Life before email: A look back at the 'vacuum post'

Shown here are the high-pressure pipes that drive the vacuum post. A build-up of pressure is needed to send message containers through the system.

The obvious gap between the pipes, shown in the image above, marks the consequences of World War II. In the Cold War period, when Germany was split in two, so was the vacuum post. The service continued with the post heading off to the different parts of divided Berlin. According to our guide for the day, making an obvious gap between the East and West Berlin tubes helped reduce mistakes.