The teenager who hunted Japanese submarines

Sydney Morning Herald

24-04-2025

Gwenda Moulton, aged just 19, sat with six other young women in their green uniforms in the small room she knew only as 'Y Hut', located at HMAS Harman outside Canberra.
It was 1942, and as a newly qualified telegraphist she had been listening to Japanese Morse code messages over her headphones well into her evening shift when, without warning, came the most important signal she recognised.
It was 'RS NO' (the women knew it as RS negative, the Japanese codeword for submarine).
'As soon as you heard that, you called out to your leading hand,' Gwenda, now Gwenda Garde, 102, told Australian National Maritime Museum historian and curator Dr Roland Leikauf at her home in Orange in the NSW Central Tablelands.
'She would then dial the direction finder operator, who was way out up on a hill in the country.
'He would contact other direction finders and they would cross reference their bearings to get a fix on where the Japanese submarine was. We never found out if they sank the submarine.'
Other Morse messages she received were sent by teleprinter to Melbourne, where they were decoded.
It was a time of change for the forces in Australia, where wartime shortages helped women break gender barriers.
'What! Women in the Royal Australian Navy? Good gracious, no. The response from officialdom was if women wanted to dress up and do something to help the war effort, why, they could work in a canteen or take a job in a factory or carry on with their knitting in a woman's proper place, the home.'
That was the reaction, according to W.R.A.N.S, a history of the Women's Royal Australian Naval Service by Margaret Curtis-Otter, the organisation's Acting First Officer.
But even before the declaration of World War II in 1939, several women's voluntary organisations had sprung up, despite the derision heaped upon them.
One was the Women's Emergency Signalling Corps, started in Sydney by Florence McKenzie (known as 'Mrs Mac'), who trained women who at the time were barred from joining any of the services in Australia but were willing to learn wireless telegraphy.
It wasn't until April 18, 1941, that the Minister for Navy approved the employment of telegraphists for HMAS Harman, the navy's communications base – with the proviso that no publicity be given to the break in gender tradition.
Gwenda was among those first 48 recruits.
'I heard about Mrs McKenzie and went to her classes in Clarence Street,' Gwenda said. 'She was the first female electrical engineer, founder of the Women's Emergency Signalling Corps and a lifelong promoter for technical education for women.
'She was a little woman, not much bigger than me at five foot, but about 20 years older,' said Gwenda.
'One day she said to me: 'We are going for a [Morse code] test, Gwenda; you had better come for the experience. I went and, of course, I passed. The next thing I knew I was joining the navy. Then I was on a train going to HMAS Harman on Dec 27, 1941.
'Mrs Mac got the navy, with great difficulty, to take girls – I was WRANS number 36. When we got to our accommodation, they wanted us to paint the place, to camouflage it. The male telegraphists went off to sea and we moved into their cottages. We ate in the mess; the girls ate on one side and the remaining men on the other.
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'There was a dance every Saturday night in Canberra. I would dance with boys from the Army and Air Force, but we weren't allowed to date naval officers, they were way above us.
'The girls were divided into two lots. One lot went to the ordinary station and did ordinary communications and the group I was in went to a very secret location called the Y Hut, it was a separate little building. It was important work, but it was so secret we didn't know what the other people on the base were doing. We weren't allowed to talk about it and we had to learn the Japanese Morse, which was a bit different to ours.
'The Japanese didn't know, but we had their code books, and we knew, for instance, what their signal was for 'submarine'. It was dit dah dit dit dit dit dah dit dah dah dah.
'You would listen in to different frequencies until you heard something that you knew was Japanese. We knew quite a lot of the frequencies that they used. We would write it down in Morse code and then we had to change it into letters [kana] so it could be sent on the teleprinter to Melbourne. We were never told what kana was.
'When you heard 'submarine' there was great excitement! You'd call to the leading hand, tell her the frequency you were on, the DF [Direction Finding] station got in touch with others and they took a bearing. There were a lot of submarines down our coast, but you never knew if that submarine was sunk.
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'In 1944, I was based in Townsville, then a petty officer in charge of 32 girls. Dengue fever was rife and everyone seemed to get it at one time or another. As soon as the war ended, they took me off listening to the Japanese and we had to listen to the Russians. I thought that was terrible because the Russians were our allies.'
Gwenda didn't speak about her wartime role to anyone until COVID, when she sat down with her oldest daughter, Robin Thompson, and told her the complete story.
Gwenda had a boyfriend, Robert, a Spitfire pilot who was killed over the north Atlantic. After the war, she married his best friend, John, who had flown Kittyhawks in New Guinea. They had three children.
'Mum may be 102, but she's as bright as ever and playing bridge four times a week – and still winning!' Thompson said.
Florence McKenzie was appointed OBE in 1950. She died in 1982.