HOW TO BUILT A FIRE BREATHING SPIDER FOR WIRED

As the clock approaches midnight, it feels like the world is about to end. Standing in a sodden field in Somerset, a huge crowd is watching a vast mechanical creature erupt into life, shooting fire and spitting lasers like the initial vanguard of an alien invasion. The only clue that this vast intruder isn't from outer space is the thundering bass heavy soundtrack that perfectly accompanies its movements. As a recorded message recounts how "the fate of those abducted by the creature remains unknown", Arcadia technical director Bertie Cole and creative director Pip Rush Jansen survey the chaos that they have created.Cole, 35, and Rush Jansen, 32, constructed their 50 tonne Spider out of reclaimed hardware from around the globe to create a unique festival stage for DJs and Arcadia's own live theatrical shows. The control booth/abdomen is composed of the turbine rotors from a TriStar jet engine, the legs began life as customs scanning machines, while the top "muscles" originate from Gazelle helicopter tails. It takes four days to set up, four articulated lorries to transport, stands 20m tall and requires a minimum of 45 people to operate; right now, it's one of the most popular stages at Glastonbury 2015.

In its present form, Arcadia's Spider currently features three hydraulic cranes that can fire jets of CO2 10m, nine flame cannons that can shoot 15m fireballs and six RGB lasers running on a Pangolin control system. All the different disciplines have their own operating systems and they are synched to the music using timecode controls. The Spider's soundtrack comes courtesy of a hefty 230kW L-Acoustics 360-degree sound system, complete with a 50 metre sound field, all linked to a mixer and two Pioneer CDJs.

Cole and Rush Jansen first debuted the Spider in 2010 at Glastonbury Festival and have been travelling the world with their upcycled extra-terrestrial ever since. A three-legged alien arthropod that recalls both HG Wells' 1898 'Fighting Machines' and Mad Max's custom jalopies from 2015's Fury Road, Arcadia's creature has become one of the most talked about spectacles of festival season. It's truly an immersive experience. "At a concert, you might see your headliner, but you're also looking at the back of everyone's heads and you're not interacting with them," Rush Jansen tells WIRED. "With the Spider, you're all in a massive series of concentric circles which creates some amazing interaction between the crowd." The pair have seen some audiences respond in surprising ways. "We've had tears. Shockwaves from the flames knock people over sometimes. We actually had someone cack their pants once."

Performers also had their own shocking moments, particularly in the early days. "In the first incarnation, DJs turned up and we sent them up a ladder with a harness on all the way to the top, then across a gangplank into a DJ booth. We made it very clear in all the emails beforehand, but a lot of them didn't read it." Despite needing a head for heights, everyone from Disclosure to Fatboy Slim to Skrillex have now ventured inside the Spider. "We try and brief them so that they know it's a really different environment," says Rush Jansen. "It's not the dance tent, it is a massive mechanical monster that you're going to step into the middle of and you've got to take it as it comes."

In September, the pair have their biggest test yet. After acclaimed recent shows in Siam Park City in Thailand and at this year's Glastonbury Festival, the Spider is heading to Arcadia's hometown of Bristol. On 4 September Roni Size Reprazent and Leftfield will be appearing, while the following night Annie Mac, Eats Everything, Monki and Gotsome take over. Cole and Rush Jansen are both particularly excited about the chance to hear Leftfield's Neil Barnes. "Leftfield shapeshifted our worlds," says Cole. "The Leftism album came out when we were teenagers and just getting into the party scene."

As well as the impressive DJ lineup, the Bristol show will also give the audience the chance to see their new show 'Metamorphosis'. After the success of their 'Arcadia Spectacular' show that they'd been working on since 2012, last year the pair came together with their team to submit ideas for a brand new showcase. "It's all about collaboration really making it happen," says Rush Jansen. "We had video tech guys, pyro people, engineers, riggers, performers, musicians." This is where the collective's real depth of talent reveals itself. As the Arcadia founder puts it: "We're somewhere between circus, set-building, production, sculpting - all those different elements all morphed together."

The challenge was to put on something that would impress the Spider's growing fanbase, explains Cole. "The basic brief was that originally we built a show that was really immersive for a crowd of 10,000 people. Over the last year the crowds have got bigger and bigger until now we're talking 20-50,000 people. What we never wanted was for people to stand right at the back, watch it like they're watching telly and just be spectators."

Naturally the idea of producing a 360-degree show that can be experienced by so many, complete with performers and animatronics moving over people's heads, posed a challenge. "We had to work out how to get the show and put it right out on top of the audience," says Rush Jansen. "We had various ideas, like hot air balloons with people hanging off them. We ended up sticking with zip wires and making mini baby spiders that actually crawl out over the arena and move people around the space. The big spider's got a bit of a reputation for picking people up out of the crowd already -- so we thought 'How can we take it further than that?'"

