Technical monitoring of the route

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The technical monitoring of the track ( TüFa ) is an assistance system for track vacancy detection in mechanical and electromechanical interlockings . The system was developed by Deutsche Bahn in response to several accidents in train stations without track vacancies. In these accidents, trains were accidentally directed to the wrong, occupied track, where they collided with a stationary train.

history

Starting position

In 2017, out of a total of 2,742 interlockings in the Deutsche Bahn network, 718 were mechanical and 311 electromechanical interlockings .

These signal boxes often do not have a track vacancy detection system . The route exclusion also ensures with these interlockings that no two crossing or touching routes are set, which prevents two moving trains from colliding. After a train has entered the station, however, the route is closed. Due to the missing track vacancy detection system, it is now technically possible to allow a train journey into the track occupied by another train, a shunting run or parked vehicles. In order to prevent this, the dispatcher has to attach auxiliary barriers to the route levers of the entry roads in the case of entry tracks that are occupied for a long time, to remind him of vehicles standing on the track. In addition, prior to admitting any train journey, he must ensure that the route is clear, which is done by looking if the track vacancy detection system is not available. The lack of technical security can lead to accidents due to human error, even during normal operation , as has happened several times in the past.

trigger

In the Leese-Stolzenau railway accident on the Nienburg – Minden railway line on June 30, 2017, a freight train coming from Minden collided with another freight train waiting at Leese-Stolzenau station . After completing the investigations, the Federal Agency for Railway Accident Investigation issued the following safety recommendation in January 2018:

“Railway stations that have not yet had an automatic track vacancy detection system should be subjected to a risk assessment. As a result, the main tracks of these stations should be successively retrofitted with an automatic track vacancy detection system in accordance with the risk classification. "

According to the 2018 safety report from the Federal Railway Authority , the Aichach railway accident was the trigger for the measures. In the accident on May 7, 2018, a regional train collided with a freight train standing in the station after the train had stopped entering the wrong track. The driver and a 73-year-old passenger died. After the accident, plans by Deutsche Bahn became known for the first time to systematically retrofit stations without track vacancy detection systems.

commitment

Test operation of the system began in January 2019 in the signal boxes at the Utting stations on the Ammerseebahn and Nieukerk on the left-hand Lower Rhine route . The DB Netz was planning to retrofit 50 additional interlocking systems by the end of 2019, including the signal box in Aichach . Commissioning was later announced there on May 13, 2020, but due to the COVID-19 pandemic , the system was not put into operation until a few weeks later.

With an investment volume of around 90 million euros, around 600 signal boxes are to be equipped with the system by 2023.

functionality

Since retrofitting a track vacancy detection system would take a lot of time due to the multiple local features of the interlockings due to the necessary planning and safety evidence, the technical monitoring of the track only uses existing interfaces so that the function of the existing interlocking cannot be impaired.

For the TüFa, the main tracks of the stations will be equipped with axle counters . This determines whether the track is free. When an attempt is made to allow a journey into a track that is reported as occupied, the signal lever is blocked and an acoustic signal sounds. Since several routes can originate from one signal, the system must also determine the position of the route lever. For example, if a route was closed by an entry signal to track 1, the TüFa locks the signal lever when track 1 is occupied. If, on the other hand, a route to track 2 is closed, this vacancy message for this track is evaluated. In the event of a fault, the TüFa can be switched off with a switch with counter so that it no longer blocks the signal lever.

The technical monitoring of the route is not a signal-technically safe system. The dispatcher may not rely on the function of the TüFa, but must continue to check the clearness of the route by looking in accordance with the specifications of the driving service regulation . In order to prevent the TüFa from being used as a substitute for a route inspection , the system only works in the background, so it has no display for track occupancy.

Web links

  • Tobias Riesbeck, Dirk Menne : Technical Monitoring of the Track (TüFa), a support for signal boxes without track vacancy detection . In: Train B practice . tape 7/8 , 2019, pp. 3–5 (English, online [PDF; 2,3 MB ; accessed on May 19, 2020]).

Individual evidence

  1. ↑ Service and financing agreement: Infrastructure status and development report 2017 (PDF; 12 MB) Deutsche Bahn AG, p. 141 , accessed on May 3, 2020 .
  2. ↑ Investigation report. Train collision, 06/30/2017, Leese-Stolzenau. (PDF) Federal Agency for Railway Accident Investigation, January 26, 2018, accessed on April 28, 2019 .
  3. ^ Report of the Federal Railway Authority. Reporting year 2018. (PDF) Retrieved on May 3, 2020 .
  4. ↑ a b investigation report. Train collision, May 7th, 2018, Aichach. (PDF) Federal Agency for Railway Accident Investigation , accessed on May 2, 2020 .
  5. ↑ a b Bahn wants to retrofit signal boxes . In: Der Spiegel . No. 28 , 2018, p. 10 ( online ).
  6. ↑ Started: 600 signal boxes are being retrofitted. January 2019, accessed May 3, 2020 .
  7. ↑ Bahn retrofits 600 old signal boxes nationwide. Süddeutsche Zeitung , accessed on May 5, 2020 .
  8. ↑ Aichach: Moderniersierung at the station delayed. Retrieved May 20, 2020 .
  9. ↑ Aichacher Bahnhof receives new technology. July 10, 2020, accessed July 27, 2020 .
  10. ^ A b c Tobias Riesbeck, Dirk Menne : Technical Monitoring of the Track (TüFa), a support for interlockings without track vacancy detection . In: Train B practice . tape 7/8 , 2019, pp. 3–5 (English, online [PDF; 2,3 MB ; accessed on May 19, 2020]).