from Artur Fürst, Das Weltreich der Technik (volume II), 1924.

"An example of the scale of supply lines that must be relaid when a rapid transit tunnel gets built underneath an important intersection. Sewer mains, Water mains, Gas mains, Pole-mains (telegraph cable, telephone cable, pneumatic tubes), High voltage cable for the electric works, Alarm mains for the fire department. After [Erich] Giese, Das zukünftige Schnellbahnnetz für Groß-Berlin [The Future Rapid Transit Network of Greater Berlin, 1919]."