Traffic tower at Potsdamer Platz

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The traffic tower at the end of November 1924 shortly before completion

The traffic tower at Potsdamer Platz in Berlin was the first traffic light in Germany . The five-sided tower was in operation from December 15, 1924 and regulated the traffic on Potsdamer Platz , at the time the busiest square in Europe.

As a new Berlin attraction, the traffic storm was depicted on many contemporary pictures and postcards and quickly became a symbol of modern Berlin in the second half of the 1920s. In the course of work on the underground Potsdamer Platz S-Bahn station , it was dismantled at the beginning of October 1937 and replaced by a hanging traffic light.

Architecture and function

description

The tower on Potsdamer Platz was 8 1 ⁄ 2   meters high, had a diameter of 2 1 ⁄ 2   meters and weighed 5 1 ⁄ 2   tons. It consisted of five steel pillars and a five-sided, roofed pulpit, in which a traffic policeman in the standing posture customary at the time observed the flow of traffic and controlled the light signals with a three-stage lever switch. The tower stood on a concrete foundation with a basement, in which the various power, signal and control lines converged and were led to the tower pulpit. Stirrups and a vertical handle bar were attached to one of the steel pillars. The officer was able to reach his workplace through a flap in the floor of the pulpit. On each of the five outer sides there was a large clock at the bottom, a viewing window in the middle and three adjacent light signals in the colors green, yellow (initially white) and red, which were provided with shields to avoid glare. Blue lights were mounted at the corners of the pulpit at the level of the light signals. In addition to the lever switch for the light signals, the pulpit was equipped with a normal clock , a second clock ( stopwatch ) and a mouthpiece for those standing at the foot of the tower. Telephone connections to the Alexanderplatz police headquarters and the fire brigade as well as fire extinguishers and heating completed the equipment.

Function and use

The traffic tower was supposed to revolutionize urban traffic regulation. Due to the excessive volume of traffic in the city center, there were not only seemingly endless traffic jams, but also more and more traffic and pedestrian accidents. The traffic tower was supposed to relieve the road police of the work and make it easier. It also served as a timer and signal and alarm tower (especially in the event of traffic accidents). The tower was initially only occupied on weekdays from 8:30 a.m. to 12:00 p.m. and from 3:00 p.m. to 6:00 p.m. In a report from September 1925 it is stated that the traffic tower with its equipment has proven itself well and that there is a plan to erect traffic towers at other important traffic junctions in Berlin.

history

prehistory

In the early 1920s, private and commercial car traffic increased steadily in the major cities of the German Empire . After the formation of Greater Berlin in October 1920, the city had over 3.9 million inhabitants in the following year . The number of motor vehicles on July 1, 1921 was 12,000. This number rose to 30,000 vehicles by 1924, and three years later it doubled to 60,000 vehicles in the summer of 1927.

26 trams and five bus routes ran across Potsdamer Platz . 20,000 cars crossed the square every day and around 83,000 travelers were counted at Potsdam train station . In addition, there was heavy traffic in horse-drawn carts in the 1920s . This considerable traffic load on Potsdamer Platz led to constant irregularities and delays in the regular service, at the same time the Berlin police criticized the high personnel requirements for traffic control and the increasing endangerment of their officers, who had been repeatedly run over or hit.

The particularly tense situation at Potsdamer Platz was also due to the lack of parallel streets : the Französische Straße had not been continued through the Ministergärten to Tiergartenstraße and it was also not possible to extend Kochstraße and Anhalter Straße to the west. This led to the congestion of Leipziger Straße and the bottleneck Potsdamer Platz, which were also blocked by the tram.

Together with the head of the traffic police , government director Wilhelm Mosle , other Berlin traffic experts traveled to other large cities, including New York , London and Paris , in order to look for suitable solutions to improve traffic flow and traffic safety. One approach was to regulate road traffic by means of traffic lights, as they were known from the railways and elevated and underground railways . In New York in 1917 there was a brief attempt with the first traffic light system. In 1920, quite provisional-looking traffic towers with metal scaffolding and wooden pulpit were erected there along Fifth Avenue . Only two years later, Joseph H. Freedlander designed a traffic signal tower , elaborately designed with cast bronze plates , of which seven copies were installed on Fifth Avenue in December 1922.

