsible supervisory authority is now testing the trams’ technical emergency braking systems.
The ghost ride of the 66 tram line could have an effect on all German trams. "The aim is to assess whether such an incident can be avoided in future through technical or organisational improvements," says Dagmar Groß from the Düsseldorf district government, which is investigating the incident as the technical supervisory authority. It seems that there are gaps in the security system that were previously unknown - or were considered so unlikely that they were ruled out. Deutsche Bahn's long-distance trains include other mechanisms that are intended to prevent ghost rides.
According to the information available so far, the events that took place in the night from Saturday to Sunday on line 66 between Siegburg and Bonn were as follows: The driver loses consciousness at around 0.40 a.m. and lies on top of one of the two dead man's switches that he does not trip and the train does not stop automatically. The tram then passes through eight stations. Several emergency calls are received by the police, who then inform Stadtwerke Bonn (the public utility company). Under instructions, passengers broke open the door to the driver's cab and brought the train to a halt.
Investigations of the tram itself, parked at the Stadtwerke's depot in Dransdorf, were completed a week later. "The vehicles and all technical records (data storage device, video recordings, maintenance documents, etc.) were checked by employees of the technical supervisory authority," explains Groß. The findings will now be evaluated. "It cannot yet be determined how long this will take". The public prosecutor's office in Bonn is also carrying out its own investigations.
To the knowledge of the district government in North Rhine-Westphalia, this is the first time that a driver has become unconscious while driving and continued to operate the dead man's switch. "This is therefore regarded as an absolutely isolated incident and does not justify any emergency action such as a shutdown." Even though a reoccurrence cannot be ruled out. Furthermore, tram drivers are subject to regular health checks and would not be allowed to work if their health was impaired. "Nevertheless, the technical supervisory authority will examine measures to improve the existing technology."
The Deutsche Bahn long-distance trains could serve as a model. Their so-called safety drive circuit works in such a way that the driver either has to briefly release the switch after a certain period of time or operate it briefly at regular intervals. So if a driver were to faint and remain lying on the switch, the train would stop. The dead man's switch on trams – a nationwide requirement under the Ordinance on the Construction and Operation of Trams (BOStrab) - works differently and is pressed continuously: If it is released, an acoustic signal follows and after a few seconds, an automatic emergency brake is applied. In Bonn, drivers can choose between pressing a manual switch on the knob of the control lever or a foot pedal. "The switch and the pedal have the same function," says SWB spokesman Michael Henseler. However, the foot pedal must be held in a central position - if it is pressed down, the dead man's switch is triggered. The justification of the district government: "With trams - which in contrast to the railways also travel in road traffic - there is, however, the danger that either the driver could be distracted too much from the traffic which would lead to accidents, or there could be frequent emergency braking, which could cause passengers to fall over and injure themselves”.
(Original text: Nicolas Ottersbach, Translation: Caroline Kusch)