Cole is particularly proud of the three miniature spiders that the team has constructed. "We've done an awful lot of pretty cutting edge engineering, making something really light that can go over people's heads safely. It can't be too heavy as it's got to carry two people." The show also can't suffer as a result. "It's got to look like a creature and it's got to walk like a creature," says Cole. "It's been a really exciting process: we've worked with some puppet makers who've got more experience in giving character to machines." Thanks to the help of puppet companies Rusty Squid and Green Ginger, Arcadia has succeeded -- one of the highlights of 'Metamorphosis' is watching the trio scuttle towards the primary sculpture.

The real standout performers, however, are the Lords Of Lightning -- where Tesla coil operators generate lightning arcs of up to four metres. Depending on your age, they either recall Storm from Marvel Comics or Raiden of Mortal Kombat; the effects are overseen by New Zealander Carlos Van Camp, an Arcadia veteran who has perfected the technique of playing musical notes through four million volts. "Rather than a Tesla coil just doing its thing, you can actually get the lighting to modulate the notes of the music -- you can use it like an instrument," says Cole. Notoriously erratic, Tesla coils are one of the most technically demanding elements of the show -- not least their effect on other equipment. "We've fried a few lights," says Cole. "There are lots of things [in the show] that have microprocessors and switch-mode power supplies inside -- and the Tesla Coil plays havoc with them. It was actually effecting one of our computer's front of house the other night. We had to change where we were striking the lighting to make sure the computers didn't crap themselves."

The final change the team has made for 2015 is perhaps the most significant: the flame system is now is running on biodiesel. As a company based around reclaimed hardware, it makes sense that they would now be looking for a greener alternative. "Our stage is made of 99 percent recycled materials, so we've developed a biofuel flame system which we beta-tested at Glastonbury," says Cole. "It uses diesel fuel made from recycled chip fat and restaurant cooking oil.”

The biggest challenge the pair had to overcome is atomisation. "You've got to atomise the fuel before you really set fire to it, so that you burn all of it and none of it comes back down afterwards. Then you've got to produce fire of a decent size. The physics of it mean that it will never be the same as the gas but it's sustainably made, so it's cool in its own right." Having now upgraded to the cleaner technology, they're currently working on a button that DJs can push so that they can control the flame bursts from the Spider themselves.

The combination of all these various elements -- huge jets of fire, acrobats dressed as jellyfish in costumes fitted with mappable LED systems, the crawling miniature spiders, the thundering breaks and dubstep soundtrack, to say nothing of the main sculpture itself -- means that watching 'Metamorphosis' is truly extraordinary. From the Orson Welles-esque public service announcement that starts the show (courtesy of Arcadia's garrulous communications specialist Cyrus Bozorgmehr), the pace doesn't let up for a moment.

Arcadia also hopes that the performances at Glastonbury and Bristol might lead to a collaboration with DJs or artists in the future. "If Aphex Twin wanted to get involved in it, I think the results would be amazing," says Cole. "Someone who has got a real lateral thinking towards sound and what's possible with an instrument."

Cole and Rush Jansen are also aware that they are in a constant arms race with other promoters and festival stages for audience attention. At Glastonbury alone, Arcadia had to compete with countless upturned cars, huge wooden sculptures and the Block 9 area, complete with a 50ft tower block with a tube train stuck out of its side. Asked about their competition, Cole sees a distinction between the Spider and its rivals. "There are a lot of set build stages which I suppose are the most similar thing. But when you look behind the plywood they are just a fascia. What's amazing about the Spider is that it's actually real: it weighs 50 tonnes. It resonates a slightly different energy. You can go up to it, hit it, and you can feel it -- it's a proper thing and it's totally 3D.”

The pair are now looking at venturing further afield to search for scrap to either add to it or build a completely new project. (Russia, South East Asia and Taiwan are on the hit list.) Their quest to develop the Spider even further has coincided with more and more requests for international events. "There was a mad guy the other day who said 'I want you to come to Korea... but it's going to be inside,'" says Cole. "We told him 'Don't be ridiculous'. Then he came back and he's found this baseball stadium that's 110m across and about six times the height of the Spider. He wants to put it inside in December." (The show is currently TBC). "It's an unruly beast,” Cole says with a smile. "Fucking heavy, fairly antisocial. Pretty hard to drag out of bed in the mornings. But when you get it out there, it's well worth it."