The unambiguous regulation sought required a clear management of the traffic flows, in which pedestrians should only cross the lanes via defined and marked crossings. In the summer of 1924 an attempt was made - with police officers on a provisionally erected wooden platform - to regulate road and pedestrian traffic on Potsdamer Platz by means of horn signals. Pedestrian traffic was also channeled with boards attached to trees. These attempts were astonished by the daily press. Finally, the tram tracks in both directions were moved to the east side of the two large arc lamp candelabra and five traffic islands were created.

View from below of the pulpit, August 1925

As a legal basis, specifications for traffic regulations also had to be developed. On October 28, 1924, the interim status of a police ordinance for the reorganization of Berlin traffic was published in the Vossische Zeitung . Among other things, it introduced first and second order roads , on which parking was no longer permitted during the day. In addition, the colors and the meaning of light signals (initially red - white - green) were defined. The new traffic regulations were initially heavily criticized, especially by trade and industry. The drafting of the traffic ordinance occupied the interest groups for many years until the present and was regularly discussed in the daily newspapers. In June 1928, for example, groups of cyclists from the working class turned against the proposed ban on cycling in the first-rate streets and called for a rally at which the creation of cycle paths should also be demanded. After years of intense negotiation, Berlin's new traffic regulations , the police regulations governing traffic and maintaining order in the streets of Berlin (road regulations) came into force on January 23, 1929, repealing around 200 older police regulations.

Construction, design and operation of the traffic tower

The building application for the traffic tower was submitted on August 25, 1924 by the Berliner Straßenbahn-Betriebs-GmbH to the building police of the city of Berlin, Tiergarten district office . The design came from Jean Krämer , who also took over the construction management . The construction work was awarded to the iron construction and art forge factory Eduard Puls GmbH in Berlin-Tempelhof . Siemens & Halske supplied the electrical and signaling equipment . The steel components of the traffic tower were erected on the night of October 20-21, 1924, for which traffic was completely blocked on and around Potsdamer Platz. The tower then stood on the square for around eight weeks without any function and received critical comments. An article in the Österreichische Illustrierte Zeitung from November 9, 1924 shows the Berlin traffic tower still in its shell with scaffolding. At the end of November 1924 the traffic tower was about to be completed; a picture shows the wooden formwork for the pentagonal concrete base that has not yet been removed. The static calculation submitted with the application by the civil engineering office G. Mensch was initially not accepted by the building police and had to be supplemented with a supplement dated December 8, 1924. On December 14, 1924, the Berliner Tageblatt reported that the traffic tower on Potsdamer Platz had been in place for a number of weeks, but none of the parties involved had yet to say when it would be operational. Only one day later, on December 15, 1924, the municipal building police finally approved the building. The then 39-year-old Friedrich Lange was the first police officer to climb the ladder to the tower pulpit and put the traffic tower into operation, as the picture by Robert Sennecke in the Vossische Zeitung documents.

The Berlin traffic tower was thus completed before the first traffic lights in Hamburg at the intersection of Mönckebergstrasse and Glockengießerwall , for which commissioning is specified on November 14, 1925. The first traffic light system in Germany, now known as traffic lights , was put into operation at Potsdamer Platz in Berlin .

Potsdamer Platz in April 1927. Over the ABOAG - double-decker is the dome of the house Potsdam (later Haus Vaterland to see). Left the Hotel Fürstenhof . In the background between the arc lamp candelabra and the traffic tower is the reception building of the Potsdam train station

New territory was also broken with the clocks of the traffic storm. The clocking of clocks from a central clock system based on the Siemens & Halske system , which had already been introduced at the Reichsbahn and the Berliner Hochbahngesellschaft , was now extended to squares and streets for the first time and the five outer clocks and the tower's internal clock were connected to it.

