The communication intelligence (COMINT) history of Guam dates from March 1929 with the establishment of a one-man intercept position. The initial intercept operator was sent to Guam from Shanghai, when that station was disestablished.
Prior to that-date the Navy Security Group (NSG) had intended to establish an intercept station in Guam as early as June 23, 1926; however, the plans were not carried out, and a later 1928 outline of a proposed war-time COMINT organization published by the Director of Naval Communications made no mention of Guam. The original intercept facility was established in building #62 in the palace grounds on the U. S. Naval Station, Guam in the city of Aciana, but was moved to building #84 sometime between 20 December 1932 and January 5, 1933. The station’s intercept complement was increased by seven graduates of the first radio intelligence class in Washington, D.C. in 1929, known as On-The-Roof Gang.  Notable successes were achieved by Guam during the Japanese fleet maneuvers of 1929 and 1930 and the station was commended by the CNO on March 5, 1932 for its diligence and initiative.


Despite the commendation, budget limitations may have forced the CNO to reduce Guam to a minimum in 1932 with most of its coverage being reassigned to Hawaii. Whether this actually took place is not known, but is considered doubtful in view of CNO’s commendation and later activity of the station.

The intercept site was moved from the Naval Station to an abandoned Tuberculosis hospital on a hill outside of Agana sometime in 1933 or 1934 and was located there until relocation to Libugon.

On October 11, 1934 the Commander-in-Chief Asiatic Fleet inspected Guam and recommended that the Commandant, U. S. Naval Station, Guam move the intercept facility to an abandoned radio station at Libugon. The station at Libugon located four miles from Agana had been established in 1917 as a transmitter site, with its remote control and receiving station at Agana, as a link in the Navy’s Trans Pacific High Power (Arc) circuit. A low power high frequency transmitter had been installed in 1927, and was operated until the station was decommissioned and abandoned in March 1932 as an economy measure. The intercept facility was transferred from Agana to Libugon in October 11, 1934 where it remained until 1941 at which time it was overrun by the Japanese in the initial phase of World War II. The Bureau of Engineering attempted to move the intercept facility back to Agana as an economy measure in 1935; however, the CNO intervened and settled the issue by indicating that Guam was by this time a vital part of the Navy’s COMINT effort.

Radio Libugon, Guam 1934 – Station B

Intercept equipment at Guam was generally obsolete and excess from other stations such as Cavite. On October 15, 1934, the USS Gold Star (AK 12) was directed to transfer an RF receiver to Guam. Three Kana typewriters (RIP-5) were sent to Guam in December 1936 and recording equipment in March 1938.

09.22.1893 RIP-5 Underwood Code Machine
In 1924, Safford, in consultation with the Underwood Typewriting Company, designed a “special code machine” for the use of U.S. Navy intercept operators. Instead of Roman letters, the “RIP-5” printed
“Kana” characters for the interception of Japanese radio messages.

Personnel strength had been increased to 10 by 1940, and an additional increase to 14 was requested in January 1940. The allowance increase was not approved, and Station B approached World War II with an on board complement of eight men, including the radioman-in-charge, CRM D. W. Barnum. On September 21, 1941 Chief Barnum had relieved CRM J. W. Pearson who was ordered to the 14th Naval District for duty. In addition to Barnum, RM2 D. L. McCune reported for duty sometime in October 1941.

COMINT Operators September, 1944


Orders were issued by OPNAV to destroy all classified publications except for those essential for operations on December 4, 1941. According to an OP-2OGX wartime diary entry, contact with Guam was lost on December 8, 1941, and all eight intercept men were taken prisoner by the Japanese. A post-war memorandum prepared by OP20-G-3 indicates that an excellent job of destruction was performed by Guam. That same memorandum also reflects that eight men were captured at Guam. Taken from the last available documents at Crane (September 1941), the following men were at Guam on the day the island was captured and is believed to be accurate, since no future losses or gains were reported other than Pearson and McCune:

CRM D. W. Barnum (Radiomen In-Charge)
*RM1 M. T. Smith
RM1 R. R. Ellis
RM2 S. T. Faulkner
RM2 E. J. Dullard
RM2 R. G. Parr
RM2 H. E. Joslin
RM2 D. L. McCune

*Advancement papers had been mailed, advancing him to CRM; however, they were not received prior to his capture.

