The Man Who Tore The Tate In Two: Stuart Smith on making Doris Salcedo's Shibboleth a reality

When an artist drives a gully through the heart of the world’s most-visited art gallery it’s almost unthinkable that it’s the product of anything less than divine intervention. Though your gut tells you there’s a rational explanation for what you’re seeing, your inner fantasist doesn’t want to let go of the magic of the piece, the fantastical tear in the fabric of the gallery. In fact, the reality is much more interesting.

“Somewhere out there is an engineer that made all of this happen,” said journalist Mark Miodownik speaking on BBC Radio 4 in late 2007. He was referring to Doris Salcedo’s Shibboleth, the work of dramatic sculptural presence that transformed the Tate Modern’s main atrium from a polished exhibition space into the scene of some ambiguous natural disaster. Slap bang in the middle of the Turbine Hall’s vast concrete floor was a crack of alarming proportions, splitting the floor right down the centre. The inexplicable crevice began at the gallery doors and trailed down into the body of the room, expanding as it progressed but, mysteriously, revealing nothing of the space beneath.

The work was a massive critical success; as an allegory for the colonial foundations of Western society it had heavyweight conceptual punch and for the weekend art admirer it looked utterly spectacular. But the greatest success of Shibboleth was its ambiguity; nobody knew how the concrete chasm arrived there. Salcedo wasn’t for telling and neither were the people she’d enlisted to help.

Five years later the memory of Shibboleth persists, albeit distorted by time and our own fallible perceptions. Some people remember being able to step into the crack completely (you couldn’t) others that it was possible to see through to the earth below (it wasn’t) and I remember the opening growing in size as the exhibition wore on (it definitely didn’t). By preserving the mystique of its genesis, Salcedo allowed her viewers to create a lasting personal mythology around Shibboleth that’s as complex and uncertain as the work of art itself, and that’s largely thanks to the complicity of Stuart Smith. “I love looking at these pictures,” he says, thumbing through the exhibition catalogue. “I’m still very proud of what we did.”

Stuart has every right to be proud – as the mathematical brain behind some of the world’s most complex architectural structures he ought to have achieved rockstar status by now. But in an industry that produces few celebrities, it’s unsurprising to find he cuts a pretty unassuming figure in person. Stuart is a structural engineer at Arup, a global firm of consulting engineers famed for their work on structures like the Sydney Opera House, The Pompidou Centre, the Olympic Aquatics centres in both Beijing and London and the redevelopment of King’s Cross Station. He’s also the brains behind making Shibboleth a reality; his specialist understanding of concrete facilitated that ominous crack and allowed Salcedo to produce a bewildering spectacle without blowing the Tate’s budget or compromising the building’s structural integrity.

Stuart’s involvement came about quite by coincidence. “The Tate had commissioned Doris to do this piece and she’d proposed the idea of putting a crack through the Turbine Hall. It had to open in October, but around February they were going nowhere – they couldn’t work out how to do it. The idea was to cut directly into the concrete which obviously wasn’t going to work. At the time I was working on the extension to the Tate and they asked me to help work out whether the piece could be done.”

Making Salcedo’s idea a physical reality turned into a six-month personal project which saw the pair slaving through many successive nights (to allow for the time difference between London and Bogota) planning the piece out via Skype and plotting the best way to create the illusion they were looking for.

“It was a very personal project, one-to-one with Doris.” Stuart tells me. “I went to Bogota to her studio to figure out how it would all work and how the pieces would be made and installed. The complexity of it was enormous because there were lots of ways of doing it that just wouldn’t have delivered what Doris wanted and wouldn’t have been as mystical. The most important thing was for the illusion to work straight away, and for that to happen all the details had to be exactly right.”

Constructing that illusion required patience and skill, working in minute detail to ensure the fissure upheld its mysteries throughout its length. “When you looked into the crack, you couldn’t see the bottom, so nobody knew how deep it was, even in the main section.”

For all its final polish, driving a chasm through the heart of the Tate was not without its difficulties. The main problem was the solid concrete slope that serves as the main entrance to the gallery. Cutting into it would have blown the entire budget, leaving no room to extend the piece through the rest of the space, but it was difficult to see how else the effect could be achieved. “Looking at it I realised that you could cast something on top of the slab, and it would be almost invisible that that was what had happened.” But even producing a simple concrete cast was frustratingly complex – the manufacturing all took place in Colombia before being shipped to the UK. Stuart only had a couple of inches to work with as the steps running down the side of the gallery only allowed for a limited amount of adjustment before things started looking awry. Furthermore the resulting fissure had to appear imperceptibly deep.

