Royal Australian Air Force (RAAF) 44/56 Radar Station

Radar Station military camp

Type
Radar/signal station
Region
North and Cape York

Hope Street, Grassy Hill, Cooktown 4895

During World War II radar was a most secret technology. It had been developed in Britain prior to the war and the details were shared with Australia and other commonwealth countries. Delays in acquiring British radar equipment, due to the demands of the Battle of Britain, spurred an innovative period of radar development by Australian scientists at the Radiophysics Laboratory (RPL) of the University of Sydney during 1941.

It was fortunate that as the war with Japan approached, there were in Sydney two very important manufacturers with the expertise to produce specialised radar equipment, namely HMV (His Master’s Voice), also known as the Gramophone Company, and the New South Wales Government Railway Workshop. These two organisations were capable of providing the Australian air warning (AW) equipment, particularly the RPL-designed transmitter/receivers and aerials. However, in September 1941 it was apparent it would take at least a year for construction of the local sets required for each of the planned 32 ground stations around the country, including Cooktown. The RAAF order for British equipment, including the latest Mk V COL, was dependent on availability and delivery times were uncertain.

On news of the Japanese attack on Pearl Harbor, scientists at RPL began building an AW radar set by modifying the electronics of an experimental coast defence radar developed by the army. The rough but effective AW set was completed in a week and provided Sydney’s first air warning system. The Australian-designed AW Mk I radar was developed from this. The AW Mk I was based on the same aerial array as the army radar, but with a simpler tower. However, the army aerial was built to maximize signals received from surface targets and was not ideal for air warning where high angle coverage was needed against aircraft.

History

In mid-November 1942 the personnel of RAAF 44 Radar Station arrived at Cooktown aboard a coastal vessel to install an Australian AW Mk I set. The radar unit was formed in Townsville in August 1942. The radio direction finding (RDF-or radar) station was located on top of Grassy Hill, overlooking Cooktown, and alongside the early lighthouse erected in 1886. On arrival the unit found that work on the transmitter and camp had not started due to confusion regarding building approvals by the Main Roads Commission which was the constructing authority. A disused house at the base of the hill was pressed into service as a temporary mess, store and orderly room. As usual sleeping accommodation was in tents. The unit personnel themselves completed the radar transmitter and operations building and installed most of the technical equipment. After further delays awaiting valves for the equipment, it was the end of January 1943 before the radar station was finally operational. Even then the permanent camp, constructed on a steep spur half-way up Grassy Hill, was still unfinished, only one building being completed and this was used as an orderly room and wireless telephone room.

In April 1943 the unit was redesignated RAAF 56 Radar Station. Unit personnel set about camouflaging the radar receiver tower and antenna alongside the lighthouse to resemble the lighthouse keeper’s cottage. This was done by surrounding the tower and operations building with a steel frame in the shape of a house. To this was attached Hessian strips leaving gaps to represent windows and doors. The shape assisted in disguising the antenna above the roof.

New equipment was finally installed at 56 Radar Station in December 1944. The new radar was the long-awaited British Mk V COL set, equipped with an Australian-made tower and AW Mk II type aerial. The transmitter/receiver set was designed by the Royal Air Force for use in coast defence. COL was the overseas version of the CHL (Chain Home Low Flying). CHL stations were for low flying aircraft detection and formed part of the British Chain Home network. Of 32 COL-type units ordered by the RAAF in November 1941, ten went to Queensland, four to Western Australia, three to the Northern Territory, and one each to Victoria, South Australia and Papua New Guinea. A further two were apparently 'cannibalised' and used in conjunction with Australian AW components. The remaining ten were set up as GCI (Ground Controlled Interception Radar) units.

As with most other RAAF radar stations in north Queensland it is presumed the Cooktown unit ceased operations and was disbanded after Japan’s surrender in August 1945. All serviceable and salvageable equipment was dismantled and removed and the only evidence of the radar station today is a plaque atop Grassy Hill on the site of the operations building and tower. Several concrete slabs hidden in scrub on the west side of the hill, identify the camp area.

Source/comments

Pearce, Howard (contributing author).

Howard Pearce. WWII: NQ: A cultural heritage overview of significant places in the defence of north Queensland during World War II. Environmental Protection Agency, Brisbane, 2009.

Don Sinclair, Cooktown at War: A record of activities in Cooktown during World War Two, Cooktown and District Historical Society, 1997.