The Coastal Radio Service in Australia was first proposed in a report on Australian Naval Defence dated 1 March 1911 complied by British Admiral Sir Reginald G. Henderson. He recommended the installation of three high-powered radio stations for fleet communications and 13 medium powered radio stations for commercial maritime communications. Two long range stations were eventually constructed at Sydney and Perth and a chain of less powerful radio stations were constructed around the coastline of Australia.

The 1912 Navigation Act required any ship able to carry more than 50 passengers to be equipped with wireless communications and one or more qualified operators. The ship's wireless was required to be able to transmit and receive messages a distance of at least 160 kms day and night.

The Commonwealth Government appointed John Graeme Balsillie, on the 4 September 1911, to the position of Engineer for Radiotelegraphy with the Postmasters General's Department (PMG). His role initial was to fast track the building of a chain of coastal wireless stations. From his office in Treasury Gardens in Melbourne he oversaw the commissioning of the first government owned coastal radio station located in Melbourne's Domain on 8 February 1912.

A new wireless station in the Queen's Domain in Hobart overlooking the River Derwent was operating a few weeks later. Four more wireless stations were operating by the end of 1912 at Adelaide, Brisbane, Perth and Sydney equipped with German Telefunken 25kW quenched spark transmitters.

The long-range Sydney Wireless Station located in the rural district of Pennant Hills replaced an older privately contracted wireless station located in the Hotel Australia. The new Sydney station was operational in about August 1912. It was located in what is now the Sydney suburb of Carlingford. Its initial call-sign of POS was later changed to VIS. The Sydney Station closed in the 1950's after WWII. The station's machinery room later became the first church of St. Gerard Majella at Carlingford in 1962. It later became a parish recreation hall.

The Perth long-range Wireless station at Applecross, south of the Swan River near Fremantle opened at the end of September 1912 with the call-sign POP which later changed to VIP. The Perth Station closed in 1967 and later became the Wireless Hill Telecommunications Museum.

By August 1914 at the start of the First World War a network of 19 Coastal Radio Stations had been established around Australia as follows:-


Radio Station  Callsign Commissioned
Melbourne VIM  8 Feb 1912
Hobart VIH 30 Apr 1912
Sydney VIS 19 Aug 1912
Brisbane VIB  2 Sep 1912
Perth VIP 30 Sep 1912
Adelaide VIA  1 Oct 1912
Thursday Island VII 26 Feb 1913
Port Moresby VJZ 26 Feb 1913
Mount Gambier    1 Mar 1913
Geraldton VIN 12 May 1913
Rockhampton VIR 24 May 1913
Cooktown   12 Jun 1913
Esperance VIE 21 Jul 1913
Townsville VIT  7 Aug 1913
Broome VIO 18 Aug 1913
Darwin VID 25 Sep 1913
Flinders Island    8 Oct 1913
Roebourne   26 Jan 1914
Wyndham VIW 18 May 1914


The above Wireless stations were all equipped with crystal receivers and 5kW transmitters using the Balsillie system of spark transmission.

Further stations were quickly established by Amalgamated Wireless (Australia) Ltd at Aitape, Madang, Morobe, Manus, Kavieng, Kieta, Woodlark Island, King Island (Jan 1916), Samarai Island (Sep 1917).

One frequency of 500 kHz was initially used for communications with ships. The long-range Perth and Sydney stations could also operated at 125 kHz to allow communication between each other.

During WWI the Navy Department took over control of the Coastal Radio Service in 1915.  The PMG resumed control of the Coastal Radio Service from the Navy department  in October 1920.

On 28 March 1922 the Commonwealth granted AWA an exclusive right to construct and operate stations in Australia for a direct commercial wireless telegraph service linking Australia with Great Britain and Canada. Control of the existing Coastal Radio Service (27 stations) also transferred to AWA. 150 engineers and operators also transferred to AWA. By this time Mount Gambier, Roebourne and Woodlark Island were decommissioned by this time. One of the 27 stations was a new one on Willis Island commissioned in 1921. The stations around Australia were referred to as the Coastal Radio Service and those in New Guinea and the islands was referred to as the Island Radio Service.

The Navigation Act 1921 required that all ships registered in Australia of more than 1600 tons or carrying more than 12 passengers should be fitted with an efficient wireless installation.

The Pennant Hill Station stopped operating as a Receiver Station in March 1926 and its transmitters were remotely keyed from the Willoughby Station. On 8 February 1927, Willoughby Station was replaced by the new Sydney Radio Station at La Perouse.

At the outbreak of WWII on 3 September 1939 the operations of the Coastal and Island Radio Services came under the control of the Royal Australian Navy whilst AWA retained ownership and its management role of the network. Existing staff continued to be paid by AWA. Military Guards were placed at all Radio Stations.

