October 1, 1928, the first class was held for specially selected enlisted Navy and Marine Corps radio operators. These men were specially trained to intercept and analyze foreign radio communications at a unique school on the roof of the old navy department building.
There were a total of 176 graduates that completed the course (150 Sailors and 26 Marines) 1928-1941. Since these classes were held in a wood structure set atop the Navy Headquarters Building in Washington, and since the radiomen could not explain their classwork to others, they eventually acquired the nickname, “The On-the-Roof Gang.” This small group was the vanguard of the U.S. Naval Communications Intelligence efforts and laid the cornerstone of Naval Cryptology.
The United States had maintained squadrons of ships in the Pacific since the mid-19th century. In 1907, the Asiatic and Pacific Squadrons were consolidated into the United States Pacific Fleet. In 1922, the Atlantic and Pacific Fleets were combined to form the U.S. Battle Fleet, with subordinate Atlantic and Asiatic Fleets. Another reorganization, in February 1941, created three separate fleets, Atlantic, Pacific, and Asiatic.
In the 1920s and 1930s, with units along the China coast the U.S. Asiatic Fleet became embroiled in the international conflict among the many powers and China. Factions in China were struggling to unify their country and to rid it of foreign imperialist enclaves. The Japanese military in China, however, often acting independently from Tokyo, was seeking to expand its control of Chinese territory.
Then, as now, accurate and timely information was at a premium.
Early intercept of Japanese naval radio traffic was done on an ad hoc basis; the Chief of Naval Operations let it be known that the Navy had an interest in acquiring encrypted Japanese communications. A number of Navy and Marine Corps radiomen spent their spare time learning to copy Japanese messages.
As might be expected, the Commander in Chief of the U.S. Asiatic Fleet (CINCAF) had an interest in eavesdropping on the Grand Maneuvers of the Japanese Navy. This was done by some radiomen assigned to the Asiatic Fleet, although the results of the intercept operations are no longer known.
In May 1928, however, the CINCAF complained in a letter to the Chief of Naval Operations about how few operators he had who were qualified to copy Japanese kana code. The fleet had only nine qualified operators, all self-taught. Self-study and ad hoc operations were no longer sufficient to produce the number of needed qualified intercept operators.
Therefore, in July, the CNO announced the establishment of a school to instruct radio operators in intercept operations, particularly for Japanese kana. The first class would begin on October 1, 1928, and instructors were to be two of the self-taught radiomen from the Asiatic fleet.
The first class was considered a success, so five more were held in 1929. The instructor for the first three was Chief Radioman Harry Kidder. The last two were taught by Chief Radioman Dorman Chauncey. Both were veterans of intercept operations in the Asiatic Fleet. Chauncey had conducted intercept at the U.S. Navy sites in Hawaii and Peking.
The first classes of trainees were composed largely of experienced radiomen of senior enlisted rank. To ensure that there would be continuity of service, the second and third groups of trainees were relatively junior.
Marine Corps personnel participated in the training from the third class, which began in November 1929. The class that trained from December 1930 to April 1931 was composed entirely of Marine enlisted men. Marines engaged in intercept activities for most of the 1930s, but the number dwindled late in the decade, since intercept operations were not a Marine rating and promotion possibilities were less for intercept operators than general service radiomen.
With a larger pool of intercept operators to deploy, additional collection sites were opened: Guam, Olongapo, Philippine Islands, and Astoria, Oregon. Some intercept was conducted aboard ships, principally the USS Agusta and the USS Gold Star.
The Navy Building in the District of Columbia, by the way, was demolished after World War II. Part of the area where it once stood is now occupied by the Vietnam Memorial.
Doug Adams, “The Early Years,” NCVA (Paducah, Ky.: Turner Publishing Company, 1996), pp. 9-10.
Carl A. Jensen, “The Story of the ‘On-The-Roof’ Gang (OTRG),” NCVA (Paducah, Ky.: Turner Publishing Company, 1996), pp. 17-18.
James McIntire & R. D. Howell, Sr., “U.S. Marine Corps in COMINT,” NCVA (Paducah, Ky.: Turner Publishing Company, 1996), pp. 46-50.
NCVA, Echoes of Our Past