In December 1940, during World War II, the Royal Australian Navy (hereafter RAN) issued an order that all naval and coastal ships on the Australian register must be equipped with degaussing equipment for protection against magnetic mines. This consisted of cables placed around the hull which acted as a demagnetising agent (Sydney Morning Herald, 21 December 1940). In 1942 the United States Navy (hereafter USN), having now entered the war, constructed a Degaussing Range at Bradleys Head, on Sydney Harbour. This consisted of electronic devices laid on the harbour floor beneath the shipping lanes – as ships crossed this range the magnetism of their hulls was measured to ensure they were still fully protected.

The Range was supported by a shore station located on the point at Bradleys Head. It was on the water’s edge, slightly to the east of and almost below the HMAS Sydney memorial. This was a two storey, wooden building on a raised platform, suspended above the shoreline on timber piles embedded in the rock. It was painted in camouflage colours, had its own generator and septic system, and a jetty, all protected by a high security fence. The building had a rather nautical appearance, with a telescope, flagpole and other semaphore equipment housed on a harbour side balcony known as the ‘signalling deck’. Originally staffed by USN personnel while local staff were being trained, in early 1943 the installation was handed over, fully equipped and furnished and with a modern galley, to the RAN. It was staffed by four naval officers and eleven Women’s Royal Australian Navy Service personnel (WRANS).

Gwenda Southcombe (Cornwallis) and Gwyneth Seesby were two of the WRANS stationed at the Degaussing Range. They describe it as an idyllic spot, accessible only by bush tracks through Ashton Park, or by boat. Initially they only worked during the day, four hours on and four off, but when the RAN took over, the Range was in operation for 24 hours a day. They worked in shifts and often cooked and slept there. Staff were locked in during the night and the area patrolled by naval policemen to protect the valuable instruments. The WRANS worked as signallers, instrument panel operators and clerks. Ships entering the harbour were identified and monitored, and as they crossed the underwater Degaussing Range the WRANS recorded readings of their magnetism. Naval officers analysed these readings and calculated the effectiveness of the ship’s degaussing equipment. If the result was unsatisfactory, naval engineers made adjustments, and the ship was re-tested over the Range before it could leave port.

When the war ended in 1945 the Degaussing Range became redundant. By December 1945 the electrical equipment, instruments and office furnishings of the shore station had been removed. It was used briefly as a naval store until, in October 1946, the Commonwealth Disposals Commission advertised it (and other components of the range) for sale and removal. It was described as ‘an attractive two-storey weatherboard building, suitable in its present form as a residence, already divided into 7 large rooms and offices’ (Sydney Morning Herald, 9 October 1946, p 12). In January 1947 the underwater structures and dolphin used by the Degaussing Range were removed, and the building was dismantled soon after.

All that remains now are some rapidly decaying wooden stumps among the rocks and sand, and remnants of brick structures which, according to Gwenda Southcombe, were the septic tanks.


Daily Commercial News, 28 January 1947.

EagleSpeak, Sunday ship history: Degaussing ships,, accessed 3 May 2015.

Shirley Fenton Huie, Ships Belles: The Story of the Women’s Royal Australian Naval Service in War and Peace, 1941-1985, Watermark Press, Sydney, 2000.

Interview with Gwenyth Sneesby,, accessed 23 February 2015.

National Archives of Australia. Degaussing range – Bradleys Head – disposal of,, accessed 3 May 2015.

Gwenda Southcombe (Cornwallis), ‘Home, Home on the Range(Degaussing) or Impressions and Confessions of a D.G. Bunting Tosser’, in Naval Historical Review, Vol 9, No 1, December 1988.

Sydney Morning Herald, 21 December 1940, 6 September 1945, 9 October 1946.




(Noela Gill, 2015)

Phillipa Morris