The Latin inscription on Sir Christopher Wren’s tomb in St Paul’s Cathedral urges the reader to look around if you want to see his monument. That’s all you need to do at the Goodwood Festival Of Speed for an insight into artist Gerry Judah.

Every year, his sculptures swoop and tower and gleam over proceedings, and then they are gone. If you don’t see it in ‘the metal’ over that one weekend, then you never will.

“Yeah, this year’s was an extraordinarily physical presence,” Gerry says, rocking back in a paint-spattered swivel chair in his north London studio. “But you build it and then you rip it down. I’m not precious about that because I worked in film and TV for years, where everything is temporary. Actually, I like it: it makes the ideas stronger than the actual things.”

Gerry first met the Earl of March when the Goodwood heir was plain Charles Settrington, photographer. He was one of many 1970s and ‘80s creative types, David Bailey, Terence Donovan and pop video pioneers Godley & Creme among them, who wanted his input as a set designer, backdrop visionary and model-maker.

“I knew he was some sort of aristocrat, but we all worked equally, we were all just looking for ideas and making films and photos together. No reliance on computers – just direct collaboration. It was later that he tracked me down to make a triumphal arch for Goodwood, and I realised there were these wonderful structures we could make with the actual cars themselves.

“Museums have to trust you, and that level of trust is quite extraordinarily humbling. Their cars are worth millions of pounds and just to be allowed to whack them upside down high in the air and in all kinds of weather is incredible. The work has to soar, and I want it to anyway. It’s got to work well in the space, make people say ‘Oh, my God’ because it’s about the power of sculpture mixed with motor sport. It appears and looks cavalier but, of course, that’s not how we approach it.”

The artist describes to me the physical creation of his Goodwood sculptures, including the cutting process in Sheffield and the fabrication in a huge yard in Littlehampton. From Mercedes-Benz and Alfa Romeo to Audi and Jaguar, all the key sponsors have had their priceless racing icons suspended in the sky by Gerry. He recalls the orgy of ideas needed to find something that BMW felt hit home. And the Mazda exhibit where the mashed-up creative process started with the design of a 1962 Enzo Mari letter opener, and finished with Gerry’s shifting, twisting skyscraper of metal beams, with a Le Mans car dangling off its peak.

“Suddenly the aspirations of the client and the twisting form gelled together, the sense of wonder and danger that has to be in a Goodwood cantilever.”

Gerry Judah has a steady intensity that beams straight at you when he talks, but then, as I’m absorbing his words, he unexpectedly lightens up.

“You know what, with a big sculpture, I sometimes think I can do it in an armchair. I mean, you start with a concept, something which doesn’t resonate with anything you’ve done before, and then it gels, it has some meat in it. I can be driving down the motorway, suddenly get an idea, stop in a lay-by, sketch it on the scrappiest bit of paper in the car, snap it on my iPhone, email it to Bruno – the engineer I work with in Sheffield – and five hours later a computer drawing comes my way. Because at this point, it’s all about the geometry, getting four or five lines into how it works. That’s all done with computers and phone calls and only [italic]then[italic] do you get down to sketching models, cutting up cardboard, plastic, plaster, resin, whatever, so you can make it work in 3D.”

Gerry says: “My beginning, middle and end is sculpture”. He also claims to be somewhat the itinerant artist because he’s changed his work and his studio location frequently since graduating in Fine Art from London’s Goldsmiths College in 1975, and then studying sculpture at the Slade.

His portfolio and list of exhibition is enormous, but as he became more established, bolder and less reliant on working for other people, the story started to serve the work, instead of the inverse. “I’m a project artist, and too much of an egotist, so I like to blaze my own trail,” he shrugs. From scouring London’s skips for waste wood to de-nail for John Napier’s acclaimed theatre set for [italic]Nicholas Nickleby[italic], he has turned to complex, three-dimensional paintings that often draw on turning points in history.

The Imperial War Museum asked him to create a model of the dreaded ‘selection ramp’ at the Auschwitz-Birkenau concentration camp for its [italic]Holocaust Exhibition[italic] and another work, called [italic]Crusader[italic], a cross-shaped, hung-askew emblem of war causing human suffering.

“I took the white cross from war graves as the symbol, and I embellished it with contemporary war zones – Aleppo, Baghdad, Homs. Because 100 years after the First World War, the carve-up of the Ottoman empire, the Sykes-Picot Agreement, all of it, we’ve ended up still fighting the same conflicts in the Middle East. They’re on the same fault lines, about the same issues. It’s not over. We’ve got stop fighting these conflicts.”

Some smaller variations on this acutely painful theme were produced for Gerry’s local church. They came to the attention of Canon Mark Oakley of St Paul’s Cathedral, no less, who, as Gerry says “liked the energy”. He suggested there’d be space on the wall of the nave there for Gerry’s work if it could commemorate the Second World War in a similarly compelling way.

“I couldn’t believe it. I immediately thought I’d like to do something specific for it. I hit the ground running and had an idea for the Crucifix with them within two weeks. And they said yes, let’s do it.”

With Christopher Wren’s notional, quizzical, all-pervading approval, Gerry cleared his studio floor to make the piece. The organised frenzy the sculptor outlines is darkly impressive.

“I started making maquettes, developing it, cutting, pasting, painting. It’s a steel armature clad in cardboard and plaster. All the buildings were accurately-designed, computer cut-out and then glued on. And then I smashed them up. I painted the wreckage with acrylic gesso – a mix of plaster and paint that I make myself – and fused it all into the canvas.” Installed in 2014, St Paul’s shows no sign of wanting to take it down. Visitors continue to be gripped by it.

The studio has witnessed several more of these three-dimensional paintings reflecting environmental catastrophes and conflicts. Sometimes the destroyed cityscapes, blitzed architect’s models packed with tiny exposed stairwells and blasted-open lift shafts, take two years to complete.

“I build them and smash them on the canvas, and then glue them back together as detritus while adding new details like water towers. Then I smash them up again and then I build another city on top.” Bucolic they are not; the power of devastation is all-consuming.

Gerry’s newest work is differently discomfiting. The charity Christian Aid took him to Calcutta, West Bengal to look at its projects around climate change – trying to overcome the drought and corruption that relentlessly hold poverty.

“It was where I was born and grew up. It’s hard to take, and I’m doing a series of sculptures based on my visit. They are all rickshaws with different structures on them – power stations, pylons, temples made from ash and polluted materials that reflect the legacy and the future. They’re lashed together as they would be in real life in India. They don’t rely on technology, just whatever they can find and put together. And that’s what I’ve done.”

Jane Morrow, Curator of the influential Wolverhampton Art Gallery summed them up: “These intricate, fragile and colourful works reflect the beauty of India amongst its degradation,”

Gerry is only vaguely interested in cars, emphatic only in his view that modern cars are hideous and samey because of the need to pack them with technology. “We’ve accustomed ourselves to these ugly objects on our streets – we’ve adapted our eyes rather than objected.

“But, then, I’m not a petrolhead. I want to just keep making stuff, and I’m not answerable to anyone when I’m working; dealing with uncompromising materials and trying to bend them towards my will – constantly in collaboration and confrontation with them.”