“What we did was put a new slab on top which met the top of the gallery steps. To the eye it looks like nothing’s changed; you can’t see unless you know exactly what you’re looking for. The BBC employed three or four industry experts to come down and work out how we’d done it, and each one of them guessed something right, but they all got something wrong. Everything we’d done somebody guessed, but no one person managed to guess all of it.”

Stuart takes visible pleasure in having fooled so many people. Day-to-day he doesn’t get much of a chance to play tricks on the public – he’s too preoccupied ensuring the buildings they spend their lives in stay standing – but working with artists allows him the opportunity to experiment. Arup has a longstanding partnership with architects Herzog & de Meuron, a Swiss practice responsible for The Serpentine Gallery’s 2012 summer pavilion.

For the artists involved the pavilion serves as a three-dimensional playground for their ideas. For their architect and engineer collaborators it’s a chance to test themselves, allowing them to explore the themes and materials in a low-risk environment.

Last year Ai Wei Wei and Herzog & de Meuron created a piece that referenced all of its predecessors, tracing out the previous blueprints into the earth and then excavating them into a deep, cork-lined cavern. “Because of the nature of the project finding all the old plans was quite an adventure,” Stuart said. “Some of them were done as sketches, some of them were done on computer, some of them were just done on site, so you have to piece together a lot of information.” The aim was to create a kind of archaeological history of Kensington Gardens and the pavilion project itself so they needed a material that would reflect the historic, earthy nature of the structure.

“Cork works very well in terms of this sense of the excavation of the earth, so it seemed like a good choice.” Now that Stuart’s worked with the material he’s keen to exploit it on an industrial level, but as with everything in the architectural world, these ideas take time to come to light. “I’ve got some rather large lumps of cork upstairs that I’m just waiting for something to do with.”

Given the long-term nature of most architectural projects – the years of planning and design that take place even before the first foundations can be sunk – it’s refreshing for Stuart to work on these smaller-scale structures where the pace is faster and the time constraints more immediate.The planning takes months instead of years, and you’re less likely to endanger any lives if the work is rushed. But with the fast pace, experimentation and excitement comes a trade-off – the added stress of quick turnarounds and preparing work for high-profile launch parties. The design and build of the 2012 Serpentine Pavilion was executed at speed and under pressure, and as the June deadline neared a problem emerged.

The structure required water to complete the final touches and the country was in the middle of a strict hosepipe ban. The design team was at a loss as to how they were going to fill the pavilion roof with water, but thankfully Arup had been involved in a nearby project, The Princess Diana Memorial Fountain, which boasted a deeply-sunk bore hole. To fill the pavilion basin for opening night, they took water bowsers to the bore hole beneath the fountain and lugged them back to the gallery gardens. Even experimental projects have their mishaps, but Stuart and his colleagues are adept at finding solutions.

Similarly with Shibboleth, Stuart was under enormous pressure to deliver the piece on time and was still figuring things out on the fly. “I took on a lot of responsibility for delivering it. This one really did have to be done on time. The Unilever series and the opening party is quite a big deal for the Tate, so this was one you really didn’t want to be late for.” In the end Stuart and his team had only about six weeks to transform the gallery.

“We really had no leeway and no way of testing all the things we wanted to as it was the Turbine Hall. The Tate were very brave to do it, to stick with it. Sometimes on The Serpentine Pavilion too there have been moments where the gallery has been very brave to stick with the concepts and carry on supporting the project when they’ve got very high-profile events at stake.”

For some, the stress of dealing with a worried Tate or Serpentine curator would be too much, but Stuart takes it all in his stride. “You do these things over and over again and just get used to the feeling of anxiety. You start to learn what is a problem and what isn’t really a problem and you find your way through it. Almost always these projects are successful.”

And under this kind of pressure, it’s imperative that Stuart understands why he is finding these solutions. When you’re making judgement calls on giant structures and choosing which piece of a building can and can’t be built in accordance with a budget then that understanding is key. It’s no different when you’re slicing up a gallery floor.

“I’m interested in the thinking and developing of ideas around topics. It was interesting to me that Doris was trying to describe different things with her work. She was going around interviewing victims of torture and creating pieces that somehow referred to them. I find getting involved in that kind of discussion really interesting. Once you understand why the object is there and what it’s doing conceptually you can start to think about how to make it work as an illusion. You need to understand these things to make the piece successful, to know why you’re spending all night, every night working on this thing. If I don’t understand the concept then I’m just fishing in the dark.”

So next time you’re sticking your leg down a crack in a gallery or leaping across a temporary structure, spare a thought for the Stuarts of this world, or maybe even spare a thought for Stuart himself. Thanks to his quiet complicity, all the magic of witnessing breathtakingly incomprehensible art is preserved for your enjoyment. “I have never really spoken very much about it,” he says as we part ways, “but I don’t mind so much.”