The tower stood on a traffic island in the middle of the spacious square, from the Budapester Strasse - Königgrätzer Strasse (today: Ebertstrasse - Stresemannstrasse ) running in north-south direction and the Leipziger Strasse - Potsdamer street running in east-west direction Road was crossed. Busy tram tracks ran in close succession in both streets; there were also connecting curves between the tram routes. In addition, Bellevuestrasse flowed into Potsdamer Platz from the northwest .

The traffic tower was in operation for around 13 years, even after construction work began on the underground Potsdamer Platz S-Bahn station in 1935. It was not removed until the night of October 1st, 1937 and replaced by a five-sided hanging traffic light that was attached to taut wire ropes hung in the middle of the square. After completion of the S-Bahn station, the traffic area was restored without the central island. In the tram tracks were direct only from Potsdam in the Leipziger Strasse and the Hermann Goering -Straße in the Saarland road (now Ebert and Stresemannstrasse) built; the two connecting track curves were omitted.

After the Second World War

October 1945: View over Potsdamer Platz (without central island and traffic tower) into Potsdamer Straße . On the left the former Pschorr house . The ruin was demolished in 1952.

After the end of the war , Potsdamer Platz in divided Berlin formed a " triangle " between the British and American sectors on the west side and the Soviet sector on the east side. Almost all of its peripheral buildings were badly damaged and the black market dominated the streets . There was no longer any need for a new traffic light or even a new traffic tower, as there was no longer any noteworthy tram or car traffic flowing across the square. In January 1953, continuous tram traffic at the sector border was even interrupted, and passengers had to cross the border on foot. With the uprising of June 17, 1953 , the Columbushaus and the Fatherland house finally burned out. Much of the building remains was removed in the 1950s and the land was leveled. With the construction of the Berlin Wall on August 13, 1961, Potsdamer Platz remained completely impassable to traffic for 28 years and developed into a wasteland in the city center .

Since both the grounds of the disused Potsdamer Bahnhof and Stresemannstrasse belonged to East Berlin , road traffic from Kreuzberg to Tiergarten could no longer run via Potsdamer Platz, but had to be rerouted via the streets on the Landwehr Canal. It was only with the area swap in June 1972 that a new road connection could be established as an extension of Bernburger Strasse over the site of Potsdamer Bahnhof, which was led over the (old route ) of Linkstrasse and thus a few meters west of Potsdamer Platz to the relief road .

Traffic towers with integrated light signals were no longer built in the 1950s and 1960s. However, traffic pulpits were built at particularly important intersections . Berlin examples of this are the traffic pulpit at the intersection of Kurfürstendamm at the corner of Joachimsthaler Strasse , the traffic pulpit at the Frankfurter Tor and the traffic pulpit at the intersection of Unter den Linden and Friedrichstrasse. These traffic pulpits had a pure control and observation function; the associated light signals were set up on their own masts directly at the crossroads. The traffic pulpits were soon only manned by personnel in special traffic situations so that the traffic lights could be controlled manually.

The reconstruction of the traffic tower built in 1997 , March 2005

After the political change and the subsequent reunification of Berlin , a new city quarter was designed on Potsdamer Platz and built after controversial discussions. The old route of Potsdamer Straße was interrupted in 1967 by the construction of the new state library . As a replacement, in a straight extension of Leipziger Strasse across Potsdamer Platz and through the former Josty Corner , a wider new route was created, which leads through the Kulturforum planned by Hans Scharoun with the New National Gallery , St. Matthew's Church , Philharmonic Hall and State Library . The rest of the way today runs as Alte Potsdamer Strasse to Marlene-Dietrich-Platz .

