The spy who made the Sydney Opera House sails possible

Joe Bertony, the engineer who invented the Sydney Opera House erection arch, which made the building of Sydney’s most famous white sails possible, has died at his Hornsby home at the age of 97.

Stage one of the build was a podium built to resemble a Mayan pyramid. Stage two was the roof, which began on March 25, 1963, and was handled by Queensland construction company Hornibrook. Project manager Dundas Corbett Gore employed some exceptional engineers, including Bertony.

Bertony’s crucial contribution was the truss that supported the arches before each concrete segment was glued in place.

Joe Bertony, the engineer who invented the Sydney Opera House erection arch.
Joe Bertony, the engineer who invented the Sydney Opera House erection arch. CREDIT:HELEN PITT

One of the great stories about the building of the Sydney Opera House is the role played by Bertony, a French spy who twice escaped from concentration camps in World War II and was awarded France’s Croix de Guerre.

Bertony was born in Corsica in 1922 and was intrigued by maths from a young age. He went into the French navy to study naval engineering at Saint-Tropez where he was recruited to work as a spy.

Bertony worked as a French agent and was twice captured by the Gestapo and sent to concentration camps to die. He escaped both times; once jumping off a train almost naked, surviving in the snow with few clothes and no food for 10 days.

“I used up way more than my nine lives,” Bertony, who lived in Hornsby, said.

The first camp he was at was Mauthausen-Gusen near Vienna, Austria, where an estimated 320,000 people were killed. He escaped during a transfer due to an administrative error and went back to work for the military in France.

He was again arrested in Paris and sent to Buchenwald as one of 350 western Allied prisoners forced to work for the local armament factories.

Of the 238,380 incarcerated, there were the mentally ill, physically disabled, religious and political prisoners, immigrants, criminals and homosexuals. He worked as a technician in the control unit making the liquid-propelled V1 and V2 German bombs. The Allied forces called the V1s buzz bombs, or doodlebugs, Hitler’s secret weapon.

Joe Bertony at work on a model of the erection arch in 1963.
Joe Bertony at work on a model of the erection arch in 1963. CREDIT:FAIRFAX MEDIA ARCHIVE

“Because we were working on the rocket control, we were working in an underground factory,” Bertony told me. There was no such thing as lunch. They were lucky to get a loaf of bread a day to be shared between five of them – once an SS soldier got angry because they shared it only four ways. “It is lucky I have a good metabolism as I was able to survive on very little food,” he said.

From time to time they would work on a farm, where they would occasionally boil up grass to give some greenery to the inmates. At Buchenwald, he was referred to as the “carotenfuhrer” the “fuhrer” (leader) of the carrots. His job, when not designing armaments, was to guard the silos filled with carrots.

“If any inmate of my party were found eating or stealing a carrot he was punished for it – stripped naked and whipped and I was forced to watch, then I was dealt the same punishment,” he said. It happened many times because many people were hungry.

Bertony ate so little he survived purely on his wits. At the end of the war, when the Americans came to liberate those at Buchenwald in 1945, he was elated. He could hear the Americans approach his underground tunnel. But before Germany capitulated, the SS soldiers rounded them up and foot-marched them out of the camp towards the centre of Germany. At the Czech border near the mountains, they put the prisoners onto a train carrying cattle.

“They started to empty us off the train and dug a big hole and shot people and put them in. Another guy and I decided we were going to take pot luck and we jumped off the moving train into the snow. We walked in the snow almost naked – just the camp jacket and flimsy pants – and no food for 10 days.

“When we arrived back past the SS line we were almost dead. The Americans were coming in with tanks – we made our own luck. The other fellow and I split before we got to the line because we could not pass together. He passed the border some kilometres away. He found a farm near the frontline, so the Germans were protecting him. We stayed in touch with each other for many years – he was a year older than me but he died about 10 years ago.”

Bertony was awarded the Croix de Guerre by the French government for valour for his wartime activities. General Charles De Gaulle said that during both deportations he proved his heroism to France through “courageous discipline”. Much like the “courageous discipline” he was later to show at Bennelong Point, as one of the many migrant workers known then as “new Australians”.

After the war, Bertony fled Europe looking for a better life. In 1952 he arrived in Western Australia and headed to Rum Jungle, to work in the uranium mines in the Northern Territory. Bertony lived in nearby Bachelor, 100 kilometres south of Darwin, a town that was built pretty much overnight to house workers, mostly single foreign bachelors without work papers like Bertony.

With the money he earned there – along with the good references he got for his impeccable problem-solving skills – he found himself in Queensland in the early 1960s where he got a job with Hornibrook. He was then asked to go to Sydney to solve the biggest construction problem they had encountered: the Sydney Opera House.

To a significant extent it was Bertony’s complex hand-written mathematical equations that made the roof construction possible; it took 30,000 separate equations just to work out how much stress should be applied. The margin of error could be no more than 12.7mm when putting the segments together; anything more would have thrown the whole thing out of alignment. Everything is curved and there is not one flat plane in the entire roof, so the geometry is highly complex.

When Hornibrook wanted to double-check some of Bertony’s calculations by computer, he was relieved. It was frightening for him to think that if he had made a mistake no one would find it in all that mass of numbers. So he welcomed the work of a younger colleague, David Evans, who taught himself computer programming to test the calculations.

Opera House CEO Louise Herron and Joe Bertony, inventor of the Opera House erection arch at the building's 45th anniversary.
Opera House CEO Louise Herron and Joe Bertony, inventor of the Opera House erection arch at the building’s 45th anniversary.CREDIT:HELEN PITT

At that time in Australia there was only one computer large enough to cope with such a job: the IBM 7090 at the Weapons Research Establishment in South Australia.

Evans spent one week a month working the night shift in South Australia, since that was the only time the computer was free. At no point were Bertony’s calculations incorrect.

Evans later said of his colleague: “I doubt if there was anyone with Joe’s genius to see how to develop the telescopic truss and to build the ribs with it, or to do a dozen other things of importance on that site. It would have taken many minds and many rounds of trial and error, and a much longer time and a much bigger budget, to get those ribs in the air if Joe hadn’t been there. Other solutions would have lacked his elegance and genius.”

After the Opera House, Bertony went back to bridges. His other major projects include Sydney’s Roseville Bridge and the Hume Highway’s Pheasants’ Nest Bridge across the Nepean River.

Bertony, who owns the copyright to the 30,000 longhand equations used to design the erection arch, gifted them to the Museum of Applied Arts and Sciences and they are now part of the collection at the Powerhouse Museum.

What astounded him whenever he looked at the sails of the Sydney Opera House was that he helped build them with little more than schoolboy geometry.

In his last year Bertony, a widower, was living in the northern Sydney suburb of Hornsby and driving a recently purchased electric car. He was working on a wind technology project for Scotland.

Joe Bertony 1922-2019

Helen Pitt is author of The House the story of the Sydney Opera House.


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