1950s Boeing Wind Tunnel Beer Can Microphones, a History of Military and Civilian Developments
The Boeing supersonic wind tunnel, once used to test Cold War-era aircraft models at speeds of up to 3,000 mph, has been dismantled, uncovering a trove of 1950s beer cans used for temperature control in its steel air-compression spheres. These beer cans, used to absorb shocking cold & winds to prevent ice formation during supersonic tests, have been used as solid steel casings to become Darwin Audio microphones, and are among some of the rarest and most unique mics ever created.
Built in 1955 for projects like the Dyna-Soar spaceplane, the wind tunnel supported major Boeing initiatives in Seattle, Washington (Google Map of where these spheres were located) including the Supersonic Transport (SST) and the X-32B (Joint Strike Fighter). Critical to decades of testing, the tunnel's demolition in 2016 revealed pristine, lifetime-old beer and soda cans, which had not seen the sun in over 70 years.
Boeing Used Empty Beer Cans to Control Wind Tunnel Temperature
Imagine the cooling effect of compressed air escaping from a can as you clean your keyboard. Now scale that up to twin 38-foot spheres at Boeing's Seattle facility, where air was compressed and released at speeds of up to 3,000 mph.
To manage the intense frost caused by rapid air release, empty beer cans—most open at both ends—were used. These cans allowed airflow while their steel absorbed the freezing temperatures, preventing damage to critical machinery.
Photo of workers loading empty cans from railcars and into the spheres
View of the Recently Re-Discovered Cans
Photo of the wind tunnel spheres in the 2010s, still filled with thousands of empty beer cans
The Cans as Microphones
Since most of these cans had no top or bottom, a bottom plate for the 1/4 inch output jack has been added, and then a piezo disc based microphone component is used as the actual device.
Military and Civilian Aircraft Projects Developed in the Wind Tunnel
Boeing X-32B (Joint Strike Fighter)
Boeing AGM-86 (Air Launched Cruise Missile)
Boeing 2707 Supersonic Transport (Civilian)
Boeing X-20 Dyna-Soar (Military Spaceplane concept; view of scale model and artist rendering)
View of Live Testing