The large intersection with the Ebertstrasse - Stresemannstrasse street was equipped with a conventional set of traffic lights. As a reminiscence of the historic traffic tower of 1924, the companies Siemens and Daimler-Benz had a reconstruction made in original size in 1997 , which was initially set up in September 1997 in front of the red info box on Leipziger Platz without any function. On this occasion, the brochure A landmark returns with a greeting from the Governing Mayor of Berlin , Eberhard Diepgen , was published (see section Reception ). After completion of the Kollhoff Tower and the square in front of it, the replica was moved to its final location in September 2000 in front of the southern entrance hall of the new regional train station Potsdamer Platz . The traffic tower shows changing light signals again, but no longer controls the traffic flow.

The reconstruction was significantly damaged in the night of October 29, 2010 by a booth that caught fire for the Winterwelt Christmas market . But it could be repaired until September 2011 and then returned to the public.

In June 2018, a memorial plaque for the architect Jean Krämer was attached to the replica of the traffic tower.

Functionality and role model

Even then, the light signals of the Berlin traffic storm had largely the same meaning as those of today's traffic lights. The two opposite arms of the two main road trains were given green at the same time, the crossing arms red. Left and right turners had to pay attention to the traffic flows of the tram routes in the middle of the street as well as to oncoming traffic and pedestrian traffic and give them priority. A phase was then interposed to clear the intersection area before the crossing traffic got green. This clearing phase was signaled in white when the traffic tower went into operation in December 1924. In the course of 1925, the clearing phase was switched to yellow. The change between the phases was announced on the traffic tower by briefly lighting up the five blue corner lights.

Bellevuestrasse, the fifth arm of the intersection at Potsdamer Platz, could usually not be controlled by the light signals from the traffic tower, because this would have required additional clearing phases and would have meant a significant reduction in throughput capacity. Therefore, there was a ban on entering the square and it was displayed in permanent red. The traffic could only flow from the square into Bellevuestrasse.

The light signals of the traffic tower at Potsdamer Platz were initially controlled manually when the system went into operation in December 1924.

Police Exhibition Berlin September 1926: Model of an armored car, behind it a miniature model of the traffic tower on Potsdamer Platz

The traffic tower designed by Heinrich Kosina for Berlin's Alexanderplatz in 1925 , which should still have signal lights and which is based very much on the American model of Joseph H. Freedlander in its design and proportions, was not installed there.

According to a newspaper report in Vorwärts of September 25, 1926, the original of the tower planned for Alexanderplatz was displayed in the second hall of the Berlin Police Exhibition in 1926 . There was also an American traffic tower that the New York police gave to the Berlin police. This exhibition also featured the police's own training model for the traffic tower at Potsdamer Platz.

In June 1925, a model of a new type of traffic tower was presented for the Friedrich- corner Leipziger Strasse intersection, with which the light signals at the neighboring intersections should also be controlled manually. The architecture office "Bau undeinrichtung" ( Paul Mahlberg , Heinrich Kosina) designed it together with Ludwig Mies van der Rohe , the company Paul Marcus "Eisenkonstruktion und Bronzebau" built the model. This traffic tower was supposed to consist only of an observation and control pulpit mounted on a cantilever arm , but no longer received any signal lights and thus corresponded to the traffic pulpits that were later named so . The signal lights should be attached directly to the streets on their own masts. This traffic tower was not realized, but in 1925 and 1926 additional traffic lights were added at heavily used intersections. On November 23, 1925, three more traffic lights were put into operation on Leipziger Strasse: at the intersections with Wilhelmstrasse , Mauerstrasse and Friedrichstrasse.

On October 1, 1926, during the Berlin police exhibition, a central control of the signal systems in Leipziger Strasse and Friedrichstrasse was put into operation from the police headquarters, which initially led to a fiasco because the green phases were not coordinated. In 1926, the traffic lights along a street, such as Leipziger Strasse, were coordinated, i.e. switched in the sense of a green wave . If necessary, individual traffic lights could be switched to manual operation. After a few attempts, a progression speed of the green wave of 18 km / h was established.

reception

The traffic tower on Potsdamer Platz is a symbol of modern Berlin in the late 1920s and early 1930s and was depicted in numerous photographs and postcards.

