An important story

Dedicated to those who worked in Building 26, 1942-1946

The mission of this site is to tell the story of hundreds of people who worked at the United States Naval Computing Machine Laboratory, a top secret project in Dayton during World War Two. These people kept their secret for over fifty years. They produced machines which were crucial to the war effort and helped to save the lives of tens of thousands of troops, on land and sea, around the world.

Please take a look–there are hundreds of pages of declassified documents, rosters of personnel, photographs and more. (An easy way to check this out is to visit the Sitemap page.) I have added a new bibliography page brought up to date to include burgeoning information about cryptography on the web.

This site originates with and is maintained by Debbie Anderson in Dayton, Ohio. My father was Joseph Desch, Research Director for the NCML. This site is an outgrowth of my own efforts to learn more about the story behind my father’s secret work and a desire to share what I have learned. It also is a resource for the facts behind the documentary Dayton Codebreakers.

I am grateful to the Archive Center at Dayton History, the Wenger Command Display in Pensacola, Florida, friends at the NSA Center for Cryptologic History and the National Cryptologic Museum, and the many veterans–WAVES and sailors– who have been so generous over the years for a share of the photographs presented here.

Thanks for learning about a part of Dayton’s, and the nation’s, history.

Launched 2001


The National Cryptologic Museum has been increasing its presence on the web by offering new ways to appreciate cryptology. First, puzzles and intriguing factoids are posted several times a week at their Facebook page, National Cryptologic Museum. Join in the fun and get a workout for your brain. Second, the Cryptologic Foundation has launched a podcast channel for “cyber fanatics”, ages 11-18 (but, I think, fun for all). At their web page, #CyberChats you can also submit questions and find further challenges. I’m not too old to listen.

February 9, 2023

Once in a while code breaking appears in the news. Recently I found an intriguing story.Lost Letters by Mary, Queen of Scots, Uncovered by Amateur Code Breakers It can be found at the BBC Mary Queen of Scots: Secret letters written during imprisonment decoded

A different author analyzed the steganography of another crafty member of the Tudors, Catherine of Aragon. I discovered it in the New York Times, but I also found the article at the Smithsonian Magazine, The Secrets of a Long-Overlooked Cipher Linked to Catherine of Aragon. These stories also give insight in the methodology of code breaking.


A popular page on my site, The US Navy Cryptanalytic Bombe, now with new photos and a link to a bombe simulator.

Excellent update of a page at Virmuze [network of Virtual Museums] about the US Bombe with information about some components.

Watch a YouTube video about the US Navy Cryptanalytic Bombe from the Nat’l Crypto Museum

My favorite page: The incredible amount of production at the US NCML reflected in the By the Numbers page.

Redone page of Cryptanalytic Equipment in operation at Nebraska Avenue, linked to full-size photos

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  • Sources

    This site has material from many sources. Some are use by permission. Before using, ASK. More specific information here.
  • Dayton Codebreakers DVDs

    To inquire about a DVD of the Dayton Codebreakers documentary, contact me at this link
  • Inside You’ll Find…

    WHO worked during the war? Find the Personnel section. Also, Joseph R. Desch
    WHAT were their goals? By the Numbers. Also, The US Bombe
    WHY? History of the Bombe Project A contemporary account of the reasons and the plans for their project for the Director of Naval Communications, 1944.
    WHERE was the project: In Dayton, it was in Building 26. In Washington, it was housed at the Naval Communications Annex