DB class 423

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DB class 423/433
423 449 on the Main-Weser Railway
423 449 on the Main-Weser Railway
Numbering: 001 / 501-462 / 962
Number: 462 units
Manufacturer: Adtranz , Alstom LHB , ABB , Bombardier
Year of construction (s): 1998-2007
Axis formula : Bo '(Bo') (2 ') (Bo') Bo '
Gauge : 1435 mm ( standard gauge )
Length over coupling: 67,400 mm
Height: 4,295 mm
Width: 3,020 mm
Trunnion Distance: 15,140 mm (end car)
15,460 mm (middle car)
Bogie axle base: 2,200 mm (end DG)
2,700 mm (Jakobs DG)
Empty mass: 105.0 t
Service mass: 119.4 t
Wheel set mass : 18 t
Top speed: 140 km / h
Hourly output : 2350 kW
Acceleration: 1.0 m / s²
Braking delay: 0.9 m / s²
Wheel diameter: 850/780 mm
Motor type: 4 WIA 3558 G
Power system : 15 kV 16.7 Hz AC
Power transmission: Overhead line
Drive: Hollow shaft drive - wedge pack coupling
Train control : PZB , Munich: additionally LZB
Coupling type: Scharfenberg coupling type 10
Seats: 176 + 16 (of which 0, 8 or 16 1st class)
Standing room: 352
Floor height: 1,025 mm
Loading height: 995 mm

The multiple units of Series 423/433 are S-Bahn - train sets that since 1998 the previous DB Class 420 to replace. The vehicles were originally designed for the Munich S-Bahn designed, but are also used in the S-Bahn Cologne , the S-Bahn Stuttgart and Rhine-Main S-Bahn used.

With series 423 the two driven end cars are called, while also driven intermediate cars in the series 433 are classified.


The four-part multiple units of the 423 series are 67.40 meters long. The multiple unit is designed for S-Bahn operation and therefore does not have a toilet. As a lightweight vehicle, it is largely made of aluminum . Three-phase current technology with regenerative braking is used as the drive , the output is 2350  kilowatts . The maximum permissible speed of the multiple unit is 140 km / h.

Schematic side view of a class 423 S-Bahn multiple unit

A "short train" of the 423 series consists of four cars :

  1. Control car 1: 423 001 - 462
  2. Intermediate car 1: 433 001 - 462
  3. Intermediate car 2: 433 501 - 962
  4. Control car 2: 423 501 - 962

The serial numbers of the individual cars are always based on the same scheme in the delivery condition, the two front cars have the same serial number, while the two rear cars have the serial number increased by 500.

Two short trains form a "complete train", three short trains form a "long train".

View of the passenger compartment

You can look through from one end to the other of the vehicle, whereby in the original version a lockable door was built in in the middle of the railcar, with which it should be possible in times of low demand to leave part of the vehicle empty in order to increase social control to be obtained by denser occupancy. The railcars have a passenger information system (FIS) inside , which alternately shows the destination stop and the next stop and is supplemented by a single acoustic announcement of the next stop. There is also an announcement on which side the exit will be possible. They are also equipped with a system for technical clearance (TAV), whereby the driver does not have to monitor the doors himself, this is done by light barriers . In 2007, however, this process was temporarily put out of operation until light grids were retrofitted over almost the entire height of the entrance area (see door locking and light barriers ).

The vehicles differ from the similar-looking regional transport series 424 , 425 and 426 in that the car body is 180 millimeters wider, three instead of two doors on each side of the car, the missing toilet, a floor height of 1,025 millimeters above the top of the rails, which is 20 km / h lower Maximum speed as well as the possibility of being able to drive a maximum of three traction (424–426: maximum of four traction). Driving and braking technology, on the other hand, are almost identical.

The triple headlights can be switched from low beam to high beam during operation . Some railcars (423 238 and 423 268 of the Munich S-Bahn) were used instead of normal beam headlights with LED headlights , in which the light from green and red LEDs was mixed in to achieve a more balanced spectral distribution. With the modernization, all vehicles were converted to warm white LED modules.

