First Bombe Shipped to Nebraska Ave, September 1, 1943

September 1, 1943, the first Bombe was shipped to U.S. Navy’s Nebraska Avenue Building in Washington, DC.

A BOMBE was a large electro-mechanical machine used to recover the keys used by German ENIGMA cipher machines. This encryption machine was used by the German armed forces and other governmental agencies. The Navy BOMBES were used for key recoveries of German naval four rotor ENIGMA machines. Once key recoveries were made, it was possible to decipher German naval messages including those to and from U-Boats. This work was done in cooperation with the British cryptanalysis at Bletchley Park, England.

Physically, the BOMBES were about 6 or 7 feet tall, 10 feet wide, and 2 or 3 feet deep, weighed 5,000 pounds, and were mounted on large rollers. On their gray metal faces were two rows of black disks marked 00 to 25 around their circumference with a rotatable brass pointer. Below, there were four rows of eight wheels each. Women Accepted for Volunteer Emergency Service (WAVES) who operated the BOMBES were given a Top Secret (ULTRA) clearance. The cryptanalytic operations were highly compartmentalized and most BOMBE WAVES were not told exactly what they were doing; however, they soon were able to what their very important work was about.