Communications Hut, September 26, 1944

Direction Finding

Installation of DF equipment was initially requested for Guam by OP-2OGX on June 22, 1935. Inspections were made in early July 1935 to find land suitable for the proposed construction; however, little else was done until 1937. In March 1937 an XAB-RAB – 2 rotating Adcock-type DF was shipped to Guam. The XAB-RAB was an HFDF developed in 1930 at the Navy Research Laboratory, installed initially at Mare Island in 1934, and was considered to be the first successful HFDF, despite its poor performance. The HFDF intercept site at Guam was commissioned in July 1937, and became the Navy’s second “intelligence” DF station, the first being Cavite, Philippines. A newer model DF, the Gordon Adcock rotating antenna (DT) was shipped to Guam via USS Chaumont (AP 5) arriving October 18, 1938. The XAB-RAB-2 was then surveyed and shipped to Cavite aboard USS Canopus (AS 5).

On November 3, 1940 a typhoon hit Guam and destroyed the entire DT system with the exception of the receiver unit. Fortunately, a newer Gordon direction finder model DY, an improved model of the SAB/HRO, had been ordered in July of that year. However the DY had not arrived until after the typhoon hit. In the interim, a model DT was ordered from station “AFIRM” (Shanghai), via USS Goldstar (AK 12), and Guam was back in DF operation shortly thereafter.

On November 29, 1940 DT and DR models were received from Shanghai, and the model DY-1 was received on December 27, 1940. Construction on the DY-1 site was begun immediately; however, in July 1941 the equipment was being used only on a limited basis.  The following are a list of Radiomen-In Charge at Station B:

CRM J. Goldstein              October 1929 – ?
CRM M. W. Hyon               June 1932 – ?
CRM Antone Novack        January 1938 – July 1939
CRM J. W. Pearson           July 1939 – 21 September 1941
CRM D. W. Barnum          September 21 1941 – December 1941

Post WWII:

Following WWII, Guam faced major reconstruction of areas that had suffered war damage. Agana, the capital, was completely destroyed by bombardment during the war. From 1944 to 1949, the Naval officers who served as Commander, U.S. Naval Forces Marianas (COMNAVMARIANAS) were also charged with civil responsibilities as the Governor of Guam, the Governor of the Marshalls-Gilberts, Deputy Military Governor Pacific Ocean Areas, and Deputy Military Governor, Bonin-Volcano Islands. On August 1, 1950, with the passing of the Organic Act of Guam, the administration of Guam was turned over to the U.S. Department of the Interior and became an unincorporated territory. Guam serves as the headquarters of the government of the Trust Territory of the Pacific Islands.

From 1944 until March 29, 1952, Naval Station served as a Naval Operations Base (NOB), providing every type of fleet service. In September 1956, the Naval Base was disestablished and the Naval Station was reassigned under the military command of Commander, U.S. Naval Forces Marianas.

In 1954, the Naval Communications Station (NCS) at Finnegayan, Guam was established. COMSUPACT (COMSEC Unit #701), formerly known as Station Able, was redesignated as the Naval Security Group Dept, NCS Finnegayan, Guam.

NCS Guam, Building 200 and CDAA, Naval Security Group Operations, 1965

The U.S. Naval Security Group Dept Finnegayan maintained and operated a high frequency direction finding (HFDF) facility and provided communication support to Navy and other Department of Defense elements. The communications facility located on the island included an operations building located in the center of an AN/FRD-10A Circularly Disposed Antenna Array (CDAA), also known as a Wullenweber antenna array. The CDAA ceased operations on December 31, 1999 and was abandoned in place and remains unused on the property of active NAVCOMTELSTA Guam.


A special thanks to CTRCM John “Gus” Gustafson, USN (Ret)