The openings of the twelve doors on each side are 1300 mm wide.

old (above) door buttons installed for testing (below)

Electronic buttons are used to open the door, which signal the door release with a few light-emitting diodes and react to mechanical pressure . The original buttons with about the size of a thumb only gave visual feedback when they were touched. On multiple unit 423 089 of the Munich S-Bahn, new buttons were installed for testing purposes in March 2012, which, in contrast, functioned capacitively (in Munich these buttons can also be found on all public buses as well as newer subways and trams ). In the course of the modernization, the vehicles received buttons with a larger pressure surface, illuminated ring and audible and perceptible actuation.

The series was delivered in five series:

  • 1st construction series: 423 001 - 423 190
  • 2nd series: 423 191 - 423 305
  • 3rd series: 423 306 - 423 371
  • 4th series: 423 372 - 423 396
  • 5th series: 423 397 - 423 462

The last vehicles 423 444 - 456 built in 2007 were not put into operation until the beginning of 2010 because of the problems with the door security.

Building on the 423 series, the 422 series was delivered from 2008 to 2010 as the successor . The new vehicle head has increased the length of a multiple unit by two meters compared to the 420 and 423 series. Derived from the 422 series, the 430 series has been delivered since 2012 , which is only 90 centimeters longer than the 420 and 423 series and therefore also as a long train fits on 210 meter long platforms.

Development and procurement

The Bundesbahn Central Offices Munich dealt since 1990 as part of a feasibility study with the succession of the built in eight series and 480 copies to 1997, multiple units of class 420th

On November 30, 1994, Deutsche Bahn commissioned a consortium of the companies ABB Henschel (consortium leader, later Adtranz ) and LHB (later Alstom ) with the development and delivery of 100 multiple units of the 423 series.In parallel, the series 424 to 426 multiple units were also produced instructed. In 1996, a reorder for 90 more multiple units followed. At the end of 1999, Deutsche Bahn redeemed an option for 110 additional class 423 multiple units, especially for the Munich S-Bahn.

Subsequent modifications


The middle of the five bogies is neither driven nor braked.

In the autumn of 2003 in North Rhine-Westphalia, multiple units of the series 423, 424 and 425/426 were found to have exceeded the braking distance, which led to platform and signal failures and in individual cases reached several hundred meters. Such behavior had not previously been observed on any other multiple unit series. The causes were found to be turbulence when sanding at higher speed, very unfavorable braking conditions with unfavorable rail conditions and defects in the anti-skid protection .

Repeatedly, the Federal Railway Authority (EBA) issued rulings due to insufficient braking effect during autumn operations . With effect from September 29, 2007, the EBA decreed a reduction in the braking percentage (BrH) during the autumn months to 110 BrH (instead of the previous 142 BrH). This results in the PZB train type M in signal-controlled operation with lower monitoring speeds and curves, which again reduces the maximum speed to 120 km / h. LZB -guided, the reduced braking percentage does not result in a change in the top speed, but flatter braking curves. In particular in the Munich S-Bahn network, this meant that there were sometimes considerable delays during rush hour and the S7 no longer drove through the main line tunnel , but ended at the main train station (above). Since the timetable change in December 2008, after an update of the brake software, starting in Munich, driving again without restrictions; on September 15, 2009, the braking percentage was again reduced for the duration of autumn. In 2010, the sanding systems of the Munich vehicles were modified and additional spreading devices were added on the second and fourth bogies (previously sanding could only be carried out on the first and fifth bogies). After the renovation measures were approved in the summer, the renovation of the Rhein-Main S-Bahn also followed. The speed restrictions were finally eliminated.

