The Bunker was designed to operate when cut off from outside help. If one of the teletype machines—and there were a lot of teletype machines in the Bunker—went down, it had to be repaired on site.

Teletype machines were the workhorses of government communications from the 1950s until the wide-spread use of fax machines and computers in the mid-1990s. Teletype machines look like large typewriters, but they are actually secure communication devices.

Here’s how it works: a military clerk types in a message on the machine at the Bunker. Then they send it via a designated cable to another machine elsewhere—perhaps at a departmental office or military base across the country, or around the world. The teletype machine there prints out the message.

Many office workers from the era remember the familiar sound of busy teletype machines, chattering out reams of paper! Teletype operator Brenda Langman remembers the noise:

“… clacking, clack clack clack clack little machines that were spitting out ticker tape […] and it’s piling up on the ground. You’ve gotta stand in there with you know your military boots on and try not to tear any of it because if you are, you’re tearing a message in half, and God help you cause you can’t splice it back together.”