No.1 Wireless Unit

Radar/signal station

Sycamore and French Street, Pimlico 4812

In early 1942, the gravity of the war situation and the scarcity of building materials meant that civilian homes could be requisitioned under Commonwealth Security regulations by the military forces.

By mid-March 1942 it was decided to set up a wireless intercept station in a forward area consisting of RAAF and US personnel. Townsville was considered an ideal location for the interception and decoding of Japanese transmissions.


In French Street Pimlico, several fashionable Inter-War style homes had just been completed for their owners when the Japanese attacked Pearl Harbour in December 1941.

Two of these homes were initially commandeered, 24 French St and 21 Sycamore St. Expansion of the intercept station meant that 25 and 26 French St, plus 3 Sycamore St were also required. Another house at 20 French Street was requested however the owner refused to leave. The authorities relented and several tents were placed on a spare block across from 24 French St. On 25 April 1942 this secretive unit was given the deliberately ambiguous title of 1 Wireless Unit (1WU).

The Japanese used several codes to disguise plain language messages. Unknown to them, their codes and subsequent updates were broken by the Allies before the commencement of the Pacific War. The Japanese were using codes based on German code machines which had also been broken.

The houses in French and Sycamore Streets contained intelligence analysts, cipher experts, telegraphists, teleprinter operators, Japanese linguists and translators.

The priority for 1WU was to locate and intercept Japanese transmissions from airfields and aircraft in New Guinea. They also liaised with direction finding stations (such as Kissing Point and Paluma) to pinpoint aircraft locations en-route. This information then gave prior air raid warnings.

One of the US personnel at 1WU was Captain H W Brown whose quarters were at 25 French St. Somewhat of a character, Brown honed his pistol skills by shooting through his window at pigeons outside on the electrical wires. He was also known to target his light globe before going to bed at night.

During Brown’s 1WU period in French Street, his personal US command car was stolen. A group of off duty serviceman were organised to locate it and it was soon found abandoned. These men were then ordered by Brown to perform a stakeout in French Street in case the thieves returned and to shoot anyone interfering with it. The culprits however, did not return.

Although Brown’s behavior was considered unusual to his staff, his dedication to 1WU was solid. Handwritten intelligence reports list Captain Brown being in contact with Townsville’s Three Fighter Sector Headquarters (3FSHQ) leading up to the 2nd and 3rd raids on Townsville.

Extracts from the 2nd raid 27 July 1942 reveal 1WU role:

  • On the evening of 26 July 1942 Captain Brown informed 3FSHQ that two flights (aircraft) had left Rabaul. They would arrive over Townsville at 12.20am if their current speed of 180 miles per hour were maintained. Brown stated that he would try to intercept any messages between the planes.
  • An hour later Brown intercepted a Japanese message to “Plane 2” from Rabaul station with a message being sent every twenty minutes. (note - The second aircraft did not arrive over Townsville. Captured Japanese records reveal that it returned to base with engine difficulties.)
  • The 3FSHQ report concludes that after the aircraft bombed Townsville and was 113 miles north east of the city, it radioed its Rabaul base saying it was 'experiencing difficulties'.

Extracts from the third air raid include:

  • 1WU at Pimlico reported that the tracked hostile aircraft was using radio telephony and that speech was in English using the call sign 'One Ball'.
  • After being attacked over Cleveland Bay and jettisoning its bombs, the aircraft was attacked and damaged by US fighters. 1WU reported that as the aircraft left Townsville it reported to its base that it had been attacked by fighters on both sides.
  • The final transmission intercepted by 1WU was that the aircraft asked Rabaul to turn on the (flare path) lights when it arrived.

These advance warnings provided by 1WU in French Street prior to the 2nd and 3rd raids gave Townsville anti-aircraft and fighter units time to prepare. This definitely hindered the Japanese aircraft’s bombing run meaning bombs were jettisoned rather than accurately targeting populated areas.

1WU occupied the houses in French Street between March and September 1942. After this they began moving into a new reinforced concrete building at Stuart on the outskirts of Townsville.

By May 1943, 24 French Street’s secretive role had been downgraded to that of being the parcel sorting and storage depot for No. 6 RAAF postal unit. By years end this operation was transferred to the School of Arts at the corner of Walker and Stanley Streets.

In 2011 there is no sign of French Street’s former secretive role; however a concrete lined air raid trench was recently unearthed in the yard of a former 1WU house. And pigeons still sit on the electrical wires and roofs of French Street.


RAAF NEA Townsville buildings and services Pt 2, 1944-47, A705/1, 171/19/86 ACT.

Reports by Intelligence Officer - operation of No.3 Fighter Sector HQ, AA 1969/100/445, 5/7/Air ACT.

Bleakley, Jack. The Eavesdroppers, AGPS Press, Canberra, 1991.

The North Queensland Line: The Defence of Townsville in 1942. Ray Holyoak unpublished Honours Thesis, James Cook University, Townsville 1998.