Door closure and light barriers

Retrofitted light grids (infrared view), the factory light barrier below

In January 2008, the Cologne public prosecutor's office investigated officials from the Federal Railway Authority (EBA) who had approved the commissioning of the series even though the automatically closing doors did not function safely. Passengers were not recognized by the light barriers, which led to accidents in possibly 60, verifiably in 27 cases. The built-in light barriers are close to the floor and therefore could not detect when people entering, for example, try to hold the closing door open with their hands or objects. These were then sometimes too thin to be recognized by the anti-trap protection. In two cases a train started in such a situation; as passengers noticed this and pulled the emergency brake, no serious accidents occurred. Other minor accidents occurred with passengers who were pushed off the doors by the closing process and sometimes fell as a result. The officials are accused of negligent bodily harm and negligent endangerment of rail traffic.

After these accidents, the driver was again required to monitor the door closing; From a length of three (sometimes even two) multiple units, there is also a train attendant. Occasionally, train handling is also supported by local staff who are only deployed for this purpose (e.g. on the S 12 in the network of the Cologne S-Bahn in Merten (Sieg) and Rosbach (Sieg) , both stops are in curves). Initially, the so-called forced closing by the driver was mandatory, while the doors could still close independently without contact with light barriers. In December 2007, the EBA ordered the complete shutdown of the light barriers. This also meant that all open doors were kept open under the supervision of the driver until they were forced to close and, during longer stays such as overhauls or at end stations, very cold or warm outside air quickly penetrated the passenger compartment. Since this was not planned, in contrast to other locomotives, there are no electromechanical options (push-button control) or options that can be easily operated with physical strength (handle, e.g. 420 series) for passengers to close the doors by hand.

The light barriers were gradually supplemented with light grids that work the entire height of the doors, which, according to railway spokesman Helmut Lange, should take about a year. According to newspaper reports, the railway brought an action against the EBA because of the deactivation of the automatic door system. The costs would be disproportionate to the incidents. While the conversion in Munich was completed in August 2008, the first converted units were on the way in Frankfurt at that time. Since the end of November, the first converted vehicles have been running in Munich with adapted software with which the doors now close automatically after six seconds (previously: three), provided the light curtain and the light barrier are not interrupted. A warning tone also sounds with every closing process. The technology-based handling procedure (TAV) has been permitted again at the Munich S-Bahn since January 11, 2009, as all vehicles in use there have actively switched light grids. Since February, two multiple units with active light grids have been running in the Rhine-Main area; Since its acceptance in July, the light grids on the remaining multiple units have been activated with the next visit to the workshop. However, a check by the driver before departure is still required. On May 19, 2009, improved software for the light grids was approved; Multiple units equipped with this can now be driven again without an attendant.


Interior view of a modernized class 423 train in Stuttgart. The new seats, the changes in the door area and the screens are clearly visible.

S-Bahn Stuttgart and Rhein-Main

From 2013, all units of the Stuttgart and Rhein-Main S-Bahn will be modernized and adapted to the newly acquired trains of the second successor series 430 . The 60 Stuttgart trains are to be converted in the company's own workshop in Plochingen with an investment volume of around 30 million euros. The modernization in Frankfurt, which cost around 100 million euros, was carried out from 2013 to 2015 in the Krefeld subsidiary in Hagen, five weeks are planned for each vehicle. In both cases, the vehicles are given a new exterior paintwork, reconditioned seats and LED interior lighting. The door areas are also optically and tactilely adapted for visually impaired passengers and the passenger information system is equipped with larger displays and additional displays; The voice of the Berlin news anchor Barbara Becker was exchanged for Ingo Ruff . Finally, there is a software change to the vehicle computer. While the vehicles in Stuttgart will still be equipped with remote diagnosis and vehicle tracking systems and the interior will not be changed until 2019, the vehicles in Frankfurt will receive additional buttons for wheelchair users, refreshed ceiling and wall paneling and video surveillance (based on the 430 series). In addition, the folding seats in the multi-purpose compartments are being expanded on one side to guarantee parking spaces for wheelchair users, cyclists and prams. The first modernized unit in Frankfurt was under way in early August 2013.

