Heuer Traffic Light at the Kortumstraße/Bongardstraße intersection

The name Heuer-Ampel goes back to the inventor Josef Heuer and the company Heuer-Hammer, a processing plant in Iserlohn-Grüne. Heuer traffic lights are a special form of traffic light systems that were used from the 1930s to the 1960s in the Netherlands and Austria (Vienna), but also in Germany (e.g. Dresden, Albertplatz, from the 1930s). They are roughly cube-shaped structures that hung over an intersection with wire ropes. They were mainly suitable for simple conditions, for example when two streets crossed at right angles.The internally illuminated traffic lights had a translucent disk for each direction of travel with opposite red and green circular segments. The traffic light phases were shown with a pointer driven by an electric motor that rotated slowly in a clockwise direction. The color to which the pointer pointed was valid. Since the pointers were linked on all sides (and thus had the same speed of rotation) it was almost impossible for signaling errors to occur. By manually interrupting the power supply, it was possible to stop the rotation during peak traffic times in order to achieve longer green phases for the main traffic direction.There was no yellow intermediate phase. The pointer position showed how long each phase lasted. However, indirectly there was a yellow phase, as the red sections were larger than the green for safety reasons. This resulted in a brief overlap of the red phases.The last Heuer traffic lights in Germany were up until 1972, after which the new traffic regulations no longer allowed traffic lights. The replica of a Heuer traffic light can be seen here in Bochum at a historical location above the intersection of Bongardstrasse / Kortumstrasse.Source: de.wikipedia.org/wiki/Ampel

A replica of a Heuer traffic light.Traffic lights with red and green circular segments and a pointer that signaled the respective red or green phase, attached to wire ropes above the middle of a street crossing.

"The Heuer traffic light above the 'turntable' intersection was a technical innovation at the beginning of the 20th century. Pointers indicated 'drive' or 'stop'."
waz.de/staedte/bochum/haenge-ampel-in-bochum-schrieb-verkehrsgeschichte-id216018043.htmllokalkompass.de/bochum/c-kultur/die-erste-ampel-in-bochum_a100579
de.wiktionary.org/wiki/Heuerampel
de.wikipedia.org/wiki/Datei:HeuerAmpel_Bochum.jpg