In the film adaptation of Erich Kästner's novel Emil and the Detectives from 1931, the intoxicated main actor Emil Tischbein hovers around the traffic storm on an umbrella after he has accepted a prepared candy from the fraudster Grundis. In the center of a game released by UFA in 1931 to promote this film, it was not the Brandenburg Gate but the traffic tower on Potsdamer Platz that was depicted.

Documentary films from the 1920s, for example City of Millions by Adolf Sportwetten from 1925 and the traffic education film Im Strudel des Verkehrs by Leo Peukert , also from 1925, contain scenes with the traffic tower at Potsdamer Platz. The advertising sheet for the feature film Das Veilchen vom Potsdamer Platz from 1936 also revolves around the traffic tower, although it was only drawn here with four pages.

In 1925, the Berlin police owned a two-meter high functional model of the traffic tower, which was used to train the traffic police , but was lost in World War II . On the occasion of the 750th anniversary of the city of Berlin in 1987, apprentices from Siemens built a slightly smaller model of the traffic tower and gave it to the then newly founded police museum. This model of the traffic tower was borrowed to celebrate the groundbreaking of the new city quarter at Potsdamer Platz, but it was stolen from an exhibition tent on the night of October 11th to 12th, 1993. Another model was recreated in the Siemens apprentice workshop and handed over to the Berlin Police History Collection on November 22, 1994 . This model is now at the entrance to the museum in the service building at Platz der Luftbrücke .

The impressionist painter Lesser Ury created a pastel from the traffic tower around 1925 , which is now in the holdings of the Berlin National Gallery .

Pentagonal traffic tower as a contemporary wooden miniature from the Ore Mountains

In October 1926, the designer Edmund Rumpler described in his future vision Tomorrow we all fly in the Uhu magazine that the old traffic tower at Potsdamer Platz would no longer be needed in 1950 because traffic would then only move through the air.

In June 1933, Hermann Abeking caricatured the increasing need for traffic regulation in Scherl's Magazin and presented a new pioneering invention with the traffic storm in the forest .

The toy manufacturer Carl Heinrich Frohs & Sons from Seiffen in the Ore Mountains took up the topic in the 1920s and 1930s and made ten centimeter high wooden miniatures of the traffic tower. The Brandenburg tin toy manufacturer Lehmann Patentwerke also produced a money box in which a coin was inserted and the traffic police officer raised the flag.

On the occasion of the handover of the replica of the traffic tower in September 1997, the then Governing Mayor of Berlin , Eberhard Diepgen , paid tribute to the traffic tower "as a landmark of Potsdamer Platz" and "the new modern Berlin" of the 1920s. In the following description of its history it is emphasized that the traffic tower, based on the New York model, quickly advanced to "the most photographed building in the city center" and symbolized the characteristics of the then imperial capital "as a city of restless work, constant modernization and practiced cosmopolitanism". Even if the tower was only used for traffic observation from 1926, it retained “its magical cosmopolitan aura until it was dismantled. […] In an environment in which the Nazi regime "after the end of the Summer Olympics in 1936 " set about destroying the last vestiges of cosmopolitan openness, the tower was literally out of place as a symbol of the urban flair of modernity ".

In his 2012 Berlin novel The Fatherland Files , Volker Kutscher stages the insidious murder of a traffic policeman in the pulpit of the traffic tower.

The traffic storm and the new traffic regulations to be introduced with it were also the subject of contemporary authors who, like Joseph Roth in the Frankfurter Zeitung of November 15, 1924, made their own critical thoughts about such innovations and their sometimes longer implementation in Berlin. Ignaz Wrobel ( pseudonym of Kurt Tucholsky ) made particularly drastic tones about the new traffic regulations on November 9, 1926 on the Weltbühne :

“It is downright ridiculous what is currently being set up in this city to organize the traffic, to record it statistically, to describe, to regulate, to derive, to route. Is it too big? No."

