Reflecting on the history of my previous profession as a Cryptologic Technician as it intersects with my current pioneering I asked Grok to “Tell me about On The Roof Gang”.

Some of the history I knew but some was new to me. Regardless, it highlighted to me that the pioneers historically carve out places to make things happen without regard for comfort or recognition. They’re mission driven and focused on an outcome.

The other piece that stood out to me was education and training were critical to success and proliferation of skills and technology needed to overcome and adversary.

Share openly and often the lessons you learn as you pioneer a new future.

Grok’s response

The On the Roof Gang (OTRG) was a group of United States Navy cryptologists and radiomen, along with 26 Marines, who pioneered U.S. Navy cryptology and cryptanalysis from 1928 to 1941. They are considered the forerunners of modern naval cryptology, laying the foundation for the Navy’s signals intelligence (SIGINT) and communications intelligence (COMINT) efforts, now part of the Naval Information Warfare Community.

### Origins

The OTRG began in 1921 when the Office of Naval Intelligence (ONI) covertly obtained a photographic copy of the Imperial Japanese Navy’s (IJN) Secret Operating Code-1918, a dictionary with 100,000 entries. Translating it took five years due to limited Japanese linguists and the complexity of the Japanese katakana telegraphic code, which differed from standard Morse code. By 1928, the Chief of Naval Operations recognized the need for formally trained operators to monitor Japanese naval communications in the Pacific, as only a small group of self-taught operators existed.[]( https://en.wikipedia.org/wiki/Ontheroof_gang)(https://stationhypo.com/2021/10/01/on-the-roof-gang-nucleus-of-our-community/)

Chief Radioman Harry Kidder, who discovered and deciphered Japanese katakana code in the 1920s while stationed in the Philippines, became a key figure. His meeting with Lieutenant Laurance Safford, later known as the Father of Naval Cryptology, led to the establishment of a training program. The program was housed in a specially constructed blockhouse on the roof of the Main Navy Building in Washington, D.C., due to limited space, giving the group its name. The first class convened on October 1, 1928, with Kidder as the initial instructor, followed by Chief Radioman Dorman Chauncey for later classes.[]( https://dod.overdrive.com/media/6301809)(https://stationhypo.com/2021/10/01/on-the-roof-gang-nucleus-of-our-community/)

### Training and Operations

From 1928 to 1941, 176 Sailors and 26 Marines in 25 classes were trained to intercept and analyze Japanese radio communications, focusing on katakana code. Graduates were deployed to radio intercept sites across the Pacific, including Station BAKER (Guam), Station ABLE (China), Station HYPO (Hawaii), and Station CAST (Philippines). They monitored IJN movements and intercepted encrypted messages, often under challenging conditions like caves, tunnels, or Quonset huts. Some operators even worked aboard American President Lines ships as first-class passengers to conduct intercept operations at sea from 1933 to 1934.[]( https://www.usni.org/magazines/naval-history-magazine/2022/june/roof-gang-us-navys-cryptologic-pioneers)(https://dod.overdrive.com/media/6301809)(https://ontheroofgang.com/stories/)

A notable early success was in 1930, when OTRG operators at Station BAKER detected a surge in radio traffic during the IJN’s Orange Grand Maneuvers, identifying a high percentage of encrypted messages. This demonstrated the value of their work in tracking Japanese naval activities.[]( https://ontheroofgang.com/stories/)

### Impact During World War II

The OTRG’s efforts were critical in the lead-up to and during World War II. Their intelligence supported key victories, including the Solomon Islands, Guadalcanal, Marianas, Iwo Jima, and the Battle of Midway, where codebreaking by Station HYPO, led by Captain Joseph Rochefort, proved decisive. Operators faced significant hardships, including those captured on Guam who endured POW camps. Their work provided operational commanders with a strategic advantage, shaping the Navy’s island-hopping campaign and contributing to Japan’s attrition.[]( https://www.usni.org/magazines/naval-history-magazine/2022/june/roof-gang-us-navys-cryptologic-pioneers)(https://ontheroofgang.com/)(https://www.amazon.com/US-Navys-Roof-Gang-Pacific/dp/1735152722)

### Legacy and Recognition

The OTRG remained a closely guarded secret for decades, with many members’ families unaware of their contributions until the 1980s. In 1983, a memorial was dedicated at the Naval Security Group Command headquarters in Washington, D.C., now located at Fort George G. Meade, Maryland. Another plaque was placed at the Cryptologic Command Display at Corry Station, Pensacola, Florida, in 1986. The Naval Network Warfare Command honors their legacy with the “On-the-Roof-Gang” Award, recognizing lifetime achievements in cryptography.[]( https://en.wikipedia.org/wiki/Ontheroof_gang)(https://usncva.org/history/on-the-roof-gang.html)(https://stationhypo.com/2025/04/16/from-all-hands-magazine-october-1983-on-the-roof-gang-55-years-of-silence/)

Pearly Phillips was instrumental in preserving OTRG history, earning the Naval Security Group Meritorious Service Award in 1983 for reuniting members and archiving records. Harry Kidder was inducted into the NSA’s Cryptologic Hall of Honor in 2019. Building 511 at Corry Station, where Morse code training continued into the 1980s, is named after Kidder.[]( https://usncva.org/history/on-the-roof-gang.html)(https://stationhypo.com/2021/10/01/on-the-roof-gang-nucleus-of-our-community/)(https://www.kirkusreviews.com/book-reviews/matt-zullo/the-us-navys-on-the-roof-gang/)

### Historical Accounts

Matt Zullo, a retired Navy Master Chief with over 35 years in communications intelligence, authored a two-volume historical novel series, The US Navy’s On-the-Roof Gang. Volume 1, Prelude to War, covers the group’s formation and pre-war efforts, while Volume 2, War in the Pacific, details their wartime contributions. Zullo’s work, based on extensive research and first-hand accounts, has been praised for bringing this obscure history to life.[]( https://www.amazon.com/US-Navys-Roof-Gang-Pacific/dp/1735152722)(https://www.amazon.com/US-Navys-Roof-Gang-Prelude/dp/1735152706)(https://www.everand.com/book/506997554/The-US-Navy-s-On-the-Roof-Gang-Volume-I-Prelude-to-War)

The OTRG’s story is preserved by the Naval Cryptologic Veterans Association (NCVA), founded in 1978, which maintains records and promotes the group’s legacy. Their work not only established naval cryptology but also set a standard of secrecy and professionalism that endured for generations.[]( https://www.everand.com/book/506997554/The-US-Navy-s-On-the-Roof-Gang-Volume-I-Prelude-to-War)(https://usncva.org//component/content/article.html?id=5)

For further details, Matt Zullo’s books are available on Amazon, and additional resources can be found through the NCVA or the NSA’s Cryptologic History Center.[]( https://www.amazon.com/US-Navys-Roof-Gang-Pacific/dp/1735152722)(https://www.amazon.com/US-Navys-Roof-Gang-Prelude/dp/1735152706)