Zach Copley

I thought I’d do a little post for Ada Lovelace Day. But rather than just point to a single “tech heroine,” instead I have a World War II-era technology story I find interesting, which involves a whole bunch of women. A technological Rosie the Riveter story.

One of the lesser-known stories of World War II is the American role in cracking the notorious “Enigma” machine’s encryption codes. The Enigma encryption system was used by the Germans to coordinate submarine attacks against the the Allies to devastating effect.

Probably even fewer know the bulk of the work building and running the decryption machines and much of the cryptoanalysis was accomplished by women.

The credit for cracking the Enigma codes almost always goes entirely to the British “Ultra” program and Bletchley Park. The Brits cracked the Enigma using a gigantic electromechanical decryption machine known as a “bombe.” However, in 1942, the Germans found out and improved the design of the Enigma by adding a fourth rotor. The newer Enigma machine rendered the British decryption machines practically useless.

Enter the United States, which ramped up its own parallel Enigma-breaking initiative in 1943. The program was created and run by the Navy in cooperation with The National Cash Register Company (NCR) of Dayton, Ohio. The site of the operation was Building 26 on the NCR campus. (Incidentally, I know about this story because my father worked for NCR in building 26 in the late 1970s — on things completely unrelated to the Enigma, or code breaking.)

Inside Building 26, six hundred Navy WAVES (Women Accepted for Volunteer Emergency Service) worked in shifts, 24-hours per day, to build approximately 120 newer, faster code-breaking “bombes” of an American design that could crack the new Enigma codes. WAVES had equal status with their male Navy counterparts, serving mostly stateside to free up Navy men for duty overseas.

The manufacturing of the American bombes involved the state-of-the-art electronics techniques of the time, which included complicated wiring, mechanical relays, vacuum tubes and motors. Each bombe was seven feet high, two feet wide, ten feet long and weighed 5000 pounds. WAVES also operated the machines and deciphered the messages transmitted by the U-boat captains, which helped the Allies out maneuver and terminate the U-boats. While all told there were several thousand people involved in the project, the WAVES did the bulk of the work involving the bombe machines. It has been estimated that World War II was shortened by one or more years due to the American bombes, and the contribution of the WAVES participating in the American Enigma-cracking program.

The project was one of the best kept secrets of the war, and remained secret until it was declassified, something the WAVES involved were very proud of. In fact, many passed away without ever revealing the secret.

I think it’s a cool story that highlights some of the tech contributions of women to the war effort. If you’re interested in learning more, here are some links to follow:

• Keeping the Secret: The Waves and NCR Dayton, Ohio 1943-1946 by Curt Dalton.
• Dayton Codebreakers
• The Secret in Building 26 By Jim DeBrosse, Colin Burke

UPDATE: My dad and I were talking about this earlier; as I said he’s the original source for the idea for this post. He got excited about it and wrote his own essay on the WAVES and the American bombe machines, which is an order of magnitude better written and more exciting than this blog post. I highly recommend that anyone interested in the story read his post as well.