- Ignaz Wrobel : Berlin Transport II

literature

Web links

Commons : Verkehrsturm am Potsdamer Platz  - collection of pictures, videos and audio files

References and comments

  1. ↑ a b Note: Despite intensive research and questioning of the Hamburg Police Museum, no contemporary evidence could be found for a system at Hamburg 's Stephansplatz that was put into operation as the first traffic light in the German Reich in 1922 and is occasionally mentioned. See also: November 14, 1925: Hamburg's first traffic light goes into operation. In: Hamburger Morgenpost , February 8, 2016, accessed on May 21, 2019.
  2. ↑ a b Berlin in historical recordings The traffic light tower from Potsdamer Platz In: Berliner Zeitung , April 12, 2018, accessed on June 9, 2019.
  3. ^ A b c Karl August Tramm, chief engineer: Traffic storms . (PDF) In employee magazine Berliner Straßenbahn , 22nd year, issue 18, 4th September 1925, Berliner Straßenbahn-Betriebs-GmbH , Berlin, p. 2 ff, accessed on 13 July 2019.
  4. ↑ a b Dr. H .: Berlin traffic regulation . In: Städtebau , Edition XIII, year 1928, Verlag Ernst Wasmuth AG , Berlin, p. 192 ff, accessed on July 13, 2019.
  5. ↑ Walther Kiaulehn: Berlin - fate of a cosmopolitan city . Biederstein Verlag, C. H. Beck, Munich 1980, ISBN 3-406-06454-X , p. 22 .
  6. ^ A History of New York Traffic Lights In: The New York Times , May 16, 2014, accessed June 9, 2019.
  7. ↑ History of Traffic - Traffic Signal Tower designed by Joseph H. Freedlander, 1922 , accessed on June 9, 2019.
  8. ^ October 13, 1921: Automobile traffic in America. (With report on the "traffic regulations in fifth avenue") In: Vorwärts , supplement 'Heimwelt', October 13, 1921, p. 4, accessed on June 9, 2019.
  9. ↑ August 16, 1924: Traffic Regulations in America. In: Vorwärts , August 16, 1924, morning edition No. 384, p. 6, accessed on August 25, 2019.
  10. ↑ Potsdamer Platz as a metaphor for Berlin. The depiction of Potsdamer Platz in features texts of the 20s, 30s and 90s with a quote from Fred Hildenbrandt : Circus Potsdamer Platz. In: Berliner Tageblatt , August 8, 1924. From: Christian Jäger, Erhard Schütz (Hrsg.): Shiny Asphalt: Berlin in the feuilleton of the Weimar Republic. Fannei & Walz, Berlin 1994, pp. 124–125, accessed on August 26, 2019.
  11. ↑ August 9, 1924: Auf der Kommandobrücke In: Vorwärts , August 9, 1924, morning edition No. 372, p. 5 f., Accessed on August 24, 2019.
  12. ↑ August 17, 1924: The traffic regulation on Potsdamer Platz. In: Vorwärts , August 17, 1924, Sunday edition No. 386, p. 6, accessed on August 25, 2019.
  13. ↑ August 21, 1924: Order on Potsdamer Platz. (With picture of the planned traffic storm and picture of the new traffic islands to be created) In: Vorwärts , August 21, 1924, morning edition No. 392, p. 5, accessed on August 25, 2019.
  14. ↑ October 28, 1924: The new regulation of traffic, signals and signs . In: Vossische Zeitung , October 28, 1924, evening edition, p. 4, accessed on May 30, 2019.
  15. ↑ November 4, 1924: Away with the traffic regulations, trade and industry unanimously against it. In: Vossische Zeitung , November 4, 1924, evening edition, p. 5, accessed on May 30, 2019.
  16. ↑ June 1, 1928: Berlin cyclists against driving bans. In: Der Abend - Spätausgabe des Vorwärts , June 1, 1928, evening edition, p. 7, accessed on June 8, 2019.
