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Monday, August 31, 2020

Most Important American radio station in the South Pacific during WW II

 Somerville Communication-Centre WWII
Back during the Pacific War in the middle of last century, American forces installed shortwave radio equipment at the direction of General Douglas MacArthur in five different locations in the areas around the city of Brisbane in Queensland Australia.

In our previous programs, we have presented the story of three of these interconnected shortwave radio facilities:
AMP Building Brisbane, Major Communication Center, WVJJ-WTO
Somerville House, South Brisbane (secondary station, one transmitter, receiver)
Golf Course, Redland Bay (secondary station, one transmitter)

Today we present the story of the two primary shortwave stations that the Americans installed near Brisbane, a transmitter station and a receiver station.  These two units formed the largest and most important of all of the American communication radio stations established throughout the South Pacific arena in the middle of last century.

We examine first, the record of the transmitter station that was established near Hemmant, just ten miles east of downtown Brisbane. Early in the year 1942, American Signal Corps personnel took over a large tract of swampy vacant farm land at 180 Youngs Road near Hemmant on which a solidly constructed thick-walled T-shaped brick building was constructed.  This tidal swampy site near the coast was chosen in order to enhance the transmission of shortwave signals, though the new transmitter building itself was constructed on short brick-stilted pylons above any possible danger of flooding. 

A total of five rhombic antennas were constructed and they spanned the swampy areas on both sides of Youngs Road. Each three-wire rhombic antenna was supported on wooden poles standing 100 feet tall. These diamond-shaped antenna systems provided radio coverage within Australia and to the scattered Pacific Islands, and also to Hawaii and California, as well as to Asia.

In addition to the main transmitter building, an additional smaller building housed a 250 kW diesel power generator, due to the fact that no locally generated electrical power was available in the Hemmant area. Their first power generator was built by Buckeye in Lima Ohio. 

Over a period of time, several different shortwave transmitters were installed at the American army communication station in Hemmant, including an Australian made 10 kW AWA unit for the communication circuit to Hawaii, and an American made 40 kW PWI transmitter for the circuit to New Delhi in India and to California in the United States.  Contact with the MacArthur Communication Center in the basement of the AMP Building in Brisbane was provided by an above ground wire circuit thirty miles long.

The Hemmant Transmitter station was taken into service towards the end of the year 1942, and it provided widespread communication with American bases throughout the Pacific and Asia.  In addition, this station provided communication circuits for wartime news dispatches from forward areas back to the news media in the United States and elsewhere. 

Additionally in December 1943, the Hemmant station began the regular daily transmission of time signals at 7:00 and 11:00 am, and 7:00 and 11:00 pm.  A new antenna system was installed for this particular purpose. These time signals were provided by two transmitters, the 1 kW American made Federal, and the Australian made 10 kW AWA unit, and they were broadcast, surprisingly, on exactly 5 MHz, 10 MHz, and 15 MHz.  Back in those days, the well known WWV was located too far away, in Washington DC, and the Australian VNG was not yet on the air.  American personnel needed an accurate time signal service back then much closer, in the Pacific arena.

When the American armed forces moved “up north” towards Japan in 1944 and 1945, they simply abandoned their most important radio transmitter station in the South Pacific, Hemmant, and left it as it was. The equally important receiver station was located at Capalaba, a dozen miles southeast from Brisbane and ten miles south of the Hemmant transmitter station. The land was owned at the time by the Cotton family, and it was commandeered by the American forces in 1942. In earlier times, this land had been known as the Willard’s Old Property.

The main building for the receiver station at Capalaba was similar to the main building at the  Hemmant transmitter station.  The original receivers installed at Capalaba were four American made Wilcox Model CW3D units and they were initially capable of receiving teletype and Morse Code, though speech capability was subsequently enabled.  There was also landline connection with the MacArthur Communication Center in the AMP Building in Brisbane, as well as to the transmitter facility at Hemmant.

The original receiving antennas were small and simple in design, though three diamond shaped rhombics were installed subsequently. The Capalaba Receiver Station was taken into service towards the end of the year 1942 and it received from the same Pacific and Asian areas as covered by the Hemmant transmitter station. Likewise when the American armed forces moved “up north” towards Japan in 1944 and 1945, they simply abandoned their most important radio receiver station in the South Pacific, Capalaba, and left it as it was. 

But that is not the end of the story. Very little is known, even in Australia, as to what happened to these two important radio stations; and that will be the story here in Wavescan, on another program.
(AWR Wavescan/NWS 599)
(photo/wikipedia)