Direct lines were established from the major Radio Stations to the closest Naval Intelligence, Coding and Operational Centres. Despatch riders were used as required at various Radio Stations. After the Japanese attacked Pearl Harbor on 7 December 1941, staff at Darwin, Thursday island and Port Moresby were given RAN rank. Operators became Chief Petty Officers and Officer-in-charge became Warrant Officers.


Photo:- National Archives of Australia

Radio Station VID Darwin in 1924


Normal commercial communications with ships were stopped for the duration of the war with ships maintaining radio silence except in case of emergencies. All shore-to-ship transmission emanated fro the Royal Australian Navy whether addressed to naval or commercial vessels. Radio Officers of ships were required not  to acknowledge receipt of messages.

The "I" Broadcast method was used to communicate with Allied naval units. A Coastal Radio Station would would send its message to another Australian Coastal Radio Station, transmitting on two frequencies simultaneously. The 2nd station would then repeat the message, again on two frequencies, addressing it to the originating radio station. Naval ships therefore received two broadcasts, each on two different wavelengths.

RAN Radio Station HMAS Harman became operational in December 1939 with call-sign VHP. HMAS Harman and the long range Radio Stations at Sydney and Perth were able to communicate with all Naval ships around Australian waters.

For Naval communications the Coastal Radio Stations added the number 6 to their call-signs. Thus Perth Radio Station became VIP6 and Darwin became VID6.

The RAN Radio Station at HMAS Coonawarra at Darwin was commissioned in February 1941 with call-sign VHM. HMAS Coonawarra then took over Naval communications from the Darwin Coastal Radio Station which continued to communicate with Merchant shipping.

Any Allied Naval ship wanting to contact a Coastal Radio Station would call "VIXO". HMAS Coonawarra, HMAS Harman and Perth Radio monitored on a multiple frequencies in the HF Band whilst the other Coastal Radio Stations monitored one or two "VIXO" frequencies. All communications were normally encoded. A variant of the standard International Morse Code known as "Tiddly" Morse was used.

All Naval and merchant ships were allocated special wartime call-signs. There were also call-signs identifying a particular fleet or class of ships:-

"GBXZ" meant "Calling and British warship"
"NERK" meant "Calling any US warship"
"GBMS" meant "Great Britain Merchant Shipping"
"BAMS" meant "British Allied Merchant Shipping".

There were also various codes to describe certain situations:-

AAAA indicated an attack by aircraft
SSSS meant an attack by submarine
RRRR meant an attack by Naval surface vessel
QQQQ meant an attack by disguised merchant raider

Confidential Naval codes were held at all Coastal Radio Stations and Naval Shore Establishments and on board Allied Naval and merchant ships.

The Naval Board would send out coded message advising of suspected enemy submarines, surface raiders and minefields.

The Coastal Radio Stations at Darwin, Thursday Island, Townsville, Port Moresby and Rabaul assisted the RAN Coast Watching scheme. They received and relayed information about enemy military activity to and from Coast Watchers who operated behind Japanese lines. These Coastal Radio Stations had a dedicated receiver constantly tuned to a particular frequency in the 6 MHz band, which was know as "X" frequency. The Coast Watchers used Teleradios which were fitted with specially cut crystals which operated on this same frequency. The "X" frequency receivers at the Coastal Radio Stations were left on loudspeaker 24 hours  a day to ensure all messages were heard.

Darwin Radio Station provided the link between Naval Intelligence and the Coast Watchers around the north west coast. Thursday Island Radio Station covered the Torres Strait islands and Cape York Peninsula. The AWA Radio Stations at Port Moresby and Rabaul covered the islands of Papua and New Guinea.

RAN Intelligence Officers were stationed at Fremantle, Darwin, Thursday Island, Townsville, Rabaul, Port Moresby, Tulagai, and Vila to provide local supervision. All intelligence information was channeled to Naval Intelligence Division, Navy Office, Melbourne.

Area Combined Headquarters were initially established at Melbourne and Port Moresby which received all local intelligence reports. By mid 1941 ACH's had also been established at Fremantle, Darwin and Townsville.

Townsville ACH temporarily replaced ACH Port Moresby. The Headquarters for the Coast Watching Service moved from Port Moresby to Townsville staying there until November 1942. Messages were encode and transmitted by telegraphy using the Playfair Royal Naval code. This code was later modified and eventually replaced by new codes. Messages reporting approaching Japanese aircraft were not encoded.



"The Seawatchers - The Story of Australia's Coast Radio Service"
by Lawrence Durrant


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This page first produced 4 January 2009

This page last updated 27 April 2018