By the end of 2016, the vehicles in Munich and Stuttgart were equipped to open doors centrally in order to shorten stopping times on the main routes.

S-Bahn Munich

Interior view of a modernized class 423 train in Munich. The interior was swapped and the interior displays were replaced by LCD screens.

In the course of the transitional agreement until 2019 and to secure operations until at least 2023 on behalf of the Free State of Bavaria , the Munich S-Bahn will also start on March 2nd / 3rd. In the first quarter of 2018, all 238 units of the 423 were modernized by the end of 2020. The first modernized units went into operation in the third quarter of 2018. The modernization is being carried out in the DB plants in Nuremberg and Krefeld, the number of seats will drop from 192 to 166, but the total capacity will increase from 544 to 612 in order to cope with the increasing number of passengers until the second main line is operational. Currently, passengers are often concentrated in the boarding area and luggage is in the way. This unused capacity leads to delays when changing passengers. A more open and transparent spatial concept is intended to remedy this, as the passengers are better and more evenly distributed in the vehicle and the passenger change is to be accelerated. In addition, many pieces of luggage have blocked aisles or seats. In the course of the modernization program, the situation should improve with wider aisles, floating seats and more storage space. The old luggage racks made of metal grids are replaced by shelves made of transparent glass. This means that smaller pieces of luggage cannot fall through the grille; Nevertheless, the passengers have a good view of their luggage. The storage areas are exactly the opposite of what they used to be, only in the seating groups at the car crossing. New double-sided broadband monitors, a total of 8 per vehicle, replace the technically obsolete single-line passenger information displays at the car crossings. This expands the information content, as information is provided in real time about the course of the journey, transfer options, disruptions and changes to the timetable. Outside, the greenish LCD - destination displays by colored LED replaced annunciator, display the additional important intermediate stations. Pictograms are attached to the doors , as well as a new variant of the door button and a wide LED light strip above the door, which turns red or green depending on the status. Major changes are taking place, particularly at the two ends of the vehicle. Instead of the conventional seats, a new family and group area with a corner bench will be created. The multi-purpose area will be rebuilt in such a way that fewer conflicts of use arise between cyclists , wheelchair users , people with prams and other passengers. Large pictograms are placed on the vehicle floor and outside above the doors so that the areas are easier to recognize. In order to improve safety in the vehicle, additional holding options in the form of mushrooms in the entry area (16 per vehicle) and larger handles on the seats are planned. A completely new, bright, time-of-day-dependent LED lighting concept is used above the windows and in the middle of the ceiling and replaces the old fluorescent tubes in the middle of the ceiling. This is the largest vehicle modernization program in the history of Deutsche Bahn . In addition to the work in the interior, the vehicles are technically serviced, the outside repainted and also provided with graffiti protection.

Since the vehicles will be taken out of service one after the other and the strength of the vehicle fleet must be maintained, 21 used vehicles of the same type will be integrated into the fleet in addition to the 15 units of the 420 series already in use in 2018 . After the modernization of the 423 series has been completed, the 36 units of the 420 series will strengthen the S-Bahn fleet.

The first modernized trains have been in operation since July 2018.


S-Bahn Munich

Train of the Munich S-Bahn on the Munich-Giesing – Kreuzstraße line

The Munich S-Bahn was the first German S-Bahn company due to its outdated fleet (consisting of 420 series vehicles, some of which were more than 30 years old ), whose entire fleet was replaced by the new 423 series from the end of the 1990s should. Nevertheless, the first brand-new trains did not come to Munich in 2000, but to Hanover for passenger use at EXPO 2000 . The reason for this was that the new trains of the sister series 424 for the Hanover S-Bahn could not be completed in time or made suitable for passenger use. From autumn 2000, the vehicles were also used by passengers on the Munich S-Bahn. The change from 420 to 423 was implemented line by line in Munich in order to avoid problems with weaknesses and strengths, as the two series cannot be coupled with one another. A total of 211 trains were delivered to the Munich S-Bahn within two years.

