- Reed, R.A. (Bill)
- Naval Intelligence, Ship histories and stories
- RAN Ships
- HMAS Harman (base)
- June 1997 edition of the Naval Historical Review (all rights reserved)
To those of us familiar only with ship-borne radio, “Bels 44” was positively awe-inspiring. The aerial-coil room alone occupied as much floor space as a small house. Such was its electromagnetic induction power that an isolated hand-held household fluorescent tube would light up in its vicinity. At full-bore, it generated so much heat that its output valves had to be water-cooled to prevent meltdown. And it took a full half-hour to bring it back up to full power from shut-down.
Short-Wave (High/Frequency) transmitters – two 20kW and one 10kW – were also installed at inception. Some of these H/F transmitters were used for the `Ship-Shore’ service. They were so state-of-the-art that they were tuned to ten pre-set frequencies, any one of which could be called up by ‘sparkers’ (telegraphists) at Harman in the time it took to select one digit on a telephone dial.
In total, this Belconnen equipment had quite a large electric mains power consumption. A hefty diesel-powered generator was therefore necessary to make the station independent of external (civilian) power in emergency conditions.
The 18km separation between the two establishments was necessary to reduce interference between megapower transmission and micro-power reception, interference-suppression techniques, in those days, being in their infancy. The distance separation added to administration difficulties in so far as Belconnen with its smaller personnel numbers was, seemingly, part of an altogether different Navy. It was also a long way into town for recreation. Canberra was very sparsely populated 50-odd years ago. Limited numbers of “liberty boats” (buses) were available, and it was a very long, lonely walk to either base for those who missed the last for the day.
`Bels’ and Harman were linked by dedicated telephone landlines, over which telegraphist operators sent their Morse-code messages – previously encrypted by `coders’ for secrecy – to allied ships and bases. Top secret British supplied ‘Typex” cipher machines were wondrous electromechanical devices that randomly changed settings at irregular intervals from an original set-up that changed according to the date. It was hoped that this would produce an ‘uncrackable code’. Teletype/teleprinters, inkrecorder machines, etc., also provided a certain amount of automation. But when electrical interference took over, making reception difficult, it became necessary to revert to hand-operation and the plodding dedication and skill of both sailors and members of the Women’s Royal Australian Navy Service (WRANS) – of which, more later.
As H/F (Short-Wave) radio gained in efficiency over the years, more and more equipment was acquired, with corresponding increases in aerial requirements. These, mainly at Belconnen, occupied many hectares of country on which sheep still grazed.
Harman Receiving Station – commissioned as HMAS Harman only in mid-1943 – also, necessarily, had a maze of aerials for both ‘frequency-diversity’ and space-diversity’ reception to ensure continuing reception against the vagaries of H/F.
Belconnen’s H/F aerials were often rhomboid shaped – known as “rhombics” – and geographically aligned. This was to maximise directional power towards specific allied bases such as Whitehall (UK), Colombo (in then, Ceylon), Hollandia (in then, Dutch New Guinea), and Pearl Harbour (Hawaii). Depending upon the vagaries of the ionosphere, transmission is often better on the long-route, rather than the short route around the world. There was, necessarily, elaborate switching gear situated at the aerial base far out in the paddocks.
Unfortunate sailors were therefore required to venture out into the often overcast, pitch-black and freezing night to make the essential switching change. Stories are told that more than a few were lost for hours, unable to find their way back to the station. Strongly enforced war-time black-out conditions meant there was not a light to be seen anywhere.
Belconnen’s many aerial arrays made excellent targets for lightning storms. At certain times of the year, when storms were prevalent, it was both exhilarating and scary as lightning blasted around the transmitter room, with occasional dire results for some transmitters.
From 1942 until the end of the war, the stations were staffed by communications personnel from the RAN Shore Wireless Service, RANR, RANVR, WRANS and even the US Navy. Guard duties were undertaken by soldiers – older men recruited for guard duties – releasing sailor guards for sea duties. During the war years – especially after 1942 – the WRANS was the largest group at Harman.