> In its full glory, the pneumatic tubes covered a 27-mile route, connecting 23 post offices. Berlin once had a 400 km tube mail system [0], which was in servi

> In its full glory, the pneumatic tubes covered a 27-mile route, connecting 23 post offices. Berlin once had a 400 km tube mail system [0], which was in service from 1865 until 1976 (West Berlin) or 1986 (East Berlin). Before WWII, there were nearly 8 million items send via tube mail per year. Several hotels, large department stores or newspapers had their own private connection [1, 2, 3] [0] https://www.berliner-unterwelten.de/fileadmin/_processed_/2/9/csm_Untergrund_Netzwerke_Rohrpostnetz_Archiv_Berliner_Unterwelten_eV_web_54e3e00c1b.jpg https://www.berliner-unterwelten.de/fileadmin/_processed_/2/... [1] https://de.wikipedia.org/wiki/Rohrpost_in_Berlin https://de.wikipedia.org/wiki/Rohrpost_in_Berlin [2] https://en.wikipedia.org/wiki/Rohrpost_in_Berlin https://en.wikipedia.org/wiki/Rohrpost_in_Berlin [3] https://www.berliner-unterwelten.de/verein/forschungsthema-untergrund/netzwerke/die-berliner-stadtrohrpost.html https://www.berliner-unterwelten.de/verein/forschungsthema-u...