In 2004, 23 more sets were delivered to cover the increased demand due to the start-up of the "Cycle 10" program. From December 5, 2004 to December 13, 2014, only the 423 series operated on the Munich S-Bahn. Another four 423 sets followed in 2005, so that a total of 238 trains of this series are available today. Today they run on all lines of the Munich S-Bahn. In regular service, there are mostly full trains (two coupled units), in rush-hour traffic sometimes long trains (three coupled units) and in evening and Sunday traffic mainly short trains (one single unit). All S-Bahn trains in Munich are only second class.

Since autumn 2004 the trains have been equipped with the LZB CIR-ELKE  II line train control system, which enables a 2-minute cycle on the main line.

Rhein-Main S-Bahn

Railcar of the class 423 of the S-Bahn Rhein-Main on the S8 in Mainz-Bischofsheim station on the way to Hanau main station

On the Rhein-Main S-Bahn , lines S2 to S6 are only served by class 423 trains. The 423 series was rarely used on the S8 and S9 lines, and until the changeover to the 430 series, almost all rounds were made with the 420 series. The S1, S7, S8 and S9 lines have been operated with the single type series 430 since November 3, 2014. Since 2019, modernized trains of the 425 series have also been in use on the S7 and the main train station - airport regional train station section of the S8 . These have a floor height of 780 mm and are barrier-free in their area of ​​use, but cannot be used in the Frankfurt City Tunnel .

Due to a lack of approval, 13 of 100 units ordered were only delivered at the beginning of 2010. Line S3 was switched on March 28, 2010 after years of delay.

S-Bahn Stuttgart

In the Stuttgart S-Bahn network , the trains of the 423 series run exclusively on lines S4, S5, S6, S60 and the S1 amplifiers between Esslingen and Schwabstraße. Before the new 430 series was launched, they only operated on the S1 and S3 lines.

On July 1, 2013, the first modernized multiple unit of the 423 series of the Stuttgart S-Bahn was officially presented. The remaining trains are also to be modernized. The redesign of the last vehicle in the Plochingen plant was completed on October 12, 2016. In the three years of the redesign program, 60,000 meters of cable, 11,340 seats, 720 intercom stations, 480 RIS monitors, 12,000 contacts, 3,000 plugs, 2,880 door buttons and 2,640 LED lamps were replaced / exchanged. 500,000 euros were invested per vehicle. The second part of the redesign program will start in 2019 with the replacement of side and ceiling panels.

The multiple units are to be equipped with ETCS Level 2 by 2025 . The contract to equip the multiple units with ETCS and ATO was put out to tender in July 2020. The trains should u. a. Level 3 capable, equipped with train integrity monitoring and prepared for FRMCS . The project is scheduled to start in January 2021 and run until December 2027. The equipping of a first multiple unit (first in class) is to begin in October 2021, and test and preliminary operations will begin in April 2024. All vehicles are to be equipped with ETCS Level 2 (according to Baseline 3 Release 2 ) and ATO (with static timetable data) by January 2025 . In the years 2026 and 2027, the continuous commissioning and approval according to TSI ZZS 2022 , including further "innovations", should take place.

The time for a complete door opening and closing process is 10 seconds.

S-Bahn Cologne

On the Cologne S-Bahn , the class 423 multiple units run on lines S 11, S 12, S 13 and S 19. Due to a high level of damage, two rounds of line S 11 with class 143 and x-wagons have been in the road since February 23, 2011 Commitment. Today the S-Bahn Cologne owns 63 multiple units of the 423 series. Of these, the last series 423 multiple units according to number 27 with first-class seats are only used on the S 11, with the remaining 36 trains without first class only on the S 12/13 / 19 can be used.

Guest assignments

Guest assignment in Berlin: Class 423 from Munich (August 2009)

With an entry height of 995 millimeters, the 423 is optimized for the platforms of the S-Bahn trains in Cologne , Munich , Stuttgart and Frankfurt am Main . At major events, multiple units of the 423 series also run on the Hanover S-Bahn , where otherwise only series 424 and 425 multiple units with the lower floor height of 798 millimeters are used.

