APL Colloquium

January 8, 2021

Colloquium Topic: The U.S. Navy's On-the-Roof Gang

The US Navy’s On-the-Roof Gang is a two-volume historical novel based on the unknown true-life story of the "On-The-Roof Gang," the U.S. Navy's fledgling radio intelligence organization in the years leading up to and including World War II. Volume 1 is based on the real life of Harry Kidder, a U.S. Navy radioman who first discovered and deciphered Japanese katakana telegraphic code while stationed in the Philippines in the 1920s, discovering the he was listening to Imperial Japanese Navy (IJN) radio communications. Kidder strongly believed in the future of radio intelligence and a chance meeting with Lieutenant Laurance Safford led to the birth of the Navy's Radio Intelligence community. Kidder taught others the nascent art of intercepting IJN communications on the roof of the Main Navy Building in Washington, DC. From 1928 to 1941, 176 Sailors and Marines attended this training and were then stationed as radio intercept operators around the Pacific. These men would become known as the On-The-Roof Gang and were charged with keeping track of the IJN as they prepared for war with the United States. The circumstances of America's entry into World War II hinged on success or failure of the On-The-Roof Gang, and Harry Kidder knew this. Volume I concludes with the "date which will live in infamy," December 7, 1941.

Volume 2 begins with the Japanese surprise attack on Pearl Harbor and documents the contributions of the On-the-Roof Gang during World War II. It focuses on the wartime stories of the On-the-Roof Gang intercept operators, some who were stationed in Hawaii, some who survived a tortuous existence in a POW camp, others who had to evacuate their intercept sites, and still others who performed intercept operations while at sea during some of the most famous naval battles of World War II.



Colloquium Speaker: Matt Zullo

Matt Zullo is a retired U.S. Navy Master Chief Petty Officer who has more than 35 years' experience in Radio Intelligence, now more commonly known as Communications Intelligence. He holds a Master's degree in Strategic Intelligence from the National Intelligence University, where he researched and wrote his master's thesis on the On-the-Roof Gang. He has published numerous articles on the On-the-Roof Gang in the Naval Cryptologic Veterans Association's Cryptolog magazine and on social media platforms. As one of only a few quantifiable experts on the subject, Matt has spoken at the 2009, 2011, and 2013 Cryptologic History Symposiums, as well as at several Navy events around the world. He recently (Nov 2019) attended the induction of Harry Kidder into NSA's Cryptologic Hall of Honor and spoke about Harry Kidder at a subsequent event for the sailors of Cryptologic Warfare Group Six.