  17. ↑ 23 January 1929: Berlin's new traffic regulations - come into force today. In: Vorwärts , January 23, 1929, morning edition, p. 6, accessed on June 9, 2019.
  18. ↑ File inspection in the Landesarchiv Berlin , File B Rep. 202/5154, sheet 1 of August 25, 1924.
  19. ↑ a b The traffic tower in Berlin. In: Die Umschau , Ed. J. H. Bechhold , Frankfurt, 28th year, issue 51, December 20, 1924, p. 986 f.
  20. ↑ October 20, 1924: Start of traffic regulation? and (listing of the traffic storm in the coming night) In: Vossische Zeitung , October 20, 1924, evening edition, p. 4, accessed on June 2, 2019.
  21. ↑ a b November 15, 1924: Consideration about traffic. In: Frankfurter Zeitung , November 15, 1924, printed in Joseph Roths Werke 2, Das Journalistische Werk 1924–1928, Verlag Kiepenheuer & Witsch , Cologne and Allert de Lange , Amsterdam 1989, ISBN 3-7632-2988-4 , accessed on May 8th June 2019.
  22. ↑ November 9, 1924: Pictures of Time - The first traffic storm in Berlin In: Österreichische Illustrierte Zeitung , November 9, 1924, p. 14, accessed on June 22, 2019.
  23. ↑ End of November 1924, image 102-00843 . Federal Archives, no author given (the traffic tower is already largely completed, the wooden formwork for the pentagonal concrete base has not yet been removed).
  24. ↑ Inspection of files in the Berlin State Archives , File B Rep. 202/5154, Sheet 10 and Sheet 15 of August 23 and December 8, 1924.
  25. ↑ December 14, 1924: A "Transport Parliament" for Berlin (traffic tower not yet in operation) In: Berliner Tageblatt , December 14, 1924, morning edition, p. 52, accessed on June 9, 2019.
  26. ↑ December 15, 1924: The traffic tower is ready. In: Vorwärts , December 15, 1924, evening edition, p. 3, accessed on June 3, 2019.
  27. ↑ December 15, 1924: Approval of the traffic tower by the municipal building police, the first officer climbs the tower (Photo: Robert Sennecke) . In: Vossische Zeitung , January 3, 1925, foreign edition, p. 1, accessed on May 21, 2019.
  28. ↑ My father - the first tower policeman from Potsdamer Platz . In: BZ , May 14, 1990.
  29. ↑ December 9, 1924: Berlin standard time? In: Vorwärts , December 9, 1924, morning edition, p. 6, accessed on June 3, 2019.
  30. ^ Michael Braun: North-South S-Bahn Berlin . GVE, Berlin 2008, ISBN 978-3-89218-112-5 , pp. 107 .
  31. ↑ Evaluation of historical postcards and photographs from 1938–1940.
  32. ↑ Pschorr-Haus (formerly: Bierhaus Siechen) on potsdamer-platz.org
  33. ↑ a b A landmark returns. Brochure for the installation of the replica of the traffic tower in September 1997. Ed .: Siemens AG and Daimler-Benz AG, Berlin, 1997.
  34. ↑ Inscription on the donor plaque. “Traffic tower from Potsdamer Platz from 1924. Replica of the first traffic light system in Germany donated by the city of Berlin by Daimler-Benz AG and Siemens AG. Installation at Leipziger Platz, Berlin, September 26, 1997. Installation at Potsdamer Platz, Berlin, September 29, 2000. "
  35. ↑ Traffic lights without red, yellow, green . In: taz , July 15, 1997, accessed on May 21, 2019.
  36. ↑ Historic traffic lights damaged by fire . In: Der Tagesspiegel , September 29, 2010, accessed on May 21, 2019.
  37. ↑ The historic traffic tower at Potsdamer Platz is flashing again. Press release of the district office in the center of Berlin from August 24, 2011, accessed on May 21, 2019.