The models of the 423 series, which were new at the time and actually intended for Cologne, Munich and Stuttgart, were initially used in Hanover during the Expo in 2000. During the 2006 World Cup , trains of the 423 series with the line designation "S 21" also ran through the new Berlin north-south long-distance tunnel , which is not suitable for conventional Berlin S-Bahn trains built for DC voltage . The trains came from the S-Bahn networks in Frankfurt and Munich.

In the autumn of 2006, some 423s from Frankfurt, Stuttgart and Cologne were loaned to Munich, because there was a considerably increased number of offers due to the papal visit. For major events, especially soccer games, Munich 423s are often loaned out to Nuremberg for a short time .

In July / August and again in September 2009, four 423 units ran for a few weeks as a result of the S-Bahn crisis in Berlin between Gesundbrunnen and Südkreuz via the main station and Potsdamer Platz . After further problems with the S-Bahn Berlin, partly brand-new units were used in the relief traffic between Potsdam Hauptbahnhof and Berlin Ostbahnhof and in spring 2010 between Berlin Gesundbrunnen and Hennigsdorf due to a construction-related closure of the S-Bahn line on long -distance tracks.

When the Meridian started operating , the Bavarian Oberlandbahn used Munich's 423 units on the route of the former Munich S-Bahn line S27. This was the first time 423 were used outside of the service of Deutsche Bahn.

At times, trains of this series were also on the move in the Augsburg electrical network. They mostly ran there as a regional train between Augsburg Hauptbahnhof and Meitingen .


The multiple units are driven by eight four-pole, water-cooled three-phase asynchronous traction motors with a total output of 2350 kilowatts. The two traction systems of the trains, which are supplied with energy via a common pantograph, are largely independent of one another.

Each train has two central control units (ZSGs). The data exchange within the trains takes place via a Multifunction Vehicle Bus , in the train set via a Wire Train Bus (WTB) with a maximum transmission rate of one megabit per second. The train set is also configured automatically via the WTB.

The trains have an emergency brake override .

Service brakes take place via electrodynamic brakes. Six of the 16 brake cylinders of the electropneumatic brake are equipped with a spring-loaded brake.


  • Martin Pabst: U- and S-Bahn vehicles in Germany. 1st edition. GeraMond Verlag, Munich 2000, ISBN 3-932785-18-5 .

