Flying Sunflowers: the logistical secrets of the NGA's Botticelli to Van Gogh blockbuster

Over the past two months, a discreet convoy of unmarked trucks has been traversing the 290km stretch of the Hume Highway between Sydney and Canberra.

They probably had an Australian federal police escort, but we can’t say for sure. The security arrangements for the transportation of the most priceless collection of artworks to reach Australian shores has been cloaked in secrecy.

All the director of the National Gallery of Australia, Nick Mitzevich, would tell Guardian Australia was that there was “heightened security” to transport 61 priceless works from the National Gallery in London to Canberra over many weeks earlier this year.

“We worked with local authorities and international authorities to ensure that the highest of security levels were applied to these shipments,” he said.

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On 5 March, the NGA’s Botticelli to Van Gogh exhibition opens, bringing the UK’s National Gallery treasures – including Rembrandt’s self portrait (age 34), Botticelli’s Scenes from the Early Life of St Zenobius, and Vincent van Gogh’s Sunflowers – to Australia for the first time.

The project has been more than four years in the making, with negotiations already well under way before Mitzevich took over directorship of the NGA from Gerard Vaughan in early 2018.

Then Covid-19 hit.

Over the past two weeks, NGA curators and conservationists have been cautiously unpacking the priceless works and beginning the meticulous process of inspecting and hanging the pictures under constant vigilance of the National Gallery in London via live streaming.

Under normal circumstances a team of conservators would have chaperoned the Botticellis, Titians, Rembrandts, Vermeers, El Grecos, Velázquezs, Goyas, Turners, Constables, Van Dycks, Gainsboroughs, Renoirs, Cézannes, Monets, Gauguins and Van Goghs in person. Pandemic restrictions meant the artworks had to travel unaccompanied, each in its own hermetically sealed, custom-made crate.

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Like any overly cautious and arguably pessimistic family with a tradition of always travelling on separate planes (sports history is littered with aviation tragedies wiping out entire teams), the 61 masterpieces did not all travel on the same London to Sydney flight.

The paintings have been arriving in a steady stream of separate cargo planes since January.

“It’s part of the risk mitigation measures,” Mitzevich told the Guardian. “I’m sure you can understand why I’m not at liberty to talk about how many shipments there are when they’re coming in, but they’re over an extended period of time to really ensure that we mitigate any risks.”

When a 500-year-old Botticelli or Vermeer takes to the skies, it does not just fly incognito. It must also be insulated and then hibernate during and after the long haul.

Bubble wrap will simply not suffice. Conservators at the National Gallery in London swathe each work in acid-free material – paper-based or fabric-based, depending on the individual painting’s requirement – before sliding each masterpiece into its own laser-cut, form-fitting timber pod, insulating the work from as much vibration as possible during transportation. Works without protective glass are glazed beforehand.

Once in Australia, each unbolted crate is transported by road in a climate-controlled truck before entering a period of acclimatisation in the nation’s capital – a kind of hotel quarantine for modern antiquities.

On 15 February, NGA staff began unbolting the pods. On 22 February, Vincent van Gogh’s Sunflowers was roused from its slumber.

“There was such an anticipation around this work that when we actually opened it, everyone became quite emotional,” the exhibition’s coordinating curator, Sally Foster, told the Guardian.

“When you actually see it in the flesh, when you see how he’s painted it, it is such an extraordinary work … when we opened that crate, that really was a moment.”

This kind of project is expensive. As with all travelling exhibitions of similar scale, the prohibitive insurance costs have been met by the federal government’s indemnity scheme.

The NGA expects to cover the outstanding costs of labour and transportation between ticketing, corporate sponsorship and the proceeds from a concerted drive for private philanthropy that has been running for the past four years.

At about $28.00 for a standard adult admission – and with Covid-19 social distancing restrictions limiting the number of viewers at any given time during the exhibition’s three-month showing in Canberra – Mitzevich said he still hoped the blockbuster would break even.

He witnessed Sunflowers being hung on the NGA’s walls.

“It was a very exciting moment because finally we had that work on the wall and we could see its luminescence. We could see the brushstrokes of the artist, taking pride of place in our gallery space.”

• Botticelli to Van Gogh is showing at the National Gallery of Australia, Canberra, from 5 March