  38. ^ Jean Krämer memorial plaque unveiled. Press release No. 8445 of the Reinickendorf District Office of Berlin from June 29, 2018, accessed on May 21, 2019.
  39. ↑ Memorial plaque on the traffic tower. In: Berliner Woche , July 10, 2018, accessed on May 21, 2019.
  40. ↑ Karl August Tramm, Senior Engineer: From the signpost to the modern traffic tower with a diagram of the light signal phases of the traffic tower. In: Das neue Universum , Union Deutsche Verlagsgesellschaft, Stuttgart / Berlin / Leipzig, Volume 47, 1926, pp. 106 ff
  41. ↑ Traffic tower on Alexanderplatz? In: Berliner Polizeihistoriker , No. 58, May 2017, accessed on August 27, 2019.
  42. ↑ September 25, 1926: Under the Police Star - Opening on Kaiserdamm - A tour of the halls. In: Vorwärts , September 25, 1926, evening edition No. 453, p. 3, accessed on August 28, 2019.
  43. ↑ June 4, 1925: A new traffic tower - corner of Friedrichstrasse and Leipziger Strasse. In: Vorwärts , June 4, 1925, morning edition, p. 6, accessed on June 3, 2019.
  44. ↑ June 27, 1925: The planned traffic tower in Berlin, corner of Leipzigerstrasse and Friedrichstrasse. by Dr.-Ing. Alfred Wedemeyer (PDF). In: Deutsche Bauzeitung , June 27, 1925, No. 51, p. 99 ff., 3 illustrations, accessed on January 26, 2020.
  45. ↑ November 23, 1925: The light signals in Leipziger Strasse . In: Vossische Zeitung , November 20, 1925, No. 549 morning edition, p. 13, accessed on June 3, 2019.
  46. ↑ October 1, 1926: The fiasco of the traffic lights . In: Vossische Zeitung , October 2, 1926, No. 466 morning edition, p. 5, accessed on June 2, 2019.
  47. ↑ October 1, 1926: The impossible traffic lights - new regulation already today . In: Vossische Zeitung , October 2, 1926, No. 467 evening edition, p. 6, accessed on June 2, 2019.
  48. ^ Michael Bienert : Kästners Berlin. Literary settings . Verlag für Berlin-Brandenburg, Berlin 2015, ISBN 978-3-945256-00-8 , pp. 60 .
  49. ↑ Advertising sheet for the feature film Das Veilchen vom Potsdamer Platz by Lothar Stark , premiered on November 16, 1936.
  50. ↑ Access to files in the Berlin Police History Collection , Verkehrsturm file, on May 28, 2019
  51. ↑ October 1926: Edmund Rumpler - Tomorrow we will all fly . In: Uhu , Vol. 3, Issue 1, October 1926, pp. 36–43, accessed on June 23, 2019.
  52. ↑ June 1933: Hermann Abeking - The traffic tower in the forest - a new groundbreaking invention . In: Scherl's Magazin , Volume 9, Issue 6, June 1933, p. 328, accessed on June 24, 2019.
  53. ^ Walter Neumann: Seiffener miniature toys . Saxon State Office for Folk Culture, Schneeberg / Erzgebirge 1999, ISBN 3-931770-19-2 , p. 70 .
  54. ↑ A copy of the miniature tower is in the collection of the Stadtmuseum Berlin : photos and detailed description. From: sammlung-online.stadtmuseum.de , accessed on August 24, 2019
  55. ↑ Around 1925 until after 1933: Lehmann Verkehrsturm money box BEROLINA # 761 . From: historytoy.com , accessed July 8, 2019.
  56. ↑ Volker Kutscher: The Fatherland Files - Gereon Rath's fourth case . Kiepenheuer & Witsch, Cologne 2012, ISBN 978-3-462-04466-9 , pp. 297 ff .
  57. ^ November 9, 1926: Kurt Tucholsky - Berliner Verkehr II . In: Die Weltbühne , November 2, 1926, vol. 22, no. 45, pp. 739–741 ( Wikisource ).

Coordinates: 52 ° 30 ′ 34 ″  N , 13 ° 22 ′ 36 ″  E