Web links

Commons : DB Class 423  - Collection of pictures, videos and audio files

Individual evidence

  1. a b c d e f g h i j k l Daniel Lurz: Technical data - Series 423. Archived from the original on August 21, 2006 ; accessed on March 4, 2015 .
  2. a b c d e f g Drawing series 423. Accessed on March 4, 2015 .
  3. a b c d e f g h i Daniel Riechers: S-Bahn multiple units - New vehicles for Germany's urban express traffic . 1st edition. transpress, Stuttgart 2000, ISBN 3-613-71128-1 , p. 36-61 .
  4. ^ IG S-Bahn Munich eV S-Bahn Gallery
  5. ^ Eisenbahn-magazin 4/2010, p. 22.
  6. ^ A. Lang, B. Hartmann: New electric locomotive family series 423-426 for Deutsche Bahn AG. ZEV + DET glass. Annalen, 122, 1998, pp. 394-406.
  7. Klaus-Rüdiger Hase, Sebastian Müther, Peter Spiess: New findings on the anti-skid behavior of electric multiple units . In: Railway technical review . tape 55 , no. 10 , 2005, pp. 599-610 .
  8. Press release of the Munich S-Bahn ( memento from August 19, 2013 in the web archive archive.today )
  9. FR Online: Investigations against EBA after accidents on train doors
  10. RP Online
  11. WDR, topic traffic ( memento from January 11, 2008 in the Internet Archive )
  12. FR Online: Dangerous S-Bahn doors
  13. The train has problems with the train doors. In: welt.de April 3, 2008.
  14. eisenbahn-magazin 7/2009, p. 17.
  15. Press release Deutsche Bahn AG ( Memento from August 6, 2013 in the web archive archive.today )
  16. Press release Deutsche Bahn AG ( Memento from August 3, 2013 in the Internet Archive )
  17. press release. (PDF; 50 KiB) Deutsche Bahn AG, July 1, 2013, accessed on August 6, 2013 .
  18. RMV press release (illustrated) ( Memento from August 6, 2013 in the web archive archive.today )
  19. Every second counts - S-Bahn trains now open doors on the main route centrally and automatically. (No longer available online.) Deutsche Bahn, December 5, 2016, archived from the original on December 20, 2016 ; accessed on October 2, 2019 .
  20. Every second counts: doors on all S-Bahn trains can be opened centrally as soon as the timetable changes. (No longer available online.) Deutsche Bahn, December 8, 2016, archived from the original on February 11, 2017 ; accessed on May 26, 2019 .
  21. Background modernization project. Retrieved January 2, 2018 .
  22. ^ Andreas Schubert: S-Bahn Munich puts modernized trains into operation. In: Süddeutsche. July 2018, accessed August 25, 2018 .
  23. More space for everyone. Retrieved January 2, 2018 .
  24. New passenger information system. Retrieved January 2, 2018 .
  25. ↑ Resolve usage conflicts. Retrieved January 2, 2018 .
  26. Improve security. Retrieved January 2, 2018 .
  27. More space for passengers on the Munich S-Bahn. DB - press office - Munich, accessed on January 2, 2018 .
  28. milestones. Retrieved January 2, 2018 .
  29. Bahn wants to redesign Munich's S-Bahn. Süddeutsche Zeitung, July 6, 2017, accessed on July 7, 2017 .
  30. Jens Fleischmann and BahnInfo-Team: Modernization concept of the Munich ET 423 presented. In: bahninfo.de. Retrieved July 9, 2017 .
  31. Modernized 423 in use . In: railway magazine . No. 9 , 2018, ISSN  0342-1902 , p. 28 .
  32. Customer magazine of the S-Bahn Munich, edition 2/2004, page 3, ZDB -ID 2106694-2
  33. Customer magazine of the Munich S-Bahn, issue 6/2004, page 4, ZDB -ID 2106694-2
  34. New S-Bahn for line 3 . In: Frankfurter Rundschau from January 14, 2010.
  35. Markus Heffner: Bumpy start into the new S-Bahn era . In: Stuttgarter Zeitung . July 2, 2013, p. 21 .
  36. A second life for the 423 series . In: DB Welt , regional section southwest . No. 11 , November 2016, p. 18 .
  37. Clear vote for the ETCS pilot project and more S-Bahn vehicles. In: vrs.de. Verband Region Stuttgart, January 23, 2019, accessed on January 23, 2019 .
  38. Germany-Frankfurt am Main: Railway and tram locomotives and rolling stock and associated parts. In: ted.europa.eu. July 14, 2020, accessed July 14, 2020 .
  39. Hagen Ssykor: project description. (PDF) Award unit: Equipment planning booklet for multiple units of the Stuttgart S-Bahn (series 423 and 430) with ETCS and ATO GoA 2 for “first-in-class” and series. DB Regio, July 9, 2020, pp. 3, 6 , accessed on July 14, 2020 (file 20FEF46179 project description ETCS ATO SBS.pdf in ZIP archive).
  40. German Bundestag (ed.): Answer of the federal government to the small question of the MPs Matthias Gastel, Stefan Gelbhaar, Stephan Kühn (Dresden), other MPs and the parliamentary group Alliance 90 / THE GREENS . -Bahns in Germany - optimize door control. tape 19 , no. 10451 , May 24, 2019, ISSN  0722-8333 , p. 4 ( BT-Drs. 19/10451 ).
  41. s-bahn-berlin.de (PDF; page 9)